libgo: update to Go 1.8 release candidate 1

    
    Compiler changes:
      * Change map assignment to use mapassign and assign value directly.
      * Change string iteration to use decoderune, faster for ASCII strings.
      * Change makeslice to take int, and use makeslice64 for larger values.
      * Add new noverflow field to hmap struct used for maps.
    
    Unresolved problems, to be fixed later:
      * Commented out test in go/types/sizes_test.go that doesn't compile.
      * Commented out reflect.TestStructOf test for padding after zero-sized field.
    
    Reviewed-on: https://go-review.googlesource.com/35231

gotools/:
	Updates for Go 1.8rc1.
	* Makefile.am (go_cmd_go_files): Add bug.go.
	(s-zdefaultcc): Write defaultPkgConfig.
	* Makefile.in: Rebuild.

From-SVN: r244456

9 files changed, 2069 insertions, 367 deletions

diff --git a/libgo/go/database/sql/convert.go b/libgo/go/database/sql/convert.go
index 99aed23..ea2f377 100644
--- a/libgo/go/database/sql/convert.go
+++ b/libgo/go/database/sql/convert.go
@@ -13,16 +13,36 @@ import (
 	"reflect"
 	"strconv"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var errNilPtr = errors.New("destination pointer is nil") // embedded in descriptive error
 
+func describeNamedValue(nv *driver.NamedValue) string {
+	if len(nv.Name) == 0 {
+		return fmt.Sprintf("$%d", nv.Ordinal)
+	}
+	return fmt.Sprintf("with name %q", nv.Name)
+}
+
+func validateNamedValueName(name string) error {
+	if len(name) == 0 {
+		return nil
+	}
+	r, _ := utf8.DecodeRuneInString(name)
+	if unicode.IsLetter(r) {
+		return nil
+	}
+	return fmt.Errorf("name %q does not begin with a letter", name)
+}
+
 // driverArgs converts arguments from callers of Stmt.Exec and
 // Stmt.Query into driver Values.
 //
 // The statement ds may be nil, if no statement is available.
-func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
-	dargs := make([]driver.Value, len(args))
+func driverArgs(ds *driverStmt, args []interface{}) ([]driver.NamedValue, error) {
+	nvargs := make([]driver.NamedValue, len(args))
 	var si driver.Stmt
 	if ds != nil {
 		si = ds.si
@@ -33,26 +53,45 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
 	if !ok {
 		for n, arg := range args {
 			var err error
-			dargs[n], err = driver.DefaultParameterConverter.ConvertValue(arg)
+			nv := &nvargs[n]
+			nv.Ordinal = n + 1
+			if np, ok := arg.(NamedArg); ok {
+				if err := validateNamedValueName(np.Name); err != nil {
+					return nil, err
+				}
+				arg = np.Value
+				nvargs[n].Name = np.Name
+			}
+			nv.Value, err = driver.DefaultParameterConverter.ConvertValue(arg)
+
 			if err != nil {
-				return nil, fmt.Errorf("sql: converting Exec argument #%d's type: %v", n, err)
+				return nil, fmt.Errorf("sql: converting Exec argument %s type: %v", describeNamedValue(nv), err)
 			}
 		}
-		return dargs, nil
+		return nvargs, nil
 	}
 
 	// Let the Stmt convert its own arguments.
 	for n, arg := range args {
+		nv := &nvargs[n]
+		nv.Ordinal = n + 1
+		if np, ok := arg.(NamedArg); ok {
+			if err := validateNamedValueName(np.Name); err != nil {
+				return nil, err
+			}
+			arg = np.Value
+			nv.Name = np.Name
+		}
 		// First, see if the value itself knows how to convert
 		// itself to a driver type. For example, a NullString
 		// struct changing into a string or nil.
-		if svi, ok := arg.(driver.Valuer); ok {
-			sv, err := svi.Value()
+		if vr, ok := arg.(driver.Valuer); ok {
+			sv, err := callValuerValue(vr)
 			if err != nil {
-				return nil, fmt.Errorf("sql: argument index %d from Value: %v", n, err)
+				return nil, fmt.Errorf("sql: argument %s from Value: %v", describeNamedValue(nv), err)
 			}
 			if !driver.IsValue(sv) {
-				return nil, fmt.Errorf("sql: argument index %d: non-subset type %T returned from Value", n, sv)
+				return nil, fmt.Errorf("sql: argument %s: non-subset type %T returned from Value", describeNamedValue(nv), sv)
 			}
 			arg = sv
 		}
@@ -66,18 +105,18 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.Value, error) {
 		// same error.
 		var err error
 		ds.Lock()
-		dargs[n], err = cc.ColumnConverter(n).ConvertValue(arg)
+		nv.Value, err = cc.ColumnConverter(n).ConvertValue(arg)
 		ds.Unlock()
 		if err != nil {
-			return nil, fmt.Errorf("sql: converting argument #%d's type: %v", n, err)
+			return nil, fmt.Errorf("sql: converting argument %s type: %v", describeNamedValue(nv), err)
 		}
-		if !driver.IsValue(dargs[n]) {
-			return nil, fmt.Errorf("sql: driver ColumnConverter error converted %T to unsupported type %T",
-				arg, dargs[n])
+		if !driver.IsValue(nv.Value) {
+			return nil, fmt.Errorf("sql: for argument %s, driver ColumnConverter error converted %T to unsupported type %T",
+				describeNamedValue(nv), arg, nv.Value)
 		}
 	}
 
-	return dargs, nil
+	return nvargs, nil
 }
 
 // convertAssign copies to dest the value in src, converting it if possible.
@@ -330,3 +369,25 @@ func asBytes(buf []byte, rv reflect.Value) (b []byte, ok bool) {
 	}
 	return
 }
+
+var valuerReflectType = reflect.TypeOf((*driver.Valuer)(nil)).Elem()
+
+// callValuerValue returns vr.Value(), with one exception:
+// If vr.Value is an auto-generated method on a pointer type and the
+// pointer is nil, it would panic at runtime in the panicwrap
+// method. Treat it like nil instead.
+// Issue 8415.
+//
+// This is so people can implement driver.Value on value types and
+// still use nil pointers to those types to mean nil/NULL, just like
+// string/*string.
+//
+// This function is mirrored in the database/sql/driver package.
+func callValuerValue(vr driver.Valuer) (v driver.Value, err error) {
+	if rv := reflect.ValueOf(vr); rv.Kind() == reflect.Ptr &&
+		rv.IsNil() &&
+		rv.Type().Elem().Implements(valuerReflectType) {
+		return nil, nil
+	}
+	return vr.Value()
+}
diff --git a/libgo/go/database/sql/convert_test.go b/libgo/go/database/sql/convert_test.go
index ab81f2f..4dfab1f 100644
--- a/libgo/go/database/sql/convert_test.go
+++ b/libgo/go/database/sql/convert_test.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"reflect"
 	"runtime"
+	"strings"
 	"testing"
 	"time"
 )
@@ -389,3 +390,85 @@ func TestUserDefinedBytes(t *testing.T) {
 		t.Fatal("userDefinedBytes got potentially dirty driver memory")
 	}
 }
+
+type Valuer_V string
+
+func (v Valuer_V) Value() (driver.Value, error) {
+	return strings.ToUpper(string(v)), nil
+}
+
+type Valuer_P string
+
+func (p *Valuer_P) Value() (driver.Value, error) {
+	if p == nil {
+		return "nil-to-str", nil
+	}
+	return strings.ToUpper(string(*p)), nil
+}
+
+func TestDriverArgs(t *testing.T) {
+	var nilValuerVPtr *Valuer_V
+	var nilValuerPPtr *Valuer_P
+	var nilStrPtr *string
+	tests := []struct {
+		args []interface{}
+		want []driver.NamedValue
+	}{
+		0: {
+			args: []interface{}{Valuer_V("foo")},
+			want: []driver.NamedValue{
+				driver.NamedValue{
+					Ordinal: 1,
+					Value:   "FOO",
+				},
+			},
+		},
+		1: {
+			args: []interface{}{nilValuerVPtr},
+			want: []driver.NamedValue{
+				driver.NamedValue{
+					Ordinal: 1,
+					Value:   nil,
+				},
+			},
+		},
+		2: {
+			args: []interface{}{nilValuerPPtr},
+			want: []driver.NamedValue{
+				driver.NamedValue{
+					Ordinal: 1,
+					Value:   "nil-to-str",
+				},
+			},
+		},
+		3: {
+			args: []interface{}{"plain-str"},
+			want: []driver.NamedValue{
+				driver.NamedValue{
+					Ordinal: 1,
+					Value:   "plain-str",
+				},
+			},
+		},
+		4: {
+			args: []interface{}{nilStrPtr},
+			want: []driver.NamedValue{
+				driver.NamedValue{
+					Ordinal: 1,
+					Value:   nil,
+				},
+			},
+		},
+	}
+	for i, tt := range tests {
+		ds := new(driverStmt)
+		got, err := driverArgs(ds, tt.args)
+		if err != nil {
+			t.Errorf("test[%d]: %v", i, err)
+			continue
+		}
+		if !reflect.DeepEqual(got, tt.want) {
+			t.Errorf("test[%d]: got %v, want %v", i, got, tt.want)
+		}
+	}
+}
diff --git a/libgo/go/database/sql/ctxutil.go b/libgo/go/database/sql/ctxutil.go
new file mode 100644
index 0000000..1071446
--- /dev/null
+++ b/libgo/go/database/sql/ctxutil.go
@@ -0,0 +1,163 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sql
+
+import (
+	"context"
+	"database/sql/driver"
+	"errors"
+)
+
+func ctxDriverPrepare(ctx context.Context, ci driver.Conn, query string) (driver.Stmt, error) {
+	if ciCtx, is := ci.(driver.ConnPrepareContext); is {
+		return ciCtx.PrepareContext(ctx, query)
+	}
+	si, err := ci.Prepare(query)
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			si.Close()
+			return nil, ctx.Err()
+		}
+	}
+	return si, err
+}
+
+func ctxDriverExec(ctx context.Context, execer driver.Execer, query string, nvdargs []driver.NamedValue) (driver.Result, error) {
+	if execerCtx, is := execer.(driver.ExecerContext); is {
+		return execerCtx.ExecContext(ctx, query, nvdargs)
+	}
+	dargs, err := namedValueToValue(nvdargs)
+	if err != nil {
+		return nil, err
+	}
+
+	resi, err := execer.Exec(query, dargs)
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			return resi, ctx.Err()
+		}
+	}
+	return resi, err
+}
+
+func ctxDriverQuery(ctx context.Context, queryer driver.Queryer, query string, nvdargs []driver.NamedValue) (driver.Rows, error) {
+	if queryerCtx, is := queryer.(driver.QueryerContext); is {
+		ret, err := queryerCtx.QueryContext(ctx, query, nvdargs)
+		return ret, err
+	}
+	dargs, err := namedValueToValue(nvdargs)
+	if err != nil {
+		return nil, err
+	}
+
+	rowsi, err := queryer.Query(query, dargs)
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			rowsi.Close()
+			return nil, ctx.Err()
+		}
+	}
+	return rowsi, err
+}
+
+func ctxDriverStmtExec(ctx context.Context, si driver.Stmt, nvdargs []driver.NamedValue) (driver.Result, error) {
+	if siCtx, is := si.(driver.StmtExecContext); is {
+		return siCtx.ExecContext(ctx, nvdargs)
+	}
+	dargs, err := namedValueToValue(nvdargs)
+	if err != nil {
+		return nil, err
+	}
+
+	resi, err := si.Exec(dargs)
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			return resi, ctx.Err()
+		}
+	}
+	return resi, err
+}
+
+func ctxDriverStmtQuery(ctx context.Context, si driver.Stmt, nvdargs []driver.NamedValue) (driver.Rows, error) {
+	if siCtx, is := si.(driver.StmtQueryContext); is {
+		return siCtx.QueryContext(ctx, nvdargs)
+	}
+	dargs, err := namedValueToValue(nvdargs)
+	if err != nil {
+		return nil, err
+	}
+
+	rowsi, err := si.Query(dargs)
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			rowsi.Close()
+			return nil, ctx.Err()
+		}
+	}
+	return rowsi, err
+}
+
+var errLevelNotSupported = errors.New("sql: selected isolation level is not supported")
+
+func ctxDriverBegin(ctx context.Context, opts *TxOptions, ci driver.Conn) (driver.Tx, error) {
+	if ciCtx, is := ci.(driver.ConnBeginTx); is {
+		dopts := driver.TxOptions{}
+		if opts != nil {
+			dopts.Isolation = driver.IsolationLevel(opts.Isolation)
+			dopts.ReadOnly = opts.ReadOnly
+		}
+		return ciCtx.BeginTx(ctx, dopts)
+	}
+
+	if ctx.Done() == context.Background().Done() {
+		return ci.Begin()
+	}
+
+	if opts != nil {
+		// Check the transaction level. If the transaction level is non-default
+		// then return an error here as the BeginTx driver value is not supported.
+		if opts.Isolation != LevelDefault {
+			return nil, errors.New("sql: driver does not support non-default isolation level")
+		}
+
+		// If a read-only transaction is requested return an error as the
+		// BeginTx driver value is not supported.
+		if opts.ReadOnly {
+			return nil, errors.New("sql: driver does not support read-only transactions")
+		}
+	}
+
+	txi, err := ci.Begin()
+	if err == nil {
+		select {
+		default:
+		case <-ctx.Done():
+			txi.Rollback()
+			return nil, ctx.Err()
+		}
+	}
+	return txi, err
+}
+
+func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
+	dargs := make([]driver.Value, len(named))
+	for n, param := range named {
+		if len(param.Name) > 0 {
+			return nil, errors.New("sql: driver does not support the use of Named Parameters")
+		}
+		dargs[n] = param.Value
+	}
+	return dargs, nil
+}
diff --git a/libgo/go/database/sql/driver/driver.go b/libgo/go/database/sql/driver/driver.go
index 4dba85a..d66196f 100644
--- a/libgo/go/database/sql/driver/driver.go
+++ b/libgo/go/database/sql/driver/driver.go
@@ -8,7 +8,11 @@
 // Most code should use package sql.
 package driver
 
-import "errors"
+import (
+	"context"
+	"errors"
+	"reflect"
+)
 
 // Value is a value that drivers must be able to handle.
 // It is either nil or an instance of one of these types:
@@ -21,6 +25,21 @@ import "errors"
 //   time.Time
 type Value interface{}
 
+// NamedValue holds both the value name and value.
+type NamedValue struct {
+	// If the Name is not empty it should be used for the parameter identifier and
+	// not the ordinal position.
+	//
+	// Name will not have a symbol prefix.
+	Name string
+
+	// Ordinal position of the parameter starting from one and is always set.
+	Ordinal int
+
+	// Value is the parameter value.
+	Value Value
+}
+
 // Driver is the interface that must be implemented by a database
 // driver.
 type Driver interface {
@@ -54,6 +73,17 @@ var ErrSkip = errors.New("driver: skip fast-path; continue as if unimplemented")
 // you shouldn't return ErrBadConn.
 var ErrBadConn = errors.New("driver: bad connection")
 
