Source file src/database/sql/sql_test.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package sql
     6  
     7  import (
     8  	"bytes"
     9  	"context"
    10  	"database/sql/driver"
    11  	"errors"
    12  	"fmt"
    13  	"internal/race"
    14  	"internal/testenv"
    15  	"math/rand"
    16  	"reflect"
    17  	"runtime"
    18  	"slices"
    19  	"strings"
    20  	"sync"
    21  	"sync/atomic"
    22  	"testing"
    23  	"time"
    24  )
    25  
    26  func init() {
    27  	type dbConn struct {
    28  		db *DB
    29  		c  *driverConn
    30  	}
    31  	freedFrom := make(map[dbConn]string)
    32  	var mu sync.Mutex
    33  	getFreedFrom := func(c dbConn) string {
    34  		mu.Lock()
    35  		defer mu.Unlock()
    36  		return freedFrom[c]
    37  	}
    38  	setFreedFrom := func(c dbConn, s string) {
    39  		mu.Lock()
    40  		defer mu.Unlock()
    41  		freedFrom[c] = s
    42  	}
    43  	putConnHook = func(db *DB, c *driverConn) {
    44  		if slices.Contains(db.freeConn, c) {
    45  			// print before panic, as panic may get lost due to conflicting panic
    46  			// (all goroutines asleep) elsewhere, since we might not unlock
    47  			// the mutex in freeConn here.
    48  			println("double free of conn. conflicts are:\nA) " + getFreedFrom(dbConn{db, c}) + "\n\nand\nB) " + stack())
    49  			panic("double free of conn.")
    50  		}
    51  		setFreedFrom(dbConn{db, c}, stack())
    52  	}
    53  }
    54  
    55  // pollDuration is an arbitrary interval to wait between checks when polling for
    56  // a condition to occur.
    57  const pollDuration = 5 * time.Millisecond
    58  
    59  const fakeDBName = "foo"
    60  
    61  var chrisBirthday = time.Unix(123456789, 0)
    62  
    63  func newTestDB(t testing.TB, name string) *DB {
    64  	return newTestDBConnector(t, &fakeConnector{name: fakeDBName}, name)
    65  }
    66  
    67  func newTestDBConnector(t testing.TB, fc *fakeConnector, name string) *DB {
    68  	fc.name = fakeDBName
    69  	db := OpenDB(fc)
    70  	if _, err := db.Exec("WIPE"); err != nil {
    71  		t.Fatalf("exec wipe: %v", err)
    72  	}
    73  	if name == "people" {
    74  		exec(t, db, "CREATE|people|name=string,age=int32,photo=blob,dead=bool,bdate=datetime")
    75  		exec(t, db, "INSERT|people|name=Alice,age=?,photo=APHOTO", 1)
    76  		exec(t, db, "INSERT|people|name=Bob,age=?,photo=BPHOTO", 2)
    77  		exec(t, db, "INSERT|people|name=Chris,age=?,photo=CPHOTO,bdate=?", 3, chrisBirthday)
    78  	}
    79  	if name == "magicquery" {
    80  		// Magic table name and column, known by fakedb_test.go.
    81  		exec(t, db, "CREATE|magicquery|op=string,millis=int32")
    82  		exec(t, db, "INSERT|magicquery|op=sleep,millis=10")
    83  	}
    84  	if name == "tx_status" {
    85  		// Magic table name and column, known by fakedb_test.go.
    86  		exec(t, db, "CREATE|tx_status|tx_status=string")
    87  		exec(t, db, "INSERT|tx_status|tx_status=invalid")
    88  	}
    89  	return db
    90  }
    91  
    92  func TestOpenDB(t *testing.T) {
    93  	db := OpenDB(dsnConnector{dsn: fakeDBName, driver: fdriver})
    94  	if db.Driver() != fdriver {
    95  		t.Fatalf("OpenDB should return the driver of the Connector")
    96  	}
    97  }
    98  
    99  func TestDriverPanic(t *testing.T) {
   100  	// Test that if driver panics, database/sql does not deadlock.
   101  	db, err := Open("test", fakeDBName)
   102  	if err != nil {
   103  		t.Fatalf("Open: %v", err)
   104  	}
   105  	expectPanic := func(name string, f func()) {
   106  		defer func() {
   107  			err := recover()
   108  			if err == nil {
   109  				t.Fatalf("%s did not panic", name)
   110  			}
   111  		}()
   112  		f()
   113  	}
   114  
   115  	expectPanic("Exec Exec", func() { db.Exec("PANIC|Exec|WIPE") })
   116  	exec(t, db, "WIPE") // check not deadlocked
   117  	expectPanic("Exec NumInput", func() { db.Exec("PANIC|NumInput|WIPE") })
   118  	exec(t, db, "WIPE") // check not deadlocked
   119  	expectPanic("Exec Close", func() { db.Exec("PANIC|Close|WIPE") })
   120  	exec(t, db, "WIPE")             // check not deadlocked
   121  	exec(t, db, "PANIC|Query|WIPE") // should run successfully: Exec does not call Query
   122  	exec(t, db, "WIPE")             // check not deadlocked
   123  
   124  	exec(t, db, "CREATE|people|name=string,age=int32,photo=blob,dead=bool,bdate=datetime")
   125  
   126  	expectPanic("Query Query", func() { db.Query("PANIC|Query|SELECT|people|age,name|") })
   127  	expectPanic("Query NumInput", func() { db.Query("PANIC|NumInput|SELECT|people|age,name|") })
   128  	expectPanic("Query Close", func() {
   129  		rows, err := db.Query("PANIC|Close|SELECT|people|age,name|")
   130  		if err != nil {
   131  			t.Fatal(err)
   132  		}
   133  		rows.Close()
   134  	})
   135  	db.Query("PANIC|Exec|SELECT|people|age,name|") // should run successfully: Query does not call Exec
   136  	exec(t, db, "WIPE")                            // check not deadlocked
   137  }
   138  
   139  func exec(t testing.TB, db *DB, query string, args ...any) {
   140  	t.Helper()
   141  	_, err := db.Exec(query, args...)
   142  	if err != nil {
   143  		t.Fatalf("Exec of %q: %v", query, err)
   144  	}
   145  }
   146  
   147  func closeDB(t testing.TB, db *DB) {
   148  	if e := recover(); e != nil {
   149  		fmt.Printf("Panic: %v\n", e)
   150  		panic(e)
   151  	}
   152  	defer setHookpostCloseConn(nil)
   153  	setHookpostCloseConn(func(_ *fakeConn, err error) {
   154  		if err != nil {
   155  			t.Errorf("Error closing fakeConn: %v", err)
   156  		}
   157  	})
   158  	db.mu.Lock()
   159  	for i, dc := range db.freeConn {
   160  		if n := len(dc.openStmt); n > 0 {
   161  			// Just a sanity check. This is legal in
   162  			// general, but if we make the tests clean up
   163  			// their statements first, then we can safely
   164  			// verify this is always zero here, and any
   165  			// other value is a leak.
   166  			t.Errorf("while closing db, freeConn %d/%d had %d open stmts; want 0", i, len(db.freeConn), n)
   167  		}
   168  	}
   169  	db.mu.Unlock()
   170  
   171  	err := db.Close()
   172  	if err != nil {
   173  		t.Fatalf("error closing DB: %v", err)
   174  	}
   175  
   176  	var numOpen int
   177  	if !waitCondition(t, func() bool {
   178  		numOpen = db.numOpenConns()
   179  		return numOpen == 0
   180  	}) {
   181  		t.Fatalf("%d connections still open after closing DB", numOpen)
   182  	}
   183  }
   184  
   185  // numPrepares assumes that db has exactly 1 idle conn and returns
   186  // its count of calls to Prepare
   187  func numPrepares(t *testing.T, db *DB) int {
   188  	if n := len(db.freeConn); n != 1 {
   189  		t.Fatalf("free conns = %d; want 1", n)
   190  	}
   191  	return db.freeConn[0].ci.(*fakeConn).numPrepare
   192  }
   193  
   194  func (db *DB) numDeps() int {
   195  	db.mu.Lock()
   196  	defer db.mu.Unlock()
   197  	return len(db.dep)
   198  }
   199  
   200  // Dependencies are closed via a goroutine, so this polls waiting for
   201  // numDeps to fall to want, waiting up to nearly the test's deadline.
   202  func (db *DB) numDepsPoll(t *testing.T, want int) int {
   203  	var n int
   204  	waitCondition(t, func() bool {
   205  		n = db.numDeps()
   206  		return n <= want
   207  	})
   208  	return n
   209  }
   210  
   211  func (db *DB) numFreeConns() int {
   212  	db.mu.Lock()
   213  	defer db.mu.Unlock()
   214  	return len(db.freeConn)
   215  }
   216  
   217  func (db *DB) numOpenConns() int {
   218  	db.mu.Lock()
   219  	defer db.mu.Unlock()
   220  	return db.numOpen
   221  }
   222  
   223  // clearAllConns closes all connections in db.
   224  func (db *DB) clearAllConns(t *testing.T) {
   225  	db.SetMaxIdleConns(0)
   226  
   227  	if g, w := db.numFreeConns(), 0; g != w {
   228  		t.Errorf("free conns = %d; want %d", g, w)
   229  	}
   230  
   231  	if n := db.numDepsPoll(t, 0); n > 0 {
   232  		t.Errorf("number of dependencies = %d; expected 0", n)
   233  		db.dumpDeps(t)
   234  	}
   235  }
   236  
   237  func (db *DB) dumpDeps(t *testing.T) {
   238  	for fc := range db.dep {
   239  		db.dumpDep(t, 0, fc, map[finalCloser]bool{})
   240  	}
   241  }
   242  
   243  func (db *DB) dumpDep(t *testing.T, depth int, dep finalCloser, seen map[finalCloser]bool) {
   244  	seen[dep] = true
   245  	indent := strings.Repeat("  ", depth)
   246  	ds := db.dep[dep]
   247  	for k := range ds {
   248  		t.Logf("%s%T (%p) waiting for -> %T (%p)", indent, dep, dep, k, k)
   249  		if fc, ok := k.(finalCloser); ok {
   250  			if !seen[fc] {
   251  				db.dumpDep(t, depth+1, fc, seen)
   252  			}
   253  		}
   254  	}
   255  }
   256  
   257  func TestQuery(t *testing.T) {
   258  	db := newTestDB(t, "people")
   259  	defer closeDB(t, db)
   260  	prepares0 := numPrepares(t, db)
   261  	rows, err := db.Query("SELECT|people|age,name|")
   262  	if err != nil {
   263  		t.Fatalf("Query: %v", err)
   264  	}
   265  	defer rows.Close()
   266  	type row struct {
   267  		age  int
   268  		name string
   269  	}
   270  	got := []row{}
   271  	for rows.Next() {
   272  		var r row
   273  		err = rows.Scan(&r.age, &r.name)
   274  		if err != nil {
   275  			t.Fatalf("Scan: %v", err)
   276  		}
   277  		got = append(got, r)
   278  	}
   279  	err = rows.Err()
   280  	if err != nil {
   281  		t.Fatalf("Err: %v", err)
   282  	}
   283  	want := []row{
   284  		{age: 1, name: "Alice"},
   285  		{age: 2, name: "Bob"},
   286  		{age: 3, name: "Chris"},
   287  	}
   288  	if !slices.Equal(got, want) {
   289  		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got, want)
   290  	}
   291  
   292  	// And verify that the final rows.Next() call, which hit EOF,
   293  	// also closed the rows connection.
   294  	if n := db.numFreeConns(); n != 1 {
   295  		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
   296  	}
   297  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
   298  		t.Errorf("executed %d Prepare statements; want 1", prepares)
   299  	}
   300  }
   301  
   302  // TestQueryContext tests canceling the context while scanning the rows.
   303  func TestQueryContext(t *testing.T) {
   304  	db := newTestDB(t, "people")
   305  	defer closeDB(t, db)
   306  	prepares0 := numPrepares(t, db)
   307  
   308  	ctx, cancel := context.WithCancel(context.Background())
   309  	defer cancel()
   310  
   311  	rows, err := db.QueryContext(ctx, "SELECT|people|age,name|")
   312  	if err != nil {
   313  		t.Fatalf("Query: %v", err)
   314  	}
   315  	type row struct {
   316  		age  int
   317  		name string
   318  	}
   319  	got := []row{}
   320  	index := 0
   321  	for rows.Next() {
   322  		if index == 2 {
   323  			cancel()
   324  			waitForRowsClose(t, rows)
   325  		}
   326  		var r row
   327  		err = rows.Scan(&r.age, &r.name)
   328  		if err != nil {
   329  			if index == 2 {
   330  				break
   331  			}
   332  			t.Fatalf("Scan: %v", err)
   333  		}
   334  		if index == 2 && err != context.Canceled {
   335  			t.Fatalf("Scan: %v; want context.Canceled", err)
   336  		}
   337  		got = append(got, r)
   338  		index++
   339  	}
   340  	select {
   341  	case <-ctx.Done():
   342  		if err := ctx.Err(); err != context.Canceled {
   343  			t.Fatalf("context err = %v; want context.Canceled", err)
   344  		}
   345  	default:
   346  		t.Fatalf("context err = nil; want context.Canceled")
   347  	}
   348  	want := []row{
   349  		{age: 1, name: "Alice"},
   350  		{age: 2, name: "Bob"},
   351  	}
   352  	if !slices.Equal(got, want) {
   353  		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got, want)
   354  	}
   355  
   356  	// And verify that the final rows.Next() call, which hit EOF,
   357  	// also closed the rows connection.
   358  	waitForRowsClose(t, rows)
   359  	waitForFree(t, db, 1)
   360  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
   361  		t.Errorf("executed %d Prepare statements; want 1", prepares)
   362  	}
   363  }
   364  
   365  func waitCondition(t testing.TB, fn func() bool) bool {
   366  	timeout := 5 * time.Second
   367  
   368  	type deadliner interface {
   369  		Deadline() (time.Time, bool)
   370  	}
   371  	if td, ok := t.(deadliner); ok {
   372  		if deadline, ok := td.Deadline(); ok {
   373  			timeout = time.Until(deadline)
   374  			timeout = timeout * 19 / 20 // Give 5% headroom for cleanup and error-reporting.
   375  		}
   376  	}
   377  
   378  	deadline := time.Now().Add(timeout)
   379  	for {
   380  		if fn() {
   381  			return true
   382  		}
   383  		if time.Until(deadline) < pollDuration {
   384  			return false
   385  		}
   386  		time.Sleep(pollDuration)
   387  	}
   388  }
   389  
   390  // waitForFree checks db.numFreeConns until either it equals want or
   391  // the maxWait time elapses.
   392  func waitForFree(t *testing.T, db *DB, want int) {
   393  	var numFree int
   394  	if !waitCondition(t, func() bool {
   395  		numFree = db.numFreeConns()
   396  		return numFree == want
   397  	}) {
   398  		t.Fatalf("free conns after hitting EOF = %d; want %d", numFree, want)
   399  	}
   400  }
   401  
   402  func waitForRowsClose(t *testing.T, rows *Rows) {
   403  	if !waitCondition(t, func() bool {
   404  		rows.closemu.RLock()
   405  		defer rows.closemu.RUnlock()
   406  		return rows.closed
   407  	}) {
   408  		t.Fatal("failed to close rows")
   409  	}
   410  }
   411  
   412  // TestQueryContextWait ensures that rows and all internal statements are closed when
   413  // a query context is closed during execution.
   414  func TestQueryContextWait(t *testing.T) {
   415  	db := newTestDB(t, "people")
   416  	defer closeDB(t, db)
   417  	prepares0 := numPrepares(t, db)
   418  
   419  	ctx, cancel := context.WithCancel(context.Background())
   420  	defer cancel()
   421  
   422  	// This will trigger the *fakeConn.Prepare method which will take time
   423  	// performing the query. The ctxDriverPrepare func will check the context
   424  	// after this and close the rows and return an error.
   425  	c, err := db.Conn(ctx)
   426  	if err != nil {
   427  		t.Fatal(err)
   428  	}
   429  
   430  	c.dc.ci.(*fakeConn).waiter = func(c context.Context) {
   431  		cancel()
   432  		<-ctx.Done()
   433  	}
   434  	_, err = c.QueryContext(ctx, "SELECT|people|age,name|")
   435  	c.Close()
   436  	if err != context.Canceled {
   437  		t.Fatalf("expected QueryContext to error with context deadline exceeded but returned %v", err)
   438  	}
   439  
   440  	// Verify closed rows connection after error condition.
   441  	waitForFree(t, db, 1)
   442  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
   443  		t.Fatalf("executed %d Prepare statements; want 1", prepares)
   444  	}
   445  }
   446  
   447  // TestTxContextWait tests the transaction behavior when the tx context is canceled
   448  // during execution of the query.
   449  func TestTxContextWait(t *testing.T) {
   450  	testContextWait(t, false)
   451  }
   452  
   453  // TestTxContextWaitNoDiscard is the same as TestTxContextWait, but should not discard
   454  // the final connection.
   455  func TestTxContextWaitNoDiscard(t *testing.T) {
   456  	testContextWait(t, true)
   457  }
   458  
   459  func testContextWait(t *testing.T, keepConnOnRollback bool) {
   460  	db := newTestDB(t, "people")
   461  	defer closeDB(t, db)
   462  
   463  	ctx, cancel := context.WithCancel(context.Background())
   464  
   465  	tx, err := db.BeginTx(ctx, nil)
   466  	if err != nil {
   467  		t.Fatal(err)
   468  	}
   469  	tx.keepConnOnRollback = keepConnOnRollback
   470  
   471  	tx.dc.ci.(*fakeConn).waiter = func(c context.Context) {
   472  		cancel()
   473  		<-ctx.Done()
   474  	}
   475  	// This will trigger the *fakeConn.Prepare method which will take time
   476  	// performing the query. The ctxDriverPrepare func will check the context
   477  	// after this and close the rows and return an error.
   478  	_, err = tx.QueryContext(ctx, "SELECT|people|age,name|")
   479  	if err != context.Canceled {
   480  		t.Fatalf("expected QueryContext to error with context canceled but returned %v", err)
   481  	}
   482  
   483  	if keepConnOnRollback {
   484  		waitForFree(t, db, 1)
   485  	} else {
   486  		waitForFree(t, db, 0)
   487  	}
   488  }
   489  
   490  // TestUnsupportedOptions checks that the database fails when a driver that
   491  // doesn't implement ConnBeginTx is used with non-default options and an
   492  // un-cancellable context.
   493  func TestUnsupportedOptions(t *testing.T) {
   494  	db := newTestDB(t, "people")
   495  	defer closeDB(t, db)
   496  	_, err := db.BeginTx(context.Background(), &TxOptions{
   497  		Isolation: LevelSerializable, ReadOnly: true,
   498  	})
   499  	if err == nil {
   500  		t.Fatal("expected error when using unsupported options, got nil")
   501  	}
   502  }
   503  
   504  func TestMultiResultSetQuery(t *testing.T) {
   505  	db := newTestDB(t, "people")
   506  	defer closeDB(t, db)
   507  	prepares0 := numPrepares(t, db)
   508  	rows, err := db.Query("SELECT|people|age,name|;SELECT|people|name|")
   509  	if err != nil {
   510  		t.Fatalf("Query: %v", err)
   511  	}
   512  	type row1 struct {
   513  		age  int
   514  		name string
   515  	}
   516  	type row2 struct {
   517  		name string
   518  	}
   519  	got1 := []row1{}
   520  	for rows.Next() {
   521  		var r row1
   522  		err = rows.Scan(&r.age, &r.name)
   523  		if err != nil {
   524  			t.Fatalf("Scan: %v", err)
   525  		}
   526  		got1 = append(got1, r)
   527  	}
   528  	err = rows.Err()
   529  	if err != nil {
   530  		t.Fatalf("Err: %v", err)
   531  	}
   532  	want1 := []row1{
   533  		{age: 1, name: "Alice"},
   534  		{age: 2, name: "Bob"},
   535  		{age: 3, name: "Chris"},
   536  	}
   537  	if !slices.Equal(got1, want1) {
   538  		t.Errorf("mismatch.\n got1: %#v\nwant: %#v", got1, want1)
   539  	}
   540  
   541  	if !rows.NextResultSet() {
   542  		t.Errorf("expected another result set")
   543  	}
   544  
   545  	got2 := []row2{}
   546  	for rows.Next() {
   547  		var r row2
   548  		err = rows.Scan(&r.name)
   549  		if err != nil {
   550  			t.Fatalf("Scan: %v", err)
   551  		}
   552  		got2 = append(got2, r)
   553  	}
   554  	err = rows.Err()
   555  	if err != nil {
   556  		t.Fatalf("Err: %v", err)
   557  	}
   558  	want2 := []row2{
   559  		{name: "Alice"},
   560  		{name: "Bob"},
   561  		{name: "Chris"},
   562  	}
   563  	if !slices.Equal(got2, want2) {
   564  		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got2, want2)
   565  	}
   566  	if rows.NextResultSet() {
   567  		t.Errorf("expected no more result sets")
   568  	}
   569  
   570  	// And verify that the final rows.Next() call, which hit EOF,
   571  	// also closed the rows connection.
   572  	waitForFree(t, db, 1)
   573  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
   574  		t.Errorf("executed %d Prepare statements; want 1", prepares)
   575  	}
   576  }
   577  
   578  func TestQueryNamedArg(t *testing.T) {
   579  	db := newTestDB(t, "people")
   580  	defer closeDB(t, db)
   581  	prepares0 := numPrepares(t, db)
   582  	rows, err := db.Query(
   583  		// Ensure the name and age parameters only match on placeholder name, not position.
   584  		"SELECT|people|age,name|name=?name,age=?age",
   585  		Named("age", 2),
   586  		Named("name", "Bob"),
   587  	)
   588  	if err != nil {
   589  		t.Fatalf("Query: %v", err)
   590  	}
   591  	type row struct {
   592  		age  int
   593  		name string
   594  	}
   595  	got := []row{}
   596  	for rows.Next() {
   597  		var r row
   598  		err = rows.Scan(&r.age, &r.name)
   599  		if err != nil {
   600  			t.Fatalf("Scan: %v", err)
   601  		}
   602  		got = append(got, r)
   603  	}
   604  	err = rows.Err()
   605  	if err != nil {
   606  		t.Fatalf("Err: %v", err)
   607  	}
   608  	want := []row{
   609  		{age: 2, name: "Bob"},
   610  	}
   611  	if !slices.Equal(got, want) {
   612  		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got, want)
   613  	}
   614  
   615  	// And verify that the final rows.Next() call, which hit EOF,
   616  	// also closed the rows connection.
   617  	if n := db.numFreeConns(); n != 1 {
   618  		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
   619  	}
   620  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
   621  		t.Errorf("executed %d Prepare statements; want 1", prepares)
   622  	}
   623  }
   624  
   625  func TestPoolExhaustOnCancel(t *testing.T) {
   626  	if testing.Short() {
   627  		t.Skip("long test")
   628  	}
   629  
   630  	max := 3
   631  	var saturate, saturateDone sync.WaitGroup
   632  	saturate.Add(max)
   633  	saturateDone.Add(max)
   634  
   635  	donePing := make(chan bool)
   636  	state := 0
   637  
   638  	// waiter will be called for all queries, including
   639  	// initial setup queries. The state is only assigned when
   640  	// no queries are made.
   641  	//
   642  	// Only allow the first batch of queries to finish once the
   643  	// second batch of Ping queries have finished.
   644  	waiter := func(ctx context.Context) {
   645  		switch state {
   646  		case 0:
   647  			// Nothing. Initial database setup.
   648  		case 1:
   649  			saturate.Done()
   650  			select {
   651  			case <-ctx.Done():
   652  			case <-donePing:
   653  			}
   654  		case 2:
   655  		}
   656  	}
   657  	db := newTestDBConnector(t, &fakeConnector{waiter: waiter}, "people")
   658  	defer closeDB(t, db)
   659  
   660  	db.SetMaxOpenConns(max)
   661  
   662  	// First saturate the connection pool.
