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

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