+// Pinger is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement Pinger, the sql package's DB.Ping and
+// DB.PingContext will check if there is at least one Conn available.
+//
+// If Conn.Ping returns ErrBadConn, DB.Ping and DB.PingContext will remove
+// the Conn from pool.
+type Pinger interface {
+	Ping(ctx context.Context) error
+}
+
 // Execer is an optional interface that may be implemented by a Conn.
 //
 // If a Conn does not implement Execer, the sql package's DB.Exec will
@@ -61,10 +91,25 @@ var ErrBadConn = errors.New("driver: bad connection")
 // statement.
 //
 // Exec may return ErrSkip.
+//
+// Deprecated: Drivers should implement ExecerContext instead (or additionally).
 type Execer interface {
 	Exec(query string, args []Value) (Result, error)
 }
 
+// ExecerContext is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement ExecerContext, the sql package's DB.Exec will
+// first prepare a query, execute the statement, and then close the
+// statement.
+//
+// ExecerContext may return ErrSkip.
+//
+// ExecerContext must honor the context timeout and return when the context is canceled.
+type ExecerContext interface {
+	ExecContext(ctx context.Context, query string, args []NamedValue) (Result, error)
+}
+
 // Queryer is an optional interface that may be implemented by a Conn.
 //
 // If a Conn does not implement Queryer, the sql package's DB.Query will
@@ -72,10 +117,25 @@ type Execer interface {
 // statement.
 //
 // Query may return ErrSkip.
+//
+// Deprecated: Drivers should implement QueryerContext instead (or additionally).
 type Queryer interface {
 	Query(query string, args []Value) (Rows, error)
 }
 
+// QueryerContext is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement QueryerContext, the sql package's DB.Query will
+// first prepare a query, execute the statement, and then close the
+// statement.
+//
+// QueryerContext may return ErrSkip.
+//
+// QueryerContext must honor the context timeout and return when the context is canceled.
+type QueryerContext interface {
+	QueryContext(ctx context.Context, query string, args []NamedValue) (Rows, error)
+}
+
 // Conn is a connection to a database. It is not used concurrently
 // by multiple goroutines.
 //
@@ -95,9 +155,50 @@ type Conn interface {
 	Close() error
 
 	// Begin starts and returns a new transaction.
+	//
+	// Deprecated: Drivers should implement ConnBeginTx instead (or additionally).
 	Begin() (Tx, error)
 }
 
+// ConnPrepareContext enhances the Conn interface with context.
+type ConnPrepareContext interface {
+	// PrepareContext returns a prepared statement, bound to this connection.
+	// context is for the preparation of the statement,
+	// it must not store the context within the statement itself.
+	PrepareContext(ctx context.Context, query string) (Stmt, error)
+}
+
+// IsolationLevel is the transaction isolation level stored in TxOptions.
+//
+// This type should be considered identical to sql.IsolationLevel along
+// with any values defined on it.
+type IsolationLevel int
+
+// TxOptions holds the transaction options.
+//
+// This type should be considered identical to sql.TxOptions.
+type TxOptions struct {
+	Isolation IsolationLevel
+	ReadOnly  bool
+}
+
+// ConnBeginTx enhances the Conn interface with context and TxOptions.
+type ConnBeginTx interface {
+	// BeginTx starts and returns a new transaction.
+	// If the context is canceled by the user the sql package will
+	// call Tx.Rollback before discarding and closing the connection.
+	//
+	// This must check opts.Isolation to determine if there is a set
+	// isolation level. If the driver does not support a non-default
+	// level and one is set or if there is a non-default isolation level
+	// that is not supported, an error must be returned.
+	//
+	// This must also check opts.ReadOnly to determine if the read-only
+	// value is true to either set the read-only transaction property if supported
+	// or return an error if it is not supported.
+	BeginTx(ctx context.Context, opts TxOptions) (Tx, error)
+}
+
 // Result is the result of a query execution.
 type Result interface {
 	// LastInsertId returns the database's auto-generated ID
@@ -132,13 +233,35 @@ type Stmt interface {
 
 	// Exec executes a query that doesn't return rows, such
 	// as an INSERT or UPDATE.
+	//
+	// Deprecated: Drivers should implement StmtExecContext instead (or additionally).
 	Exec(args []Value) (Result, error)
 
 	// Query executes a query that may return rows, such as a
 	// SELECT.
+	//
+	// Deprecated: Drivers should implement StmtQueryContext instead (or additionally).
 	Query(args []Value) (Rows, error)
 }
 
+// StmtExecContext enhances the Stmt interface by providing Exec with context.
+type StmtExecContext interface {
+	// ExecContext executes a query that doesn't return rows, such
+	// as an INSERT or UPDATE.
+	//
+	// ExecContext must honor the context timeout and return when it is canceled.
+	ExecContext(ctx context.Context, args []NamedValue) (Result, error)
+}
+
+// StmtQueryContext enhances the Stmt interface by providing Query with context.
+type StmtQueryContext interface {
+	// QueryContext executes a query that may return rows, such as a
+	// SELECT.
+	//
+	// QueryContext must honor the context timeout and return when it is canceled.
+	QueryContext(ctx context.Context, args []NamedValue) (Rows, error)
+}
+
 // ColumnConverter may be optionally implemented by Stmt if the
 // statement is aware of its own columns' types and can convert from
 // any type to a driver Value.
@@ -169,6 +292,76 @@ type Rows interface {
 	Next(dest []Value) error
 }
 
+// RowsNextResultSet extends the Rows interface by providing a way to signal
+// the driver to advance to the next result set.
+type RowsNextResultSet interface {
+	Rows
+
+	// HasNextResultSet is called at the end of the current result set and
+	// reports whether there is another result set after the current one.
+	HasNextResultSet() bool
+
+	// NextResultSet advances the driver to the next result set even
+	// if there are remaining rows in the current result set.
+	//
+	// NextResultSet should return io.EOF when there are no more result sets.
+	NextResultSet() error
+}
+
+// RowsColumnTypeScanType may be implemented by Rows. It should return
+// the value type that can be used to scan types into. For example, the database
+// column type "bigint" this should return "reflect.TypeOf(int64(0))".
+type RowsColumnTypeScanType interface {
+	Rows
+	ColumnTypeScanType(index int) reflect.Type
+}
+
+// RowsColumnTypeDatabaseTypeName may be implemented by Rows. It should return the
+// database system type name without the length. Type names should be uppercase.
+// Examples of returned types: "VARCHAR", "NVARCHAR", "VARCHAR2", "CHAR", "TEXT",
+// "DECIMAL", "SMALLINT", "INT", "BIGINT", "BOOL", "[]BIGINT", "JSONB", "XML",
+// "TIMESTAMP".
+type RowsColumnTypeDatabaseTypeName interface {
+	Rows
+	ColumnTypeDatabaseTypeName(index int) string
+}
+
+// RowsColumnTypeLength may be implemented by Rows. It should return the length
+// of the column type if the column is a variable length type. If the column is
+// not a variable length type ok should return false.
+// If length is not limited other than system limits, it should return math.MaxInt64.
+// The following are examples of returned values for various types:
+//   TEXT          (math.MaxInt64, true)
+//   varchar(10)   (10, true)
+//   nvarchar(10)  (10, true)
+//   decimal       (0, false)
+//   int           (0, false)
+//   bytea(30)     (30, true)
+type RowsColumnTypeLength interface {
+	Rows
+	ColumnTypeLength(index int) (length int64, ok bool)
+}
+
+// RowsColumnTypeNullable may be implemented by Rows. The nullable value should
+// be true if it is known the column may be null, or false if the column is known
+// to be not nullable.
+// If the column nullability is unknown, ok should be false.
+type RowsColumnTypeNullable interface {
+	Rows
+	ColumnTypeNullable(index int) (nullable, ok bool)
+}
+
+// RowsColumnTypePrecisionScale may be implemented by Rows. It should return
+// the precision and scale for decimal types. If not applicable, ok should be false.
+// The following are examples of returned values for various types:
+//   decimal(38, 4)    (38, 4, true)
+//   int               (0, 0, false)
+//   decimal           (math.MaxInt64, math.MaxInt64, true)
+type RowsColumnTypePrecisionScale interface {
+	Rows
+	ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool)
+}
+
 // Tx is a transaction.
 type Tx interface {
 	Commit() error
diff --git a/libgo/go/database/sql/driver/types.go b/libgo/go/database/sql/driver/types.go
index e480e70..8b3cb6c 100644
--- a/libgo/go/database/sql/driver/types.go
+++ b/libgo/go/database/sql/driver/types.go
@@ -198,9 +198,9 @@ func IsScanValue(v interface{}) bool {
 // Value method is used to return a Value. As a fallback, the provided
 // argument's underlying type is used to convert it to a Value:
 // underlying integer types are converted to int64, floats to float64,
-// and strings to []byte. If the argument is a nil pointer,
-// ConvertValue returns a nil Value. If the argument is a non-nil
-// pointer, it is dereferenced and ConvertValue is called
+// bool, string, and []byte to themselves. If the argument is a nil
+// pointer, ConvertValue returns a nil Value. If the argument is a
+// non-nil pointer, it is dereferenced and ConvertValue is called
 // recursively. Other types are an error.
 var DefaultParameterConverter defaultConverter
 
@@ -208,13 +208,35 @@ type defaultConverter struct{}
 
 var _ ValueConverter = defaultConverter{}
 
+var valuerReflectType = reflect.TypeOf((*Valuer)(nil)).Elem()
+
+// callValuerValue returns vr.Value(), with one exception:
+// If vr.Value is an auto-generated method on a pointer type and the
+// pointer is nil, it would panic at runtime in the panicwrap
+// method. Treat it like nil instead.
+// Issue 8415.
+//
+// This is so people can implement driver.Value on value types and
+// still use nil pointers to those types to mean nil/NULL, just like
+// string/*string.
+//
+// This function is mirrored in the database/sql package.
+func callValuerValue(vr Valuer) (v Value, err error) {
+	if rv := reflect.ValueOf(vr); rv.Kind() == reflect.Ptr &&
+		rv.IsNil() &&
+		rv.Type().Elem().Implements(valuerReflectType) {
+		return nil, nil
+	}
+	return vr.Value()
+}
+
 func (defaultConverter) ConvertValue(v interface{}) (Value, error) {
 	if IsValue(v) {
 		return v, nil
 	}
 
-	if svi, ok := v.(Valuer); ok {
-		sv, err := svi.Value()
+	if vr, ok := v.(Valuer); ok {
+		sv, err := callValuerValue(vr)
 		if err != nil {
 			return nil, err
 		}
@@ -245,6 +267,16 @@ func (defaultConverter) ConvertValue(v interface{}) (Value, error) {
 		return int64(u64), nil
 	case reflect.Float32, reflect.Float64:
 		return rv.Float(), nil
+	case reflect.Bool:
+		return rv.Bool(), nil
+	case reflect.Slice:
+		ek := rv.Type().Elem().Kind()
+		if ek == reflect.Uint8 {
+			return rv.Bytes(), nil
+		}
+		return nil, fmt.Errorf("unsupported type %T, a slice of %s", v, ek)
+	case reflect.String:
+		return rv.String(), nil
 	}
 	return nil, fmt.Errorf("unsupported type %T, a %s", v, rv.Kind())
 }
diff --git a/libgo/go/database/sql/driver/types_test.go b/libgo/go/database/sql/driver/types_test.go
index 1ce0ff0..0379bf8 100644
--- a/libgo/go/database/sql/driver/types_test.go
+++ b/libgo/go/database/sql/driver/types_test.go
@@ -20,6 +20,16 @@ type valueConverterTest struct {
 var now = time.Now()
 var answer int64 = 42
 
+type (
+	i  int64
+	f  float64
+	b  bool
+	bs []byte
+	s  string
+	t  time.Time
+	is []int
+)
+
 var valueConverterTests = []valueConverterTest{
 	{Bool, "true", true, ""},
 	{Bool, "True", true, ""},
@@ -41,6 +51,12 @@ var valueConverterTests = []valueConverterTest{
 	{DefaultParameterConverter, (*int64)(nil), nil, ""},
 	{DefaultParameterConverter, &answer, answer, ""},
 	{DefaultParameterConverter, &now, now, ""},
+	{DefaultParameterConverter, i(9), int64(9), ""},
+	{DefaultParameterConverter, f(0.1), float64(0.1), ""},
+	{DefaultParameterConverter, b(true), true, ""},
+	{DefaultParameterConverter, bs{1}, []byte{1}, ""},
+	{DefaultParameterConverter, s("a"), "a", ""},
+	{DefaultParameterConverter, is{1}, nil, "unsupported type driver.is, a slice of int"},
 }
 
 func TestValueConverters(t *testing.T) {
diff --git a/libgo/go/database/sql/fakedb_test.go b/libgo/go/database/sql/fakedb_test.go
index 5b238bf..4b15f5b 100644
--- a/libgo/go/database/sql/fakedb_test.go
+++ b/libgo/go/database/sql/fakedb_test.go
@@ -5,11 +5,13 @@
 package sql
 
 import (
+	"context"
 	"database/sql/driver"
 	"errors"
 	"fmt"
 	"io"
 	"log"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -32,10 +34,16 @@ var _ = log.Printf
 //     where types are: "string", [u]int{8,16,32,64}, "bool"
 //   INSERT|<tablename>|col=val,col2=val2,col3=?
 //   SELECT|<tablename>|projectcol1,projectcol2|filtercol=?,filtercol2=?
+//   SELECT|<tablename>|projectcol1,projectcol2|filtercol=?param1,filtercol2=?param2
 //
 // Any of these can be preceded by PANIC|<method>|, to cause the
 // named method on fakeStmt to panic.
 //
+// Any of these can be proceeded by WAIT|<duration>|, to cause the
+// named method on fakeStmt to sleep for the specified duration.
+//
+// Multiple of these can be combined when separated with a semicolon.
+//
 // When opening a fakeDriver's database, it starts empty with no
 // tables. All tables and data are stored in memory only.
 type fakeDriver struct {
@@ -101,6 +109,12 @@ type fakeTx struct {
 	c *fakeConn
 }
 
+type boundCol struct {
+	Column      string
+	Placeholder string
+	Ordinal     int
+}
+
 type fakeStmt struct {
 	c *fakeConn
 	q string // just for debugging
@@ -108,6 +122,9 @@ type fakeStmt struct {
 	cmd   string
 	table string
 	panic string
+	wait  time.Duration
+
+	next *fakeStmt // used for returning multiple results.
 