   663  	// Then start new requests for a connection that is canceled after it is requested.
   664  
   665  	state = 1
   666  	for i := 0; i < max; i++ {
   667  		go func() {
   668  			rows, err := db.Query("SELECT|people|name,photo|")
   669  			if err != nil {
   670  				t.Errorf("Query: %v", err)
   671  				return
   672  			}
   673  			rows.Close()
   674  			saturateDone.Done()
   675  		}()
   676  	}
   677  
   678  	saturate.Wait()
   679  	if t.Failed() {
   680  		t.FailNow()
   681  	}
   682  	state = 2
   683  
   684  	// Now cancel the request while it is waiting.
   685  	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
   686  	defer cancel()
   687  
   688  	for i := 0; i < max; i++ {
   689  		ctxReq, cancelReq := context.WithCancel(ctx)
   690  		go func() {
   691  			time.Sleep(100 * time.Millisecond)
   692  			cancelReq()
   693  		}()
   694  		err := db.PingContext(ctxReq)
   695  		if err != context.Canceled {
   696  			t.Fatalf("PingContext (Exhaust): %v", err)
   697  		}
   698  	}
   699  	close(donePing)
   700  	saturateDone.Wait()
   701  
   702  	// Now try to open a normal connection.
   703  	err := db.PingContext(ctx)
   704  	if err != nil {
   705  		t.Fatalf("PingContext (Normal): %v", err)
   706  	}
   707  }
   708  
   709  func TestRowsColumns(t *testing.T) {
   710  	db := newTestDB(t, "people")
   711  	defer closeDB(t, db)
   712  	rows, err := db.Query("SELECT|people|age,name|")
   713  	if err != nil {
   714  		t.Fatalf("Query: %v", err)
   715  	}
   716  	cols, err := rows.Columns()
   717  	if err != nil {
   718  		t.Fatalf("Columns: %v", err)
   719  	}
   720  	want := []string{"age", "name"}
   721  	if !slices.Equal(cols, want) {
   722  		t.Errorf("got %#v; want %#v", cols, want)
   723  	}
   724  	if err := rows.Close(); err != nil {
   725  		t.Errorf("error closing rows: %s", err)
   726  	}
   727  }
   728  
   729  func TestRowsColumnTypes(t *testing.T) {
   730  	db := newTestDB(t, "people")
   731  	defer closeDB(t, db)
   732  	rows, err := db.Query("SELECT|people|age,name|")
   733  	if err != nil {
   734  		t.Fatalf("Query: %v", err)
   735  	}
   736  	tt, err := rows.ColumnTypes()
   737  	if err != nil {
   738  		t.Fatalf("ColumnTypes: %v", err)
   739  	}
   740  
   741  	types := make([]reflect.Type, len(tt))
   742  	for i, tp := range tt {
   743  		st := tp.ScanType()
   744  		if st == nil {
   745  			t.Errorf("scantype is null for column %q", tp.Name())
   746  			continue
   747  		}
   748  		types[i] = st
   749  	}
   750  	values := make([]any, len(tt))
   751  	for i := range values {
   752  		values[i] = reflect.New(types[i]).Interface()
   753  	}
   754  	ct := 0
   755  	for rows.Next() {
   756  		err = rows.Scan(values...)
   757  		if err != nil {
   758  			t.Fatalf("failed to scan values in %v", err)
   759  		}
   760  		if ct == 1 {
   761  			if age := *values[0].(*int32); age != 2 {
   762  				t.Errorf("Expected 2, got %v", age)
   763  			}
   764  			if name := *values[1].(*string); name != "Bob" {
   765  				t.Errorf("Expected Bob, got %v", name)
   766  			}
   767  		}
   768  		ct++
   769  	}
   770  	if ct != 3 {
   771  		t.Errorf("expected 3 rows, got %d", ct)
   772  	}
   773  
   774  	if err := rows.Close(); err != nil {
   775  		t.Errorf("error closing rows: %s", err)
   776  	}
   777  }
   778  
   779  func TestQueryRow(t *testing.T) {
   780  	db := newTestDB(t, "people")
   781  	defer closeDB(t, db)
   782  	var name string
   783  	var age int
   784  	var birthday time.Time
   785  
   786  	err := db.QueryRow("SELECT|people|age,name|age=?", 3).Scan(&age)
   787  	if err == nil || !strings.Contains(err.Error(), "expected 2 destination arguments") {
   788  		t.Errorf("expected error from wrong number of arguments; actually got: %v", err)
   789  	}
   790  
   791  	err = db.QueryRow("SELECT|people|bdate|age=?", 3).Scan(&birthday)
   792  	if err != nil || !birthday.Equal(chrisBirthday) {
   793  		t.Errorf("chris birthday = %v, err = %v; want %v", birthday, err, chrisBirthday)
   794  	}
   795  
   796  	err = db.QueryRow("SELECT|people|age,name|age=?", 2).Scan(&age, &name)
   797  	if err != nil {
   798  		t.Fatalf("age QueryRow+Scan: %v", err)
   799  	}
   800  	if name != "Bob" {
   801  		t.Errorf("expected name Bob, got %q", name)
   802  	}
   803  	if age != 2 {
   804  		t.Errorf("expected age 2, got %d", age)
   805  	}
   806  
   807  	err = db.QueryRow("SELECT|people|age,name|name=?", "Alice").Scan(&age, &name)
   808  	if err != nil {
   809  		t.Fatalf("name QueryRow+Scan: %v", err)
   810  	}
   811  	if name != "Alice" {
   812  		t.Errorf("expected name Alice, got %q", name)
   813  	}
   814  	if age != 1 {
   815  		t.Errorf("expected age 1, got %d", age)
   816  	}
   817  
   818  	var photo []byte
   819  	err = db.QueryRow("SELECT|people|photo|name=?", "Alice").Scan(&photo)
   820  	if err != nil {
   821  		t.Fatalf("photo QueryRow+Scan: %v", err)
   822  	}
   823  	want := []byte("APHOTO")
   824  	if !slices.Equal(photo, want) {
   825  		t.Errorf("photo = %q; want %q", photo, want)
   826  	}
   827  }
   828  
   829  func TestRowErr(t *testing.T) {
   830  	db := newTestDB(t, "people")
   831  
   832  	err := db.QueryRowContext(context.Background(), "SELECT|people|bdate|age=?", 3).Err()
   833  	if err != nil {
   834  		t.Errorf("Unexpected err = %v; want %v", err, nil)
   835  	}
   836  
   837  	ctx, cancel := context.WithCancel(context.Background())
   838  	cancel()
   839  
   840  	err = db.QueryRowContext(ctx, "SELECT|people|bdate|age=?", 3).Err()
   841  	exp := "context canceled"
   842  	if err == nil || !strings.Contains(err.Error(), exp) {
   843  		t.Errorf("Expected err = %v; got %v", exp, err)
   844  	}
   845  }
   846  
   847  func TestTxRollbackCommitErr(t *testing.T) {
   848  	db := newTestDB(t, "people")
   849  	defer closeDB(t, db)
   850  
   851  	tx, err := db.Begin()
   852  	if err != nil {
   853  		t.Fatal(err)
   854  	}
   855  	err = tx.Rollback()
   856  	if err != nil {
   857  		t.Errorf("expected nil error from Rollback; got %v", err)
   858  	}
   859  	err = tx.Commit()
   860  	if err != ErrTxDone {
   861  		t.Errorf("expected %q from Commit; got %q", ErrTxDone, err)
   862  	}
   863  
   864  	tx, err = db.Begin()
   865  	if err != nil {
   866  		t.Fatal(err)
   867  	}
   868  	err = tx.Commit()
   869  	if err != nil {
   870  		t.Errorf("expected nil error from Commit; got %v", err)
   871  	}
   872  	err = tx.Rollback()
   873  	if err != ErrTxDone {
   874  		t.Errorf("expected %q from Rollback; got %q", ErrTxDone, err)
   875  	}
   876  }
   877  
   878  func TestStatementErrorAfterClose(t *testing.T) {
   879  	db := newTestDB(t, "people")
   880  	defer closeDB(t, db)
   881  	stmt, err := db.Prepare("SELECT|people|age|name=?")
   882  	if err != nil {
   883  		t.Fatalf("Prepare: %v", err)
   884  	}
   885  	err = stmt.Close()
   886  	if err != nil {
   887  		t.Fatalf("Close: %v", err)
   888  	}
   889  	var name string
   890  	err = stmt.QueryRow("foo").Scan(&name)
   891  	if err == nil {
   892  		t.Errorf("expected error from QueryRow.Scan after Stmt.Close")
   893  	}
   894  }
   895  
   896  func TestStatementQueryRow(t *testing.T) {
   897  	db := newTestDB(t, "people")
   898  	defer closeDB(t, db)
   899  	stmt, err := db.Prepare("SELECT|people|age|name=?")
   900  	if err != nil {
   901  		t.Fatalf("Prepare: %v", err)
   902  	}
   903  	defer stmt.Close()
   904  	var age int
   905  	for n, tt := range []struct {
   906  		name string
   907  		want int
   908  	}{
   909  		{"Alice", 1},
   910  		{"Bob", 2},
   911  		{"Chris", 3},
   912  	} {
   913  		if err := stmt.QueryRow(tt.name).Scan(&age); err != nil {
   914  			t.Errorf("%d: on %q, QueryRow/Scan: %v", n, tt.name, err)
   915  		} else if age != tt.want {
   916  			t.Errorf("%d: age=%d, want %d", n, age, tt.want)
   917  		}
   918  	}
   919  }
   920  
   921  type stubDriverStmt struct {
   922  	err error
   923  }
   924  
   925  func (s stubDriverStmt) Close() error {
   926  	return s.err
   927  }
   928  
   929  func (s stubDriverStmt) NumInput() int {
   930  	return -1
   931  }
   932  
   933  func (s stubDriverStmt) Exec(args []driver.Value) (driver.Result, error) {
   934  	return nil, nil
   935  }
   936  
   937  func (s stubDriverStmt) Query(args []driver.Value) (driver.Rows, error) {
   938  	return nil, nil
   939  }
   940  
   941  // golang.org/issue/12798
   942  func TestStatementClose(t *testing.T) {
   943  	want := errors.New("STMT ERROR")
   944  
   945  	tests := []struct {
   946  		stmt *Stmt
   947  		msg  string
   948  	}{
   949  		{&Stmt{stickyErr: want}, "stickyErr not propagated"},
   950  		{&Stmt{cg: &Tx{}, cgds: &driverStmt{Locker: &sync.Mutex{}, si: stubDriverStmt{want}}}, "driverStmt.Close() error not propagated"},
   951  	}
   952  	for _, test := range tests {
   953  		if err := test.stmt.Close(); err != want {
   954  			t.Errorf("%s. Got stmt.Close() = %v, want = %v", test.msg, err, want)
   955  		}
   956  	}
   957  }
   958  
   959  // golang.org/issue/3734
   960  func TestStatementQueryRowConcurrent(t *testing.T) {
   961  	db := newTestDB(t, "people")
   962  	defer closeDB(t, db)
   963  	stmt, err := db.Prepare("SELECT|people|age|name=?")
   964  	if err != nil {
   965  		t.Fatalf("Prepare: %v", err)
   966  	}
   967  	defer stmt.Close()
   968  
   969  	const n = 10
   970  	ch := make(chan error, n)
   971  	for i := 0; i < n; i++ {
   972  		go func() {
   973  			var age int
   974  			err := stmt.QueryRow("Alice").Scan(&age)
   975  			if err == nil && age != 1 {
   976  				err = fmt.Errorf("unexpected age %d", age)
   977  			}
   978  			ch <- err
   979  		}()
   980  	}
   981  	for i := 0; i < n; i++ {
   982  		if err := <-ch; err != nil {
   983  			t.Error(err)
   984  		}
   985  	}
   986  }
   987  
   988  // just a test of fakedb itself
   989  func TestBogusPreboundParameters(t *testing.T) {
   990  	db := newTestDB(t, "foo")
   991  	defer closeDB(t, db)
   992  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
   993  	_, err := db.Prepare("INSERT|t1|name=?,age=bogusconversion")
   994  	if err == nil {
   995  		t.Fatalf("expected error")
   996  	}
   997  	if err.Error() != `fakedb: invalid conversion to int32 from "bogusconversion"` {
   998  		t.Errorf("unexpected error: %v", err)
   999  	}
  1000  }
  1001  
  1002  func TestExec(t *testing.T) {
  1003  	db := newTestDB(t, "foo")
  1004  	defer closeDB(t, db)
  1005  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  1006  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1007  	if err != nil {
  1008  		t.Errorf("Stmt, err = %v, %v", stmt, err)
  1009  	}
  1010  	defer stmt.Close()
  1011  
  1012  	type execTest struct {
  1013  		args    []any
  1014  		wantErr string
  1015  	}
  1016  	execTests := []execTest{
  1017  		// Okay:
  1018  		{[]any{"Brad", 31}, ""},
  1019  		{[]any{"Brad", int64(31)}, ""},
  1020  		{[]any{"Bob", "32"}, ""},
  1021  		{[]any{7, 9}, ""},
  1022  
  1023  		// Invalid conversions:
  1024  		{[]any{"Brad", int64(0xFFFFFFFF)}, "sql: converting argument $2 type: sql/driver: value 4294967295 overflows int32"},
  1025  		{[]any{"Brad", "strconv fail"}, `sql: converting argument $2 type: sql/driver: value "strconv fail" can't be converted to int32`},
  1026  
  1027  		// Wrong number of args:
  1028  		{[]any{}, "sql: expected 2 arguments, got 0"},
  1029  		{[]any{1, 2, 3}, "sql: expected 2 arguments, got 3"},
  1030  	}
  1031  	for n, et := range execTests {
  1032  		_, err := stmt.Exec(et.args...)
  1033  		errStr := ""
  1034  		if err != nil {
  1035  			errStr = err.Error()
  1036  		}
  1037  		if errStr != et.wantErr {
  1038  			t.Errorf("stmt.Execute #%d: for %v, got error %q, want error %q",
  1039  				n, et.args, errStr, et.wantErr)
  1040  		}
  1041  	}
  1042  }
  1043  
  1044  func TestTxPrepare(t *testing.T) {
  1045  	db := newTestDB(t, "")
  1046  	defer closeDB(t, db)
  1047  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  1048  	tx, err := db.Begin()
  1049  	if err != nil {
  1050  		t.Fatalf("Begin = %v", err)
  1051  	}
  1052  	stmt, err := tx.Prepare("INSERT|t1|name=?,age=?")
  1053  	if err != nil {
  1054  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1055  	}
  1056  	defer stmt.Close()
  1057  	_, err = stmt.Exec("Bobby", 7)
  1058  	if err != nil {
  1059  		t.Fatalf("Exec = %v", err)
  1060  	}
  1061  	err = tx.Commit()
  1062  	if err != nil {
  1063  		t.Fatalf("Commit = %v", err)
  1064  	}
  1065  	// Commit() should have closed the statement
  1066  	if !stmt.closed {
  1067  		t.Fatal("Stmt not closed after Commit")
  1068  	}
  1069  }
  1070  
  1071  func TestTxStmt(t *testing.T) {
  1072  	db := newTestDB(t, "")
  1073  	defer closeDB(t, db)
  1074  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  1075  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1076  	if err != nil {
  1077  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1078  	}
  1079  	defer stmt.Close()
  1080  	tx, err := db.Begin()
  1081  	if err != nil {
  1082  		t.Fatalf("Begin = %v", err)
  1083  	}
  1084  	txs := tx.Stmt(stmt)
  1085  	defer txs.Close()
  1086  	_, err = txs.Exec("Bobby", 7)
  1087  	if err != nil {
  1088  		t.Fatalf("Exec = %v", err)
  1089  	}
  1090  	err = tx.Commit()
  1091  	if err != nil {
  1092  		t.Fatalf("Commit = %v", err)
  1093  	}
  1094  	// Commit() should have closed the statement
  1095  	if !txs.closed {
  1096  		t.Fatal("Stmt not closed after Commit")
  1097  	}
  1098  }
  1099  
  1100  func TestTxStmtPreparedOnce(t *testing.T) {
  1101  	db := newTestDB(t, "")
  1102  	defer closeDB(t, db)
  1103  	exec(t, db, "CREATE|t1|name=string,age=int32")
  1104  
  1105  	prepares0 := numPrepares(t, db)
  1106  
  1107  	// db.Prepare increments numPrepares.
  1108  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1109  	if err != nil {
  1110  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1111  	}
  1112  	defer stmt.Close()
  1113  
  1114  	tx, err := db.Begin()
  1115  	if err != nil {
  1116  		t.Fatalf("Begin = %v", err)
  1117  	}
  1118  
  1119  	txs1 := tx.Stmt(stmt)
  1120  	txs2 := tx.Stmt(stmt)
  1121  
  1122  	_, err = txs1.Exec("Go", 7)
  1123  	if err != nil {
  1124  		t.Fatalf("Exec = %v", err)
  1125  	}
  1126  	txs1.Close()
  1127  
  1128  	_, err = txs2.Exec("Gopher", 8)
  1129  	if err != nil {
  1130  		t.Fatalf("Exec = %v", err)
  1131  	}
  1132  	txs2.Close()
  1133  
  1134  	err = tx.Commit()
  1135  	if err != nil {
  1136  		t.Fatalf("Commit = %v", err)
  1137  	}
  1138  
  1139  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
  1140  		t.Errorf("executed %d Prepare statements; want 1", prepares)
  1141  	}
  1142  }
  1143  
  1144  func TestTxStmtClosedRePrepares(t *testing.T) {
  1145  	db := newTestDB(t, "")
  1146  	defer closeDB(t, db)
  1147  	exec(t, db, "CREATE|t1|name=string,age=int32")
  1148  
  1149  	prepares0 := numPrepares(t, db)
  1150  
  1151  	// db.Prepare increments numPrepares.
  1152  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1153  	if err != nil {
  1154  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1155  	}
  1156  	tx, err := db.Begin()
  1157  	if err != nil {
  1158  		t.Fatalf("Begin = %v", err)
  1159  	}
  1160  	err = stmt.Close()
  1161  	if err != nil {
  1162  		t.Fatalf("stmt.Close() = %v", err)
  1163  	}
  1164  	// tx.Stmt increments numPrepares because stmt is closed.
  1165  	txs := tx.Stmt(stmt)
  1166  	if txs.stickyErr != nil {
  1167  		t.Fatal(txs.stickyErr)
  1168  	}
  1169  	if txs.parentStmt != nil {
  1170  		t.Fatal("expected nil parentStmt")
  1171  	}
  1172  	_, err = txs.Exec(`Eric`, 82)
  1173  	if err != nil {
  1174  		t.Fatalf("txs.Exec = %v", err)
  1175  	}
  1176  
  1177  	err = txs.Close()
  1178  	if err != nil {
  1179  		t.Fatalf("txs.Close = %v", err)
  1180  	}
  1181  
  1182  	tx.Rollback()
  1183  
  1184  	if prepares := numPrepares(t, db) - prepares0; prepares != 2 {
  1185  		t.Errorf("executed %d Prepare statements; want 2", prepares)
  1186  	}
  1187  }
  1188  
  1189  func TestParentStmtOutlivesTxStmt(t *testing.T) {
  1190  	db := newTestDB(t, "")
  1191  	defer closeDB(t, db)
  1192  	exec(t, db, "CREATE|t1|name=string,age=int32")
  1193  
  1194  	// Make sure everything happens on the same connection.
  1195  	db.SetMaxOpenConns(1)
  1196  
  1197  	prepares0 := numPrepares(t, db)
  1198  
  1199  	// db.Prepare increments numPrepares.
  1200  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1201  	if err != nil {
  1202  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1203  	}
  1204  	defer stmt.Close()
  1205  	tx, err := db.Begin()
  1206  	if err != nil {
  1207  		t.Fatalf("Begin = %v", err)
  1208  	}
  1209  	txs := tx.Stmt(stmt)
  1210  	if len(stmt.css) != 1 {
  1211  		t.Fatalf("len(stmt.css) = %v; want 1", len(stmt.css))
  1212  	}
  1213  	err = txs.Close()
  1214  	if err != nil {
  1215  		t.Fatalf("txs.Close() = %v", err)
  1216  	}
  1217  	err = tx.Rollback()
  1218  	if err != nil {
  1219  		t.Fatalf("tx.Rollback() = %v", err)
  1220  	}
  1221  	// txs must not be valid.
  1222  	_, err = txs.Exec("Suzan", 30)
  1223  	if err == nil {
  1224  		t.Fatalf("txs.Exec(), expected err")
  1225  	}
  1226  	// Stmt must still be valid.
  1227  	_, err = stmt.Exec("Janina", 25)
  1228  	if err != nil {
  1229  		t.Fatalf("stmt.Exec() = %v", err)
  1230  	}
  1231  
  1232  	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
  1233  		t.Errorf("executed %d Prepare statements; want 1", prepares)
  1234  	}
  1235  }
  1236  
  1237  // Test that tx.Stmt called with a statement already
  1238  // associated with tx as argument re-prepares the same
  1239  // statement again.
  1240  func TestTxStmtFromTxStmtRePrepares(t *testing.T) {
  1241  	db := newTestDB(t, "")
  1242  	defer closeDB(t, db)
  1243  	exec(t, db, "CREATE|t1|name=string,age=int32")
  1244  	prepares0 := numPrepares(t, db)
  1245  	// db.Prepare increments numPrepares.
  1246  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1247  	if err != nil {
  1248  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1249  	}
  1250  	defer stmt.Close()
  1251  
  1252  	tx, err := db.Begin()
  1253  	if err != nil {
  1254  		t.Fatalf("Begin = %v", err)
  1255  	}
  1256  	txs1 := tx.Stmt(stmt)
  1257  
  1258  	// tx.Stmt(txs1) increments numPrepares because txs1 already
  1259  	// belongs to a transaction (albeit the same transaction).
  1260  	txs2 := tx.Stmt(txs1)
  1261  	if txs2.stickyErr != nil {
  1262  		t.Fatal(txs2.stickyErr)
  1263  	}
  1264  	if txs2.parentStmt != nil {
  1265  		t.Fatal("expected nil parentStmt")
  1266  	}
  1267  	_, err = txs2.Exec(`Eric`, 82)
  1268  	if err != nil {
  1269  		t.Fatal(err)
  1270  	}
  1271  
  1272  	err = txs1.Close()
  1273  	if err != nil {
  1274  		t.Fatalf("txs1.Close = %v", err)
  1275  	}
  1276  	err = txs2.Close()
  1277  	if err != nil {
  1278  		t.Fatalf("txs1.Close = %v", err)
  1279  	}
  1280  	err = tx.Rollback()
  1281  	if err != nil {
  1282  		t.Fatalf("tx.Rollback = %v", err)
  1283  	}
  1284  
  1285  	if prepares := numPrepares(t, db) - prepares0; prepares != 2 {
  1286  		t.Errorf("executed %d Prepare statements; want 2", prepares)
  1287  	}
  1288  }
  1289  
  1290  // Issue: https://golang.org/issue/2784
  1291  // This test didn't fail before because we got lucky with the fakedb driver.