 	closed bool
 
@@ -116,7 +133,7 @@ type fakeStmt struct {
 	colValue     []interface{} // used by INSERT (mix of strings and "?" for bound params)
 	placeholders int           // used by INSERT/SELECT: number of ? params
 
-	whereCol []string // used by SELECT (all placeholders)
+	whereCol []boundCol // used by SELECT (all placeholders)
 
 	placeholderConverter []driver.ValueConverter // used by INSERT
 }
@@ -335,18 +352,23 @@ func (c *fakeConn) Close() (err error) {
 	return nil
 }
 
-func checkSubsetTypes(args []driver.Value) error {
-	for n, arg := range args {
-		switch arg.(type) {
+func checkSubsetTypes(args []driver.NamedValue) error {
+	for _, arg := range args {
+		switch arg.Value.(type) {
 		case int64, float64, bool, nil, []byte, string, time.Time:
 		default:
-			return fmt.Errorf("fakedb_test: invalid argument #%d: %v, type %T", n+1, arg, arg)
+			return fmt.Errorf("fakedb_test: invalid argument ordinal %[1]d: %[2]v, type %[2]T", arg.Ordinal, arg.Value)
 		}
 	}
 	return nil
 }
 
 func (c *fakeConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	// Ensure that ExecContext is called if available.
+	panic("ExecContext was not called.")
+}
+
+func (c *fakeConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
 	// This is an optional interface, but it's implemented here
 	// just to check that all the args are of the proper types.
 	// ErrSkip is returned so the caller acts as if we didn't
@@ -359,6 +381,11 @@ func (c *fakeConn) Exec(query string, args []driver.Value) (driver.Result, error
 }
 
 func (c *fakeConn) Query(query string, args []driver.Value) (driver.Rows, error) {
+	// Ensure that ExecContext is called if available.
+	panic("QueryContext was not called.")
+}
+
+func (c *fakeConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
 	// This is an optional interface, but it's implemented here
 	// just to check that all the args are of the proper types.
 	// ErrSkip is returned so the caller acts as if we didn't
@@ -377,12 +404,13 @@ func errf(msg string, args ...interface{}) error {
 // parts are table|selectCol1,selectCol2|whereCol=?,whereCol2=?
 // (note that where columns must always contain ? marks,
 //  just a limitation for fakedb)
-func (c *fakeConn) prepareSelect(stmt *fakeStmt, parts []string) (driver.Stmt, error) {
+func (c *fakeConn) prepareSelect(stmt *fakeStmt, parts []string) (*fakeStmt, error) {
 	if len(parts) != 3 {
 		stmt.Close()
 		return nil, errf("invalid SELECT syntax with %d parts; want 3", len(parts))
 	}
 	stmt.table = parts[0]
+
 	stmt.colName = strings.Split(parts[1], ",")
 	for n, colspec := range strings.Split(parts[2], ",") {
 		if colspec == "" {
@@ -399,19 +427,19 @@ func (c *fakeConn) prepareSelect(stmt *fakeStmt, parts []string) (driver.Stmt, e
 			stmt.Close()
 			return nil, errf("SELECT on table %q references non-existent column %q", stmt.table, column)
 		}
-		if value != "?" {
+		if !strings.HasPrefix(value, "?") {
 			stmt.Close()
 			return nil, errf("SELECT on table %q has pre-bound value for where column %q; need a question mark",
 				stmt.table, column)
 		}
-		stmt.whereCol = append(stmt.whereCol, column)
 		stmt.placeholders++
+		stmt.whereCol = append(stmt.whereCol, boundCol{Column: column, Placeholder: value, Ordinal: stmt.placeholders})
 	}
 	return stmt, nil
 }
 
 // parts are table|col=type,col2=type2
-func (c *fakeConn) prepareCreate(stmt *fakeStmt, parts []string) (driver.Stmt, error) {
+func (c *fakeConn) prepareCreate(stmt *fakeStmt, parts []string) (*fakeStmt, error) {
 	if len(parts) != 2 {
 		stmt.Close()
 		return nil, errf("invalid CREATE syntax with %d parts; want 2", len(parts))
@@ -430,7 +458,7 @@ func (c *fakeConn) prepareCreate(stmt *fakeStmt, parts []string) (driver.Stmt, e
 }
 
 // parts are table|col=?,col2=val
-func (c *fakeConn) prepareInsert(stmt *fakeStmt, parts []string) (driver.Stmt, error) {
+func (c *fakeConn) prepareInsert(stmt *fakeStmt, parts []string) (*fakeStmt, error) {
 	if len(parts) != 2 {
 		stmt.Close()
 		return nil, errf("invalid INSERT syntax with %d parts; want 2", len(parts))
@@ -450,7 +478,7 @@ func (c *fakeConn) prepareInsert(stmt *fakeStmt, parts []string) (driver.Stmt, e
 		}
 		stmt.colName = append(stmt.colName, column)
 
-		if value != "?" {
+		if !strings.HasPrefix(value, "?") {
 			var subsetVal interface{}
 			// Convert to driver subset type
 			switch ctype {
@@ -473,7 +501,7 @@ func (c *fakeConn) prepareInsert(stmt *fakeStmt, parts []string) (driver.Stmt, e
 		} else {
 			stmt.placeholders++
 			stmt.placeholderConverter = append(stmt.placeholderConverter, converterForType(ctype))
-			stmt.colValue = append(stmt.colValue, "?")
+			stmt.colValue = append(stmt.colValue, value)
 		}
 	}
 	return stmt, nil
@@ -483,6 +511,10 @@ func (c *fakeConn) prepareInsert(stmt *fakeStmt, parts []string) (driver.Stmt, e
 var hookPrepareBadConn func() bool
 
 func (c *fakeConn) Prepare(query string) (driver.Stmt, error) {
+	panic("use PrepareContext")
+}
+
+func (c *fakeConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
 	c.numPrepare++
 	if c.db == nil {
 		panic("nil c.db; conn = " + fmt.Sprintf("%#v", c))
@@ -492,38 +524,72 @@ func (c *fakeConn) Prepare(query string) (driver.Stmt, error) {
 		return nil, driver.ErrBadConn
 	}
 
-	parts := strings.Split(query, "|")
-	if len(parts) < 1 {
-		return nil, errf("empty query")
-	}
-	stmt := &fakeStmt{q: query, c: c}
-	if len(parts) >= 3 && parts[0] == "PANIC" {
-		stmt.panic = parts[1]
-		parts = parts[2:]
-	}
-	cmd := parts[0]
-	stmt.cmd = cmd
-	parts = parts[1:]
+	var firstStmt, prev *fakeStmt
+	for _, query := range strings.Split(query, ";") {
+		parts := strings.Split(query, "|")
+		if len(parts) < 1 {
+			return nil, errf("empty query")
+		}
+		stmt := &fakeStmt{q: query, c: c}
+		if firstStmt == nil {
+			firstStmt = stmt
+		}
+		if len(parts) >= 3 {
+			switch parts[0] {
+			case "PANIC":
+				stmt.panic = parts[1]
+				parts = parts[2:]
+			case "WAIT":
+				wait, err := time.ParseDuration(parts[1])
+				if err != nil {
+					return nil, errf("expected section after WAIT to be a duration, got %q %v", parts[1], err)
+				}
+				parts = parts[2:]
+				stmt.wait = wait
+			}
+		}
+		cmd := parts[0]
+		stmt.cmd = cmd
+		parts = parts[1:]
+
+		if stmt.wait > 0 {
+			wait := time.NewTimer(stmt.wait)
+			select {
+			case <-wait.C:
+			case <-ctx.Done():
+				wait.Stop()
+				return nil, ctx.Err()
+			}
+		}
 
-	c.incrStat(&c.stmtsMade)
-	switch cmd {
-	case "WIPE":
-		// Nothing
-	case "SELECT":
-		return c.prepareSelect(stmt, parts)
-	case "CREATE":
-		return c.prepareCreate(stmt, parts)
-	case "INSERT":
-		return c.prepareInsert(stmt, parts)
-	case "NOSERT":
-		// Do all the prep-work like for an INSERT but don't actually insert the row.
-		// Used for some of the concurrent tests.
-		return c.prepareInsert(stmt, parts)
-	default:
-		stmt.Close()
-		return nil, errf("unsupported command type %q", cmd)
+		c.incrStat(&c.stmtsMade)
+		var err error
+		switch cmd {
+		case "WIPE":
+			// Nothing
+		case "SELECT":
+			stmt, err = c.prepareSelect(stmt, parts)
+		case "CREATE":
+			stmt, err = c.prepareCreate(stmt, parts)
+		case "INSERT":
+			stmt, err = c.prepareInsert(stmt, parts)
+		case "NOSERT":
+			// Do all the prep-work like for an INSERT but don't actually insert the row.
+			// Used for some of the concurrent tests.
+			stmt, err = c.prepareInsert(stmt, parts)
+		default:
+			stmt.Close()
+			return nil, errf("unsupported command type %q", cmd)
+		}
+		if err != nil {
+			return nil, err
+		}
+		if prev != nil {
+			prev.next = stmt
+		}
+		prev = stmt
 	}
-	return stmt, nil
+	return firstStmt, nil
 }
 
 func (s *fakeStmt) ColumnConverter(idx int) driver.ValueConverter {
@@ -550,6 +616,9 @@ func (s *fakeStmt) Close() error {
 		s.c.incrStat(&s.c.stmtsClosed)
 		s.closed = true
 	}
+	if s.next != nil {
+		s.next.Close()
+	}
 	return nil
 }
 
@@ -559,6 +628,9 @@ var errClosed = errors.New("fakedb: statement has been closed")
 var hookExecBadConn func() bool
 
 func (s *fakeStmt) Exec(args []driver.Value) (driver.Result, error) {
+	panic("Using ExecContext")
+}
+func (s *fakeStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
 	if s.panic == "Exec" {
 		panic(s.panic)
 	}
@@ -575,6 +647,16 @@ func (s *fakeStmt) Exec(args []driver.Value) (driver.Result, error) {
 		return nil, err
 	}
 
+	if s.wait > 0 {
+		time.Sleep(s.wait)
+	}
+
+	select {
+	default:
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	}
+
 	db := s.c.db
 	switch s.cmd {
 	case "WIPE":
@@ -599,7 +681,7 @@ func (s *fakeStmt) Exec(args []driver.Value) (driver.Result, error) {
 // When doInsert is true, add the row to the table.
 // When doInsert is false do prep-work and error checking, but don't
 // actually add the row to the table.
-func (s *fakeStmt) execInsert(args []driver.Value, doInsert bool) (driver.Result, error) {
+func (s *fakeStmt) execInsert(args []driver.NamedValue, doInsert bool) (driver.Result, error) {
 	db := s.c.db
 	if len(args) != s.placeholders {
 		panic("error in pkg db; should only get here if size is correct")
@@ -625,8 +707,18 @@ func (s *fakeStmt) execInsert(args []driver.Value, doInsert bool) (driver.Result
 			return nil, fmt.Errorf("fakedb: column %q doesn't exist or dropped since prepared statement was created", colname)
 		}
 		var val interface{}
-		if strvalue, ok := s.colValue[n].(string); ok && strvalue == "?" {
-			val = args[argPos]
+		if strvalue, ok := s.colValue[n].(string); ok && strings.HasPrefix(strvalue, "?") {
+			if strvalue == "?" {
+				val = args[argPos].Value
+			} else {
+				// Assign value from argument placeholder name.
+				for _, a := range args {
+					if a.Name == strvalue[1:] {
+						val = a.Value
+						break
+					}
+				}
+			}
 			argPos++
 		} else {
 			val = s.colValue[n]
@@ -646,6 +738,10 @@ func (s *fakeStmt) execInsert(args []driver.Value, doInsert bool) (driver.Result
 var hookQueryBadConn func() bool
 
 func (s *fakeStmt) Query(args []driver.Value) (driver.Rows, error) {
+	panic("Use QueryContext")
+}
+
+func (s *fakeStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
 	if s.panic == "Query" {
 		panic(s.panic)
 	}
@@ -667,65 +763,101 @@ func (s *fakeStmt) Query(args []driver.Value) (driver.Rows, error) {
 		panic("error in pkg db; should only get here if size is correct")
 	}
 
-	db.mu.Lock()
-	t, ok := db.table(s.table)
-	db.mu.Unlock()
-	if !ok {
-		return nil, fmt.Errorf("fakedb: table %q doesn't exist", s.table)
-	}
+	setMRows := make([][]*row, 0, 1)
+	setColumns := make([][]string, 0, 1)
+	setColType := make([][]string, 0, 1)
 
-	if s.table == "magicquery" {
-		if len(s.whereCol) == 2 && s.whereCol[0] == "op" && s.whereCol[1] == "millis" {
-			if args[0] == "sleep" {
-				time.Sleep(time.Duration(args[1].(int64)) * time.Millisecond)
-			}
+	for {
+		db.mu.Lock()
+		t, ok := db.table(s.table)
+		db.mu.Unlock()
+		if !ok {
+			return nil, fmt.Errorf("fakedb: table %q doesn't exist", s.table)
 		}
-	}
-
-	t.mu.Lock()
-	defer t.mu.Unlock()
 
-	colIdx := make(map[string]int) // select column name -> column index in table
-	for _, name := range s.colName {
-		idx := t.columnIndex(name)
-		if idx == -1 {
-			return nil, fmt.Errorf("fakedb: unknown column name %q", name)
+		if s.table == "magicquery" {
+			if len(s.whereCol) == 2 && s.whereCol[0].Column == "op" && s.whereCol[1].Column == "millis" {
+				if args[0].Value == "sleep" {
+					time.Sleep(time.Duration(args[1].Value.(int64)) * time.Millisecond)
+				}
+			}
 		}
-		colIdx[name] = idx
-	}
 
-	mrows := []*row{}
-rows:
-	for _, trow := range t.rows {
-		// Process the where clause, skipping non-match rows. This is lazy
-		// and just uses fmt.Sprintf("%v") to test equality. Good enough
-		// for test code.
-		for widx, wcol := range s.whereCol {
-			idx := t.columnIndex(wcol)
+		t.mu.Lock()
+
+		colIdx := make(map[string]int) // select column name -> column index in table
+		for _, name := range s.colName {
+			idx := t.columnIndex(name)
 			if idx == -1 {
-				return nil, fmt.Errorf("db: invalid where clause column %q", wcol)
+				t.mu.Unlock()
+				return nil, fmt.Errorf("fakedb: unknown column name %q", name)
 			}
-			tcol := trow.cols[idx]
-			if bs, ok := tcol.([]byte); ok {
-				// lazy hack to avoid sprintf %v on a []byte
-				tcol = string(bs)
+			colIdx[name] = idx
+		}
+
+		mrows := []*row{}
+	rows:
+		for _, trow := range t.rows {
+			// Process the where clause, skipping non-match rows. This is lazy
+			// and just uses fmt.Sprintf("%v") to test equality. Good enough
+			// for test code.
+			for _, wcol := range s.whereCol {
+				idx := t.columnIndex(wcol.Column)
+				if idx == -1 {
+					t.mu.Unlock()
+					return nil, fmt.Errorf("db: invalid where clause column %q", wcol)
+				}
+				tcol := trow.cols[idx]
+				if bs, ok := tcol.([]byte); ok {
+					// lazy hack to avoid sprintf %v on a []byte
+					tcol = string(bs)
+				}
+				var argValue interface{}
+				if wcol.Placeholder == "?" {
+					argValue = args[wcol.Ordinal-1].Value
+				} else {
+					// Assign arg value from placeholder name.
+					for _, a := range args {
+						if a.Name == wcol.Placeholder[1:] {
+							argValue = a.Value
+							break
+						}
+					}
+				}
+				if fmt.Sprintf("%v", tcol) != fmt.Sprintf("%v", argValue) {
+					continue rows
+				}
 			}
-			if fmt.Sprintf("%v", tcol) != fmt.Sprintf("%v", args[widx]) {
-				continue rows
+			mrow := &row{cols: make([]interface{}, len(s.colName))}
+			for seli, name := range s.colName {
+				mrow.cols[seli] = trow.cols[colIdx[name]]
 			}
+			mrows = append(mrows, mrow)
 		}
-		mrow := &row{cols: make([]interface{}, len(s.colName))}
-		for seli, name := range s.colName {
-			mrow.cols[seli] = trow.cols[colIdx[name]]
+
+		var colType []string
+		for _, column := range s.colName {
+			colType = append(colType, t.coltype[t.columnIndex(column)])
 		}
-		mrows = append(mrows, mrow)
+
+		t.mu.Unlock()
+
+		setMRows = append(setMRows, mrows)
+		setColumns = append(setColumns, s.colName)
+		setColType = append(setColType, colType)
+
+		if s.next == nil {
+			break
+		}
+		s = s.next
 	}
 
 	cursor := &rowsCursor{
-		pos:    -1,
-		rows:   mrows,
-		cols:   s.colName,
-		errPos: -1,
+		posRow:  -1,
+		rows:    setMRows,
+		cols:    setColumns,
+		colType: setColType,
+		errPos:  -1,
 	}
 	return cursor, nil
 }
@@ -760,10 +892,12 @@ func (tx *fakeTx) Rollback() error {
 }
 
 type rowsCursor struct {
-	cols   []string
-	pos    int
-	rows   []*row
-	closed bool
+	cols    [][]string
+	colType [][]string
+	posSet  int
+	posRow  int
+	rows    [][]*row
+	closed  bool
 
 	// errPos and err are for making Next return early with error.
 	errPos int
@@ -786,7 +920,11 @@ func (rc *rowsCursor) Close() error {
 }
 
 func (rc *rowsCursor) Columns() []string {
-	return rc.cols
+	return rc.cols[rc.posSet]
+}
+
+func (rc *rowsCursor) ColumnTypeScanType(index int) reflect.Type {
+	return colTypeToReflectType(rc.colType[rc.posSet][index])
 }
 
 var rowsCursorNextHook func(dest []driver.Value) error
@@ -799,14 +937,14 @@ func (rc *rowsCursor) Next(dest []driver.Value) error {
 	if rc.closed {
 		return errors.New("fakedb: cursor is closed")
 	}
-	rc.pos++
-	if rc.pos == rc.errPos {
+	rc.posRow++
+	if rc.posRow == rc.errPos {
 		return rc.err
 	}
-	if rc.pos >= len(rc.rows) {
+	if rc.posRow >= len(rc.rows[rc.posSet]) {
 		return io.EOF // per interface spec
 	}
-	for i, v := range rc.rows[rc.pos].cols {
+	for i, v := range rc.rows[rc.posSet][rc.posRow].cols {
 		// TODO(bradfitz): convert to subset types? naah, I
 		// think the subset types should only be input to
 		// driver, but the sql package should be able to handle
@@ -831,6 +969,19 @@ func (rc *rowsCursor) Next(dest []driver.Value) error {
 	return nil
 }
 
+func (rc *rowsCursor) HasNextResultSet() bool {
+	return rc.posSet < len(rc.rows)-1
+}
+
+func (rc *rowsCursor) NextResultSet() error {
+	if rc.HasNextResultSet() {
+		rc.posSet++
+		rc.posRow = -1
+		return nil
+	}
+	return io.EOF // Per interface spec.
+}
+
 // fakeDriverString is like driver.String, but indirects pointers like
 // DefaultValueConverter.
 //
@@ -882,3 +1033,29 @@ func converterForType(typ string) driver.ValueConverter {
 	}
 	panic("invalid fakedb column type of " + typ)
 }
+
+func colTypeToReflectType(typ string) reflect.Type {
+	switch typ {
+	case "bool":
+		return reflect.TypeOf(false)
+	case "nullbool":
+		return reflect.TypeOf(NullBool{})
+	case "int32":
+		return reflect.TypeOf(int32(0))
+	case "string":
+		return reflect.TypeOf("")
+	case "nullstring":
+		return reflect.TypeOf(NullString{})
+	case "int64":
+		return reflect.TypeOf(int64(0))
+	case "nullint64":
+		return reflect.TypeOf(NullInt64{})
+	case "float64":
+		return reflect.TypeOf(float64(0))
+	case "nullfloat64":
+		return reflect.TypeOf(NullFloat64{})
+	case "datetime":
+		return reflect.TypeOf(time.Time{})
+	}
+	panic("invalid fakedb column type of " + typ)
+}
diff --git a/libgo/go/database/sql/sql.go b/libgo/go/database/sql/sql.go
index 09de1c3..0fa7c34 100644
--- a/libgo/go/database/sql/sql.go
+++ b/libgo/go/database/sql/sql.go
@@ -8,15 +8,20 @@
 // The sql package must be used in conjunction with a database driver.
 // See https://golang.org/s/sqldrivers for a list of drivers.
 //
-// For more usage examples, see the wiki page at
+// Drivers that do not support context cancelation will not return until
+// after the query is completed.
+//
+// For usage examples, see the wiki page at
 // https://golang.org/s/sqlwiki.
 package sql
 
 import (
+	"context"
 	"database/sql/driver"
 	"errors"
 	"fmt"
 	"io"
+	"reflect"
 	"runtime"
 	"sort"
 	"sync"
@@ -66,6 +71,75 @@ func Drivers() []string {
 	return list
 }
 
+// A NamedArg is a named argument. NamedArg values may be used as
+// arguments to Query or Exec and bind to the corresponding named
+// parameter in the SQL statement.
+//
+// For a more concise way to create NamedArg values, see
+// the Named function.
+type NamedArg struct {
+	_Named_Fields_Required struct{}
+
+	// Name is the name of the parameter placeholder.
+	//
+	// If empty, the ordinal position in the argument list will be
+	// used.
+	//
+	// Name must omit any symbol prefix.
+	Name string
+
+	// Value is the value of the parameter.
+	// It may be assigned the same value types as the query
+	// arguments.
+	Value interface{}
+}
+
+// Named provides a more concise way to create NamedArg values.
+//
+// Example usage:
+//
+//     db.ExecContext(ctx, `
+//         delete from Invoice
+//         where
+//             TimeCreated < @end
+//             and TimeCreated >= @start;`,
+//         sql.Named("start", startTime),
+//         sql.Named("end", endTime),
+//     )
+func Named(name string, value interface{}) NamedArg {
+	// This method exists because the go1compat promise
+	// doesn't guarantee that structs don't grow more fields,
+	// so unkeyed struct literals are a vet error. Thus, we don't
+	// want to allow sql.NamedArg{name, value}.
+	return NamedArg{Name: name, Value: value}
+}
+
+// IsolationLevel is the transaction isolation level used in TxOptions.
+type IsolationLevel int
+
+// Various isolation levels that drivers may support in BeginTx.
+// If a driver does not support a given isolation level an error may be returned.
+//
+// See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
+const (
+	LevelDefault IsolationLevel = iota
+	LevelReadUncommitted
+	LevelReadCommitted
+	LevelWriteCommitted
+	LevelRepeatableRead
+	LevelSnapshot
+	LevelSerializable
+	LevelLinearizable
+)
+
+// TxOptions holds the transaction options to be used in DB.BeginTx.
+type TxOptions struct {
+	// Isolation is the transaction isolation level.
+	// If zero, the driver or database's default level is used.
+	Isolation IsolationLevel
+	ReadOnly  bool
+}
+
 // RawBytes is a byte slice that holds a reference to memory owned by
 // the database itself. After a Scan into a RawBytes, the slice is only
 // valid until the next call to Next, Scan, or Close.
@@ -272,7 +346,7 @@ type driverConn struct {
 	ci          driver.Conn
 	closed      bool
 	finalClosed bool // ci.Close has been called
-	openStmt    map[driver.Stmt]bool
+	openStmt    map[*driverStmt]bool
 
 	// guarded by db.mu
 	inUse      bool
@@ -284,10 +358,10 @@ func (dc *driverConn) releaseConn(err error) {
 	dc.db.putConn(dc, err)
 }
 
-func (dc *driverConn) removeOpenStmt(si driver.Stmt) {
+func (dc *driverConn) removeOpenStmt(ds *driverStmt) {
 	dc.Lock()
 	defer dc.Unlock()
-	delete(dc.openStmt, si)
+	delete(dc.openStmt, ds)
 }
 
 func (dc *driverConn) expired(timeout time.Duration) bool {
@@ -297,28 +371,23 @@ func (dc *driverConn) expired(timeout time.Duration) bool {
 	return dc.createdAt.Add(timeout).Before(nowFunc())
 }
 
-func (dc *driverConn) prepareLocked(query string) (driver.Stmt, error) {
-	si, err := dc.ci.Prepare(query)
-	if err == nil {
-		// Track each driverConn's open statements, so we can close them
-		// before closing the conn.
-		//
-		// TODO(bradfitz): let drivers opt out of caring about
-		// stmt closes if the conn is about to close anyway? For now
-		// do the safe thing, in case stmts need to be closed.
-		//
-		// TODO(bradfitz): after Go 1.2, closing driver.Stmts
-		// should be moved to driverStmt, using unique
-		// *driverStmts everywhere (including from
-		// *Stmt.connStmt, instead of returning a
-		// driver.Stmt), using driverStmt as a pointer
-		// everywhere, and making it a finalCloser.
-		if dc.openStmt == nil {
-			dc.openStmt = make(map[driver.Stmt]bool)
-		}
-		dc.openStmt[si] = true
+func (dc *driverConn) prepareLocked(ctx context.Context, query string) (*driverStmt, error) {
+	si, err := ctxDriverPrepare(ctx, dc.ci, query)
+	if err != nil {
+		return nil, err
 	}
-	return si, err
+
+	// Track each driverConn's open statements, so we can close them
+	// before closing the conn.
+	//
+	// Wrap all driver.Stmt is *driverStmt to ensure they are only closed once.
+	if dc.openStmt == nil {
+		dc.openStmt = make(map[*driverStmt]bool)
+	}
+	ds := &driverStmt{Locker: dc, si: si}
+	dc.openStmt[ds] = true
+
+	return ds, nil
 }
 
 // the dc.db's Mutex is held.
@@ -350,17 +419,26 @@ func (dc *driverConn) Close() error {
 }
 
 func (dc *driverConn) finalClose() error {
-	dc.Lock()
+	var err error
 
-	for si := range dc.openStmt {
-		si.Close()
+	// Each *driverStmt has a lock to the dc. Copy the list out of the dc
+	// before calling close on each stmt.
+	var openStmt []*driverStmt
+	withLock(dc, func() {
+		openStmt = make([]*driverStmt, 0, len(dc.openStmt))
+		for ds := range dc.openStmt {
+			openStmt = append(openStmt, ds)
+		}
+		dc.openStmt = nil
+	})
+	for _, ds := range openStmt {
+		ds.Close()
 	}
-	dc.openStmt = nil
-
-	err := dc.ci.Close()
-	dc.ci = nil
-	dc.finalClosed = true
-	dc.Unlock()
+	withLock(dc, func() {
+		dc.finalClosed = true
+		err = dc.ci.Close()
+		dc.ci = nil
+	})
 
 	dc.db.mu.Lock()
 	dc.db.numOpen--
@@ -377,12 +455,21 @@ func (dc *driverConn) finalClose() error {
 type driverStmt struct {
 	sync.Locker // the *driverConn
 	si          driver.Stmt
+	closed      bool
+	closeErr    error // return value of previous Close call
 }
 
+// Close ensures dirver.Stmt is only closed once any always returns the same
+// result.
 func (ds *driverStmt) Close() error {
 	ds.Lock()
 	defer ds.Unlock()
-	return ds.si.Close()
+	if ds.closed {
+		return ds.closeErr
+	}
+	ds.closed = true
+	ds.closeErr = ds.si.Close()
+	return ds.closeErr
 }
 
 // depSet is a finalCloser's outstanding dependencies
@@ -494,18 +581,36 @@ func Open(driverName, dataSourceName string) (*DB, error) {
 	return db, nil
 }
 
-// Ping verifies a connection to the database is still alive,
+// PingContext verifies a connection to the database is still alive,
 // establishing a connection if necessary.
-func (db *DB) Ping() error {
-	// TODO(bradfitz): give drivers an optional hook to implement
-	// this in a more efficient or more reliable way, if they
-	// have one.
-	dc, err := db.conn(cachedOrNewConn)
+func (db *DB) PingContext(ctx context.Context) error {
+	var dc *driverConn
+	var err error
+
+	for i := 0; i < maxBadConnRetries; i++ {
+		dc, err = db.conn(ctx, cachedOrNewConn)
+		if err != driver.ErrBadConn {
+			break
+		}
+	}
+	if err == driver.ErrBadConn {
+		dc, err = db.conn(ctx, alwaysNewConn)
+	}
 	if err != nil {
 		return err
 	}
-	db.putConn(dc, nil)
-	return nil
+
+	if pinger, ok := dc.ci.(driver.Pinger); ok {
+		err = pinger.Ping(ctx)
+	}
+	db.putConn(dc, err)
+	return err
+}
+
+// Ping verifies a connection to the database is still alive,
+// establishing a connection if necessary.
+func (db *DB) Ping() error {
+	return db.PingContext(context.Background())
 }
 
 // Close closes the database, releasing any open resources.
@@ -777,12 +882,19 @@ type connRequest struct {
 var errDBClosed = errors.New("sql: database is closed")
 
 // conn returns a newly-opened or cached *driverConn.
-func (db *DB) conn(strategy connReuseStrategy) (*driverConn, error) {
+func (db *DB) conn(ctx context.Context, strategy connReuseStrategy) (*driverConn, error) {
 	db.mu.Lock()
 	if db.closed {
 		db.mu.Unlock()
 		return nil, errDBClosed
 	}
+	// Check if the context is expired.
+	select {
+	default:
+	case <-ctx.Done():
+		db.mu.Unlock()
+		return nil, ctx.Err()
+	}
 	lifetime := db.maxLifetime
 