  1292  // It was failing, and now not, in github.com/bradfitz/go-sql-test
  1293  func TestTxQuery(t *testing.T) {
  1294  	db := newTestDB(t, "")
  1295  	defer closeDB(t, db)
  1296  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  1297  	exec(t, db, "INSERT|t1|name=Alice")
  1298  
  1299  	tx, err := db.Begin()
  1300  	if err != nil {
  1301  		t.Fatal(err)
  1302  	}
  1303  	defer tx.Rollback()
  1304  
  1305  	r, err := tx.Query("SELECT|t1|name|")
  1306  	if err != nil {
  1307  		t.Fatal(err)
  1308  	}
  1309  	defer r.Close()
  1310  
  1311  	if !r.Next() {
  1312  		if r.Err() != nil {
  1313  			t.Fatal(r.Err())
  1314  		}
  1315  		t.Fatal("expected one row")
  1316  	}
  1317  
  1318  	var x string
  1319  	err = r.Scan(&x)
  1320  	if err != nil {
  1321  		t.Fatal(err)
  1322  	}
  1323  }
  1324  
  1325  func TestTxQueryInvalid(t *testing.T) {
  1326  	db := newTestDB(t, "")
  1327  	defer closeDB(t, db)
  1328  
  1329  	tx, err := db.Begin()
  1330  	if err != nil {
  1331  		t.Fatal(err)
  1332  	}
  1333  	defer tx.Rollback()
  1334  
  1335  	_, err = tx.Query("SELECT|t1|name|")
  1336  	if err == nil {
  1337  		t.Fatal("Error expected")
  1338  	}
  1339  }
  1340  
  1341  // Tests fix for issue 4433, that retries in Begin happen when
  1342  // conn.Begin() returns ErrBadConn
  1343  func TestTxErrBadConn(t *testing.T) {
  1344  	db, err := Open("test", fakeDBName+";badConn")
  1345  	if err != nil {
  1346  		t.Fatalf("Open: %v", err)
  1347  	}
  1348  	if _, err := db.Exec("WIPE"); err != nil {
  1349  		t.Fatalf("exec wipe: %v", err)
  1350  	}
  1351  	defer closeDB(t, db)
  1352  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  1353  	stmt, err := db.Prepare("INSERT|t1|name=?,age=?")
  1354  	if err != nil {
  1355  		t.Fatalf("Stmt, err = %v, %v", stmt, err)
  1356  	}
  1357  	defer stmt.Close()
  1358  	tx, err := db.Begin()
  1359  	if err != nil {
  1360  		t.Fatalf("Begin = %v", err)
  1361  	}
  1362  	txs := tx.Stmt(stmt)
  1363  	defer txs.Close()
  1364  	_, err = txs.Exec("Bobby", 7)
  1365  	if err != nil {
  1366  		t.Fatalf("Exec = %v", err)
  1367  	}
  1368  	err = tx.Commit()
  1369  	if err != nil {
  1370  		t.Fatalf("Commit = %v", err)
  1371  	}
  1372  }
  1373  
  1374  func TestConnQuery(t *testing.T) {
  1375  	db := newTestDB(t, "people")
  1376  	defer closeDB(t, db)
  1377  
  1378  	ctx := t.Context()
  1379  	conn, err := db.Conn(ctx)
  1380  	if err != nil {
  1381  		t.Fatal(err)
  1382  	}
  1383  	conn.dc.ci.(*fakeConn).skipDirtySession = true
  1384  	defer conn.Close()
  1385  
  1386  	var name string
  1387  	err = conn.QueryRowContext(ctx, "SELECT|people|name|age=?", 3).Scan(&name)
  1388  	if err != nil {
  1389  		t.Fatal(err)
  1390  	}
  1391  	if name != "Chris" {
  1392  		t.Fatalf("unexpected result, got %q want Chris", name)
  1393  	}
  1394  
  1395  	err = conn.PingContext(ctx)
  1396  	if err != nil {
  1397  		t.Fatal(err)
  1398  	}
  1399  }
  1400  
  1401  func TestConnRaw(t *testing.T) {
  1402  	db := newTestDB(t, "people")
  1403  	defer closeDB(t, db)
  1404  
  1405  	ctx := t.Context()
  1406  	conn, err := db.Conn(ctx)
  1407  	if err != nil {
  1408  		t.Fatal(err)
  1409  	}
  1410  	conn.dc.ci.(*fakeConn).skipDirtySession = true
  1411  	defer conn.Close()
  1412  
  1413  	sawFunc := false
  1414  	err = conn.Raw(func(dc any) error {
  1415  		sawFunc = true
  1416  		if _, ok := dc.(*fakeConn); !ok {
  1417  			return fmt.Errorf("got %T want *fakeConn", dc)
  1418  		}
  1419  		return nil
  1420  	})
  1421  	if err != nil {
  1422  		t.Fatal(err)
  1423  	}
  1424  	if !sawFunc {
  1425  		t.Fatal("Raw func not called")
  1426  	}
  1427  
  1428  	func() {
  1429  		defer func() {
  1430  			x := recover()
  1431  			if x == nil {
  1432  				t.Fatal("expected panic")
  1433  			}
  1434  			conn.closemu.Lock()
  1435  			closed := conn.dc == nil
  1436  			conn.closemu.Unlock()
  1437  			if !closed {
  1438  				t.Fatal("expected connection to be closed after panic")
  1439  			}
  1440  		}()
  1441  		err = conn.Raw(func(dc any) error {
  1442  			panic("Conn.Raw panic should return an error")
  1443  		})
  1444  		t.Fatal("expected panic from Raw func")
  1445  	}()
  1446  }
  1447  
  1448  func TestCursorFake(t *testing.T) {
  1449  	db := newTestDB(t, "people")
  1450  	defer closeDB(t, db)
  1451  
  1452  	ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
  1453  	defer cancel()
  1454  
  1455  	exec(t, db, "CREATE|peoplecursor|list=table")
  1456  	exec(t, db, "INSERT|peoplecursor|list=people!name!age")
  1457  
  1458  	rows, err := db.QueryContext(ctx, `SELECT|peoplecursor|list|`)
  1459  	if err != nil {
  1460  		t.Fatal(err)
  1461  	}
  1462  	defer rows.Close()
  1463  
  1464  	if !rows.Next() {
  1465  		t.Fatal("no rows")
  1466  	}
  1467  	var cursor = &Rows{}
  1468  	err = rows.Scan(cursor)
  1469  	if err != nil {
  1470  		t.Fatal(err)
  1471  	}
  1472  	defer cursor.Close()
  1473  
  1474  	const expectedRows = 3
  1475  	var currentRow int64
  1476  
  1477  	var n int64
  1478  	var s string
  1479  	for cursor.Next() {
  1480  		currentRow++
  1481  		err = cursor.Scan(&s, &n)
  1482  		if err != nil {
  1483  			t.Fatal(err)
  1484  		}
  1485  		if n != currentRow {
  1486  			t.Errorf("expected number(Age)=%d, got %d", currentRow, n)
  1487  		}
  1488  	}
  1489  	if currentRow != expectedRows {
  1490  		t.Errorf("expected %d rows, got %d rows", expectedRows, currentRow)
  1491  	}
  1492  }
  1493  
  1494  func TestInvalidNilValues(t *testing.T) {
  1495  	var date1 time.Time
  1496  	var date2 int
  1497  
  1498  	tests := []struct {
  1499  		name          string
  1500  		input         any
  1501  		expectedError string
  1502  	}{
  1503  		{
  1504  			name:          "time.Time",
  1505  			input:         &date1,
  1506  			expectedError: `sql: Scan error on column index 0, name "bdate": unsupported Scan, storing driver.Value type <nil> into type *time.Time`,
  1507  		},
  1508  		{
  1509  			name:          "int",
  1510  			input:         &date2,
  1511  			expectedError: `sql: Scan error on column index 0, name "bdate": converting NULL to int is unsupported`,
  1512  		},
  1513  	}
  1514  
  1515  	for _, tt := range tests {
  1516  		t.Run(tt.name, func(t *testing.T) {
  1517  			db := newTestDB(t, "people")
  1518  			defer closeDB(t, db)
  1519  
  1520  			ctx := t.Context()
  1521  			conn, err := db.Conn(ctx)
  1522  			if err != nil {
  1523  				t.Fatal(err)
  1524  			}
  1525  			conn.dc.ci.(*fakeConn).skipDirtySession = true
  1526  			defer conn.Close()
  1527  
  1528  			err = conn.QueryRowContext(ctx, "SELECT|people|bdate|age=?", 1).Scan(tt.input)
  1529  			if err == nil {
  1530  				t.Fatal("expected error when querying nil column, but succeeded")
  1531  			}
  1532  			if err.Error() != tt.expectedError {
  1533  				t.Fatalf("Expected error: %s\nReceived: %s", tt.expectedError, err.Error())
  1534  			}
  1535  
  1536  			err = conn.PingContext(ctx)
  1537  			if err != nil {
  1538  				t.Fatal(err)
  1539  			}
  1540  		})
  1541  	}
  1542  }
  1543  
  1544  func TestConnTx(t *testing.T) {
  1545  	db := newTestDB(t, "people")
  1546  	defer closeDB(t, db)
  1547  
  1548  	ctx := t.Context()
  1549  	conn, err := db.Conn(ctx)
  1550  	if err != nil {
  1551  		t.Fatal(err)
  1552  	}
  1553  	conn.dc.ci.(*fakeConn).skipDirtySession = true
  1554  	defer conn.Close()
  1555  
  1556  	tx, err := conn.BeginTx(ctx, nil)
  1557  	if err != nil {
  1558  		t.Fatal(err)
  1559  	}
  1560  	insertName, insertAge := "Nancy", 33
  1561  	_, err = tx.ExecContext(ctx, "INSERT|people|name=?,age=?,photo=APHOTO", insertName, insertAge)
  1562  	if err != nil {
  1563  		t.Fatal(err)
  1564  	}
  1565  	err = tx.Commit()
  1566  	if err != nil {
  1567  		t.Fatal(err)
  1568  	}
  1569  
  1570  	var selectName string
  1571  	err = conn.QueryRowContext(ctx, "SELECT|people|name|age=?", insertAge).Scan(&selectName)
  1572  	if err != nil {
  1573  		t.Fatal(err)
  1574  	}
  1575  	if selectName != insertName {
  1576  		t.Fatalf("got %q want %q", selectName, insertName)
  1577  	}
  1578  }
  1579  
  1580  // TestConnIsValid verifies that a database connection that should be discarded,
  1581  // is actually discarded and does not re-enter the connection pool.
  1582  // If the IsValid method from *fakeConn is removed, this test will fail.
  1583  func TestConnIsValid(t *testing.T) {
  1584  	db := newTestDB(t, "people")
  1585  	defer closeDB(t, db)
  1586  
  1587  	db.SetMaxOpenConns(1)
  1588  
  1589  	ctx := context.Background()
  1590  
  1591  	c, err := db.Conn(ctx)
  1592  	if err != nil {
  1593  		t.Fatal(err)
  1594  	}
  1595  
  1596  	err = c.Raw(func(raw any) error {
  1597  		dc := raw.(*fakeConn)
  1598  		dc.stickyBad = true
  1599  		return nil
  1600  	})
  1601  	if err != nil {
  1602  		t.Fatal(err)
  1603  	}
  1604  	c.Close()
  1605  
  1606  	if len(db.freeConn) > 0 && db.freeConn[0].ci.(*fakeConn).stickyBad {
  1607  		t.Fatal("bad connection returned to pool; expected bad connection to be discarded")
  1608  	}
  1609  }
  1610  
  1611  // Tests fix for issue 2542, that we release a lock when querying on
  1612  // a closed connection.
  1613  func TestIssue2542Deadlock(t *testing.T) {
  1614  	db := newTestDB(t, "people")
  1615  	closeDB(t, db)
  1616  	for i := 0; i < 2; i++ {
  1617  		_, err := db.Query("SELECT|people|age,name|")
  1618  		if err == nil {
  1619  			t.Fatalf("expected error")
  1620  		}
  1621  	}
  1622  }
  1623  
  1624  // From golang.org/issue/3865
  1625  func TestCloseStmtBeforeRows(t *testing.T) {
  1626  	db := newTestDB(t, "people")
  1627  	defer closeDB(t, db)
  1628  
  1629  	s, err := db.Prepare("SELECT|people|name|")
  1630  	if err != nil {
  1631  		t.Fatal(err)
  1632  	}
  1633  
  1634  	r, err := s.Query()
  1635  	if err != nil {
  1636  		s.Close()
  1637  		t.Fatal(err)
  1638  	}
  1639  
  1640  	err = s.Close()
  1641  	if err != nil {
  1642  		t.Fatal(err)
  1643  	}
  1644  
  1645  	r.Close()
  1646  }
  1647  
  1648  // Tests fix for issue 2788, that we bind nil to a []byte if the
  1649  // value in the column is sql null
  1650  func TestNullByteSlice(t *testing.T) {
  1651  	db := newTestDB(t, "")
  1652  	defer closeDB(t, db)
  1653  	exec(t, db, "CREATE|t|id=int32,name=nullstring")
  1654  	exec(t, db, "INSERT|t|id=10,name=?", nil)
  1655  
  1656  	var name []byte
  1657  
  1658  	err := db.QueryRow("SELECT|t|name|id=?", 10).Scan(&name)
  1659  	if err != nil {
  1660  		t.Fatal(err)
  1661  	}
  1662  	if name != nil {
  1663  		t.Fatalf("name []byte should be nil for null column value, got: %#v", name)
  1664  	}
  1665  
  1666  	exec(t, db, "INSERT|t|id=11,name=?", "bob")
  1667  	err = db.QueryRow("SELECT|t|name|id=?", 11).Scan(&name)
  1668  	if err != nil {
  1669  		t.Fatal(err)
  1670  	}
  1671  	if string(name) != "bob" {
  1672  		t.Fatalf("name []byte should be bob, got: %q", string(name))
  1673  	}
  1674  }
  1675  
  1676  func TestPointerParamsAndScans(t *testing.T) {
  1677  	db := newTestDB(t, "")
  1678  	defer closeDB(t, db)
  1679  	exec(t, db, "CREATE|t|id=int32,name=nullstring")
  1680  
  1681  	bob := "bob"
  1682  	var name *string
  1683  
  1684  	name = &bob
  1685  	exec(t, db, "INSERT|t|id=10,name=?", name)
  1686  	name = nil
  1687  	exec(t, db, "INSERT|t|id=20,name=?", name)
  1688  
  1689  	err := db.QueryRow("SELECT|t|name|id=?", 10).Scan(&name)
  1690  	if err != nil {
  1691  		t.Fatalf("querying id 10: %v", err)
  1692  	}
  1693  	if name == nil {
  1694  		t.Errorf("id 10's name = nil; want bob")
  1695  	} else if *name != "bob" {
  1696  		t.Errorf("id 10's name = %q; want bob", *name)
  1697  	}
  1698  
  1699  	err = db.QueryRow("SELECT|t|name|id=?", 20).Scan(&name)
  1700  	if err != nil {
  1701  		t.Fatalf("querying id 20: %v", err)
  1702  	}
  1703  	if name != nil {
  1704  		t.Errorf("id 20 = %q; want nil", *name)
  1705  	}
  1706  }
  1707  
  1708  func TestQueryRowClosingStmt(t *testing.T) {
  1709  	db := newTestDB(t, "people")
  1710  	defer closeDB(t, db)
  1711  	var name string
  1712  	var age int
  1713  	err := db.QueryRow("SELECT|people|age,name|age=?", 3).Scan(&age, &name)
  1714  	if err != nil {
  1715  		t.Fatal(err)
  1716  	}
  1717  	if len(db.freeConn) != 1 {
  1718  		t.Fatalf("expected 1 free conn")
  1719  	}
  1720  	fakeConn := db.freeConn[0].ci.(*fakeConn)
  1721  	if made, closed := fakeConn.stmtsMade, fakeConn.stmtsClosed; made != closed {
  1722  		t.Errorf("statement close mismatch: made %d, closed %d", made, closed)
  1723  	}
  1724  }
  1725  
  1726  var atomicRowsCloseHook atomic.Value // of func(*Rows, *error)
  1727  
  1728  func init() {
  1729  	rowsCloseHook = func() func(*Rows, *error) {
  1730  		fn, _ := atomicRowsCloseHook.Load().(func(*Rows, *error))
  1731  		return fn
  1732  	}
  1733  }
  1734  
  1735  func setRowsCloseHook(fn func(*Rows, *error)) {
  1736  	if fn == nil {
  1737  		// Can't change an atomic.Value back to nil, so set it to this
  1738  		// no-op func instead.
  1739  		fn = func(*Rows, *error) {}
  1740  	}
  1741  	atomicRowsCloseHook.Store(fn)
  1742  }
  1743  
  1744  // Test issue 6651
  1745  func TestIssue6651(t *testing.T) {
  1746  	db := newTestDB(t, "people")
  1747  	defer closeDB(t, db)
  1748  
  1749  	var v string
  1750  
  1751  	want := "error in rows.Next"
  1752  	rowsCursorNextHook = func(dest []driver.Value) error {
  1753  		return errors.New(want)
  1754  	}
  1755  	defer func() { rowsCursorNextHook = nil }()
  1756  
  1757  	err := db.QueryRow("SELECT|people|name|").Scan(&v)
  1758  	if err == nil || err.Error() != want {
  1759  		t.Errorf("error = %q; want %q", err, want)
  1760  	}
  1761  	rowsCursorNextHook = nil
  1762  
  1763  	want = "error in rows.Close"
  1764  	setRowsCloseHook(func(rows *Rows, err *error) {
  1765  		*err = errors.New(want)
  1766  	})
  1767  	defer setRowsCloseHook(nil)
  1768  	err = db.QueryRow("SELECT|people|name|").Scan(&v)
  1769  	if err == nil || err.Error() != want {
  1770  		t.Errorf("error = %q; want %q", err, want)
  1771  	}
  1772  }
  1773  
  1774  type nullTestRow struct {
  1775  	nullParam    any
  1776  	notNullParam any
  1777  	scanNullVal  any
  1778  }
  1779  
  1780  type nullTestSpec struct {
  1781  	nullType    string
  1782  	notNullType string
  1783  	rows        [6]nullTestRow
  1784  }
  1785  
  1786  func TestNullStringParam(t *testing.T) {
  1787  	spec := nullTestSpec{"nullstring", "string", [6]nullTestRow{
  1788  		{NullString{"aqua", true}, "", NullString{"aqua", true}},
  1789  		{NullString{"brown", false}, "", NullString{"", false}},
  1790  		{"chartreuse", "", NullString{"chartreuse", true}},
  1791  		{NullString{"darkred", true}, "", NullString{"darkred", true}},
  1792  		{NullString{"eel", false}, "", NullString{"", false}},
  1793  		{"foo", NullString{"black", false}, nil},
  1794  	}}
  1795  	nullTestRun(t, spec)
  1796  }
  1797  
  1798  func TestGenericNullStringParam(t *testing.T) {
  1799  	spec := nullTestSpec{"nullstring", "string", [6]nullTestRow{
  1800  		{Null[string]{"aqua", true}, "", Null[string]{"aqua", true}},
  1801  		{Null[string]{"brown", false}, "", Null[string]{"", false}},
  1802  		{"chartreuse", "", Null[string]{"chartreuse", true}},
  1803  		{Null[string]{"darkred", true}, "", Null[string]{"darkred", true}},
  1804  		{Null[string]{"eel", false}, "", Null[string]{"", false}},
  1805  		{"foo", Null[string]{"black", false}, nil},
  1806  	}}
  1807  	nullTestRun(t, spec)
  1808  }
  1809  
  1810  func TestNullInt64Param(t *testing.T) {
  1811  	spec := nullTestSpec{"nullint64", "int64", [6]nullTestRow{
  1812  		{NullInt64{31, true}, 1, NullInt64{31, true}},
  1813  		{NullInt64{-22, false}, 1, NullInt64{0, false}},
  1814  		{22, 1, NullInt64{22, true}},
  1815  		{NullInt64{33, true}, 1, NullInt64{33, true}},
  1816  		{NullInt64{222, false}, 1, NullInt64{0, false}},
  1817  		{0, NullInt64{31, false}, nil},
  1818  	}}
  1819  	nullTestRun(t, spec)
  1820  }
  1821  
  1822  func TestNullInt32Param(t *testing.T) {
  1823  	spec := nullTestSpec{"nullint32", "int32", [6]nullTestRow{
  1824  		{NullInt32{31, true}, 1, NullInt32{31, true}},
  1825  		{NullInt32{-22, false}, 1, NullInt32{0, false}},
  1826  		{22, 1, NullInt32{22, true}},
  1827  		{NullInt32{33, true}, 1, NullInt32{33, true}},
  1828  		{NullInt32{222, false}, 1, NullInt32{0, false}},
  1829  		{0, NullInt32{31, false}, nil},
  1830  	}}
  1831  	nullTestRun(t, spec)
  1832  }
  1833  
  1834  func TestNullInt16Param(t *testing.T) {
  1835  	spec := nullTestSpec{"nullint16", "int16", [6]nullTestRow{
  1836  		{NullInt16{31, true}, 1, NullInt16{31, true}},
  1837  		{NullInt16{-22, false}, 1, NullInt16{0, false}},
  1838  		{22, 1, NullInt16{22, true}},
  1839  		{NullInt16{33, true}, 1, NullInt16{33, true}},
  1840  		{NullInt16{222, false}, 1, NullInt16{0, false}},
  1841  		{0, NullInt16{31, false}, nil},
  1842  	}}
  1843  	nullTestRun(t, spec)
  1844  }
  1845  
  1846  func TestNullByteParam(t *testing.T) {
  1847  	spec := nullTestSpec{"nullbyte", "byte", [6]nullTestRow{
  1848  		{NullByte{31, true}, 1, NullByte{31, true}},
  1849  		{NullByte{0, false}, 1, NullByte{0, false}},
  1850  		{22, 1, NullByte{22, true}},
  1851  		{NullByte{33, true}, 1, NullByte{33, true}},
  1852  		{NullByte{222, false}, 1, NullByte{0, false}},
  1853  		{0, NullByte{31, false}, nil},
  1854  	}}
  1855  	nullTestRun(t, spec)
  1856  }
  1857  
  1858  func TestNullFloat64Param(t *testing.T) {
  1859  	spec := nullTestSpec{"nullfloat64", "float64", [6]nullTestRow{
  1860  		{NullFloat64{31.2, true}, 1, NullFloat64{31.2, true}},
  1861  		{NullFloat64{13.1, false}, 1, NullFloat64{0, false}},
  1862  		{-22.9, 1, NullFloat64{-22.9, true}},
  1863  		{NullFloat64{33.81, true}, 1, NullFloat64{33.81, true}},
  1864  		{NullFloat64{222, false}, 1, NullFloat64{0, false}},
  1865  		{10, NullFloat64{31.2, false}, nil},
  1866  	}}
  1867  	nullTestRun(t, spec)
  1868  }
  1869  
  1870  func TestNullBoolParam(t *testing.T) {
  1871  	spec := nullTestSpec{"nullbool", "bool", [6]nullTestRow{
  1872  		{NullBool{false, true}, true, NullBool{false, true}},
  1873  		{NullBool{true, false}, false, NullBool{false, false}},
  1874  		{true, true, NullBool{true, true}},
  1875  		{NullBool{true, true}, false, NullBool{true, true}},
  1876  		{NullBool{true, false}, true, NullBool{false, false}},
  1877  		{true, NullBool{true, false}, nil},
  1878  	}}
  1879  	nullTestRun(t, spec)
  1880  }
  1881  
  1882  func TestNullTimeParam(t *testing.T) {
  1883  	t0 := time.Time{}
  1884  	t1 := time.Date(2000, 1, 1, 8, 9, 10, 11, time.UTC)
  1885  	t2 := time.Date(2010, 1, 1, 8, 9, 10, 11, time.UTC)
  1886  	spec := nullTestSpec{"nulldatetime", "datetime", [6]nullTestRow{
  1887  		{NullTime{t1, true}, t2, NullTime{t1, true}},
  1888  		{NullTime{t1, false}, t2, NullTime{t0, false}},
  1889  		{t1, t2, NullTime{t1, true}},
  1890  		{NullTime{t1, true}, t2, NullTime{t1, true}},
  1891  		{NullTime{t1, false}, t2, NullTime{t0, false}},
  1892  		{t2, NullTime{t1, false}, nil},
  1893  	}}
  1894  	nullTestRun(t, spec)
  1895  }
  1896  
  1897  func nullTestRun(t *testing.T, spec nullTestSpec) {
  1898  	db := newTestDB(t, "")
  1899  	defer closeDB(t, db)
  1900  	exec(t, db, fmt.Sprintf("CREATE|t|id=int32,name=string,nullf=%s,notnullf=%s", spec.nullType, spec.notNullType))
  1901  
  1902  	// Inserts with db.Exec:
  1903  	exec(t, db, "INSERT|t|id=?,name=?,nullf=?,notnullf=?", 1, "alice", spec.rows[0].nullParam, spec.rows[0].notNullParam)
  1904  	exec(t, db, "INSERT|t|id=?,name=?,nullf=?,notnullf=?", 2, "bob", spec.rows[1].nullParam, spec.rows[1].notNullParam)
  1905  
  1906  	// Inserts with a prepared statement:
  1907  	stmt, err := db.Prepare("INSERT|t|id=?,name=?,nullf=?,notnullf=?")