 	// Prefer a free connection, if possible.
@@ -808,15 +920,21 @@ func (db *DB) conn(strategy connReuseStrategy) (*driverConn, error) {
 		req := make(chan connRequest, 1)
 		db.connRequests = append(db.connRequests, req)
 		db.mu.Unlock()
-		ret, ok := <-req
-		if !ok {
-			return nil, errDBClosed
-		}
-		if ret.err == nil && ret.conn.expired(lifetime) {
-			ret.conn.Close()
-			return nil, driver.ErrBadConn
+
+		// Timeout the connection request with the context.
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case ret, ok := <-req:
+			if !ok {
+				return nil, errDBClosed
+			}
+			if ret.err == nil && ret.conn.expired(lifetime) {
+				ret.conn.Close()
+				return nil, driver.ErrBadConn
+			}
+			return ret.conn, ret.err
 		}
-		return ret.conn, ret.err
 	}
 
 	db.numOpen++ // optimistically
@@ -844,21 +962,22 @@ func (db *DB) conn(strategy connReuseStrategy) (*driverConn, error) {
 // putConnHook is a hook for testing.
 var putConnHook func(*DB, *driverConn)
 
-// noteUnusedDriverStatement notes that si is no longer used and should
+// noteUnusedDriverStatement notes that ds is no longer used and should
 // be closed whenever possible (when c is next not in use), unless c is
 // already closed.
-func (db *DB) noteUnusedDriverStatement(c *driverConn, si driver.Stmt) {
+func (db *DB) noteUnusedDriverStatement(c *driverConn, ds *driverStmt) {
 	db.mu.Lock()
 	defer db.mu.Unlock()
 	if c.inUse {
 		c.onPut = append(c.onPut, func() {
-			si.Close()
+			ds.Close()
 		})
 	} else {
 		c.Lock()
-		defer c.Unlock()
-		if !c.finalClosed {
-			si.Close()
+		fc := c.finalClosed
+		c.Unlock()
+		if !fc {
+			ds.Close()
 		}
 	}
 }
@@ -952,40 +1071,53 @@ func (db *DB) putConnDBLocked(dc *driverConn, err error) bool {
 // connection to be opened.
 const maxBadConnRetries = 2
 
-// Prepare creates a prepared statement for later queries or executions.
+// PrepareContext creates a prepared statement for later queries or executions.
 // Multiple queries or executions may be run concurrently from the
 // returned statement.
 // The caller must call the statement's Close method
 // when the statement is no longer needed.
-func (db *DB) Prepare(query string) (*Stmt, error) {
+//
+// The provided context is used for the preparation of the statement, not for the
+// execution of the statement.
+func (db *DB) PrepareContext(ctx context.Context, query string) (*Stmt, error) {
 	var stmt *Stmt
 	var err error
 	for i := 0; i < maxBadConnRetries; i++ {
-		stmt, err = db.prepare(query, cachedOrNewConn)
+		stmt, err = db.prepare(ctx, query, cachedOrNewConn)
 		if err != driver.ErrBadConn {
 			break
 		}
 	}
 	if err == driver.ErrBadConn {
-		return db.prepare(query, alwaysNewConn)
+		return db.prepare(ctx, query, alwaysNewConn)
 	}
 	return stmt, err
 }
 
-func (db *DB) prepare(query string, strategy connReuseStrategy) (*Stmt, error) {
+// Prepare creates a prepared statement for later queries or executions.
+// Multiple queries or executions may be run concurrently from the
+// returned statement.
+// The caller must call the statement's Close method
+// when the statement is no longer needed.
+func (db *DB) Prepare(query string) (*Stmt, error) {
+	return db.PrepareContext(context.Background(), query)
+}
+
+func (db *DB) prepare(ctx context.Context, query string, strategy connReuseStrategy) (*Stmt, error) {
 	// TODO: check if db.driver supports an optional
 	// driver.Preparer interface and call that instead, if so,
 	// otherwise we make a prepared statement that's bound
 	// to a connection, and to execute this prepared statement
 	// we either need to use this connection (if it's free), else
 	// get a new connection + re-prepare + execute on that one.
-	dc, err := db.conn(strategy)
+	dc, err := db.conn(ctx, strategy)
 	if err != nil {
 		return nil, err
 	}
-	dc.Lock()
-	si, err := dc.prepareLocked(query)
-	dc.Unlock()
+	var ds *driverStmt
+	withLock(dc, func() {
+		ds, err = dc.prepareLocked(ctx, query)
+	})
 	if err != nil {
 		db.putConn(dc, err)
 		return nil, err
@@ -993,7 +1125,7 @@ func (db *DB) prepare(query string, strategy connReuseStrategy) (*Stmt, error) {
 	stmt := &Stmt{
 		db:            db,
 		query:         query,
-		css:           []connStmt{{dc, si}},
+		css:           []connStmt{{dc, ds}},
 		lastNumClosed: atomic.LoadUint64(&db.numClosed),
 	}
 	db.addDep(stmt, stmt)
@@ -1001,25 +1133,31 @@ func (db *DB) prepare(query string, strategy connReuseStrategy) (*Stmt, error) {
 	return stmt, nil
 }
 
-// Exec executes a query without returning any rows.
+// ExecContext executes a query without returning any rows.
 // The args are for any placeholder parameters in the query.
-func (db *DB) Exec(query string, args ...interface{}) (Result, error) {
+func (db *DB) ExecContext(ctx context.Context, query string, args ...interface{}) (Result, error) {
 	var res Result
 	var err error
 	for i := 0; i < maxBadConnRetries; i++ {
-		res, err = db.exec(query, args, cachedOrNewConn)
+		res, err = db.exec(ctx, query, args, cachedOrNewConn)
 		if err != driver.ErrBadConn {
 			break
 		}
 	}
 	if err == driver.ErrBadConn {
-		return db.exec(query, args, alwaysNewConn)
+		return db.exec(ctx, query, args, alwaysNewConn)
 	}
 	return res, err
 }
 
-func (db *DB) exec(query string, args []interface{}, strategy connReuseStrategy) (res Result, err error) {
-	dc, err := db.conn(strategy)
+// Exec executes a query without returning any rows.
+// The args are for any placeholder parameters in the query.
+func (db *DB) Exec(query string, args ...interface{}) (Result, error) {
+	return db.ExecContext(context.Background(), query, args...)
+}
+
+func (db *DB) exec(ctx context.Context, query string, args []interface{}, strategy connReuseStrategy) (res Result, err error) {
+	dc, err := db.conn(ctx, strategy)
 	if err != nil {
 		return nil, err
 	}
@@ -1028,13 +1166,15 @@ func (db *DB) exec(query string, args []interface{}, strategy connReuseStrategy)
 	}()
 
 	if execer, ok := dc.ci.(driver.Execer); ok {
-		dargs, err := driverArgs(nil, args)
+		var dargs []driver.NamedValue
+		dargs, err = driverArgs(nil, args)
 		if err != nil {
 			return nil, err
 		}
-		dc.Lock()
-		resi, err := execer.Exec(query, dargs)
-		dc.Unlock()
+		var resi driver.Result
+		withLock(dc, func() {
+			resi, err = ctxDriverExec(ctx, execer, query, dargs)
+		})
 		if err != driver.ErrSkip {
 			if err != nil {
 				return nil, err
@@ -1043,54 +1183,63 @@ func (db *DB) exec(query string, args []interface{}, strategy connReuseStrategy)
 		}
 	}
 
-	dc.Lock()
-	si, err := dc.ci.Prepare(query)
-	dc.Unlock()
+	var si driver.Stmt
+	withLock(dc, func() {
+		si, err = ctxDriverPrepare(ctx, dc.ci, query)
+	})
 	if err != nil {
 		return nil, err
 	}
-	defer withLock(dc, func() { si.Close() })
-	return resultFromStatement(driverStmt{dc, si}, args...)
+	ds := &driverStmt{Locker: dc, si: si}
+	defer ds.Close()
+	return resultFromStatement(ctx, ds, args...)
 }
 
-// Query executes a query that returns rows, typically a SELECT.
+// QueryContext executes a query that returns rows, typically a SELECT.
 // The args are for any placeholder parameters in the query.
-func (db *DB) Query(query string, args ...interface{}) (*Rows, error) {
+func (db *DB) QueryContext(ctx context.Context, query string, args ...interface{}) (*Rows, error) {
 	var rows *Rows
 	var err error
 	for i := 0; i < maxBadConnRetries; i++ {
-		rows, err = db.query(query, args, cachedOrNewConn)
+		rows, err = db.query(ctx, query, args, cachedOrNewConn)
 		if err != driver.ErrBadConn {
 			break
 		}
 	}
 	if err == driver.ErrBadConn {
-		return db.query(query, args, alwaysNewConn)
+		return db.query(ctx, query, args, alwaysNewConn)
 	}
 	return rows, err
 }
 
-func (db *DB) query(query string, args []interface{}, strategy connReuseStrategy) (*Rows, error) {
-	ci, err := db.conn(strategy)
+// Query executes a query that returns rows, typically a SELECT.
+// The args are for any placeholder parameters in the query.
+func (db *DB) Query(query string, args ...interface{}) (*Rows, error) {
+	return db.QueryContext(context.Background(), query, args...)
+}
+
+func (db *DB) query(ctx context.Context, query string, args []interface{}, strategy connReuseStrategy) (*Rows, error) {
+	ci, err := db.conn(ctx, strategy)
 	if err != nil {
 		return nil, err
 	}
 
-	return db.queryConn(ci, ci.releaseConn, query, args)
+	return db.queryConn(ctx, ci, ci.releaseConn, query, args)
 }
 
 // queryConn executes a query on the given connection.
 // The connection gets released by the releaseConn function.
-func (db *DB) queryConn(dc *driverConn, releaseConn func(error), query string, args []interface{}) (*Rows, error) {
+func (db *DB) queryConn(ctx context.Context, dc *driverConn, releaseConn func(error), query string, args []interface{}) (*Rows, error) {
 	if queryer, ok := dc.ci.(driver.Queryer); ok {
 		dargs, err := driverArgs(nil, args)
 		if err != nil {
 			releaseConn(err)
 			return nil, err
 		}
-		dc.Lock()
-		rowsi, err := queryer.Query(query, dargs)
-		dc.Unlock()
+		var rowsi driver.Rows
+		withLock(dc, func() {
+			rowsi, err = ctxDriverQuery(ctx, queryer, query, dargs)
+		})
 		if err != driver.ErrSkip {
 			if err != nil {
 				releaseConn(err)
@@ -1103,24 +1252,25 @@ func (db *DB) queryConn(dc *driverConn, releaseConn func(error), query string, a
 				releaseConn: releaseConn,
 				rowsi:       rowsi,
 			}
+			rows.initContextClose(ctx)
 			return rows, nil
 		}
 	}
 
-	dc.Lock()
-	si, err := dc.ci.Prepare(query)
-	dc.Unlock()
+	var si driver.Stmt
+	var err error
+	withLock(dc, func() {
+		si, err = ctxDriverPrepare(ctx, dc.ci, query)
+	})
 	if err != nil {
 		releaseConn(err)
 		return nil, err
 	}
 
-	ds := driverStmt{dc, si}
-	rowsi, err := rowsiFromStatement(ds, args...)
+	ds := &driverStmt{Locker: dc, si: si}
+	rowsi, err := rowsiFromStatement(ctx, ds, args...)
 	if err != nil {
-		dc.Lock()
-		si.Close()
-		dc.Unlock()
+		ds.Close()
 		releaseConn(err)
 		return nil, err
 	}
@@ -1131,53 +1281,93 @@ func (db *DB) queryConn(dc *driverConn, releaseConn func(error), query string, a
 		dc:          dc,
 		releaseConn: releaseConn,
 		rowsi:       rowsi,
-		closeStmt:   si,
+		closeStmt:   ds,
 	}
+	rows.initContextClose(ctx)
 	return rows, nil
 }
 
+// QueryRowContext executes a query that is expected to return at most one row.
+// QueryRowContext always returns a non-nil value. Errors are deferred until
+// Row's Scan method is called.
+func (db *DB) QueryRowContext(ctx context.Context, query string, args ...interface{}) *Row {
+	rows, err := db.QueryContext(ctx, query, args...)
+	return &Row{rows: rows, err: err}
+}
+
 // QueryRow executes a query that is expected to return at most one row.
 // QueryRow always returns a non-nil value. Errors are deferred until
 // Row's Scan method is called.
 func (db *DB) QueryRow(query string, args ...interface{}) *Row {
-	rows, err := db.Query(query, args...)
-	return &Row{rows: rows, err: err}
+	return db.QueryRowContext(context.Background(), query, args...)
 }
 
-// Begin starts a transaction. The isolation level is dependent on
-// the driver.
-func (db *DB) Begin() (*Tx, error) {
+// BeginTx starts a transaction.
+//
+// The provided context is used until the transaction is committed or rolled back.
+// If the context is canceled, the sql package will roll back
+// the transaction. Tx.Commit will return an error if the context provided to
+// BeginTx is canceled.
+//
+// The provided TxOptions is optional and may be nil if defaults should be used.
+// If a non-default isolation level is used that the driver doesn't support,
+// an error will be returned.
+func (db *DB) BeginTx(ctx context.Context, opts *TxOptions) (*Tx, error) {
 	var tx *Tx
 	var err error
 	for i := 0; i < maxBadConnRetries; i++ {
-		tx, err = db.begin(cachedOrNewConn)
+		tx, err = db.begin(ctx, opts, cachedOrNewConn)
 		if err != driver.ErrBadConn {
 			break
 		}
 	}
 	if err == driver.ErrBadConn {
-		return db.begin(alwaysNewConn)
+		return db.begin(ctx, opts, alwaysNewConn)
 	}
 	return tx, err
 }
 
-func (db *DB) begin(strategy connReuseStrategy) (tx *Tx, err error) {
-	dc, err := db.conn(strategy)
+// Begin starts a transaction. The default isolation level is dependent on
+// the driver.
+func (db *DB) Begin() (*Tx, error) {
+	return db.BeginTx(context.Background(), nil)
+}
+
+func (db *DB) begin(ctx context.Context, opts *TxOptions, strategy connReuseStrategy) (tx *Tx, err error) {
+	dc, err := db.conn(ctx, strategy)
 	if err != nil {
 		return nil, err
 	}
-	dc.Lock()
-	txi, err := dc.ci.Begin()
-	dc.Unlock()
+	var txi driver.Tx
+	withLock(dc, func() {
+		txi, err = ctxDriverBegin(ctx, opts, dc.ci)
+	})
 	if err != nil {
 		db.putConn(dc, err)
 		return nil, err
 	}
-	return &Tx{
-		db:  db,
-		dc:  dc,
-		txi: txi,
-	}, nil
+
+	// Schedule the transaction to rollback when the context is cancelled.
+	// The cancel function in Tx will be called after done is set to true.
+	ctx, cancel := context.WithCancel(ctx)
+	tx = &Tx{
+		db:     db,
+		dc:     dc,
+		txi:    txi,
+		cancel: cancel,
+		ctx:    ctx,
+	}
+	go func(tx *Tx) {
+		select {
+		case <-tx.ctx.Done():
+			if !tx.isDone() {
+				// Discard and close the connection used to ensure the transaction
+				// is closed and the resources are released.
+				tx.rollback(true)
+			}
+		}
+	}(tx)
+	return tx, nil
 }
 
 // Driver returns the database's underlying driver.
@@ -1203,10 +1393,11 @@ type Tx struct {
 	dc  *driverConn
 	txi driver.Tx
 
-	// done transitions from false to true exactly once, on Commit
+	// done transitions from 0 to 1 exactly once, on Commit
 	// or Rollback. once done, all operations fail with
 	// ErrTxDone.
-	done bool
+	// Use atomic operations on value when checking value.
+	done int32
 
 	// All Stmts prepared for this transaction. These will be closed after the
 	// transaction has been committed or rolled back.
@@ -1214,22 +1405,33 @@ type Tx struct {
 		sync.Mutex
 		v []*Stmt
 	}
+
+	// cancel is called after done transitions from false to true.
+	cancel func()
+
+	// ctx lives for the life of the transaction.
+	ctx context.Context
+}
+
+func (tx *Tx) isDone() bool {
+	return atomic.LoadInt32(&tx.done) != 0
 }
 
+// ErrTxDone is returned by any operation that is performed on a transaction
+// that has already been committed or rolled back.
 var ErrTxDone = errors.New("sql: Transaction has already been committed or rolled back")
 
+// close returns the connection to the pool and
+// must only be called by Tx.rollback or Tx.Commit.
 func (tx *Tx) close(err error) {
-	if tx.done {
-		panic("double close") // internal error
-	}
-	tx.done = true
 	tx.db.putConn(tx.dc, err)
+	tx.cancel()
 	tx.dc = nil
 	tx.txi = nil
 }
 
-func (tx *Tx) grabConn() (*driverConn, error) {
-	if tx.done {
+func (tx *Tx) grabConn(ctx context.Context) (*driverConn, error) {
+	if tx.isDone() {
 		return nil, ErrTxDone
 	}
 	return tx.dc, nil
@@ -1238,20 +1440,26 @@ func (tx *Tx) grabConn() (*driverConn, error) {
 // Closes all Stmts prepared for this transaction.
 func (tx *Tx) closePrepared() {
 	tx.stmts.Lock()
+	defer tx.stmts.Unlock()
 	for _, stmt := range tx.stmts.v {
 		stmt.Close()
 	}
-	tx.stmts.Unlock()
 }
 
 // Commit commits the transaction.
 func (tx *Tx) Commit() error {
-	if tx.done {
+	if !atomic.CompareAndSwapInt32(&tx.done, 0, 1) {
 		return ErrTxDone
 	}
-	tx.dc.Lock()
-	err := tx.txi.Commit()
-	tx.dc.Unlock()
+	select {
+	default:
+	case <-tx.ctx.Done():
+		return tx.ctx.Err()
+	}
+	var err error
+	withLock(tx.dc, func() {
+		err = tx.txi.Commit()
+	})
 	if err != driver.ErrBadConn {
 		tx.closePrepared()
 	}
@@ -1259,28 +1467,42 @@ func (tx *Tx) Commit() error {
 	return err
 }
 
-// Rollback aborts the transaction.
-func (tx *Tx) Rollback() error {
-	if tx.done {
+// rollback aborts the transaction and optionally forces the pool to discard
+// the connection.
+func (tx *Tx) rollback(discardConn bool) error {
+	if !atomic.CompareAndSwapInt32(&tx.done, 0, 1) {
 		return ErrTxDone
 	}
-	tx.dc.Lock()
-	err := tx.txi.Rollback()
-	tx.dc.Unlock()
+	var err error
+	withLock(tx.dc, func() {
+		err = tx.txi.Rollback()
+	})
 	if err != driver.ErrBadConn {
 		tx.closePrepared()
 	}
+	if discardConn {
+		err = driver.ErrBadConn
+	}
 	tx.close(err)
 	return err
 }
 
+// Rollback aborts the transaction.
+func (tx *Tx) Rollback() error {
+	return tx.rollback(false)
+}
+
 // Prepare creates a prepared statement for use within a transaction.
 //
-// The returned statement operates within the transaction and can no longer
-// be used once the transaction has been committed or rolled back.
+// The returned statement operates within the transaction and will be closed
+// when the transaction has been committed or rolled back.
 //
 // To use an existing prepared statement on this transaction, see Tx.Stmt.
-func (tx *Tx) Prepare(query string) (*Stmt, error) {
+//
+// The provided context will be used for the preparation of the context, not
+// for the execution of the returned statement. The returned statement
+// will run in the transaction context.
+func (tx *Tx) PrepareContext(ctx context.Context, query string) (*Stmt, error) {
 	// TODO(bradfitz): We could be more efficient here and either
 	// provide a method to take an existing Stmt (created on
 	// perhaps a different Conn), and re-create it on this Conn if
@@ -1294,14 +1516,15 @@ func (tx *Tx) Prepare(query string) (*Stmt, error) {
 	// Perhaps just looking at the reference count (by noting
 	// Stmt.Close) would be enough. We might also want a finalizer
 	// on Stmt to drop the reference count.
-	dc, err := tx.grabConn()
+	dc, err := tx.grabConn(ctx)
 	if err != nil {
 		return nil, err
 	}
 
-	dc.Lock()
-	si, err := dc.ci.Prepare(query)
-	dc.Unlock()
+	var si driver.Stmt
+	withLock(dc, func() {
+		si, err = ctxDriverPrepare(ctx, dc.ci, query)
+	})
 	if err != nil {
 		return nil, err
 	}
@@ -1309,7 +1532,7 @@ func (tx *Tx) Prepare(query string) (*Stmt, error) {
 	stmt := &Stmt{
 		db: tx.db,
 		tx: tx,
-		txsi: &driverStmt{
+		txds: &driverStmt{
 			Locker: dc,
 			si:     si,
 		},
@@ -1321,7 +1544,17 @@ func (tx *Tx) Prepare(query string) (*Stmt, error) {
 	return stmt, nil
 }
 
-// Stmt returns a transaction-specific prepared statement from
+// Prepare creates a prepared statement for use within a transaction.
+//
+// The returned statement operates within the transaction and can no longer
+// be used once the transaction has been committed or rolled back.
+//
+// To use an existing prepared statement on this transaction, see Tx.Stmt.
+func (tx *Tx) Prepare(query string) (*Stmt, error) {
+	return tx.PrepareContext(context.Background(), query)
+}
+
+// StmtContext returns a transaction-specific prepared statement from
 // an existing statement.
 //
 // Example:
@@ -1329,11 +1562,11 @@ func (tx *Tx) Prepare(query string) (*Stmt, error) {
 //  ...
 //  tx, err := db.Begin()
 //  ...
-//  res, err := tx.Stmt(updateMoney).Exec(123.45, 98293203)
+//  res, err := tx.StmtContext(ctx, updateMoney).Exec(123.45, 98293203)
 //
-// The returned statement operates within the transaction and can no longer
-// be used once the transaction has been committed or rolled back.
-func (tx *Tx) Stmt(stmt *Stmt) *Stmt {
+// The returned statement operates within the transaction and will be closed
+// when the transaction has been committed or rolled back.
+func (tx *Tx) StmtContext(ctx context.Context, stmt *Stmt) *Stmt {
 	// TODO(bradfitz): optimize this. Currently this re-prepares
 	// each time. This is fine for now to illustrate the API but
 	// we should really cache already-prepared statements
@@ -1342,17 +1575,18 @@ func (tx *Tx) Stmt(stmt *Stmt) *Stmt {
 	if tx.db != stmt.db {
 		return &Stmt{stickyErr: errors.New("sql: Tx.Stmt: statement from different database used")}
 	}
-	dc, err := tx.grabConn()
+	dc, err := tx.grabConn(ctx)
 	if err != nil {
 		return &Stmt{stickyErr: err}
 	}
-	dc.Lock()
-	si, err := dc.ci.Prepare(stmt.query)
-	dc.Unlock()
+	var si driver.Stmt
+	withLock(dc, func() {
+		si, err = ctxDriverPrepare(ctx, dc.ci, stmt.query)
+	})
 	txs := &Stmt{
 		db: tx.db,
 		tx: tx,
-		txsi: &driverStmt{
+		txds: &driverStmt{
 			Locker: dc,
 			si:     si,
 		},
@@ -1365,10 +1599,26 @@ func (tx *Tx) Stmt(stmt *Stmt) *Stmt {
 	return txs
 }
 
-// Exec executes a query that doesn't return rows.
+// Stmt returns a transaction-specific prepared statement from
+// an existing statement.
+//
+// Example:
+//  updateMoney, err := db.Prepare("UPDATE balance SET money=money+? WHERE id=?")
+//  ...
+//  tx, err := db.Begin()
+//  ...
+//  res, err := tx.Stmt(updateMoney).Exec(123.45, 98293203)
+//
+// The returned statement operates within the transaction and will be closed
+// when the transaction has been committed or rolled back.
+func (tx *Tx) Stmt(stmt *Stmt) *Stmt {
+	return tx.StmtContext(context.Background(), stmt)
+}
+
+// ExecContext executes a query that doesn't return rows.
 // For example: an INSERT and UPDATE.
-func (tx *Tx) Exec(query string, args ...interface{}) (Result, error) {
-	dc, err := tx.grabConn()
+func (tx *Tx) ExecContext(ctx context.Context, query string, args ...interface{}) (Result, error) {
+	dc, err := tx.grabConn(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -1378,9 +1628,10 @@ func (tx *Tx) Exec(query string, args ...interface{}) (Result, error) {
 		if err != nil {
 			return nil, err
 		}
-		dc.Lock()
-		resi, err := execer.Exec(query, dargs)
-		dc.Unlock()
+		var resi driver.Result
+		withLock(dc, func() {
+			resi, err = ctxDriverExec(ctx, execer, query, dargs)
+		})
 		if err == nil {
 			return driverResult{dc, resi}, nil
 		}
@@ -1389,39 +1640,59 @@ func (tx *Tx) Exec(query string, args ...interface{}) (Result, error) {
 		}
 	}
 
-	dc.Lock()
-	si, err := dc.ci.Prepare(query)
-	dc.Unlock()
+	var si driver.Stmt
+	withLock(dc, func() {
+		si, err = ctxDriverPrepare(ctx, dc.ci, query)
+	})
 	if err != nil {
 		return nil, err
 	}
-	defer withLock(dc, func() { si.Close() })
+	ds := &driverStmt{Locker: dc, si: si}
+	defer ds.Close()
 
-	return resultFromStatement(driverStmt{dc, si}, args...)
+	return resultFromStatement(ctx, ds, args...)
 }
 
-// Query executes a query that returns rows, typically a SELECT.
-func (tx *Tx) Query(query string, args ...interface{}) (*Rows, error) {
-	dc, err := tx.grabConn()
+// Exec executes a query that doesn't return rows.
+// For example: an INSERT and UPDATE.
+func (tx *Tx) Exec(query string, args ...interface{}) (Result, error) {
+	return tx.ExecContext(context.Background(), query, args...)
+}
+
+// QueryContext executes a query that returns rows, typically a SELECT.
+func (tx *Tx) QueryContext(ctx context.Context, query string, args ...interface{}) (*Rows, error) {
+	dc, err := tx.grabConn(ctx)
 	if err != nil {
 		return nil, err
 	}
 	releaseConn := func(error) {}
-	return tx.db.queryConn(dc, releaseConn, query, args)
+	return tx.db.queryConn(ctx, dc, releaseConn, query, args)
+}
+
+// Query executes a query that returns rows, typically a SELECT.
+func (tx *Tx) Query(query string, args ...interface{}) (*Rows, error) {
+	return tx.QueryContext(context.Background(), query, args...)
+}
+
+// QueryRowContext executes a query that is expected to return at most one row.
+// QueryRowContext always returns a non-nil value. Errors are deferred until
+// Row's Scan method is called.
+func (tx *Tx) QueryRowContext(ctx context.Context, query string, args ...interface{}) *Row {
+	rows, err := tx.QueryContext(ctx, query, args...)
+	return &Row{rows: rows, err: err}
 }
 
 // QueryRow executes a query that is expected to return at most one row.
 // QueryRow always returns a non-nil value. Errors are deferred until
 // Row's Scan method is called.
 func (tx *Tx) QueryRow(query string, args ...interface{}) *Row {
-	rows, err := tx.Query(query, args...)
-	return &Row{rows: rows, err: err}
+	return tx.QueryRowContext(context.Background(), query, args...)
 }
 
 // connStmt is a prepared statement on a particular connection.
 type connStmt struct {
 	dc *driverConn
-	si driver.Stmt
+	ds *driverStmt
 }
 
 // Stmt is a prepared statement.
@@ -1436,7 +1707,7 @@ type Stmt struct {
 
 	// If in a transaction, else both nil:
 	tx   *Tx
-	txsi *driverStmt
+	txds *driverStmt
 
 	mu     sync.Mutex // protects the rest of the fields
 	closed bool
@@ -1452,15 +1723,15 @@ type Stmt struct {
 	lastNumClosed uint64
 }
 
-// Exec executes a prepared statement with the given arguments and
+// ExecContext executes a prepared statement with the given arguments and
 // returns a Result summarizing the effect of the statement.
-func (s *Stmt) Exec(args ...interface{}) (Result, error) {
+func (s *Stmt) ExecContext(ctx context.Context, args ...interface{}) (Result, error) {
 	s.closemu.RLock()
 	defer s.closemu.RUnlock()
 
 	var res Result
 	for i := 0; i < maxBadConnRetries; i++ {
-		dc, releaseConn, si, err := s.connStmt()
+		_, releaseConn, ds, err := s.connStmt(ctx)
 		if err != nil {
 			if err == driver.ErrBadConn {
 				continue
@@ -1468,7 +1739,7 @@ func (s *Stmt) Exec(args ...interface{}) (Result, error) {
 			return nil, err
 		}
 
-		res, err = resultFromStatement(driverStmt{dc, si}, args...)
+		res, err = resultFromStatement(ctx, ds, args...)
 		releaseConn(err)
 		if err != driver.ErrBadConn {
 			return res, err
@@ -1477,13 +1748,19 @@ func (s *Stmt) Exec(args ...interface{}) (Result, error) {
 	return nil, driver.ErrBadConn
 }
 