  1908  	if err != nil {
  1909  		t.Fatalf("prepare: %v", err)
  1910  	}
  1911  	defer stmt.Close()
  1912  	if _, err := stmt.Exec(3, "chris", spec.rows[2].nullParam, spec.rows[2].notNullParam); err != nil {
  1913  		t.Errorf("exec insert chris: %v", err)
  1914  	}
  1915  	if _, err := stmt.Exec(4, "dave", spec.rows[3].nullParam, spec.rows[3].notNullParam); err != nil {
  1916  		t.Errorf("exec insert dave: %v", err)
  1917  	}
  1918  	if _, err := stmt.Exec(5, "eleanor", spec.rows[4].nullParam, spec.rows[4].notNullParam); err != nil {
  1919  		t.Errorf("exec insert eleanor: %v", err)
  1920  	}
  1921  
  1922  	// Can't put null val into non-null col
  1923  	row5 := spec.rows[5]
  1924  	if _, err := stmt.Exec(6, "bob", row5.nullParam, row5.notNullParam); err == nil {
  1925  		t.Errorf("expected error inserting nil val with prepared statement Exec: NULL=%#v, NOT-NULL=%#v", row5.nullParam, row5.notNullParam)
  1926  	}
  1927  
  1928  	_, err = db.Exec("INSERT|t|id=?,name=?,nullf=?", 999, nil, nil)
  1929  	if err == nil {
  1930  		// TODO: this test fails, but it's just because
  1931  		// fakeConn implements the optional Execer interface,
  1932  		// so arguably this is the correct behavior. But
  1933  		// maybe I should flesh out the fakeConn.Exec
  1934  		// implementation so this properly fails.
  1935  		// t.Errorf("expected error inserting nil name with Exec")
  1936  	}
  1937  
  1938  	paramtype := reflect.TypeOf(spec.rows[0].nullParam)
  1939  	bindVal := reflect.New(paramtype).Interface()
  1940  
  1941  	for i := 0; i < 5; i++ {
  1942  		id := i + 1
  1943  		if err := db.QueryRow("SELECT|t|nullf|id=?", id).Scan(bindVal); err != nil {
  1944  			t.Errorf("id=%d Scan: %v", id, err)
  1945  		}
  1946  		bindValDeref := reflect.ValueOf(bindVal).Elem().Interface()
  1947  		if !reflect.DeepEqual(bindValDeref, spec.rows[i].scanNullVal) {
  1948  			t.Errorf("id=%d got %#v, want %#v", id, bindValDeref, spec.rows[i].scanNullVal)
  1949  		}
  1950  	}
  1951  }
  1952  
  1953  // golang.org/issue/4859
  1954  func TestQueryRowNilScanDest(t *testing.T) {
  1955  	db := newTestDB(t, "people")
  1956  	defer closeDB(t, db)
  1957  	var name *string // nil pointer
  1958  	err := db.QueryRow("SELECT|people|name|").Scan(name)
  1959  	want := `sql: Scan error on column index 0, name "name": destination pointer is nil`
  1960  	if err == nil || err.Error() != want {
  1961  		t.Errorf("error = %q; want %q", err.Error(), want)
  1962  	}
  1963  }
  1964  
  1965  func TestIssue4902(t *testing.T) {
  1966  	db := newTestDB(t, "people")
  1967  	defer closeDB(t, db)
  1968  
  1969  	driver := db.Driver().(*fakeDriver)
  1970  	opens0 := driver.openCount
  1971  
  1972  	var stmt *Stmt
  1973  	var err error
  1974  	for i := 0; i < 10; i++ {
  1975  		stmt, err = db.Prepare("SELECT|people|name|")
  1976  		if err != nil {
  1977  			t.Fatal(err)
  1978  		}
  1979  		err = stmt.Close()
  1980  		if err != nil {
  1981  			t.Fatal(err)
  1982  		}
  1983  	}
  1984  
  1985  	opens := driver.openCount - opens0
  1986  	if opens > 1 {
  1987  		t.Errorf("opens = %d; want <= 1", opens)
  1988  		t.Logf("db = %#v", db)
  1989  		t.Logf("driver = %#v", driver)
  1990  		t.Logf("stmt = %#v", stmt)
  1991  	}
  1992  }
  1993  
  1994  // Issue 3857
  1995  // This used to deadlock.
  1996  func TestSimultaneousQueries(t *testing.T) {
  1997  	db := newTestDB(t, "people")
  1998  	defer closeDB(t, db)
  1999  
  2000  	tx, err := db.Begin()
  2001  	if err != nil {
  2002  		t.Fatal(err)
  2003  	}
  2004  	defer tx.Rollback()
  2005  
  2006  	r1, err := tx.Query("SELECT|people|name|")
  2007  	if err != nil {
  2008  		t.Fatal(err)
  2009  	}
  2010  	defer r1.Close()
  2011  
  2012  	r2, err := tx.Query("SELECT|people|name|")
  2013  	if err != nil {
  2014  		t.Fatal(err)
  2015  	}
  2016  	defer r2.Close()
  2017  }
  2018  
  2019  func TestMaxIdleConns(t *testing.T) {
  2020  	db := newTestDB(t, "people")
  2021  	defer closeDB(t, db)
  2022  
  2023  	tx, err := db.Begin()
  2024  	if err != nil {
  2025  		t.Fatal(err)
  2026  	}
  2027  	tx.Commit()
  2028  	if got := len(db.freeConn); got != 1 {
  2029  		t.Errorf("freeConns = %d; want 1", got)
  2030  	}
  2031  
  2032  	db.SetMaxIdleConns(0)
  2033  
  2034  	if got := len(db.freeConn); got != 0 {
  2035  		t.Errorf("freeConns after set to zero = %d; want 0", got)
  2036  	}
  2037  
  2038  	tx, err = db.Begin()
  2039  	if err != nil {
  2040  		t.Fatal(err)
  2041  	}
  2042  	tx.Commit()
  2043  	if got := len(db.freeConn); got != 0 {
  2044  		t.Errorf("freeConns = %d; want 0", got)
  2045  	}
  2046  }
  2047  
  2048  func TestMaxOpenConns(t *testing.T) {
  2049  	if testing.Short() {
  2050  		t.Skip("skipping in short mode")
  2051  	}
  2052  	defer setHookpostCloseConn(nil)
  2053  	setHookpostCloseConn(func(_ *fakeConn, err error) {
  2054  		if err != nil {
  2055  			t.Errorf("Error closing fakeConn: %v", err)
  2056  		}
  2057  	})
  2058  
  2059  	db := newTestDB(t, "magicquery")
  2060  	defer closeDB(t, db)
  2061  
  2062  	driver := db.Driver().(*fakeDriver)
  2063  
  2064  	// Force the number of open connections to 0 so we can get an accurate
  2065  	// count for the test
  2066  	db.clearAllConns(t)
  2067  
  2068  	driver.mu.Lock()
  2069  	opens0 := driver.openCount
  2070  	closes0 := driver.closeCount
  2071  	driver.mu.Unlock()
  2072  
  2073  	db.SetMaxIdleConns(10)
  2074  	db.SetMaxOpenConns(10)
  2075  
  2076  	stmt, err := db.Prepare("SELECT|magicquery|op|op=?,millis=?")
  2077  	if err != nil {
  2078  		t.Fatal(err)
  2079  	}
  2080  
  2081  	// Start 50 parallel slow queries.
  2082  	const (
  2083  		nquery      = 50
  2084  		sleepMillis = 25
  2085  		nbatch      = 2
  2086  	)
  2087  	var wg sync.WaitGroup
  2088  	for batch := 0; batch < nbatch; batch++ {
  2089  		for i := 0; i < nquery; i++ {
  2090  			wg.Add(1)
  2091  			go func() {
  2092  				defer wg.Done()
  2093  				var op string
  2094  				if err := stmt.QueryRow("sleep", sleepMillis).Scan(&op); err != nil && err != ErrNoRows {
  2095  					t.Error(err)
  2096  				}
  2097  			}()
  2098  		}
  2099  		// Wait for the batch of queries above to finish before starting the next round.
  2100  		wg.Wait()
  2101  	}
  2102  
  2103  	if g, w := db.numFreeConns(), 10; g != w {
  2104  		t.Errorf("free conns = %d; want %d", g, w)
  2105  	}
  2106  
  2107  	if n := db.numDepsPoll(t, 20); n > 20 {
  2108  		t.Errorf("number of dependencies = %d; expected <= 20", n)
  2109  		db.dumpDeps(t)
  2110  	}
  2111  
  2112  	driver.mu.Lock()
  2113  	opens := driver.openCount - opens0
  2114  	closes := driver.closeCount - closes0
  2115  	driver.mu.Unlock()
  2116  
  2117  	if opens > 10 {
  2118  		t.Logf("open calls = %d", opens)
  2119  		t.Logf("close calls = %d", closes)
  2120  		t.Errorf("db connections opened = %d; want <= 10", opens)
  2121  		db.dumpDeps(t)
  2122  	}
  2123  
  2124  	if err := stmt.Close(); err != nil {
  2125  		t.Fatal(err)
  2126  	}
  2127  
  2128  	if g, w := db.numFreeConns(), 10; g != w {
  2129  		t.Errorf("free conns = %d; want %d", g, w)
  2130  	}
  2131  
  2132  	if n := db.numDepsPoll(t, 10); n > 10 {
  2133  		t.Errorf("number of dependencies = %d; expected <= 10", n)
  2134  		db.dumpDeps(t)
  2135  	}
  2136  
  2137  	db.SetMaxOpenConns(5)
  2138  
  2139  	if g, w := db.numFreeConns(), 5; g != w {
  2140  		t.Errorf("free conns = %d; want %d", g, w)
  2141  	}
  2142  
  2143  	if n := db.numDepsPoll(t, 5); n > 5 {
  2144  		t.Errorf("number of dependencies = %d; expected 0", n)
  2145  		db.dumpDeps(t)
  2146  	}
  2147  
  2148  	db.SetMaxOpenConns(0)
  2149  
  2150  	if g, w := db.numFreeConns(), 5; g != w {
  2151  		t.Errorf("free conns = %d; want %d", g, w)
  2152  	}
  2153  
  2154  	if n := db.numDepsPoll(t, 5); n > 5 {
  2155  		t.Errorf("number of dependencies = %d; expected 0", n)
  2156  		db.dumpDeps(t)
  2157  	}
  2158  
  2159  	db.clearAllConns(t)
  2160  }
  2161  
  2162  // Issue 9453: tests that SetMaxOpenConns can be lowered at runtime
  2163  // and affects the subsequent release of connections.
  2164  func TestMaxOpenConnsOnBusy(t *testing.T) {
  2165  	defer setHookpostCloseConn(nil)
  2166  	setHookpostCloseConn(func(_ *fakeConn, err error) {
  2167  		if err != nil {
  2168  			t.Errorf("Error closing fakeConn: %v", err)
  2169  		}
  2170  	})
  2171  
  2172  	db := newTestDB(t, "magicquery")
  2173  	defer closeDB(t, db)
  2174  
  2175  	db.SetMaxOpenConns(3)
  2176  
  2177  	ctx := context.Background()
  2178  
  2179  	conn0, err := db.conn(ctx, cachedOrNewConn)
  2180  	if err != nil {
  2181  		t.Fatalf("db open conn fail: %v", err)
  2182  	}
  2183  
  2184  	conn1, err := db.conn(ctx, cachedOrNewConn)
  2185  	if err != nil {
  2186  		t.Fatalf("db open conn fail: %v", err)
  2187  	}
  2188  
  2189  	conn2, err := db.conn(ctx, cachedOrNewConn)
  2190  	if err != nil {
  2191  		t.Fatalf("db open conn fail: %v", err)
  2192  	}
  2193  
  2194  	if g, w := db.numOpen, 3; g != w {
  2195  		t.Errorf("free conns = %d; want %d", g, w)
  2196  	}
  2197  
  2198  	db.SetMaxOpenConns(2)
  2199  	if g, w := db.numOpen, 3; g != w {
  2200  		t.Errorf("free conns = %d; want %d", g, w)
  2201  	}
  2202  
  2203  	conn0.releaseConn(nil)
  2204  	conn1.releaseConn(nil)
  2205  	if g, w := db.numOpen, 2; g != w {
  2206  		t.Errorf("free conns = %d; want %d", g, w)
  2207  	}
  2208  
  2209  	conn2.releaseConn(nil)
  2210  	if g, w := db.numOpen, 2; g != w {
  2211  		t.Errorf("free conns = %d; want %d", g, w)
  2212  	}
  2213  }
  2214  
  2215  // Issue 10886: tests that all connection attempts return when more than
  2216  // DB.maxOpen connections are in flight and the first DB.maxOpen fail.
  2217  func TestPendingConnsAfterErr(t *testing.T) {
  2218  	const (
  2219  		maxOpen = 2
  2220  		tryOpen = maxOpen*2 + 2
  2221  	)
  2222  
  2223  	// No queries will be run.
  2224  	db, err := Open("test", fakeDBName)
  2225  	if err != nil {
  2226  		t.Fatalf("Open: %v", err)
  2227  	}
  2228  	defer closeDB(t, db)
  2229  	defer func() {
  2230  		for k, v := range db.lastPut {
  2231  			t.Logf("%p: %v", k, v)
  2232  		}
  2233  	}()
  2234  
  2235  	db.SetMaxOpenConns(maxOpen)
  2236  	db.SetMaxIdleConns(0)
  2237  
  2238  	errOffline := errors.New("db offline")
  2239  
  2240  	defer func() { setHookOpenErr(nil) }()
  2241  
  2242  	errs := make(chan error, tryOpen)
  2243  
  2244  	var opening sync.WaitGroup
  2245  	opening.Add(tryOpen)
  2246  
  2247  	setHookOpenErr(func() error {
  2248  		// Wait for all connections to enqueue.
  2249  		opening.Wait()
  2250  		return errOffline
  2251  	})
  2252  
  2253  	for i := 0; i < tryOpen; i++ {
  2254  		go func() {
  2255  			opening.Done() // signal one connection is in flight
  2256  			_, err := db.Exec("will never run")
  2257  			errs <- err
  2258  		}()
  2259  	}
  2260  
  2261  	opening.Wait() // wait for all workers to begin running
  2262  
  2263  	const timeout = 5 * time.Second
  2264  	to := time.NewTimer(timeout)
  2265  	defer to.Stop()
  2266  
  2267  	// check that all connections fail without deadlock
  2268  	for i := 0; i < tryOpen; i++ {
  2269  		select {
  2270  		case err := <-errs:
  2271  			if got, want := err, errOffline; got != want {
  2272  				t.Errorf("unexpected err: got %v, want %v", got, want)
  2273  			}
  2274  		case <-to.C:
  2275  			t.Fatalf("orphaned connection request(s), still waiting after %v", timeout)
  2276  		}
  2277  	}
  2278  
  2279  	// Wait a reasonable time for the database to close all connections.
  2280  	tick := time.NewTicker(3 * time.Millisecond)
  2281  	defer tick.Stop()
  2282  	for {
  2283  		select {
  2284  		case <-tick.C:
  2285  			db.mu.Lock()
  2286  			if db.numOpen == 0 {
  2287  				db.mu.Unlock()
  2288  				return
  2289  			}
  2290  			db.mu.Unlock()
  2291  		case <-to.C:
  2292  			// Closing the database will check for numOpen and fail the test.
  2293  			return
  2294  		}
  2295  	}
  2296  }
  2297  
  2298  func TestSingleOpenConn(t *testing.T) {
  2299  	db := newTestDB(t, "people")
  2300  	defer closeDB(t, db)
  2301  
  2302  	db.SetMaxOpenConns(1)
  2303  
  2304  	rows, err := db.Query("SELECT|people|name|")
  2305  	if err != nil {
  2306  		t.Fatal(err)
  2307  	}
  2308  	if err = rows.Close(); err != nil {
  2309  		t.Fatal(err)
  2310  	}
  2311  	// shouldn't deadlock
  2312  	rows, err = db.Query("SELECT|people|name|")
  2313  	if err != nil {
  2314  		t.Fatal(err)
  2315  	}
  2316  	if err = rows.Close(); err != nil {
  2317  		t.Fatal(err)
  2318  	}
  2319  }
  2320  
  2321  func TestStats(t *testing.T) {
  2322  	db := newTestDB(t, "people")
  2323  	stats := db.Stats()
  2324  	if got := stats.OpenConnections; got != 1 {
  2325  		t.Errorf("stats.OpenConnections = %d; want 1", got)
  2326  	}
  2327  
  2328  	tx, err := db.Begin()
  2329  	if err != nil {
  2330  		t.Fatal(err)
  2331  	}
  2332  	tx.Commit()
  2333  
  2334  	closeDB(t, db)
  2335  	stats = db.Stats()
  2336  	if got := stats.OpenConnections; got != 0 {
  2337  		t.Errorf("stats.OpenConnections = %d; want 0", got)
  2338  	}
  2339  }
  2340  
  2341  func TestConnMaxLifetime(t *testing.T) {
  2342  	t0 := time.Unix(1000000, 0)
  2343  	offset := time.Duration(0)
  2344  
  2345  	nowFunc = func() time.Time { return t0.Add(offset) }
  2346  	defer func() { nowFunc = time.Now }()
  2347  
  2348  	db := newTestDB(t, "magicquery")
  2349  	defer closeDB(t, db)
  2350  
  2351  	driver := db.Driver().(*fakeDriver)
  2352  
  2353  	// Force the number of open connections to 0 so we can get an accurate
  2354  	// count for the test
  2355  	db.clearAllConns(t)
  2356  
  2357  	driver.mu.Lock()
  2358  	opens0 := driver.openCount
  2359  	closes0 := driver.closeCount
  2360  	driver.mu.Unlock()
  2361  
  2362  	db.SetMaxIdleConns(10)
  2363  	db.SetMaxOpenConns(10)
  2364  
  2365  	tx, err := db.Begin()
  2366  	if err != nil {
  2367  		t.Fatal(err)
  2368  	}
  2369  
  2370  	offset = time.Second
  2371  	tx2, err := db.Begin()
  2372  	if err != nil {
  2373  		t.Fatal(err)
  2374  	}
  2375  
  2376  	tx.Commit()
  2377  	tx2.Commit()
  2378  
  2379  	driver.mu.Lock()
  2380  	opens := driver.openCount - opens0
  2381  	closes := driver.closeCount - closes0
  2382  	driver.mu.Unlock()
  2383  
  2384  	if opens != 2 {
  2385  		t.Errorf("opens = %d; want 2", opens)
  2386  	}
  2387  	if closes != 0 {
  2388  		t.Errorf("closes = %d; want 0", closes)
  2389  	}
  2390  	if g, w := db.numFreeConns(), 2; g != w {
  2391  		t.Errorf("free conns = %d; want %d", g, w)
  2392  	}
  2393  
  2394  	// Expire first conn
  2395  	offset = 11 * time.Second
  2396  	db.SetConnMaxLifetime(10 * time.Second)
  2397  
  2398  	tx, err = db.Begin()
  2399  	if err != nil {
  2400  		t.Fatal(err)
  2401  	}
  2402  	tx2, err = db.Begin()
  2403  	if err != nil {
  2404  		t.Fatal(err)
  2405  	}
  2406  	tx.Commit()
  2407  	tx2.Commit()
  2408  
  2409  	// Give connectionCleaner chance to run.
  2410  	waitCondition(t, func() bool {
  2411  		driver.mu.Lock()
  2412  		opens = driver.openCount - opens0
  2413  		closes = driver.closeCount - closes0
  2414  		driver.mu.Unlock()
  2415  
  2416  		return closes == 1
  2417  	})
  2418  
  2419  	if opens != 3 {
  2420  		t.Errorf("opens = %d; want 3", opens)
  2421  	}
  2422  	if closes != 1 {
  2423  		t.Errorf("closes = %d; want 1", closes)
  2424  	}
  2425  
  2426  	if s := db.Stats(); s.MaxLifetimeClosed != 1 {
  2427  		t.Errorf("MaxLifetimeClosed = %d; want 1 %#v", s.MaxLifetimeClosed, s)
  2428  	}
  2429  }
  2430  
  2431  // golang.org/issue/5323
  2432  func TestStmtCloseDeps(t *testing.T) {
  2433  	if testing.Short() {
  2434  		t.Skip("skipping in short mode")
  2435  	}
  2436  	defer setHookpostCloseConn(nil)
  2437  	setHookpostCloseConn(func(_ *fakeConn, err error) {
  2438  		if err != nil {
  2439  			t.Errorf("Error closing fakeConn: %v", err)
  2440  		}
  2441  	})
  2442  
  2443  	db := newTestDB(t, "magicquery")
  2444  	defer closeDB(t, db)
  2445  
  2446  	driver := db.Driver().(*fakeDriver)
  2447  
  2448  	driver.mu.Lock()
  2449  	opens0 := driver.openCount
  2450  	closes0 := driver.closeCount
  2451  	driver.mu.Unlock()
  2452  	openDelta0 := opens0 - closes0
  2453  
  2454  	stmt, err := db.Prepare("SELECT|magicquery|op|op=?,millis=?")
  2455  	if err != nil {
  2456  		t.Fatal(err)
  2457  	}
  2458  
  2459  	// Start 50 parallel slow queries.
  2460  	const (
  2461  		nquery      = 50
  2462  		sleepMillis = 25
  2463  		nbatch      = 2
  2464  	)
  2465  	var wg sync.WaitGroup
  2466  	for batch := 0; batch < nbatch; batch++ {
  2467  		for i := 0; i < nquery; i++ {
  2468  			wg.Add(1)
  2469  			go func() {
  2470  				defer wg.Done()
  2471  				var op string
  2472  				if err := stmt.QueryRow("sleep", sleepMillis).Scan(&op); err != nil && err != ErrNoRows {
  2473  					t.Error(err)
  2474  				}
  2475  			}()
  2476  		}
  2477  		// Wait for the batch of queries above to finish before starting the next round.