-func driverNumInput(ds driverStmt) int {
+// Exec executes a prepared statement with the given arguments and
+// returns a Result summarizing the effect of the statement.
+func (s *Stmt) Exec(args ...interface{}) (Result, error) {
+	return s.ExecContext(context.Background(), args...)
+}
+
+func driverNumInput(ds *driverStmt) int {
 	ds.Lock()
 	defer ds.Unlock() // in case NumInput panics
 	return ds.si.NumInput()
 }
 
-func resultFromStatement(ds driverStmt, args ...interface{}) (Result, error) {
+func resultFromStatement(ctx context.Context, ds *driverStmt, args ...interface{}) (Result, error) {
 	want := driverNumInput(ds)
 
 	// -1 means the driver doesn't know how to count the number of
@@ -1493,14 +1770,15 @@ func resultFromStatement(ds driverStmt, args ...interface{}) (Result, error) {
 		return nil, fmt.Errorf("sql: expected %d arguments, got %d", want, len(args))
 	}
 
-	dargs, err := driverArgs(&ds, args)
+	dargs, err := driverArgs(ds, args)
 	if err != nil {
 		return nil, err
 	}
 
 	ds.Lock()
 	defer ds.Unlock()
-	resi, err := ds.si.Exec(dargs)
+
+	resi, err := ctxDriverStmtExec(ctx, ds.si, dargs)
 	if err != nil {
 		return nil, err
 	}
@@ -1536,7 +1814,7 @@ func (s *Stmt) removeClosedStmtLocked() {
 // connStmt returns a free driver connection on which to execute the
 // statement, a function to call to release the connection, and a
 // statement bound to that connection.
-func (s *Stmt) connStmt() (ci *driverConn, releaseConn func(error), si driver.Stmt, err error) {
+func (s *Stmt) connStmt(ctx context.Context) (ci *driverConn, releaseConn func(error), ds *driverStmt, err error) {
 	if err = s.stickyErr; err != nil {
 		return
 	}
@@ -1551,19 +1829,18 @@ func (s *Stmt) connStmt() (ci *driverConn, releaseConn func(error), si driver.St
 	// transaction was created on.
 	if s.tx != nil {
 		s.mu.Unlock()
-		ci, err = s.tx.grabConn() // blocks, waiting for the connection.
+		ci, err = s.tx.grabConn(ctx) // blocks, waiting for the connection.
 		if err != nil {
 			return
 		}
 		releaseConn = func(error) {}
-		return ci, releaseConn, s.txsi.si, nil
+		return ci, releaseConn, s.txds, nil
 	}
 
 	s.removeClosedStmtLocked()
 	s.mu.Unlock()
 
-	// TODO(bradfitz): or always wait for one? make configurable later?
-	dc, err := s.db.conn(cachedOrNewConn)
+	dc, err := s.db.conn(ctx, cachedOrNewConn)
 	if err != nil {
 		return nil, nil, nil, err
 	}
@@ -1572,36 +1849,36 @@ func (s *Stmt) connStmt() (ci *driverConn, releaseConn func(error), si driver.St
 	for _, v := range s.css {
 		if v.dc == dc {
 			s.mu.Unlock()
-			return dc, dc.releaseConn, v.si, nil
+			return dc, dc.releaseConn, v.ds, nil
 		}
 	}
 	s.mu.Unlock()
 
 	// No luck; we need to prepare the statement on this connection
-	dc.Lock()
-	si, err = dc.prepareLocked(s.query)
-	dc.Unlock()
+	withLock(dc, func() {
+		ds, err = dc.prepareLocked(ctx, s.query)
+	})
 	if err != nil {
 		s.db.putConn(dc, err)
 		return nil, nil, nil, err
 	}
 	s.mu.Lock()
-	cs := connStmt{dc, si}
+	cs := connStmt{dc, ds}
 	s.css = append(s.css, cs)
 	s.mu.Unlock()
 
-	return dc, dc.releaseConn, si, nil
+	return dc, dc.releaseConn, ds, nil
 }
 
-// Query executes a prepared query statement with the given arguments
+// QueryContext executes a prepared query statement with the given arguments
 // and returns the query results as a *Rows.
-func (s *Stmt) Query(args ...interface{}) (*Rows, error) {
+func (s *Stmt) QueryContext(ctx context.Context, args ...interface{}) (*Rows, error) {
 	s.closemu.RLock()
 	defer s.closemu.RUnlock()
 
 	var rowsi driver.Rows
 	for i := 0; i < maxBadConnRetries; i++ {
-		dc, releaseConn, si, err := s.connStmt()
+		dc, releaseConn, ds, err := s.connStmt(ctx)
 		if err != nil {
 			if err == driver.ErrBadConn {
 				continue
@@ -1609,7 +1886,7 @@ func (s *Stmt) Query(args ...interface{}) (*Rows, error) {
 			return nil, err
 		}
 
-		rowsi, err = rowsiFromStatement(driverStmt{dc, si}, args...)
+		rowsi, err = rowsiFromStatement(ctx, ds, args...)
 		if err == nil {
 			// Note: ownership of ci passes to the *Rows, to be freed
 			// with releaseConn.
@@ -1618,6 +1895,7 @@ func (s *Stmt) Query(args ...interface{}) (*Rows, error) {
 				rowsi: rowsi,
 				// releaseConn set below
 			}
+			rows.initContextClose(ctx)
 			s.db.addDep(s, rows)
 			rows.releaseConn = func(err error) {
 				releaseConn(err)
@@ -1634,10 +1912,17 @@ func (s *Stmt) Query(args ...interface{}) (*Rows, error) {
 	return nil, driver.ErrBadConn
 }
 
-func rowsiFromStatement(ds driverStmt, args ...interface{}) (driver.Rows, error) {
-	ds.Lock()
-	want := ds.si.NumInput()
-	ds.Unlock()
+// Query executes a prepared query statement with the given arguments
+// and returns the query results as a *Rows.
+func (s *Stmt) Query(args ...interface{}) (*Rows, error) {
+	return s.QueryContext(context.Background(), args...)
+}
+
+func rowsiFromStatement(ctx context.Context, ds *driverStmt, args ...interface{}) (driver.Rows, error) {
+	var want int
+	withLock(ds, func() {
+		want = ds.si.NumInput()
+	})
 
 	// -1 means the driver doesn't know how to count the number of
 	// placeholders, so we won't sanity check input here and instead let the
@@ -1646,21 +1931,22 @@ func rowsiFromStatement(ds driverStmt, args ...interface{}) (driver.Rows, error)
 		return nil, fmt.Errorf("sql: statement expects %d inputs; got %d", want, len(args))
 	}
 
-	dargs, err := driverArgs(&ds, args)
+	dargs, err := driverArgs(ds, args)
 	if err != nil {
 		return nil, err
 	}
 
 	ds.Lock()
-	rowsi, err := ds.si.Query(dargs)
-	ds.Unlock()
+	defer ds.Unlock()
+
+	rowsi, err := ctxDriverStmtQuery(ctx, ds.si, dargs)
 	if err != nil {
 		return nil, err
 	}
 	return rowsi, nil
 }
 
-// QueryRow executes a prepared query statement with the given arguments.
+// QueryRowContext executes a prepared query statement with the given arguments.
 // If an error occurs during the execution of the statement, that error will
 // be returned by a call to Scan on the returned *Row, which is always non-nil.
 // If the query selects no rows, the *Row's Scan will return ErrNoRows.
@@ -1670,15 +1956,30 @@ func rowsiFromStatement(ds driverStmt, args ...interface{}) (driver.Rows, error)
 // Example usage:
 //
 //  var name string
-//  err := nameByUseridStmt.QueryRow(id).Scan(&name)
-func (s *Stmt) QueryRow(args ...interface{}) *Row {
-	rows, err := s.Query(args...)
+//  err := nameByUseridStmt.QueryRowContext(ctx, id).Scan(&name)
+func (s *Stmt) QueryRowContext(ctx context.Context, args ...interface{}) *Row {
+	rows, err := s.QueryContext(ctx, args...)
 	if err != nil {
 		return &Row{err: err}
 	}
 	return &Row{rows: rows}
 }
 
+// QueryRow executes a prepared query statement with the given arguments.
+// If an error occurs during the execution of the statement, that error will
+// be returned by a call to Scan on the returned *Row, which is always non-nil.
+// If the query selects no rows, the *Row's Scan will return ErrNoRows.
+// Otherwise, the *Row's Scan scans the first selected row and discards
+// the rest.
+//
+// Example usage:
+//
+//  var name string
+//  err := nameByUseridStmt.QueryRow(id).Scan(&name)
+func (s *Stmt) QueryRow(args ...interface{}) *Row {
+	return s.QueryRowContext(context.Background(), args...)
+}
+
 // Close closes the statement.
 func (s *Stmt) Close() error {
 	s.closemu.Lock()
@@ -1693,13 +1994,11 @@ func (s *Stmt) Close() error {
 		return nil
 	}
 	s.closed = true
+	s.mu.Unlock()
 
 	if s.tx != nil {
-		err := s.txsi.Close()
-		s.mu.Unlock()
-		return err
+		return s.txds.Close()
 	}
-	s.mu.Unlock()
 
 	return s.db.removeDep(s, s)
 }
@@ -1709,8 +2008,8 @@ func (s *Stmt) finalClose() error {
 	defer s.mu.Unlock()
 	if s.css != nil {
 		for _, v := range s.css {
-			s.db.noteUnusedDriverStatement(v.dc, v.si)
-			v.dc.removeOpenStmt(v.si)
+			s.db.noteUnusedDriverStatement(v.dc, v.ds)
+			v.dc.removeOpenStmt(v.ds)
 		}
 		s.css = nil
 	}
@@ -1736,10 +2035,28 @@ type Rows struct {
 	releaseConn func(error)
 	rowsi       driver.Rows
 
-	closed    bool
+	// closed value is 1 when the Rows is closed.
+	// Use atomic operations on value when checking value.
+	closed    int32
+	ctxClose  chan struct{} // closed when Rows is closed, may be null.
 	lastcols  []driver.Value
 	lasterr   error       // non-nil only if closed is true
-	closeStmt driver.Stmt // if non-nil, statement to Close on close
+	closeStmt *driverStmt // if non-nil, statement to Close on close
+}
+
+func (rs *Rows) initContextClose(ctx context.Context) {
+	if ctx.Done() == context.Background().Done() {
+		return
+	}
+
+	rs.ctxClose = make(chan struct{})
+	go func() {
+		select {
+		case <-ctx.Done():
+			rs.Close()
+		case <-rs.ctxClose:
+		}
+	}()
 }
 
 // Next prepares the next result row for reading with the Scan method. It
@@ -1749,7 +2066,7 @@ type Rows struct {
 //
 // Every call to Scan, even the first one, must be preceded by a call to Next.
 func (rs *Rows) Next() bool {
-	if rs.closed {
+	if rs.isClosed() {
 		return false
 	}
 	if rs.lastcols == nil {
@@ -1757,6 +2074,47 @@ func (rs *Rows) Next() bool {
 	}
 	rs.lasterr = rs.rowsi.Next(rs.lastcols)
 	if rs.lasterr != nil {
+		// Close the connection if there is a driver error.
+		if rs.lasterr != io.EOF {
+			rs.Close()
+			return false
+		}
+		nextResultSet, ok := rs.rowsi.(driver.RowsNextResultSet)
+		if !ok {
+			rs.Close()
+			return false
+		}
+		// The driver is at the end of the current result set.
+		// Test to see if there is another result set after the current one.
+		// Only close Rows if there is no further result sets to read.
+		if !nextResultSet.HasNextResultSet() {
+			rs.Close()
+		}
+		return false
+	}
+	return true
+}
+
+// NextResultSet prepares the next result set for reading. It returns true if
+// there is further result sets, or false if there is no further result set
+// or if there is an error advancing to it. The Err method should be consulted
+// to distinguish between the two cases.
+//
+// After calling NextResultSet, the Next method should always be called before
+// scanning. If there are further result sets they may not have rows in the result
+// set.
+func (rs *Rows) NextResultSet() bool {
+	if rs.isClosed() {
+		return false
+	}
+	rs.lastcols = nil
+	nextResultSet, ok := rs.rowsi.(driver.RowsNextResultSet)
+	if !ok {
+		rs.Close()
+		return false
+	}
+	rs.lasterr = nextResultSet.NextResultSet()
+	if rs.lasterr != nil {
 		rs.Close()
 		return false
 	}
@@ -1776,7 +2134,7 @@ func (rs *Rows) Err() error {
 // Columns returns an error if the rows are closed, or if the rows
 // are from QueryRow and there was a deferred error.
 func (rs *Rows) Columns() ([]string, error) {
-	if rs.closed {
+	if rs.isClosed() {
 		return nil, errors.New("sql: Rows are closed")
 	}
 	if rs.rowsi == nil {
@@ -1785,6 +2143,107 @@ func (rs *Rows) Columns() ([]string, error) {
 	return rs.rowsi.Columns(), nil
 }
 