  2478  		wg.Wait()
  2479  	}
  2480  
  2481  	if g, w := db.numFreeConns(), 2; g != w {
  2482  		t.Errorf("free conns = %d; want %d", g, w)
  2483  	}
  2484  
  2485  	if n := db.numDepsPoll(t, 4); n > 4 {
  2486  		t.Errorf("number of dependencies = %d; expected <= 4", n)
  2487  		db.dumpDeps(t)
  2488  	}
  2489  
  2490  	driver.mu.Lock()
  2491  	opens := driver.openCount - opens0
  2492  	closes := driver.closeCount - closes0
  2493  	openDelta := (driver.openCount - driver.closeCount) - openDelta0
  2494  	driver.mu.Unlock()
  2495  
  2496  	if openDelta > 2 {
  2497  		t.Logf("open calls = %d", opens)
  2498  		t.Logf("close calls = %d", closes)
  2499  		t.Logf("open delta = %d", openDelta)
  2500  		t.Errorf("db connections opened = %d; want <= 2", openDelta)
  2501  		db.dumpDeps(t)
  2502  	}
  2503  
  2504  	if !waitCondition(t, func() bool {
  2505  		return len(stmt.css) <= nquery
  2506  	}) {
  2507  		t.Errorf("len(stmt.css) = %d; want <= %d", len(stmt.css), nquery)
  2508  	}
  2509  
  2510  	if err := stmt.Close(); err != nil {
  2511  		t.Fatal(err)
  2512  	}
  2513  
  2514  	if g, w := db.numFreeConns(), 2; g != w {
  2515  		t.Errorf("free conns = %d; want %d", g, w)
  2516  	}
  2517  
  2518  	if n := db.numDepsPoll(t, 2); n > 2 {
  2519  		t.Errorf("number of dependencies = %d; expected <= 2", n)
  2520  		db.dumpDeps(t)
  2521  	}
  2522  
  2523  	db.clearAllConns(t)
  2524  }
  2525  
  2526  // golang.org/issue/5046
  2527  func TestCloseConnBeforeStmts(t *testing.T) {
  2528  	db := newTestDB(t, "people")
  2529  	defer closeDB(t, db)
  2530  
  2531  	defer setHookpostCloseConn(nil)
  2532  	setHookpostCloseConn(func(_ *fakeConn, err error) {
  2533  		if err != nil {
  2534  			t.Errorf("Error closing fakeConn: %v; from %s", err, stack())
  2535  			db.dumpDeps(t)
  2536  			t.Errorf("DB = %#v", db)
  2537  		}
  2538  	})
  2539  
  2540  	stmt, err := db.Prepare("SELECT|people|name|")
  2541  	if err != nil {
  2542  		t.Fatal(err)
  2543  	}
  2544  
  2545  	if len(db.freeConn) != 1 {
  2546  		t.Fatalf("expected 1 freeConn; got %d", len(db.freeConn))
  2547  	}
  2548  	dc := db.freeConn[0]
  2549  	if dc.closed {
  2550  		t.Errorf("conn shouldn't be closed")
  2551  	}
  2552  
  2553  	if n := len(dc.openStmt); n != 1 {
  2554  		t.Errorf("driverConn num openStmt = %d; want 1", n)
  2555  	}
  2556  	err = db.Close()
  2557  	if err != nil {
  2558  		t.Errorf("db Close = %v", err)
  2559  	}
  2560  	if !dc.closed {
  2561  		t.Errorf("after db.Close, driverConn should be closed")
  2562  	}
  2563  	if n := len(dc.openStmt); n != 0 {
  2564  		t.Errorf("driverConn num openStmt = %d; want 0", n)
  2565  	}
  2566  
  2567  	err = stmt.Close()
  2568  	if err != nil {
  2569  		t.Errorf("Stmt close = %v", err)
  2570  	}
  2571  
  2572  	if !dc.closed {
  2573  		t.Errorf("conn should be closed")
  2574  	}
  2575  	if dc.ci != nil {
  2576  		t.Errorf("after Stmt Close, driverConn's Conn interface should be nil")
  2577  	}
  2578  }
  2579  
  2580  // golang.org/issue/5283: don't release the Rows' connection in Close
  2581  // before calling Stmt.Close.
  2582  func TestRowsCloseOrder(t *testing.T) {
  2583  	db := newTestDB(t, "people")
  2584  	defer closeDB(t, db)
  2585  
  2586  	db.SetMaxIdleConns(0)
  2587  	setStrictFakeConnClose(t)
  2588  	defer setStrictFakeConnClose(nil)
  2589  
  2590  	rows, err := db.Query("SELECT|people|age,name|")
  2591  	if err != nil {
  2592  		t.Fatal(err)
  2593  	}
  2594  	err = rows.Close()
  2595  	if err != nil {
  2596  		t.Fatal(err)
  2597  	}
  2598  }
  2599  
  2600  func TestRowsImplicitClose(t *testing.T) {
  2601  	db := newTestDB(t, "people")
  2602  	defer closeDB(t, db)
  2603  
  2604  	rows, err := db.Query("SELECT|people|age,name|")
  2605  	if err != nil {
  2606  		t.Fatal(err)
  2607  	}
  2608  
  2609  	want, fail := 2, errors.New("fail")
  2610  	r := rows.rowsi.(*rowsCursor)
  2611  	r.errPos, r.err = want, fail
  2612  
  2613  	got := 0
  2614  	for rows.Next() {
  2615  		got++
  2616  	}
  2617  	if got != want {
  2618  		t.Errorf("got %d rows, want %d", got, want)
  2619  	}
  2620  	if err := rows.Err(); err != fail {
  2621  		t.Errorf("got error %v, want %v", err, fail)
  2622  	}
  2623  	if !r.closed {
  2624  		t.Errorf("r.closed is false, want true")
  2625  	}
  2626  }
  2627  
  2628  func TestRowsCloseError(t *testing.T) {
  2629  	db := newTestDB(t, "people")
  2630  	defer db.Close()
  2631  	rows, err := db.Query("SELECT|people|age,name|")
  2632  	if err != nil {
  2633  		t.Fatalf("Query: %v", err)
  2634  	}
  2635  	type row struct {
  2636  		age  int
  2637  		name string
  2638  	}
  2639  	got := []row{}
  2640  
  2641  	rc, ok := rows.rowsi.(*rowsCursor)
  2642  	if !ok {
  2643  		t.Fatal("not using *rowsCursor")
  2644  	}
  2645  	rc.closeErr = errors.New("rowsCursor: failed to close")
  2646  
  2647  	for rows.Next() {
  2648  		var r row
  2649  		err = rows.Scan(&r.age, &r.name)
  2650  		if err != nil {
  2651  			t.Fatalf("Scan: %v", err)
  2652  		}
  2653  		got = append(got, r)
  2654  	}
  2655  	err = rows.Err()
  2656  	if err != rc.closeErr {
  2657  		t.Fatalf("unexpected err: got %v, want %v", err, rc.closeErr)
  2658  	}
  2659  }
  2660  
  2661  func TestStmtCloseOrder(t *testing.T) {
  2662  	db := newTestDB(t, "people")
  2663  	defer closeDB(t, db)
  2664  
  2665  	db.SetMaxIdleConns(0)
  2666  	setStrictFakeConnClose(t)
  2667  	defer setStrictFakeConnClose(nil)
  2668  
  2669  	_, err := db.Query("SELECT|non_existent|name|")
  2670  	if err == nil {
  2671  		t.Fatal("Querying non-existent table should fail")
  2672  	}
  2673  }
  2674  
  2675  // Test cases where there's more than maxBadConnRetries bad connections in the
  2676  // pool (issue 8834)
  2677  func TestManyErrBadConn(t *testing.T) {
  2678  	manyErrBadConnSetup := func(first ...func(db *DB)) *DB {
  2679  		db := newTestDB(t, "people")
  2680  
  2681  		for _, f := range first {
  2682  			f(db)
  2683  		}
  2684  
  2685  		nconn := maxBadConnRetries + 1
  2686  		db.SetMaxIdleConns(nconn)
  2687  		db.SetMaxOpenConns(nconn)
  2688  		// open enough connections
  2689  		func() {
  2690  			for i := 0; i < nconn; i++ {
  2691  				rows, err := db.Query("SELECT|people|age,name|")
  2692  				if err != nil {
  2693  					t.Fatal(err)
  2694  				}
  2695  				defer rows.Close()
  2696  			}
  2697  		}()
  2698  
  2699  		db.mu.Lock()
  2700  		defer db.mu.Unlock()
  2701  		if db.numOpen != nconn {
  2702  			t.Fatalf("unexpected numOpen %d (was expecting %d)", db.numOpen, nconn)
  2703  		} else if len(db.freeConn) != nconn {
  2704  			t.Fatalf("unexpected len(db.freeConn) %d (was expecting %d)", len(db.freeConn), nconn)
  2705  		}
  2706  		for _, conn := range db.freeConn {
  2707  			conn.Lock()
  2708  			conn.ci.(*fakeConn).stickyBad = true
  2709  			conn.Unlock()
  2710  		}
  2711  		return db
  2712  	}
  2713  
  2714  	// Query
  2715  	db := manyErrBadConnSetup()
  2716  	defer closeDB(t, db)
  2717  	rows, err := db.Query("SELECT|people|age,name|")
  2718  	if err != nil {
  2719  		t.Fatal(err)
  2720  	}
  2721  	if err = rows.Close(); err != nil {
  2722  		t.Fatal(err)
  2723  	}
  2724  
  2725  	// Exec
  2726  	db = manyErrBadConnSetup()
  2727  	defer closeDB(t, db)
  2728  	_, err = db.Exec("INSERT|people|name=Julia,age=19")
  2729  	if err != nil {
  2730  		t.Fatal(err)
  2731  	}
  2732  
  2733  	// Begin
  2734  	db = manyErrBadConnSetup()
  2735  	defer closeDB(t, db)
  2736  	tx, err := db.Begin()
  2737  	if err != nil {
  2738  		t.Fatal(err)
  2739  	}
  2740  	if err = tx.Rollback(); err != nil {
  2741  		t.Fatal(err)
  2742  	}
  2743  
  2744  	// Prepare
  2745  	db = manyErrBadConnSetup()
  2746  	defer closeDB(t, db)
  2747  	stmt, err := db.Prepare("SELECT|people|age,name|")
  2748  	if err != nil {
  2749  		t.Fatal(err)
  2750  	}
  2751  	if err = stmt.Close(); err != nil {
  2752  		t.Fatal(err)
  2753  	}
  2754  
  2755  	// Stmt.Exec
  2756  	db = manyErrBadConnSetup(func(db *DB) {
  2757  		stmt, err = db.Prepare("INSERT|people|name=Julia,age=19")
  2758  		if err != nil {
  2759  			t.Fatal(err)
  2760  		}
  2761  	})
  2762  	defer closeDB(t, db)
  2763  	_, err = stmt.Exec()
  2764  	if err != nil {
  2765  		t.Fatal(err)
  2766  	}
  2767  	if err = stmt.Close(); err != nil {
  2768  		t.Fatal(err)
  2769  	}
  2770  
  2771  	// Stmt.Query
  2772  	db = manyErrBadConnSetup(func(db *DB) {
  2773  		stmt, err = db.Prepare("SELECT|people|age,name|")
  2774  		if err != nil {
  2775  			t.Fatal(err)
  2776  		}
  2777  	})
  2778  	defer closeDB(t, db)
  2779  	rows, err = stmt.Query()
  2780  	if err != nil {
  2781  		t.Fatal(err)
  2782  	}
  2783  	if err = rows.Close(); err != nil {
  2784  		t.Fatal(err)
  2785  	}
  2786  	if err = stmt.Close(); err != nil {
  2787  		t.Fatal(err)
  2788  	}
  2789  
  2790  	// Conn
  2791  	db = manyErrBadConnSetup()
  2792  	defer closeDB(t, db)
  2793  	ctx := t.Context()
  2794  	conn, err := db.Conn(ctx)
  2795  	if err != nil {
  2796  		t.Fatal(err)
  2797  	}
  2798  	conn.dc.ci.(*fakeConn).skipDirtySession = true
  2799  	err = conn.Close()
  2800  	if err != nil {
  2801  		t.Fatal(err)
  2802  	}
  2803  
  2804  	// Ping
  2805  	db = manyErrBadConnSetup()
  2806  	defer closeDB(t, db)
  2807  	err = db.PingContext(ctx)
  2808  	if err != nil {
  2809  		t.Fatal(err)
  2810  	}
  2811  }
  2812  
  2813  // Issue 34775: Ensure that a Tx cannot commit after a rollback.
  2814  func TestTxCannotCommitAfterRollback(t *testing.T) {
  2815  	db := newTestDB(t, "tx_status")
  2816  	defer closeDB(t, db)
  2817  
  2818  	// First check query reporting is correct.
  2819  	var txStatus string
  2820  	err := db.QueryRow("SELECT|tx_status|tx_status|").Scan(&txStatus)
  2821  	if err != nil {
  2822  		t.Fatal(err)
  2823  	}
  2824  	if g, w := txStatus, "autocommit"; g != w {
  2825  		t.Fatalf("tx_status=%q, wanted %q", g, w)
  2826  	}
  2827  
  2828  	ctx, cancel := context.WithCancel(context.Background())
  2829  	defer cancel()
  2830  
  2831  	tx, err := db.BeginTx(ctx, nil)
  2832  	if err != nil {
  2833  		t.Fatal(err)
  2834  	}
  2835  
  2836  	// Ignore dirty session for this test.
  2837  	// A failing test should trigger the dirty session flag as well,
  2838  	// but that isn't exactly what this should test for.
  2839  	tx.txi.(*fakeTx).c.skipDirtySession = true
  2840  
  2841  	defer tx.Rollback()
  2842  
  2843  	err = tx.QueryRow("SELECT|tx_status|tx_status|").Scan(&txStatus)
  2844  	if err != nil {
  2845  		t.Fatal(err)
  2846  	}
  2847  	if g, w := txStatus, "transaction"; g != w {
  2848  		t.Fatalf("tx_status=%q, wanted %q", g, w)
  2849  	}
  2850  
  2851  	// 1. Begin a transaction.
  2852  	// 2. (A) Start a query, (B) begin Tx rollback through a ctx cancel.
  2853  	// 3. Check if 2.A has committed in Tx (pass) or outside of Tx (fail).
  2854  	sendQuery := make(chan struct{})
  2855  	// The Tx status is returned through the row results, ensure
  2856  	// that the rows results are not canceled.
  2857  	bypassRowsAwaitDone = true
  2858  	hookTxGrabConn = func() {
  2859  		cancel()
  2860  		<-sendQuery
  2861  	}
  2862  	rollbackHook = func() {
  2863  		close(sendQuery)
  2864  	}
  2865  	defer func() {
  2866  		hookTxGrabConn = nil
  2867  		rollbackHook = nil
  2868  		bypassRowsAwaitDone = false
  2869  	}()
  2870  
  2871  	err = tx.QueryRow("SELECT|tx_status|tx_status|").Scan(&txStatus)
  2872  	if err != nil {
  2873  		// A failure here would be expected if skipDirtySession was not set to true above.
  2874  		t.Fatal(err)
  2875  	}
  2876  	if g, w := txStatus, "transaction"; g != w {
  2877  		t.Fatalf("tx_status=%q, wanted %q", g, w)
  2878  	}
  2879  }
  2880  
  2881  // Issue 40985 transaction statement deadlock while context cancel.
  2882  func TestTxStmtDeadlock(t *testing.T) {
  2883  	db := newTestDB(t, "people")
  2884  	defer closeDB(t, db)
  2885  
  2886  	ctx, cancel := context.WithCancel(context.Background())
  2887  	defer cancel()
  2888  	tx, err := db.BeginTx(ctx, nil)
  2889  	if err != nil {
  2890  		t.Fatal(err)
  2891  	}
  2892  
  2893  	stmt, err := tx.Prepare("SELECT|people|name,age|age=?")
  2894  	if err != nil {
  2895  		t.Fatal(err)
  2896  	}
  2897  	cancel()
  2898  	// Run number of stmt queries to reproduce deadlock from context cancel
  2899  	for i := 0; i < 1e3; i++ {
  2900  		// Encounter any close related errors (e.g. ErrTxDone, stmt is closed)
  2901  		// is expected due to context cancel.
  2902  		_, err = stmt.Query(1)
  2903  		if err != nil {
  2904  			break
  2905  		}
  2906  	}
  2907  	_ = tx.Rollback()
  2908  }
  2909  
  2910  // Issue32530 encounters an issue where a connection may
  2911  // expire right after it comes out of a used connection pool
  2912  // even when a new connection is requested.
  2913  func TestConnExpiresFreshOutOfPool(t *testing.T) {
  2914  	execCases := []struct {
  2915  		expired  bool
  2916  		badReset bool
  2917  	}{
  2918  		{false, false},
  2919  		{true, false},
  2920  		{false, true},
  2921  	}
  2922  
  2923  	t0 := time.Unix(1000000, 0)
  2924  	offset := time.Duration(0)
  2925  	offsetMu := sync.RWMutex{}
  2926  
  2927  	nowFunc = func() time.Time {
  2928  		offsetMu.RLock()
  2929  		defer offsetMu.RUnlock()
  2930  		return t0.Add(offset)
  2931  	}
  2932  	defer func() { nowFunc = time.Now }()
  2933  
  2934  	ctx := t.Context()
  2935  
  2936  	db := newTestDB(t, "magicquery")
  2937  	defer closeDB(t, db)
  2938  
  2939  	db.SetMaxOpenConns(1)
  2940  
  2941  	for _, ec := range execCases {
  2942  		ec := ec
  2943  		name := fmt.Sprintf("expired=%t,badReset=%t", ec.expired, ec.badReset)
  2944  		t.Run(name, func(t *testing.T) {
  2945  			db.clearAllConns(t)
  2946  
  2947  			db.SetMaxIdleConns(1)
  2948  			db.SetConnMaxLifetime(10 * time.Second)
  2949  
  2950  			conn, err := db.conn(ctx, alwaysNewConn)
  2951  			if err != nil {
  2952  				t.Fatal(err)
  2953  			}
  2954  
  2955  			afterPutConn := make(chan struct{})
  2956  			waitingForConn := make(chan struct{})
  2957  
  2958  			go func() {
  2959  				defer close(afterPutConn)
  2960  
  2961  				conn, err := db.conn(ctx, alwaysNewConn)
  2962  				if err == nil {
  2963  					db.putConn(conn, err, false)
  2964  				} else {
  2965  					t.Errorf("db.conn: %v", err)
  2966  				}
  2967  			}()
  2968  			go func() {
  2969  				defer close(waitingForConn)
  2970  
  2971  				for {
  2972  					if t.Failed() {
  2973  						return
  2974  					}
  2975  					db.mu.Lock()
  2976  					ct := db.connRequests.Len()
  2977  					db.mu.Unlock()
  2978  					if ct > 0 {
  2979  						return
  2980  					}
  2981  					time.Sleep(pollDuration)
  2982  				}
  2983  			}()
  2984  
  2985  			<-waitingForConn
  2986  
  2987  			if t.Failed() {
  2988  				return
  2989  			}
  2990  
  2991  			offsetMu.Lock()
  2992  			if ec.expired {
  2993  				offset = 11 * time.Second
  2994  			} else {
  2995  				offset = time.Duration(0)
  2996  			}
  2997  			offsetMu.Unlock()
  2998  
  2999  			conn.ci.(*fakeConn).stickyBad = ec.badReset
  3000  
  3001  			db.putConn(conn, err, true)
  3002  
  3003  			<-afterPutConn
  3004  		})
  3005  	}
  3006  }
  3007  
  3008  // TestIssue20575 ensures the Rows from query does not block
  3009  // closing a transaction. Ensure Rows is closed while closing a transaction.
  3010  func TestIssue20575(t *testing.T) {
  3011  	db := newTestDB(t, "people")
  3012  	defer closeDB(t, db)
  3013  
  3014  	tx, err := db.Begin()
  3015  	if err != nil {
  3016  		t.Fatal(err)
  3017  	}
  3018  	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
  3019  	defer cancel()
  3020  	_, err = tx.QueryContext(ctx, "SELECT|people|age,name|")
  3021  	if err != nil {
  3022  		t.Fatal(err)
  3023  	}
  3024  	// Do not close Rows from QueryContext.
  3025  	err = tx.Rollback()
  3026  	if err != nil {
  3027  		t.Fatal(err)
  3028  	}
  3029  	select {
  3030  	default:
  3031  	case <-ctx.Done():
  3032  		t.Fatal("timeout: failed to rollback query without closing rows:", ctx.Err())
  3033  	}
  3034  }
  3035  
  3036  // TestIssue20622 tests closing the transaction before rows is closed, requires
  3037  // the race detector to fail.
  3038  func TestIssue20622(t *testing.T) {
  3039  	db := newTestDB(t, "people")
  3040  	defer closeDB(t, db)
  3041  
  3042  	ctx, cancel := context.WithCancel(context.Background())
  3043  	defer cancel()
  3044  
  3045  	tx, err := db.BeginTx(ctx, nil)
  3046  	if err != nil {
  3047  		t.Fatal(err)
  3048  	}
  3049  
  3050  	rows, err := tx.Query("SELECT|people|age,name|")
  3051  	if err != nil {
  3052  		t.Fatal(err)
  3053  	}
  3054  
  3055  	count := 0
  3056  	for rows.Next() {
  3057  		count++
  3058  		var age int
  3059  		var name string
  3060  		if err := rows.Scan(&age, &name); err != nil {
  3061  			t.Fatal("scan failed", err)
  3062  		}
  3063  
  3064  		if count == 1 {
  3065  			cancel()
  3066  		}
  3067  		time.Sleep(100 * time.Millisecond)
  3068  	}
  3069  	rows.Close()
  3070  	tx.Commit()
  3071  }
  3072  
  3073  // golang.org/issue/5718
  3074  func TestErrBadConnReconnect(t *testing.T) {
  3075  	db := newTestDB(t, "foo")
  3076  	defer closeDB(t, db)
  3077  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  3078  
  3079  	simulateBadConn := func(name string, hook *func() bool, op func() error) {
  3080  		broken, retried := false, false
  3081  		numOpen := db.numOpen
  3082  
  3083  		// simulate a broken connection on the first try
  3084  		*hook = func() bool {
  3085  			if !broken {
  3086  				broken = true
  3087  				return true
  3088  			}
  3089  			retried = true
  3090  			return false
  3091  		}
  3092  
  3093  		if err := op(); err != nil {
  3094  			t.Errorf(name+": %v", err)
  3095  			return
  3096  		}
  3097  
  3098  		if !broken || !retried {
  3099  			t.Error(name + ": Failed to simulate broken connection")
  3100  		}
  3101  		*hook = nil
  3102  
  3103  		if numOpen != db.numOpen {
  3104  			t.Errorf(name+": leaked %d connection(s)!", db.numOpen-numOpen)
  3105  			numOpen = db.numOpen
  3106  		}
  3107  	}
  3108  
  3109  	// db.Exec
  3110  	dbExec := func() error {
  3111  		_, err := db.Exec("INSERT|t1|name=?,age=?,dead=?", "Gordon", 3, true)
  3112  		return err
  3113  	}
  3114  	simulateBadConn("db.Exec prepare", &hookPrepareBadConn, dbExec)
  3115  	simulateBadConn("db.Exec exec", &hookExecBadConn, dbExec)
  3116  
  3117  	// db.Query
  3118  	dbQuery := func() error {
  3119  		rows, err := db.Query("SELECT|t1|age,name|")
  3120  		if err == nil {
  3121  			err = rows.Close()
  3122  		}
  3123  		return err
  3124  	}
  3125  	simulateBadConn("db.Query prepare", &hookPrepareBadConn, dbQuery)
  3126  	simulateBadConn("db.Query query", &hookQueryBadConn, dbQuery)
  3127  
  3128  	// db.Prepare
  3129  	simulateBadConn("db.Prepare", &hookPrepareBadConn, func() error {
  3130  		stmt, err := db.Prepare("INSERT|t1|name=?,age=?,dead=?")
  3131  		if err != nil {
  3132  			return err
  3133  		}
  3134  		stmt.Close()
  3135  		return nil
  3136  	})
  3137  
  3138  	// Provide a way to force a re-prepare of a statement on next execution
  3139  	forcePrepare := func(stmt *Stmt) {
  3140  		stmt.css = nil
  3141  	}
  3142  
  3143  	// stmt.Exec
  3144  	stmt1, err := db.Prepare("INSERT|t1|name=?,age=?,dead=?")
  3145  	if err != nil {
  3146  		t.Fatalf("prepare: %v", err)
  3147  	}
  3148  	defer stmt1.Close()
  3149  	// make sure we must prepare the stmt first
  3150  	forcePrepare(stmt1)
  3151  
  3152  	stmtExec := func() error {
  3153  		_, err := stmt1.Exec("Gopher", 3, false)
  3154  		return err
  3155  	}
  3156  	simulateBadConn("stmt.Exec prepare", &hookPrepareBadConn, stmtExec)
  3157  	simulateBadConn("stmt.Exec exec", &hookExecBadConn, stmtExec)
  3158  
  3159  	// stmt.Query
  3160  	stmt2, err := db.Prepare("SELECT|t1|age,name|")
  3161  	if err != nil {
  3162  		t.Fatalf("prepare: %v", err)
  3163  	}
  3164  	defer stmt2.Close()
  3165  	// make sure we must prepare the stmt first
  3166  	forcePrepare(stmt2)
  3167  
  3168  	stmtQuery := func() error {
  3169  		rows, err := stmt2.Query()
  3170  		if err == nil {
  3171  			err = rows.Close()
  3172  		}
  3173  		return err
  3174  	}
  3175  	simulateBadConn("stmt.Query prepare", &hookPrepareBadConn, stmtQuery)
  3176  	simulateBadConn("stmt.Query exec", &hookQueryBadConn, stmtQuery)
  3177  }
  3178  
  3179  // golang.org/issue/11264
  3180  func TestTxEndBadConn(t *testing.T) {
  3181  	db := newTestDB(t, "foo")
  3182  	defer closeDB(t, db)
  3183  	db.SetMaxIdleConns(0)
  3184  	exec(t, db, "CREATE|t1|name=string,age=int32,dead=bool")
  3185  	db.SetMaxIdleConns(1)
  3186  
  3187  	simulateBadConn := func(name string, hook *func() bool, op func() error) {
  3188  		broken := false
  3189  		numOpen := db.numOpen
  3190  
  3191  		*hook = func() bool {
  3192  			if !broken {
  3193  				broken = true
  3194  			}
  3195  			return broken
  3196  		}
  3197  
  3198  		if err := op(); !errors.Is(err, driver.ErrBadConn) {
  3199  			t.Errorf(name+": %v", err)
  3200  			return
  3201  		}
  3202  
  3203  		if !broken {
  3204  			t.Error(name + ": Failed to simulate broken connection")
  3205  		}
  3206  		*hook = nil
  3207  
  3208  		if numOpen != db.numOpen {
  3209  			t.Errorf(name+": leaked %d connection(s)!", db.numOpen-numOpen)
  3210  		}
  3211  	}
  3212  
  3213  	// db.Exec
  3214  	dbExec := func(endTx func(tx *Tx) error) func() error {
  3215  		return func() error {
  3216  			tx, err := db.Begin()
  3217  			if err != nil {
  3218  				return err
  3219  			}
  3220  			_, err = tx.Exec("INSERT|t1|name=?,age=?,dead=?", "Gordon", 3, true)
  3221  			if err != nil {
  3222  				return err
  3223  			}
  3224  			return endTx(tx)
  3225  		}
  3226  	}
  3227  	simulateBadConn("db.Tx.Exec commit", &hookCommitBadConn, dbExec((*Tx).Commit))
  3228  	simulateBadConn("db.Tx.Exec rollback", &hookRollbackBadConn, dbExec((*Tx).Rollback))
  3229  
  3230  	// db.Query
  3231  	dbQuery := func(endTx func(tx *Tx) error) func() error {
  3232  		return func() error {
  3233  			tx, err := db.Begin()
  3234  			if err != nil {
  3235  				return err
  3236  			}
  3237  			rows, err := tx.Query("SELECT|t1|age,name|")
  3238  			if err == nil {
  3239  				err = rows.Close()
  3240  			} else {
  3241  				return err
  3242  			}
  3243  			return endTx(tx)
  3244  		}
  3245  	}
  3246  	simulateBadConn("db.Tx.Query commit", &hookCommitBadConn, dbQuery((*Tx).Commit))
  3247  	simulateBadConn("db.Tx.Query rollback", &hookRollbackBadConn, dbQuery((*Tx).Rollback))
  3248  }
  3249  
  3250  type concurrentTest interface {
  3251  	init(t testing.TB, db *DB)
  3252  	finish(t testing.TB)
  3253  	test(t testing.TB) error
  3254  }
  3255  
  3256  type concurrentDBQueryTest struct {
  3257  	db *DB
  3258  }
  3259  
  3260  func (c *concurrentDBQueryTest) init(t testing.TB, db *DB) {
  3261  	c.db = db
  3262  }
  3263  
  3264  func (c *concurrentDBQueryTest) finish(t testing.TB) {
  3265  	c.db = nil
  3266  }
  3267  
  3268  func (c *concurrentDBQueryTest) test(t testing.TB) error {
  3269  	rows, err := c.db.Query("SELECT|people|name|")
  3270  	if err != nil {
  3271  		t.Error(err)
  3272  		return err
  3273  	}
  3274  	var name string
  3275  	for rows.Next() {
  3276  		rows.Scan(&name)
  3277  	}
  3278  	rows.Close()
  3279  	return nil
  3280  }
  3281  
  3282  type concurrentDBExecTest struct {
  3283  	db *DB
  3284  }
  3285  
  3286  func (c *concurrentDBExecTest) init(t testing.TB, db *DB) {
  3287  	c.db = db
  3288  }
  3289  
  3290  func (c *concurrentDBExecTest) finish(t testing.TB) {
  3291  	c.db = nil
  3292  }
  3293  
  3294  func (c *concurrentDBExecTest) test(t testing.TB) error {
  3295  	_, err := c.db.Exec("NOSERT|people|name=Chris,age=?,photo=CPHOTO,bdate=?", 3, chrisBirthday)
  3296  	if err != nil {
  3297  		t.Error(err)
  3298  		return err
  3299  	}
  3300  	return nil
  3301  }
  3302  
  3303  type concurrentStmtQueryTest struct {
  3304  	db   *DB
  3305  	stmt *Stmt
  3306  }
  3307  
  3308  func (c *concurrentStmtQueryTest) init(t testing.TB, db *DB) {
  3309  	c.db = db
  3310  	var err error
  3311  	c.stmt, err = db.Prepare("SELECT|people|name|")
  3312  	if err != nil {
  3313  		t.Fatal(err)
  3314  	}
  3315  }
  3316  
  3317  func (c *concurrentStmtQueryTest) finish(t testing.TB) {
  3318  	if c.stmt != nil {
  3319  		c.stmt.Close()
  3320  		c.stmt = nil
  3321  	}
  3322  	c.db = nil
  3323  }
  3324  
  3325  func (c *concurrentStmtQueryTest) test(t testing.TB) error {
  3326  	rows, err := c.stmt.Query()
  3327  	if err != nil {
  3328  		t.Errorf("error on query:  %v", err)
  3329  		return err
  3330  	}
  3331  
  3332  	var name string
  3333  	for rows.Next() {
  3334  		rows.Scan(&name)
  3335  	}
  3336  	rows.Close()
  3337  	return nil
  3338  }
  3339  
  3340  type concurrentStmtExecTest struct {
  3341  	db   *DB
  3342  	stmt *Stmt
  3343  }
  3344  
  3345  func (c *concurrentStmtExecTest) init(t testing.TB, db *DB) {
  3346  	c.db = db
  3347  	var err error
  3348  	c.stmt, err = db.Prepare("NOSERT|people|name=Chris,age=?,photo=CPHOTO,bdate=?")
  3349  	if err != nil {
  3350  		t.Fatal(err)
  3351  	}
  3352  }
  3353  
  3354  func (c *concurrentStmtExecTest) finish(t testing.TB) {
  3355  	if c.stmt != nil {
  3356  		c.stmt.Close()
  3357  		c.stmt = nil
  3358  	}
  3359  	c.db = nil
  3360  }
  3361  
  3362  func (c *concurrentStmtExecTest) test(t testing.TB) error {
  3363  	_, err := c.stmt.Exec(3, chrisBirthday)
  3364  	if err != nil {
  3365  		t.Errorf("error on exec:  %v", err)
  3366  		return err
  3367  	}
  3368  	return nil
  3369  }
  3370  
  3371  type concurrentTxQueryTest struct {
  3372  	db *DB
  3373  	tx *Tx
  3374  }
  3375  
  3376  func (c *concurrentTxQueryTest) init(t testing.TB, db *DB) {
  3377  	c.db = db
  3378  	var err error
  3379  	c.tx, err = c.db.Begin()
  3380  	if err != nil {
  3381  		t.Fatal(err)
  3382  	}
  3383  }
  3384  
  3385  func (c *concurrentTxQueryTest) finish(t testing.TB) {
  3386  	if c.tx != nil {
  3387  		c.tx.Rollback()
  3388  		c.tx = nil
  3389  	}
  3390  	c.db = nil
  3391  }
  3392  
  3393  func (c *concurrentTxQueryTest) test(t testing.TB) error {
  3394  	rows, err := c.db.Query("SELECT|people|name|")
  3395  	if err != nil {
  3396  		t.Error(err)
  3397  		return err
  3398  	}
  3399  	var name string
  3400  	for rows.Next() {
  3401  		rows.Scan(&name)
  3402  	}
  3403  	rows.Close()
  3404  	return nil
  3405  }
  3406  
  3407  type concurrentTxExecTest struct {
  3408  	db *DB
  3409  	tx *Tx
  3410  }
  3411  
  3412  func (c *concurrentTxExecTest) init(t testing.TB, db *DB) {
  3413  	c.db = db
  3414  	var err error
  3415  	c.tx, err = c.db.Begin()
  3416  	if err != nil {
  3417  		t.Fatal(err)
  3418  	}
  3419  }
  3420  
  3421  func (c *concurrentTxExecTest) finish(t testing.TB) {
  3422  	if c.tx != nil {
  3423  		c.tx.Rollback()
  3424  		c.tx = nil
  3425  	}
  3426  	c.db = nil
  3427  }
  3428  
  3429  func (c *concurrentTxExecTest) test(t testing.TB) error {
  3430  	_, err := c.tx.Exec("NOSERT|people|name=Chris,age=?,photo=CPHOTO,bdate=?", 3, chrisBirthday)
  3431  	if err != nil {
  3432  		t.Error(err)
  3433  		return err
  3434  	}
  3435  	return nil
  3436  }
  3437  
  3438  type concurrentTxStmtQueryTest struct {
  3439  	db   *DB
  3440  	tx   *Tx
  3441  	stmt *Stmt
  3442  }
  3443  
  3444  func (c *concurrentTxStmtQueryTest) init(t testing.TB, db *DB) {
  3445  	c.db = db
  3446  	var err error
  3447  	c.tx, err = c.db.Begin()
  3448  	if err != nil {
  3449  		t.Fatal(err)
  3450  	}
  3451  	c.stmt, err = c.tx.Prepare("SELECT|people|name|")
  3452  	if err != nil {
  3453  		t.Fatal(err)
  3454  	}
  3455  }
  3456  
  3457  func (c *concurrentTxStmtQueryTest) finish(t testing.TB) {
  3458  	if c.stmt != nil {
  3459  		c.stmt.Close()
  3460  		c.stmt = nil
  3461  	}
  3462  	if c.tx != nil {
  3463  		c.tx.Rollback()
  3464  		c.tx = nil
  3465  	}
  3466  	c.db = nil
  3467  }
  3468  
  3469  func (c *concurrentTxStmtQueryTest) test(t testing.TB) error {
  3470  	rows, err := c.stmt.Query()
  3471  	if err != nil {
  3472  		t.Errorf("error on query:  %v", err)
  3473  		return err
  3474  	}
  3475  
  3476  	var name string
  3477  	for rows.Next() {
  3478  		rows.Scan(&name)
  3479  	}
  3480  	rows.Close()
  3481  	return nil
  3482  }
  3483  
  3484  type concurrentTxStmtExecTest struct {
  3485  	db   *DB
  3486  	tx   *Tx
  3487  	stmt *Stmt
  3488  }
  3489  
  3490  func (c *concurrentTxStmtExecTest) init(t testing.TB, db *DB) {
  3491  	c.db = db
  3492  	var err error
  3493  	c.tx, err = c.db.Begin()
  3494  	if err != nil {
  3495  		t.Fatal(err)
  3496  	}
  3497  	c.stmt, err = c.tx.Prepare("NOSERT|people|name=Chris,age=?,photo=CPHOTO,bdate=?")
  3498  	if err != nil {
  3499  		t.Fatal(err)
  3500  	}
  3501  }
  3502  
  3503  func (c *concurrentTxStmtExecTest) finish(t testing.TB) {
  3504  	if c.stmt != nil {
  3505  		c.stmt.Close()
  3506  		c.stmt = nil
  3507  	}
  3508  	if c.tx != nil {
  3509  		c.tx.Rollback()
  3510  		c.tx = nil
  3511  	}
  3512  	c.db = nil
  3513  }
  3514  
  3515  func (c *concurrentTxStmtExecTest) test(t testing.TB) error {
  3516  	_, err := c.stmt.Exec(3, chrisBirthday)
  3517  	if err != nil {
  3518  		t.Errorf("error on exec:  %v", err)
  3519  		return err
  3520  	}
  3521  	return nil
  3522  }
  3523  
  3524  type concurrentRandomTest struct {
  3525  	tests []concurrentTest
  3526  }
  3527  
  3528  func (c *concurrentRandomTest) init(t testing.TB, db *DB) {
  3529  	c.tests = []concurrentTest{
  3530  		new(concurrentDBQueryTest),
  3531  		new(concurrentDBExecTest),
  3532  		new(concurrentStmtQueryTest),
  3533  		new(concurrentStmtExecTest),
  3534  		new(concurrentTxQueryTest),
  3535  		new(concurrentTxExecTest),
  3536  		new(concurrentTxStmtQueryTest),
  3537  		new(concurrentTxStmtExecTest),
  3538  	}
  3539  	for _, ct := range c.tests {
  3540  		ct.init(t, db)
  3541  	}
  3542  }
  3543  
  3544  func (c *concurrentRandomTest) finish(t testing.TB) {
  3545  	for _, ct := range c.tests {
  3546  		ct.finish(t)
  3547  	}
  3548  }
  3549  
  3550  func (c *concurrentRandomTest) test(t testing.TB) error {
  3551  	ct := c.tests[rand.Intn(len(c.tests))]
  3552  	return ct.test(t)
  3553  }
  3554  
  3555  func doConcurrentTest(t testing.TB, ct concurrentTest) {
  3556  	maxProcs, numReqs := 1, 500
  3557  	if testing.Short() {
  3558  		maxProcs, numReqs = 4, 50
  3559  	}
  3560  	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(maxProcs))
  3561  
  3562  	db := newTestDB(t, "people")
  3563  	defer closeDB(t, db)
  3564  
  3565  	ct.init(t, db)
  3566  	defer ct.finish(t)
  3567  
  3568  	var wg sync.WaitGroup
  3569  	wg.Add(numReqs)
  3570  
  3571  	reqs := make(chan bool)
  3572  	defer close(reqs)
  3573  
  3574  	for i := 0; i < maxProcs*2; i++ {
  3575  		go func() {
  3576  			for range reqs {
  3577  				err := ct.test(t)
  3578  				if err != nil {
  3579  					wg.Done()
  3580  					continue
  3581  				}
  3582  				wg.Done()
  3583  			}
  3584  		}()
  3585  	}
  3586  
  3587  	for i := 0; i < numReqs; i++ {
  3588  		reqs <- true
  3589  	}
  3590  
  3591  	wg.Wait()
  3592  }
  3593  
  3594  func TestIssue6081(t *testing.T) {
  3595  	db := newTestDB(t, "people")
  3596  	defer closeDB(t, db)
  3597  
  3598  	drv := db.Driver().(*fakeDriver)
  3599  	drv.mu.Lock()
  3600  	opens0 := drv.openCount
  3601  	closes0 := drv.closeCount
  3602  	drv.mu.Unlock()
  3603  
  3604  	stmt, err := db.Prepare("SELECT|people|name|")
  3605  	if err != nil {
  3606  		t.Fatal(err)
  3607  	}
  3608  	setRowsCloseHook(func(rows *Rows, err *error) {
  3609  		*err = driver.ErrBadConn
  3610  	})
  3611  	defer setRowsCloseHook(nil)
  3612  	for i := 0; i < 10; i++ {
  3613  		rows, err := stmt.Query()
  3614  		if err != nil {
  3615  			t.Fatal(err)
  3616  		}
  3617  		rows.Close()
  3618  	}
  3619  	if n := len(stmt.css); n > 1 {
  3620  		t.Errorf("len(css slice) = %d; want <= 1", n)
  3621  	}
  3622  	stmt.Close()
  3623  	if n := len(stmt.css); n != 0 {
  3624  		t.Errorf("len(css slice) after Close = %d; want 0", n)
  3625  	}
  3626  
  3627  	drv.mu.Lock()
  3628  	opens := drv.openCount - opens0
  3629  	closes := drv.closeCount - closes0
  3630  	drv.mu.Unlock()
  3631  	if opens < 9 {
  3632  		t.Errorf("opens = %d; want >= 9", opens)
  3633  	}
  3634  	if closes < 9 {
  3635  		t.Errorf("closes = %d; want >= 9", closes)
  3636  	}
  3637  }
  3638  
  3639  // TestIssue18429 attempts to stress rolling back the transaction from a
  3640  // context cancel while simultaneously calling Tx.Rollback. Rolling back from a
  3641  // context happens concurrently so tx.rollback and tx.Commit must guard against
  3642  // double entry.
  3643  //
  3644  // In the test, a context is canceled while the query is in process so
  3645  // the internal rollback will run concurrently with the explicitly called
  3646  // Tx.Rollback.
  3647  //
  3648  // The addition of calling rows.Next also tests
  3649  // Issue 21117.
  3650  func TestIssue18429(t *testing.T) {
  3651  	db := newTestDB(t, "people")
  3652  	defer closeDB(t, db)
  3653  
  3654  	ctx := context.Background()
  3655  	sem := make(chan bool, 20)
  3656  	var wg sync.WaitGroup
  3657  
  3658  	const milliWait = 30
  3659  
  3660  	for i := 0; i < 100; i++ {
  3661  		sem <- true
  3662  		wg.Add(1)
  3663  		go func() {
  3664  			defer func() {
  3665  				<-sem
  3666  				wg.Done()
  3667  			}()
  3668  			qwait := (time.Duration(rand.Intn(milliWait)) * time.Millisecond).String()
  3669  
  3670  			ctx, cancel := context.WithTimeout(ctx, time.Duration(rand.Intn(milliWait))*time.Millisecond)
  3671  			defer cancel()
  3672  
  3673  			tx, err := db.BeginTx(ctx, nil)
  3674  			if err != nil {
  3675  				return
  3676  			}
  3677  			// This is expected to give a cancel error most, but not all the time.
  3678  			// Test failure will happen with a panic or other race condition being
  3679  			// reported.
  3680  			rows, _ := tx.QueryContext(ctx, "WAIT|"+qwait+"|SELECT|people|name|")
  3681  			if rows != nil {
  3682  				var name string
  3683  				// Call Next to test Issue 21117 and check for races.
  3684  				for rows.Next() {
  3685  					// Scan the buffer so it is read and checked for races.
  3686  					rows.Scan(&name)
  3687  				}
  3688  				rows.Close()
  3689  			}
  3690  			// This call will race with the context cancel rollback to complete
  3691  			// if the rollback itself isn't guarded.
  3692  			tx.Rollback()
  3693  		}()
  3694  	}
  3695  	wg.Wait()
  3696  }
  3697  
  3698  // TestIssue20160 attempts to test a short context life on a stmt Query.
  3699  func TestIssue20160(t *testing.T) {
  3700  	db := newTestDB(t, "people")
  3701  	defer closeDB(t, db)
  3702  
  3703  	ctx := context.Background()
  3704  	sem := make(chan bool, 20)
  3705  	var wg sync.WaitGroup
  3706  
  3707  	const milliWait = 30
  3708  
  3709  	stmt, err := db.PrepareContext(ctx, "SELECT|people|name|")
  3710  	if err != nil {
  3711  		t.Fatal(err)
  3712  	}
  3713  	defer stmt.Close()
  3714  
  3715  	for i := 0; i < 100; i++ {
  3716  		sem <- true
  3717  		wg.Add(1)
  3718  		go func() {
  3719  			defer func() {
  3720  				<-sem
  3721  				wg.Done()
  3722  			}()
  3723  			ctx, cancel := context.WithTimeout(ctx, time.Duration(rand.Intn(milliWait))*time.Millisecond)
  3724  			defer cancel()
  3725  
  3726  			// This is expected to give a cancel error most, but not all the time.
  3727  			// Test failure will happen with a panic or other race condition being
  3728  			// reported.
  3729  			rows, _ := stmt.QueryContext(ctx)
  3730  			if rows != nil {
  3731  				rows.Close()
  3732  			}
  3733  		}()
  3734  	}
  3735  	wg.Wait()
  3736  }
  3737  
  3738  // TestIssue18719 closes the context right before use. The sql.driverConn
  3739  // will nil out the ci on close in a lock, but if another process uses it right after
  3740  // it will panic with on the nil ref.
  3741  //
  3742  // See https://golang.org/cl/35550 .
  3743  func TestIssue18719(t *testing.T) {
  3744  	db := newTestDB(t, "people")
  3745  	defer closeDB(t, db)
  3746  
  3747  	ctx, cancel := context.WithCancel(context.Background())
  3748  	defer cancel()
  3749  
  3750  	tx, err := db.BeginTx(ctx, nil)
  3751  	if err != nil {
  3752  		t.Fatal(err)
  3753  	}
  3754  
  3755  	hookTxGrabConn = func() {
  3756  		cancel()
  3757  
  3758  		// Wait for the context to cancel and tx to rollback.
  3759  		for !tx.isDone() {
  3760  			time.Sleep(pollDuration)
  3761  		}
  3762  	}
  3763  	defer func() { hookTxGrabConn = nil }()
  3764  
  3765  	// This call will grab the connection and cancel the context
  3766  	// after it has done so. Code after must deal with the canceled state.
  3767  	_, err = tx.QueryContext(ctx, "SELECT|people|name|")
  3768  	if err != nil {
  3769  		t.Fatalf("expected error %v but got %v", nil, err)
  3770  	}
  3771  
  3772  	// Rows may be ignored because it will be closed when the context is canceled.
  3773  
  3774  	// Do not explicitly rollback. The rollback will happen from the
  3775  	// canceled context.
  3776  
  3777  	cancel()
  3778  }
  3779  
  3780  func TestIssue20647(t *testing.T) {
  3781  	db := newTestDB(t, "people")
  3782  	defer closeDB(t, db)
  3783  
  3784  	ctx := t.Context()
  3785  
  3786  	conn, err := db.Conn(ctx)
  3787  	if err != nil {
  3788  		t.Fatal(err)
  3789  	}
  3790  	conn.dc.ci.(*fakeConn).skipDirtySession = true
  3791  	defer conn.Close()
  3792  
  3793  	stmt, err := conn.PrepareContext(ctx, "SELECT|people|name|")
  3794  	if err != nil {
  3795  		t.Fatal(err)
  3796  	}
  3797  	defer stmt.Close()
  3798  
  3799  	rows1, err := stmt.QueryContext(ctx)
  3800  	if err != nil {
  3801  		t.Fatal("rows1", err)
  3802  	}
  3803  	defer rows1.Close()
  3804  
  3805  	rows2, err := stmt.QueryContext(ctx)
  3806  	if err != nil {
  3807  		t.Fatal("rows2", err)
  3808  	}
  3809  	defer rows2.Close()
  3810  
  3811  	if rows1.dc != rows2.dc {
  3812  		t.Fatal("stmt prepared on Conn does not use same connection")
  3813  	}
  3814  }
  3815  
  3816  func TestConcurrency(t *testing.T) {
  3817  	list := []struct {
  3818  		name string
  3819  		ct   concurrentTest
  3820  	}{
  3821  		{"Query", new(concurrentDBQueryTest)},
  3822  		{"Exec", new(concurrentDBExecTest)},
  3823  		{"StmtQuery", new(concurrentStmtQueryTest)},
  3824  		{"StmtExec", new(concurrentStmtExecTest)},
  3825  		{"TxQuery", new(concurrentTxQueryTest)},
  3826  		{"TxExec", new(concurrentTxExecTest)},
  3827  		{"TxStmtQuery", new(concurrentTxStmtQueryTest)},
  3828  		{"TxStmtExec", new(concurrentTxStmtExecTest)},
  3829  		{"Random", new(concurrentRandomTest)},
  3830  	}
  3831  	for _, item := range list {
  3832  		t.Run(item.name, func(t *testing.T) {
  3833  			doConcurrentTest(t, item.ct)
  3834  		})
  3835  	}
  3836  }
  3837  
  3838  func TestConnectionLeak(t *testing.T) {
  3839  	db := newTestDB(t, "people")
  3840  	defer closeDB(t, db)
  3841  	// Start by opening defaultMaxIdleConns
  3842  	rows := make([]*Rows, defaultMaxIdleConns)
  3843  	// We need to SetMaxOpenConns > MaxIdleConns, so the DB can open
  3844  	// a new connection and we can fill the idle queue with the released
  3845  	// connections.
  3846  	db.SetMaxOpenConns(len(rows) + 1)
  3847  	for ii := range rows {
  3848  		r, err := db.Query("SELECT|people|name|")
  3849  		if err != nil {
  3850  			t.Fatal(err)
  3851  		}
  3852  		r.Next()
  3853  		if err := r.Err(); err != nil {
  3854  			t.Fatal(err)
  3855  		}
  3856  		rows[ii] = r
  3857  	}
  3858  	// Now we have defaultMaxIdleConns busy connections. Open
  3859  	// a new one, but wait until the busy connections are released
  3860  	// before returning control to DB.
  3861  	drv := db.Driver().(*fakeDriver)
  3862  	drv.waitCh = make(chan struct{}, 1)
  3863  	drv.waitingCh = make(chan struct{}, 1)
  3864  	var wg sync.WaitGroup
  3865  	wg.Add(1)
  3866  	go func() {
  3867  		r, err := db.Query("SELECT|people|name|")
  3868  		if err != nil {
  3869  			t.Error(err)
  3870  			return
  3871  		}
  3872  		r.Close()
  3873  		wg.Done()
  3874  	}()
  3875  	// Wait until the goroutine we've just created has started waiting.
  3876  	<-drv.waitingCh
  3877  	// Now close the busy connections. This provides a connection for
  3878  	// the blocked goroutine and then fills up the idle queue.
  3879  	for _, v := range rows {
  3880  		v.Close()
  3881  	}
  3882  	// At this point we give the new connection to DB. This connection is
  3883  	// now useless, since the idle queue is full and there are no pending
  3884  	// requests. DB should deal with this situation without leaking the
  3885  	// connection.
  3886  	drv.waitCh <- struct{}{}
  3887  	wg.Wait()
  3888  }
  3889  
  3890  func TestStatsMaxIdleClosedZero(t *testing.T) {
  3891  	db := newTestDB(t, "people")
  3892  	defer closeDB(t, db)
  3893  
  3894  	db.SetMaxOpenConns(1)
  3895  	db.SetMaxIdleConns(1)
  3896  	db.SetConnMaxLifetime(0)
  3897  
  3898  	preMaxIdleClosed := db.Stats().MaxIdleClosed
  3899  
  3900  	for i := 0; i < 10; i++ {
  3901  		rows, err := db.Query("SELECT|people|name|")
  3902  		if err != nil {
  3903  			t.Fatal(err)
  3904  		}
  3905  		rows.Close()
  3906  	}
  3907  
  3908  	st := db.Stats()
  3909  	maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
  3910  	t.Logf("MaxIdleClosed: %d", maxIdleClosed)
  3911  	if maxIdleClosed != 0 {
  3912  		t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
  3913  	}
  3914  }
  3915  
  3916  func TestStatsMaxIdleClosedTen(t *testing.T) {
  3917  	db := newTestDB(t, "people")
  3918  	defer closeDB(t, db)
  3919  
  3920  	db.SetMaxOpenConns(1)
  3921  	db.SetMaxIdleConns(0)
  3922  	db.SetConnMaxLifetime(0)
  3923  
  3924  	preMaxIdleClosed := db.Stats().MaxIdleClosed
  3925  
  3926  	for i := 0; i < 10; i++ {
  3927  		rows, err := db.Query("SELECT|people|name|")
  3928  		if err != nil {
  3929  			t.Fatal(err)
  3930  		}
  3931  		rows.Close()
  3932  	}
  3933  
  3934  	st := db.Stats()
  3935  	maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
  3936  	t.Logf("MaxIdleClosed: %d", maxIdleClosed)
  3937  	if maxIdleClosed != 10 {
  3938  		t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
  3939  	}
  3940  }
  3941  
  3942  // testUseConns uses count concurrent connections with 1 nanosecond apart.
  3943  // Returns the returnedAt time of the final connection.
  3944  func testUseConns(t *testing.T, count int, tm time.Time, db *DB) time.Time {
  3945  	conns := make([]*Conn, count)
  3946  	ctx := context.Background()
  3947  	for i := range conns {
  3948  		tm = tm.Add(time.Nanosecond)
  3949  		nowFunc = func() time.Time {
  3950  			return tm
  3951  		}
  3952  		c, err := db.Conn(ctx)
  3953  		if err != nil {
  3954  			t.Error(err)
  3955  		}
  3956  		conns[i] = c
  3957  	}
  3958  
  3959  	for i := len(conns) - 1; i >= 0; i-- {
  3960  		tm = tm.Add(time.Nanosecond)
  3961  		nowFunc = func() time.Time {
  3962  			return tm
  3963  		}
  3964  		if err := conns[i].Close(); err != nil {
  3965  			t.Error(err)
  3966  		}
  3967  	}
  3968  
  3969  	return tm
  3970  }
  3971  
  3972  func TestMaxIdleTime(t *testing.T) {
  3973  	usedConns := 5
  3974  	reusedConns := 2
  3975  	list := []struct {
  3976  		wantMaxIdleTime   time.Duration
  3977  		wantMaxLifetime   time.Duration
  3978  		wantNextCheck     time.Duration
  3979  		wantIdleClosed    int64
  3980  		wantMaxIdleClosed int64
  3981  		timeOffset        time.Duration
  3982  		secondTimeOffset  time.Duration
  3983  	}{
  3984  		{
  3985  			time.Millisecond,
  3986  			0,
  3987  			time.Millisecond - time.Nanosecond,
  3988  			int64(usedConns - reusedConns),
  3989  			int64(usedConns - reusedConns),
  3990  			10 * time.Millisecond,
  3991  			0,
  3992  		},
  3993  		{
  3994  			// Want to close some connections via max idle time and one by max lifetime.
  3995  			time.Millisecond,
  3996  			// nowFunc() - MaxLifetime should be 1 * time.Nanosecond in connectionCleanerRunLocked.
  3997  			// This guarantees that first opened connection is to be closed.
  3998  			// Thus it is timeOffset + secondTimeOffset + 3 (+2 for Close while reusing conns and +1 for Conn).
  3999  			10*time.Millisecond + 100*time.Nanosecond + 3*time.Nanosecond,
  4000  			time.Nanosecond,
  4001  			// Closed all not reused connections and extra one by max lifetime.
  4002  			int64(usedConns - reusedConns + 1),
  4003  			int64(usedConns - reusedConns),
  4004  			10 * time.Millisecond,
  4005  			// Add second offset because otherwise connections are expired via max lifetime in Close.
  4006  			100 * time.Nanosecond,
  4007  		},
  4008  		{
  4009  			time.Hour,
  4010  			0,
  4011  			time.Second,
  4012  			0,
  4013  			0,
  4014  			10 * time.Millisecond,
  4015  			0},
  4016  	}
  4017  	baseTime := time.Unix(0, 0)
  4018  	defer func() {
  4019  		nowFunc = time.Now
  4020  	}()
  4021  	for _, item := range list {
  4022  		nowFunc = func() time.Time {
  4023  			return baseTime
  4024  		}
  4025  		t.Run(fmt.Sprintf("%v", item.wantMaxIdleTime), func(t *testing.T) {
  4026  			db := newTestDB(t, "people")
  4027  			defer closeDB(t, db)
  4028  
  4029  			db.SetMaxOpenConns(usedConns)
  4030  			db.SetMaxIdleConns(usedConns)
  4031  			db.SetConnMaxIdleTime(item.wantMaxIdleTime)
  4032  			db.SetConnMaxLifetime(item.wantMaxLifetime)
  4033  
  4034  			preMaxIdleClosed := db.Stats().MaxIdleTimeClosed
  4035  
  4036  			// Busy usedConns.
  4037  			testUseConns(t, usedConns, baseTime, db)
  4038  
  4039  			tm := baseTime.Add(item.timeOffset)
  4040  
  4041  			// Reuse connections which should never be considered idle
  4042  			// and exercises the sorting for issue 39471.
  4043  			tm = testUseConns(t, reusedConns, tm, db)
  4044  
  4045  			tm = tm.Add(item.secondTimeOffset)
  4046  			nowFunc = func() time.Time {
  4047  				return tm
  4048  			}
  4049  
  4050  			db.mu.Lock()
  4051  			nc, closing := db.connectionCleanerRunLocked(time.Second)
  4052  			if nc != item.wantNextCheck {
  4053  				t.Errorf("got %v; want %v next check duration", nc, item.wantNextCheck)
  4054  			}
  4055  
  4056  			// Validate freeConn order.
  4057  			var last time.Time
  4058  			for _, c := range db.freeConn {
  4059  				if last.After(c.returnedAt) {
  4060  					t.Error("freeConn is not ordered by returnedAt")
  4061  					break
  4062  				}
  4063  				last = c.returnedAt
  4064  			}
  4065  
  4066  			db.mu.Unlock()
  4067  			for _, c := range closing {
  4068  				c.Close()
  4069  			}
  4070  			if g, w := int64(len(closing)), item.wantIdleClosed; g != w {
  4071  				t.Errorf("got: %d; want %d closed conns", g, w)
  4072  			}
  4073  
  4074  			st := db.Stats()
  4075  			maxIdleClosed := st.MaxIdleTimeClosed - preMaxIdleClosed
  4076  			if g, w := maxIdleClosed, item.wantMaxIdleClosed; g != w {
  4077  				t.Errorf("got: %d; want %d max idle closed conns", g, w)
  4078  			}
  4079  		})
  4080  	}
  4081  }
  4082  
  4083  type nvcDriver struct {
  4084  	fakeDriver
  4085  	skipNamedValueCheck bool
  4086  }
  4087  
  4088  func (d *nvcDriver) Open(dsn string) (driver.Conn, error) {
  4089  	c, err := d.fakeDriver.Open(dsn)
  4090  	fc := c.(*fakeConn)
  4091  	fc.db.allowAny = true
  4092  	return &nvcConn{fc, d.skipNamedValueCheck}, err
  4093  }
  4094  
  4095  type nvcConn struct {
  4096  	*fakeConn
  4097  	skipNamedValueCheck bool
  4098  }
  4099  
  4100  type decimalInt struct {
  4101  	value int
  4102  }
  4103  
  4104  type doNotInclude struct{}
  4105  
  4106  var _ driver.NamedValueChecker = &nvcConn{}
  4107  
  4108  func (c *nvcConn) CheckNamedValue(nv *driver.NamedValue) error {
  4109  	if c.skipNamedValueCheck {
  4110  		return driver.ErrSkip
  4111  	}
  4112  	switch v := nv.Value.(type) {
  4113  	default:
  4114  		return driver.ErrSkip
  4115  	case Out:
  4116  		switch ov := v.Dest.(type) {
  4117  		default:
  4118  			return errors.New("unknown NameValueCheck OUTPUT type")
  4119  		case *string:
  4120  			*ov = "from-server"
  4121  			nv.Value = "OUT:*string"
  4122  		}
  4123  		return nil
  4124  	case decimalInt, []int64:
  4125  		return nil
  4126  	case doNotInclude:
  4127  		return driver.ErrRemoveArgument
  4128  	}
  4129  }
  4130  
  4131  func TestNamedValueChecker(t *testing.T) {
  4132  	Register("NamedValueCheck", &nvcDriver{})
  4133  	db, err := Open("NamedValueCheck", "")
  4134  	if err != nil {
  4135  		t.Fatal(err)
  4136  	}
  4137  	defer db.Close()
  4138  
  4139  	ctx := t.Context()
  4140  	_, err = db.ExecContext(ctx, "WIPE")
  4141  	if err != nil {
  4142  		t.Fatal("exec wipe", err)
  4143  	}
  4144  
  4145  	_, err = db.ExecContext(ctx, "CREATE|keys|dec1=any,str1=string,out1=string,array1=any")
  4146  	if err != nil {
  4147  		t.Fatal("exec create", err)
  4148  	}
  4149  
  4150  	o1 := ""
  4151  	_, err = db.ExecContext(ctx, "INSERT|keys|dec1=?A,str1=?,out1=?O1,array1=?", Named("A", decimalInt{123}), "hello", Named("O1", Out{Dest: &o1}), []int64{42, 128, 707}, doNotInclude{})
  4152  	if err != nil {
  4153  		t.Fatal("exec insert", err)
  4154  	}
  4155  	var (
  4156  		str1 string
  4157  		dec1 decimalInt
  4158  		arr1 []int64
  4159  	)
  4160  	err = db.QueryRowContext(ctx, "SELECT|keys|dec1,str1,array1|").Scan(&dec1, &str1, &arr1)
  4161  	if err != nil {
  4162  		t.Fatal("select", err)
  4163  	}
  4164  
  4165  	list := []struct{ got, want any }{
  4166  		{o1, "from-server"},
  4167  		{dec1, decimalInt{123}},
  4168  		{str1, "hello"},
  4169  		{arr1, []int64{42, 128, 707}},
  4170  	}
  4171  
  4172  	for index, item := range list {
  4173  		if !reflect.DeepEqual(item.got, item.want) {
  4174  			t.Errorf("got %#v wanted %#v for index %d", item.got, item.want, index)
  4175  		}
  4176  	}
  4177  }
  4178  
  4179  func TestNamedValueCheckerSkip(t *testing.T) {
  4180  	Register("NamedValueCheckSkip", &nvcDriver{skipNamedValueCheck: true})
  4181  	db, err := Open("NamedValueCheckSkip", "")
  4182  	if err != nil {
  4183  		t.Fatal(err)
  4184  	}
  4185  	defer db.Close()
  4186  
  4187  	ctx := t.Context()
  4188  	_, err = db.ExecContext(ctx, "WIPE")
  4189  	if err != nil {
  4190  		t.Fatal("exec wipe", err)
  4191  	}
  4192  
  4193  	_, err = db.ExecContext(ctx, "CREATE|keys|dec1=any")
  4194  	if err != nil {
  4195  		t.Fatal("exec create", err)
  4196  	}
  4197  
  4198  	_, err = db.ExecContext(ctx, "INSERT|keys|dec1=?A", Named("A", decimalInt{123}))
  4199  	if err == nil {
  4200  		t.Fatalf("expected error with bad argument, got %v", err)
  4201  	}
  4202  }
  4203  
  4204  func TestOpenConnector(t *testing.T) {
  4205  	Register("testctx", &fakeDriverCtx{})
  4206  	db, err := Open("testctx", "people")
  4207  	if err != nil {
  4208  		t.Fatal(err)
  4209  	}
  4210  	defer db.Close()
  4211  
  4212  	c, ok := db.connector.(*fakeConnector)
  4213  	if !ok {
  4214  		t.Fatal("not using *fakeConnector")
  4215  	}
  4216  
  4217  	if err := db.Close(); err != nil {
  4218  		t.Fatal(err)
  4219  	}
  4220  
  4221  	if !c.closed {
  4222  		t.Fatal("connector is not closed")
  4223  	}
  4224  }
  4225  
  4226  type ctxOnlyDriver struct {
  4227  	fakeDriver
  4228  }
  4229  
  4230  func (d *ctxOnlyDriver) Open(dsn string) (driver.Conn, error) {
  4231  	conn, err := d.fakeDriver.Open(dsn)
  4232  	if err != nil {
  4233  		return nil, err
  4234  	}
  4235  	return &ctxOnlyConn{fc: conn.(*fakeConn)}, nil
  4236  }
  4237  
  4238  var (
  4239  	_ driver.Conn           = &ctxOnlyConn{}
  4240  	_ driver.QueryerContext = &ctxOnlyConn{}
  4241  	_ driver.ExecerContext  = &ctxOnlyConn{}
  4242  )
  4243  
  4244  type ctxOnlyConn struct {
  4245  	fc *fakeConn
  4246  
  4247  	queryCtxCalled bool
  4248  	execCtxCalled  bool
  4249  }
  4250  
  4251  func (c *ctxOnlyConn) Begin() (driver.Tx, error) {
  4252  	return c.fc.Begin()
  4253  }
  4254  
  4255  func (c *ctxOnlyConn) Close() error {
  4256  	return c.fc.Close()
  4257  }
  4258  
  4259  // Prepare is still part of the Conn interface, so while it isn't used
  4260  // must be defined for compatibility.
  4261  func (c *ctxOnlyConn) Prepare(q string) (driver.Stmt, error) {
  4262  	panic("not used")
  4263  }
  4264  
  4265  func (c *ctxOnlyConn) PrepareContext(ctx context.Context, q string) (driver.Stmt, error) {
  4266  	return c.fc.PrepareContext(ctx, q)
  4267  }
  4268  
  4269  func (c *ctxOnlyConn) QueryContext(ctx context.Context, q string, args []driver.NamedValue) (driver.Rows, error) {
  4270  	c.queryCtxCalled = true
  4271  	return c.fc.QueryContext(ctx, q, args)
  4272  }
  4273  
  4274  func (c *ctxOnlyConn) ExecContext(ctx context.Context, q string, args []driver.NamedValue) (driver.Result, error) {
  4275  	c.execCtxCalled = true
  4276  	return c.fc.ExecContext(ctx, q, args)
  4277  }
  4278  
  4279  // TestQueryExecContextOnly ensures drivers only need to implement QueryContext
  4280  // and ExecContext methods.
  4281  func TestQueryExecContextOnly(t *testing.T) {
  4282  	// Ensure connection does not implement non-context interfaces.
  4283  	var connType driver.Conn = &ctxOnlyConn{}
  4284  	if _, ok := connType.(driver.Execer); ok {
  4285  		t.Fatalf("%T must not implement driver.Execer", connType)
  4286  	}
  4287  	if _, ok := connType.(driver.Queryer); ok {
  4288  		t.Fatalf("%T must not implement driver.Queryer", connType)
  4289  	}
  4290  
  4291  	Register("ContextOnly", &ctxOnlyDriver{})
  4292  	db, err := Open("ContextOnly", "")
  4293  	if err != nil {
  4294  		t.Fatal(err)
  4295  	}
  4296  	defer db.Close()
  4297  
  4298  	ctx := t.Context()
  4299  
  4300  	conn, err := db.Conn(ctx)
  4301  	if err != nil {
  4302  		t.Fatal("db.Conn", err)
  4303  	}
  4304  	defer conn.Close()
  4305  	coc := conn.dc.ci.(*ctxOnlyConn)
  4306  	coc.fc.skipDirtySession = true
  4307  
  4308  	_, err = conn.ExecContext(ctx, "WIPE")
  4309  	if err != nil {
  4310  		t.Fatal("exec wipe", err)
  4311  	}
  4312  
  4313  	_, err = conn.ExecContext(ctx, "CREATE|keys|v1=string")
  4314  	if err != nil {
  4315  		t.Fatal("exec create", err)
  4316  	}
  4317  	expectedValue := "value1"
  4318  	_, err = conn.ExecContext(ctx, "INSERT|keys|v1=?", expectedValue)
  4319  	if err != nil {
  4320  		t.Fatal("exec insert", err)
  4321  	}
  4322  	rows, err := conn.QueryContext(ctx, "SELECT|keys|v1|")
  4323  	if err != nil {
  4324  		t.Fatal("query select", err)
  4325  	}
  4326  	v1 := ""
  4327  	for rows.Next() {
  4328  		err = rows.Scan(&v1)
  4329  		if err != nil {
  4330  			t.Fatal("rows scan", err)
  4331  		}
  4332  	}
  4333  	rows.Close()
  4334  
  4335  	if v1 != expectedValue {
  4336  		t.Fatalf("expected %q, got %q", expectedValue, v1)
  4337  	}
  4338  
  4339  	if !coc.execCtxCalled {
  4340  		t.Error("ExecContext not called")
  4341  	}
  4342  	if !coc.queryCtxCalled {
  4343  		t.Error("QueryContext not called")
  4344  	}
  4345  }
  4346  
  4347  type alwaysErrScanner struct{}
  4348  
  4349  var errTestScanWrap = errors.New("errTestScanWrap")
  4350  
  4351  func (alwaysErrScanner) Scan(any) error {
  4352  	return errTestScanWrap
  4353  }
  4354  
  4355  // Issue 38099: Ensure that Rows.Scan properly wraps underlying errors.
  4356  func TestRowsScanProperlyWrapsErrors(t *testing.T) {
  4357  	db := newTestDB(t, "people")
  4358  	defer closeDB(t, db)
  4359  
  4360  	rows, err := db.Query("SELECT|people|age|")
  4361  	if err != nil {
  4362  		t.Fatalf("Query: %v", err)
  4363  	}
  4364  
  4365  	var res alwaysErrScanner
  4366  
  4367  	for rows.Next() {
  4368  		err = rows.Scan(&res)
  4369  		if err == nil {
  4370  			t.Fatal("expecting back an error")
  4371  		}
  4372  		if !errors.Is(err, errTestScanWrap) {
  4373  			t.Fatalf("errors.Is mismatch\n%v\nWant: %v", err, errTestScanWrap)
  4374  		}
  4375  		// Ensure that error substring matching still correctly works.
  4376  		if !strings.Contains(err.Error(), errTestScanWrap.Error()) {
  4377  			t.Fatalf("Error %v does not contain %v", err, errTestScanWrap)
  4378  		}
  4379  	}
  4380  }
  4381  
  4382  type alwaysErrValuer struct{}
  4383  
  4384  // errEmpty is returned when an empty value is found
  4385  var errEmpty = errors.New("empty value")
  4386  
  4387  func (v alwaysErrValuer) Value() (driver.Value, error) {
  4388  	return nil, errEmpty
  4389  }
  4390  
  4391  // Issue 64707: Ensure that Stmt.Exec and Stmt.Query properly wraps underlying errors.
  4392  func TestDriverArgsWrapsErrors(t *testing.T) {
  4393  	db := newTestDB(t, "people")
  4394  	defer closeDB(t, db)
  4395  
  4396  	t.Run("exec", func(t *testing.T) {
  4397  		_, err := db.Exec("INSERT|keys|dec1=?", alwaysErrValuer{})
  4398  		if err == nil {
  4399  			t.Fatal("expecting back an error")
  4400  		}
  4401  		if !errors.Is(err, errEmpty) {
  4402  			t.Fatalf("errors.Is mismatch\n%v\nWant: %v", err, errEmpty)
  4403  		}
  4404  		// Ensure that error substring matching still correctly works.
  4405  		if !strings.Contains(err.Error(), errEmpty.Error()) {
  4406  			t.Fatalf("Error %v does not contain %v", err, errEmpty)
  4407  		}
  4408  	})
  4409  
  4410  	t.Run("query", func(t *testing.T) {
  4411  		_, err := db.Query("INSERT|keys|dec1=?", alwaysErrValuer{})
  4412  		if err == nil {
  4413  			t.Fatal("expecting back an error")
  4414  		}
  4415  		if !errors.Is(err, errEmpty) {
  4416  			t.Fatalf("errors.Is mismatch\n%v\nWant: %v", err, errEmpty)
  4417  		}
  4418  		// Ensure that error substring matching still correctly works.
  4419  		if !strings.Contains(err.Error(), errEmpty.Error()) {
  4420  			t.Fatalf("Error %v does not contain %v", err, errEmpty)
  4421  		}
  4422  	})
  4423  }
  4424  
  4425  func TestContextCancelDuringRawBytesScan(t *testing.T) {
  4426  	for _, mode := range []string{"nocancel", "top", "bottom", "go"} {
  4427  		t.Run(mode, func(t *testing.T) {
  4428  			testContextCancelDuringRawBytesScan(t, mode)
  4429  		})
  4430  	}
  4431  }
  4432  
  4433  // From go.dev/issue/60304
  4434  func testContextCancelDuringRawBytesScan(t *testing.T, mode string) {
  4435  	db := newTestDB(t, "people")
  4436  	defer closeDB(t, db)
  4437  
  4438  	// cancel used to call close asynchronously.
  4439  	// This test checks that it waits so as not to interfere with RawBytes.
  4440  	ctx, cancel := context.WithCancel(context.Background())
  4441  	defer cancel()
  4442  
  4443  	r, err := db.QueryContext(ctx, "SELECT|people|name|")
  4444  	if err != nil {
  4445  		t.Fatal(err)
  4446  	}
  4447  	numRows := 0
  4448  	var sink byte
  4449  	for r.Next() {
  4450  		if mode == "top" && numRows == 2 {
  4451  			// cancel between Next and Scan is observed by Scan as err = context.Canceled.
  4452  			// The sleep here is only to make it more likely that the cancel will be observed.
  4453  			// If not, the test should still pass, like in "go" mode.
  4454  			cancel()
  4455  			time.Sleep(100 * time.Millisecond)
  4456  		}
  4457  		numRows++
  4458  		var s RawBytes
  4459  		err = r.Scan(&s)
  4460  		if numRows == 3 && err == context.Canceled {
  4461  			if r.closemuScanHold {
  4462  				t.Errorf("expected closemu NOT to be held")
  4463  			}
  4464  			break
  4465  		}
  4466  		if !r.closemuScanHold {
  4467  			t.Errorf("expected closemu to be held")
  4468  		}
  4469  		if err != nil {
  4470  			t.Fatal(err)
  4471  		}
  4472  		t.Logf("read %q", s)
  4473  		if mode == "bottom" && numRows == 2 {
  4474  			// cancel before Next should be observed by Next, exiting the loop.
  4475  			// The sleep here is only to make it more likely that the cancel will be observed.
  4476  			// If not, the test should still pass, like in "go" mode.
  4477  			cancel()
  4478  			time.Sleep(100 * time.Millisecond)
  4479  		}
  4480  		if mode == "go" && numRows == 2 {
  4481  			// cancel at any future time, to catch other cases
  4482  			go cancel()
  4483  		}
  4484  		for _, b := range s { // some operation reading from the raw memory
  4485  			sink += b
  4486  		}
  4487  	}
  4488  	if r.closemuScanHold {
  4489  		t.Errorf("closemu held; should not be")
  4490  	}
  4491  
  4492  	// There are 3 rows. We canceled after reading 2 so we expect either
  4493  	// 2 or 3 depending on how the awaitDone goroutine schedules.
  4494  	switch numRows {
  4495  	case 0, 1:
  4496  		t.Errorf("got %d rows; want 2+", numRows)
  4497  	case 2:
  4498  		if err := r.Err(); err != context.Canceled {
  4499  			t.Errorf("unexpected error: %v (%T)", err, err)
  4500  		}
  4501  	default:
  4502  		// Made it to the end. This is rare, but fine. Permit it.
  4503  	}
  4504  
  4505  	if err := r.Close(); err != nil {
  4506  		t.Fatal(err)
  4507  	}
  4508  }
  4509  
  4510  func TestContextCancelBetweenNextAndErr(t *testing.T) {
  4511  	db := newTestDB(t, "people")
  4512  	defer closeDB(t, db)
  4513  	ctx, cancel := context.WithCancel(context.Background())
  4514  	defer cancel()
  4515  
  4516  	r, err := db.QueryContext(ctx, "SELECT|people|name|")
  4517  	if err != nil {
  4518  		t.Fatal(err)
  4519  	}
  4520  	for r.Next() {
  4521  	}
  4522  	cancel()                          // wake up the awaitDone goroutine
  4523  	time.Sleep(10 * time.Millisecond) // increase odds of seeing failure
  4524  	if err := r.Err(); err != nil {
  4525  		t.Fatal(err)
  4526  	}
  4527  }
  4528  
  4529  type testScanner struct {
  4530  	scanf func(src any) error
  4531  }
  4532  
  4533  func (ts testScanner) Scan(src any) error { return ts.scanf(src) }
  4534  
  4535  func TestContextCancelDuringScan(t *testing.T) {
  4536  	db := newTestDB(t, "people")
  4537  	defer closeDB(t, db)
  4538  
  4539  	ctx, cancel := context.WithCancel(context.Background())
  4540  	defer cancel()
  4541  
  4542  	scanStart := make(chan any)
  4543  	scanEnd := make(chan error)
  4544  	scanner := &testScanner{
  4545  		scanf: func(src any) error {
  4546  			scanStart <- src
  4547  			return <-scanEnd
  4548  		},
  4549  	}
  4550  
  4551  	// Start a query, and pause it mid-scan.
  4552  	want := []byte("Alice")
  4553  	r, err := db.QueryContext(ctx, "SELECT|people|name|name=?", string(want))
  4554  	if err != nil {
  4555  		t.Fatal(err)
  4556  	}
  4557  	if !r.Next() {
  4558  		t.Fatalf("r.Next() = false, want true")
  4559  	}
  4560  	go func() {
  4561  		r.Scan(scanner)
  4562  	}()
  4563  	got := <-scanStart
  4564  	defer close(scanEnd)
  4565  	gotBytes, ok := got.([]byte)
  4566  	if !ok {
  4567  		t.Fatalf("r.Scan returned %T, want []byte", got)
  4568  	}
  4569  	if !bytes.Equal(gotBytes, want) {
  4570  		t.Fatalf("before cancel: r.Scan returned %q, want %q", gotBytes, want)
  4571  	}
  4572  
  4573  	// Cancel the query.
  4574  	// Sleep to give it a chance to finish canceling.
  4575  	cancel()
  4576  	time.Sleep(10 * time.Millisecond)
  4577  
  4578  	// Cancelling the query should not have changed the result.
  4579  	if !bytes.Equal(gotBytes, want) {
  4580  		t.Fatalf("after cancel: r.Scan result is now %q, want %q", gotBytes, want)
  4581  	}
  4582  }
  4583  
  4584  func TestNilErrorAfterClose(t *testing.T) {
  4585  	db := newTestDB(t, "people")
  4586  	defer closeDB(t, db)
  4587  
  4588  	// This WithCancel is important; Rows contains an optimization to avoid
  4589  	// spawning a goroutine when the query/transaction context cannot be
  4590  	// canceled, but this test tests a bug which is caused by said goroutine.
  4591  	ctx, cancel := context.WithCancel(context.Background())
  4592  	defer cancel()
  4593  
  4594  	r, err := db.QueryContext(ctx, "SELECT|people|name|")
  4595  	if err != nil {
  4596  		t.Fatal(err)
  4597  	}
  4598  
  4599  	if err := r.Close(); err != nil {
  4600  		t.Fatal(err)
  4601  	}
  4602  
  4603  	time.Sleep(10 * time.Millisecond) // increase odds of seeing failure
  4604  	if err := r.Err(); err != nil {
  4605  		t.Fatal(err)
  4606  	}
  4607  }
  4608  
  4609  // Issue #65201.
  4610  //
  4611  // If a RawBytes is reused across multiple queries,
  4612  // subsequent queries shouldn't overwrite driver-owned memory from previous queries.
  4613  func TestRawBytesReuse(t *testing.T) {
  4614  	db := newTestDB(t, "people")
  4615  	defer closeDB(t, db)
  4616  
  4617  	var raw RawBytes
  4618  
  4619  	// The RawBytes in this query aliases driver-owned memory.
  4620  	rows, err := db.Query("SELECT|people|name|")
  4621  	if err != nil {
  4622  		t.Fatal(err)
  4623  	}
  4624  	rows.Next()
  4625  	rows.Scan(&raw) // now raw is pointing to driver-owned memory
  4626  	name1 := string(raw)
  4627  	rows.Close()
  4628  
  4629  	// The RawBytes in this query does not alias driver-owned memory.
  4630  	rows, err = db.Query("SELECT|people|age|")
  4631  	if err != nil {
  4632  		t.Fatal(err)
  4633  	}
  4634  	rows.Next()
  4635  	rows.Scan(&raw) // this must not write to the driver-owned memory in raw
  4636  	rows.Close()
  4637  
  4638  	// Repeat the first query. Nothing should have changed.
  4639  	rows, err = db.Query("SELECT|people|name|")
  4640  	if err != nil {
  4641  		t.Fatal(err)
  4642  	}
  4643  	rows.Next()
  4644  	rows.Scan(&raw) // raw points to driver-owned memory again
  4645  	name2 := string(raw)
  4646  	rows.Close()
  4647  	if name1 != name2 {
  4648  		t.Fatalf("Scan read name %q, want %q", name2, name1)
  4649  	}
  4650  }
  4651  
  4652  // badConn implements a bad driver.Conn, for TestBadDriver.
  4653  // The Exec method panics.
  4654  type badConn struct{}
  4655  
  4656  func (bc badConn) Prepare(query string) (driver.Stmt, error) {
  4657  	return nil, errors.New("badConn Prepare")
  4658  }
  4659  
  4660  func (bc badConn) Close() error {
  4661  	return nil
  4662  }
  4663  
  4664  func (bc badConn) Begin() (driver.Tx, error) {
  4665  	return nil, errors.New("badConn Begin")
  4666  }
  4667  
  4668  func (bc badConn) Exec(query string, args []driver.Value) (driver.Result, error) {
  4669  	panic("badConn.Exec")
  4670  }
  4671  
  4672  // badDriver is a driver.Driver that uses badConn.
  4673  type badDriver struct{}
  4674  
  4675  func (bd badDriver) Open(name string) (driver.Conn, error) {
  4676  	return badConn{}, nil
  4677  }
  4678  
  4679  // Issue 15901.
  4680  func TestBadDriver(t *testing.T) {
  4681  	Register("bad", badDriver{})
  4682  	db, err := Open("bad", "ignored")
  4683  	if err != nil {
  4684  		t.Fatal(err)
  4685  	}
  4686  	defer func() {
  4687  		if r := recover(); r == nil {
  4688  			t.Error("expected panic")
  4689  		} else {
  4690  			if want := "badConn.Exec"; r.(string) != want {
  4691  				t.Errorf("panic was %v, expected %v", r, want)
  4692  			}
  4693  		}
  4694  	}()
  4695  	defer db.Close()
  4696  	db.Exec("ignored")
  4697  }
  4698  
  4699  type pingDriver struct {
  4700  	fails bool
  4701  }
  4702  
  4703  type pingConn struct {
  4704  	badConn
  4705  	driver *pingDriver
  4706  }
  4707  
  4708  var pingError = errors.New("Ping failed")
  4709  
  4710  func (pc pingConn) Ping(ctx context.Context) error {
  4711  	if pc.driver.fails {
  4712  		return pingError
  4713  	}
  4714  	return nil
  4715  }
  4716  
  4717  var _ driver.Pinger = pingConn{}
  4718  
  4719  func (pd *pingDriver) Open(name string) (driver.Conn, error) {
  4720  	return pingConn{driver: pd}, nil
  4721  }
  4722  
  4723  func TestPing(t *testing.T) {
  4724  	driver := &pingDriver{}
  4725  	Register("ping", driver)
  4726  
  4727  	db, err := Open("ping", "ignored")
  4728  	if err != nil {
  4729  		t.Fatal(err)
  4730  	}
  4731  
  4732  	if err := db.Ping(); err != nil {
  4733  		t.Errorf("err was %#v, expected nil", err)
  4734  		return
  4735  	}
  4736  
  4737  	driver.fails = true
  4738  	if err := db.Ping(); err != pingError {
  4739  		t.Errorf("err was %#v, expected pingError", err)
  4740  	}
  4741  }
  4742  
  4743  // Issue 18101.
  4744  func TestTypedString(t *testing.T) {
  4745  	db := newTestDB(t, "people")
  4746  	defer closeDB(t, db)
  4747  
  4748  	type Str string
  4749  	var scanned Str
  4750  
  4751  	err := db.QueryRow("SELECT|people|name|name=?", "Alice").Scan(&scanned)
  4752  	if err != nil {
  4753  		t.Fatal(err)
  4754  	}
  4755  	expected := Str("Alice")
  4756  	if scanned != expected {
  4757  		t.Errorf("expected %+v, got %+v", expected, scanned)
  4758  	}
  4759  }
  4760  
  4761  func BenchmarkConcurrentDBExec(b *testing.B) {
  4762  	b.ReportAllocs()
  4763  	ct := new(concurrentDBExecTest)
  4764  	for i := 0; i < b.N; i++ {
  4765  		doConcurrentTest(b, ct)
  4766  	}
  4767  }
  4768  
  4769  func BenchmarkConcurrentStmtQuery(b *testing.B) {
  4770  	b.ReportAllocs()
  4771  	ct := new(concurrentStmtQueryTest)
  4772  	for i := 0; i < b.N; i++ {
  4773  		doConcurrentTest(b, ct)
  4774  	}
  4775  }
  4776  
  4777  func BenchmarkConcurrentStmtExec(b *testing.B) {
  4778  	b.ReportAllocs()
  4779  	ct := new(concurrentStmtExecTest)
  4780  	for i := 0; i < b.N; i++ {
  4781  		doConcurrentTest(b, ct)
  4782  	}
  4783  }
  4784  
  4785  func BenchmarkConcurrentTxQuery(b *testing.B) {
  4786  	b.ReportAllocs()
  4787  	ct := new(concurrentTxQueryTest)
  4788  	for i := 0; i < b.N; i++ {
  4789  		doConcurrentTest(b, ct)
  4790  	}
  4791  }
  4792  
  4793  func BenchmarkConcurrentTxExec(b *testing.B) {
  4794  	b.ReportAllocs()
  4795  	ct := new(concurrentTxExecTest)
  4796  	for i := 0; i < b.N; i++ {
  4797  		doConcurrentTest(b, ct)
  4798  	}
  4799  }
  4800  
  4801  func BenchmarkConcurrentTxStmtQuery(b *testing.B) {
  4802  	b.ReportAllocs()
  4803  	ct := new(concurrentTxStmtQueryTest)
  4804  	for i := 0; i < b.N; i++ {
  4805  		doConcurrentTest(b, ct)
  4806  	}
  4807  }
  4808  
  4809  func BenchmarkConcurrentTxStmtExec(b *testing.B) {
  4810  	b.ReportAllocs()
  4811  	ct := new(concurrentTxStmtExecTest)
  4812  	for i := 0; i < b.N; i++ {
  4813  		doConcurrentTest(b, ct)
  4814  	}
  4815  }
  4816  
  4817  func BenchmarkConcurrentRandom(b *testing.B) {
  4818  	b.ReportAllocs()
  4819  	ct := new(concurrentRandomTest)
  4820  	for i := 0; i < b.N; i++ {
  4821  		doConcurrentTest(b, ct)
  4822  	}
  4823  }
  4824  
  4825  func BenchmarkManyConcurrentQueries(b *testing.B) {
  4826  	b.ReportAllocs()
  4827  	// To see lock contention in Go 1.4, 16~ cores and 128~ goroutines are required.
  4828  	const parallelism = 16
  4829  
  4830  	db := newTestDB(b, "magicquery")
  4831  	defer closeDB(b, db)
  4832  	db.SetMaxIdleConns(runtime.GOMAXPROCS(0) * parallelism)
  4833  
  4834  	stmt, err := db.Prepare("SELECT|magicquery|op|op=?,millis=?")
  4835  	if err != nil {
  4836  		b.Fatal(err)
  4837  	}
  4838  	defer stmt.Close()
  4839  
  4840  	b.SetParallelism(parallelism)
  4841  	b.RunParallel(func(pb *testing.PB) {
  4842  		for pb.Next() {
  4843  			rows, err := stmt.Query("sleep", 1)
  4844  			if err != nil {
  4845  				b.Error(err)
  4846  				return
  4847  			}
  4848  			rows.Close()
  4849  		}
  4850  	})
  4851  }
  4852  
  4853  func TestGrabConnAllocs(t *testing.T) {
  4854  	testenv.SkipIfOptimizationOff(t)
  4855  	if race.Enabled {
  4856  		t.Skip("skipping allocation test when using race detector")
  4857  	}
  4858  	c := new(Conn)
  4859  	ctx := context.Background()
  4860  	n := int(testing.AllocsPerRun(1000, func() {
  4861  		_, release, err := c.grabConn(ctx)
  4862  		if err != nil {
  4863  			t.Fatal(err)
  4864  		}
  4865  		release(nil)
  4866  	}))
  4867  	if n > 0 {
  4868  		t.Fatalf("Conn.grabConn allocated %v objects; want 0", n)
  4869  	}
  4870  }
  4871  
  4872  func BenchmarkGrabConn(b *testing.B) {
  4873  	b.ReportAllocs()
  4874  	c := new(Conn)
  4875  	ctx := context.Background()
  4876  	for i := 0; i < b.N; i++ {
  4877  		_, release, err := c.grabConn(ctx)
  4878  		if err != nil {
  4879  			b.Fatal(err)
  4880  		}
  4881  		release(nil)
  4882  	}
  4883  }
  4884  
  4885  func TestConnRequestSet(t *testing.T) {
  4886  	var s connRequestSet
  4887  	wantLen := func(want int) {
  4888  		t.Helper()
  4889  		if got := s.Len(); got != want {
  4890  			t.Errorf("Len = %d; want %d", got, want)
  4891  		}
  4892  		if want == 0 && !t.Failed() {
  4893  			if _, ok := s.TakeRandom(); ok {
  4894  				t.Fatalf("TakeRandom returned result when empty")
  4895  			}
  4896  		}
  4897  	}
  4898  	reset := func() { s = connRequestSet{} }
  4899  
  4900  	t.Run("add-delete", func(t *testing.T) {
  4901  		reset()
  4902  		wantLen(0)
  4903  		dh := s.Add(nil)
  4904  		wantLen(1)
  4905  		if !s.Delete(dh) {
  4906  			t.Fatal("failed to delete")
  4907  		}
  4908  		wantLen(0)
  4909  		if s.Delete(dh) {
  4910  			t.Error("delete worked twice")
  4911  		}
  4912  		wantLen(0)
  4913  	})
  4914  	t.Run("take-before-delete", func(t *testing.T) {
  4915  		reset()
  4916  		ch1 := make(chan connRequest)
  4917  		dh := s.Add(ch1)
  4918  		wantLen(1)
  4919  		if got, ok := s.TakeRandom(); !ok || got != ch1 {
  4920  			t.Fatalf("wrong take; ok=%v", ok)
  4921  		}
  4922  		wantLen(0)
  4923  		if s.Delete(dh) {
  4924  			t.Error("unexpected delete after take")
  4925  		}
  4926  	})
  4927  	t.Run("get-take-many", func(t *testing.T) {
  4928  		reset()
  4929  		m := map[chan connRequest]bool{}
  4930  		const N = 100
  4931  		var inOrder, backOut []chan connRequest
  4932  		for range N {
  4933  			c := make(chan connRequest)
  4934  			m[c] = true
  4935  			s.Add(c)
  4936  			inOrder = append(inOrder, c)
  4937  		}
  4938  		if s.Len() != N {
  4939  			t.Fatalf("Len = %v; want %v", s.Len(), N)
  4940  		}
  4941  		for s.Len() > 0 {
  4942  			c, ok := s.TakeRandom()
  4943  			if !ok {
  4944  				t.Fatal("failed to take when non-empty")
  4945  			}
  4946  			if !m[c] {
  4947  				t.Fatal("returned item not in remaining set")
  4948  			}
  4949  			delete(m, c)
  4950  			backOut = append(backOut, c)
  4951  		}
  4952  		if len(m) > 0 {
  4953  			t.Error("items remain in expected map")
  4954  		}
  4955  		if slices.Equal(inOrder, backOut) { // N! chance of flaking; N=100 is fine
  4956  			t.Error("wasn't random")
  4957  		}
  4958  	})
  4959  	t.Run("close-delete", func(t *testing.T) {
  4960  		reset()
  4961  		ch := make(chan connRequest)
  4962  		dh := s.Add(ch)
  4963  		wantLen(1)
  4964  		s.CloseAndRemoveAll()
  4965  		wantLen(0)
  4966  		if s.Delete(dh) {
  4967  			t.Error("unexpected delete after CloseAndRemoveAll")
  4968  		}
  4969  	})
  4970  }
  4971  
  4972  func BenchmarkConnRequestSet(b *testing.B) {
  4973  	var s connRequestSet
  4974  	for range b.N {
  4975  		for range 16 {
  4976  			s.Add(nil)
  4977  		}
  4978  		for range 8 {
  4979  			if _, ok := s.TakeRandom(); !ok {
  4980  				b.Fatal("want ok")
  4981  			}
  4982  		}
  4983  		for range 8 {
  4984  			s.Add(nil)
  4985  		}
  4986  		for range 16 {
  4987  			if _, ok := s.TakeRandom(); !ok {
  4988  				b.Fatal("want ok")
  4989  			}
  4990  		}
  4991  		if _, ok := s.TakeRandom(); ok {
  4992  			b.Fatal("unexpected ok")
  4993  		}
  4994  	}
  4995  }
  4996  
  4997  func TestIssue69837(t *testing.T) {
  4998  	u := Null[uint]{V: 1, Valid: true}
  4999  	val, err := driver.DefaultParameterConverter.ConvertValue(u)
  5000  	if err != nil {
  5001  		t.Errorf("ConvertValue() error = %v, want nil", err)
  5002  	}
  5003  
  5004  	if v, ok := val.(int64); !ok {
  5005  		t.Errorf("val.(type): got %T, expected int64", val)
  5006  	} else if v != 1 {
  5007  		t.Errorf("val: got %d, expected 1", v)
  5008  	}
  5009  }
  5010  
  5011  type issue69728Type struct {
  5012  	ID   int
  5013  	Name string
  5014  }
  5015  
  5016  func (t issue69728Type) Value() (driver.Value, error) {
  5017  	return []byte(fmt.Sprintf("%d, %s", t.ID, t.Name)), nil
  5018  }
  5019  
  5020  func TestIssue69728(t *testing.T) {
  5021  	forValue := Null[issue69728Type]{
  5022  		Valid: true,
  5023  		V: issue69728Type{
  5024  			ID:   42,
  5025  			Name: "foobar",
  5026  		},
  5027  	}
  5028  
  5029  	v1, err := forValue.Value()
  5030  	if err != nil {
  5031  		t.Errorf("forValue.Value() error = %v, want nil", err)
  5032  	}
  5033  
  5034  	v2, err := forValue.V.Value()
  5035  	if err != nil {
  5036  		t.Errorf("forValue.V.Value() error = %v, want nil", err)
  5037  	}
  5038  
  5039  	if !reflect.DeepEqual(v1, v2) {
  5040  		t.Errorf("not equal; v1 = %v, v2 = %v", v1, v2)
  5041  	}
  5042  }
  5043  

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