+// ColumnTypes returns column information such as column type, length,
+// and nullable. Some information may not be available from some drivers.
+func (rs *Rows) ColumnTypes() ([]*ColumnType, error) {
+	if rs.isClosed() {
+		return nil, errors.New("sql: Rows are closed")
+	}
+	if rs.rowsi == nil {
+		return nil, errors.New("sql: no Rows available")
+	}
+	return rowsColumnInfoSetup(rs.rowsi), nil
+}
+
+// ColumnType contains the name and type of a column.
+type ColumnType struct {
+	name string
+
+	hasNullable       bool
+	hasLength         bool
+	hasPrecisionScale bool
+
+	nullable     bool
+	length       int64
+	databaseType string
+	precision    int64
+	scale        int64
+	scanType     reflect.Type
+}
+
+// Name returns the name or alias of the column.
+func (ci *ColumnType) Name() string {
+	return ci.name
+}
+
+// Length returns the column type length for variable length column types such
+// as text and binary field types. If the type length is unbounded the value will
+// be math.MaxInt64 (any database limits will still apply).
+// If the column type is not variable length, such as an int, or if not supported
+// by the driver ok is false.
+func (ci *ColumnType) Length() (length int64, ok bool) {
+	return ci.length, ci.hasLength
+}
+
+// DecimalSize returns the scale and precision of a decimal type.
+// If not applicable or if not supported ok is false.
+func (ci *ColumnType) DecimalSize() (precision, scale int64, ok bool) {
+	return ci.precision, ci.scale, ci.hasPrecisionScale
+}
+
+// ScanType returns a Go type suitable for scanning into using Rows.Scan.
+// If a driver does not support this property ScanType will return
+// the type of an empty interface.
+func (ci *ColumnType) ScanType() reflect.Type {
+	return ci.scanType
+}
+
+// Nullable returns whether the column may be null.
+// If a driver does not support this property ok will be false.
+func (ci *ColumnType) Nullable() (nullable, ok bool) {
+	return ci.nullable, ci.hasNullable
+}
+
+// DatabaseTypeName returns the database system name of the column type. If an empty
+// string is returned the driver type name is not supported.
+// Consult your driver documentation for a list of driver data types. Length specifiers
+// are not included.
+// Common type include "VARCHAR", "TEXT", "NVARCHAR", "DECIMAL", "BOOL", "INT", "BIGINT".
+func (ci *ColumnType) DatabaseTypeName() string {
+	return ci.databaseType
+}
+
+func rowsColumnInfoSetup(rowsi driver.Rows) []*ColumnType {
+	names := rowsi.Columns()
+
+	list := make([]*ColumnType, len(names))
+	for i := range list {
+		ci := &ColumnType{
+			name: names[i],
+		}
+		list[i] = ci
+
+		if prop, ok := rowsi.(driver.RowsColumnTypeScanType); ok {
+			ci.scanType = prop.ColumnTypeScanType(i)
+		} else {
+			ci.scanType = reflect.TypeOf(new(interface{})).Elem()
+		}
+		if prop, ok := rowsi.(driver.RowsColumnTypeDatabaseTypeName); ok {
+			ci.databaseType = prop.ColumnTypeDatabaseTypeName(i)
+		}
+		if prop, ok := rowsi.(driver.RowsColumnTypeLength); ok {
+			ci.length, ci.hasLength = prop.ColumnTypeLength(i)
+		}
+		if prop, ok := rowsi.(driver.RowsColumnTypeNullable); ok {
+			ci.nullable, ci.hasNullable = prop.ColumnTypeNullable(i)
+		}
+		if prop, ok := rowsi.(driver.RowsColumnTypePrecisionScale); ok {
+			ci.precision, ci.scale, ci.hasPrecisionScale = prop.ColumnTypePrecisionScale(i)
+		}
+	}
+	return list
+}
+
 // Scan copies the columns in the current row into the values pointed
 // at by dest. The number of values in dest must be the same as the
 // number of columns in Rows.
@@ -1837,7 +2296,7 @@ func (rs *Rows) Columns() ([]string, error) {
 // For scanning into *bool, the source may be true, false, 1, 0, or
 // string inputs parseable by strconv.ParseBool.
 func (rs *Rows) Scan(dest ...interface{}) error {
-	if rs.closed {
+	if rs.isClosed() {
 		return errors.New("sql: Rows are closed")
 	}
 	if rs.lastcols == nil {
@@ -1857,14 +2316,21 @@ func (rs *Rows) Scan(dest ...interface{}) error {
 
 var rowsCloseHook func(*Rows, *error)
 
-// Close closes the Rows, preventing further enumeration. If Next returns
-// false, the Rows are closed automatically and it will suffice to check the
+func (rs *Rows) isClosed() bool {
+	return atomic.LoadInt32(&rs.closed) != 0
+}
+
+// Close closes the Rows, preventing further enumeration. If Next is called
+// and returns false and there are no further result sets,
+// the Rows are closed automatically and it will suffice to check the
 // result of Err. Close is idempotent and does not affect the result of Err.
 func (rs *Rows) Close() error {
-	if rs.closed {
+	if !atomic.CompareAndSwapInt32(&rs.closed, 0, 1) {
 		return nil
 	}
-	rs.closed = true
+	if rs.ctxClose != nil {
+		close(rs.ctxClose)
+	}
 	err := rs.rowsi.Close()
 	if fn := rowsCloseHook; fn != nil {
 		fn(rs, &err)
diff --git a/libgo/go/database/sql/sql_test.go b/libgo/go/database/sql/sql_test.go
index 08df0c7..63e1292 100644
--- a/libgo/go/database/sql/sql_test.go
+++ b/libgo/go/database/sql/sql_test.go
@@ -5,6 +5,7 @@
 package sql
 
 import (
+	"context"
 	"database/sql/driver"
 	"errors"
 	"fmt"
@@ -23,6 +24,17 @@ func init() {
 		c  *driverConn
 	}
 	freedFrom := make(map[dbConn]string)
+	var mu sync.Mutex
+	getFreedFrom := func(c dbConn) string {
+		mu.Lock()
+		defer mu.Unlock()
+		return freedFrom[c]
+	}
+	setFreedFrom := func(c dbConn, s string) {
+		mu.Lock()
+		defer mu.Unlock()
+		freedFrom[c] = s
+	}
 	putConnHook = func(db *DB, c *driverConn) {
 		idx := -1
 		for i, v := range db.freeConn {
@@ -35,10 +47,10 @@ func init() {
 			// print before panic, as panic may get lost due to conflicting panic
 			// (all goroutines asleep) elsewhere, since we might not unlock
 			// the mutex in freeConn here.
-			println("double free of conn. conflicts are:\nA) " + freedFrom[dbConn{db, c}] + "\n\nand\nB) " + stack())
+			println("double free of conn. conflicts are:\nA) " + getFreedFrom(dbConn{db, c}) + "\n\nand\nB) " + stack())
 			panic("double free of conn.")
 		}
-		freedFrom[dbConn{db, c}] = stack()
+		setFreedFrom(dbConn{db, c}, stack())
 	}
 }
 
@@ -140,10 +152,7 @@ func closeDB(t testing.TB, db *DB) {
 	if err != nil {
 		t.Fatalf("error closing DB: %v", err)
 	}
-	db.mu.Lock()
-	count := db.numOpen
-	db.mu.Unlock()
-	if count != 0 {
+	if count := db.numOpenConns(); count != 0 {
 		t.Fatalf("%d connections still open after closing DB", count)
 	}
 }
@@ -182,6 +191,12 @@ func (db *DB) numFreeConns() int {
 	return len(db.freeConn)
 }
 
+func (db *DB) numOpenConns() int {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+	return db.numOpen
+}
+
 // clearAllConns closes all connections in db.
 func (db *DB) clearAllConns(t *testing.T) {
 	db.SetMaxIdleConns(0)
@@ -260,6 +275,257 @@ func TestQuery(t *testing.T) {
 	}
 }
 
+func TestQueryContext(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+	prepares0 := numPrepares(t, db)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	rows, err := db.QueryContext(ctx, "SELECT|people|age,name|")
+	if err != nil {
+		t.Fatalf("Query: %v", err)
+	}
+	type row struct {
+		age  int
+		name string
+	}
+	got := []row{}
+	index := 0
+	for rows.Next() {
+		if index == 2 {
+			cancel()
+			time.Sleep(10 * time.Millisecond)
+		}
+		var r row
+		err = rows.Scan(&r.age, &r.name)
+		if err != nil {
+			if index == 2 {
+				break
+			}
+			t.Fatalf("Scan: %v", err)
+		}
+		if index == 2 && err == nil {
+			t.Fatal("expected an error on last scan")
+		}
+		got = append(got, r)
+		index++
+	}
+	err = rows.Err()
+	if err != nil {
+		t.Fatalf("Err: %v", err)
+	}
+	want := []row{
+		{age: 1, name: "Alice"},
+		{age: 2, name: "Bob"},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got, want)
+	}
+
+	// And verify that the final rows.Next() call, which hit EOF,
+	// also closed the rows connection.
+	if n := db.numFreeConns(); n != 1 {
+		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
+	}
+	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
+		t.Errorf("executed %d Prepare statements; want 1", prepares)
+	}
+}
+
+func waitCondition(waitFor, checkEvery time.Duration, fn func() bool) bool {
+	deadline := time.Now().Add(waitFor)
+	for time.Now().Before(deadline) {
+		if fn() {
+			return true
+		}
+		time.Sleep(checkEvery)
+	}
+	return false
+}
+
+func TestQueryContextWait(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+	prepares0 := numPrepares(t, db)
+
+	ctx, _ := context.WithTimeout(context.Background(), time.Millisecond*15)
+
+	// This will trigger the *fakeConn.Prepare method which will take time
+	// performing the query. The ctxDriverPrepare func will check the context
+	// after this and close the rows and return an error.
+	_, err := db.QueryContext(ctx, "WAIT|1s|SELECT|people|age,name|")
+	if err != context.DeadlineExceeded {
+		t.Fatalf("expected QueryContext to error with context deadline exceeded but returned %v", err)
+	}
+
+	// Verify closed rows connection after error condition.
+	if n := db.numFreeConns(); n != 1 {
+		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
+	}
+	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
+		t.Errorf("executed %d Prepare statements; want 1", prepares)
+	}
+}
+
+func TestTxContextWait(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+
+	ctx, _ := context.WithTimeout(context.Background(), time.Millisecond*15)
+
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// This will trigger the *fakeConn.Prepare method which will take time
+	// performing the query. The ctxDriverPrepare func will check the context
+	// after this and close the rows and return an error.
+	_, err = tx.QueryContext(ctx, "WAIT|1s|SELECT|people|age,name|")
+	if err != context.DeadlineExceeded {
+		t.Fatalf("expected QueryContext to error with context deadline exceeded but returned %v", err)
+	}
+
+	var numFree int
+	if !waitCondition(5*time.Second, 5*time.Millisecond, func() bool {
+		numFree = db.numFreeConns()
+		return numFree == 0
+	}) {
+		t.Fatalf("free conns after hitting EOF = %d; want 0", numFree)
+	}
+
+	// Ensure the dropped connection allows more connections to be made.
+	// Checked on DB Close.
+	waitCondition(5*time.Second, 5*time.Millisecond, func() bool {
+		return db.numOpenConns() == 0
+	})
+}
+
+func TestMultiResultSetQuery(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+	prepares0 := numPrepares(t, db)
+	rows, err := db.Query("SELECT|people|age,name|;SELECT|people|name|")
+	if err != nil {
+		t.Fatalf("Query: %v", err)
+	}
+	type row1 struct {
+		age  int
+		name string
+	}
+	type row2 struct {
+		name string
+	}
+	got1 := []row1{}
+	for rows.Next() {
+		var r row1
+		err = rows.Scan(&r.age, &r.name)
+		if err != nil {
+			t.Fatalf("Scan: %v", err)
+		}
+		got1 = append(got1, r)
+	}
+	err = rows.Err()
+	if err != nil {
+		t.Fatalf("Err: %v", err)
+	}
+	want1 := []row1{
+		{age: 1, name: "Alice"},
+		{age: 2, name: "Bob"},
+		{age: 3, name: "Chris"},
+	}
+	if !reflect.DeepEqual(got1, want1) {
+		t.Errorf("mismatch.\n got1: %#v\nwant: %#v", got1, want1)
+	}
+
+	if !rows.NextResultSet() {
+		t.Errorf("expected another result set")
+	}
+
+	got2 := []row2{}
+	for rows.Next() {
+		var r row2
+		err = rows.Scan(&r.name)
+		if err != nil {
+			t.Fatalf("Scan: %v", err)
+		}
+		got2 = append(got2, r)
+	}
+	err = rows.Err()
+	if err != nil {
+		t.Fatalf("Err: %v", err)
+	}
+	want2 := []row2{
+		{name: "Alice"},
+		{name: "Bob"},
+		{name: "Chris"},
+	}
+	if !reflect.DeepEqual(got2, want2) {
+		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got2, want2)
+	}
+	if rows.NextResultSet() {
+		t.Errorf("expected no more result sets")
+	}
+
+	// And verify that the final rows.Next() call, which hit EOF,
+	// also closed the rows connection.
+	if n := db.numFreeConns(); n != 1 {
+		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
+	}
+	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
+		t.Errorf("executed %d Prepare statements; want 1", prepares)
+	}
+}
+
+func TestQueryNamedArg(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+	prepares0 := numPrepares(t, db)
+	rows, err := db.Query(
+		// Ensure the name and age parameters only match on placeholder name, not position.
+		"SELECT|people|age,name|name=?name,age=?age",
+		Named("age", 2),
+		Named("name", "Bob"),
+	)
+	if err != nil {
+		t.Fatalf("Query: %v", err)
+	}
+	type row struct {
+		age  int
+		name string
+	}
+	got := []row{}
+	for rows.Next() {
+		var r row
+		err = rows.Scan(&r.age, &r.name)
+		if err != nil {
+			t.Fatalf("Scan: %v", err)
+		}
+		got = append(got, r)
+	}
+	err = rows.Err()
+	if err != nil {
+		t.Fatalf("Err: %v", err)
+	}
+	want := []row{
+		{age: 2, name: "Bob"},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("mismatch.\n got: %#v\nwant: %#v", got, want)
+	}
+
+	// And verify that the final rows.Next() call, which hit EOF,
+	// also closed the rows connection.
+	if n := db.numFreeConns(); n != 1 {
+		t.Fatalf("free conns after query hitting EOF = %d; want 1", n)
+	}
+	if prepares := numPrepares(t, db) - prepares0; prepares != 1 {
+		t.Errorf("executed %d Prepare statements; want 1", prepares)
+	}
+}
+
 func TestByteOwnership(t *testing.T) {
 	db := newTestDB(t, "people")
 	defer closeDB(t, db)
@@ -317,6 +583,56 @@ func TestRowsColumns(t *testing.T) {
 	}
 }
 
+func TestRowsColumnTypes(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+	rows, err := db.Query("SELECT|people|age,name|")
+	if err != nil {
+		t.Fatalf("Query: %v", err)
+	}
+	tt, err := rows.ColumnTypes()
+	if err != nil {
+		t.Fatalf("ColumnTypes: %v", err)
+	}
+
+	types := make([]reflect.Type, len(tt))
+	for i, tp := range tt {
+		st := tp.ScanType()
+		if st == nil {
+			t.Errorf("scantype is null for column %q", tp.Name())
+			continue
+		}
+		types[i] = st
+	}
+	values := make([]interface{}, len(tt))
+	for i := range values {
+		values[i] = reflect.New(types[i]).Interface()
+	}
+	ct := 0
+	for rows.Next() {
+		err = rows.Scan(values...)
+		if err != nil {
+			t.Fatalf("failed to scan values in %v", err)
+		}
+		ct++
+		if ct == 0 {
+			if values[0].(string) != "Bob" {
+				t.Errorf("Expected Bob, got %v", values[0])
+			}
+			if values[1].(int) != 2 {
+				t.Errorf("Expected 2, got %v", values[1])
+			}
+		}
+	}
+	if ct != 3 {
+		t.Errorf("expected 3 rows, got %d", ct)
+	}
+
+	if err := rows.Close(); err != nil {
+		t.Errorf("error closing rows: %s", err)
+	}
+}
+
 func TestQueryRow(t *testing.T) {
 	db := newTestDB(t, "people")
 	defer closeDB(t, db)
@@ -367,6 +683,37 @@ func TestQueryRow(t *testing.T) {
 	}
 }
 
+func TestTxRollbackCommitErr(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+
+	tx, err := db.Begin()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = tx.Rollback()
+	if err != nil {
+		t.Errorf("expected nil error from Rollback; got %v", err)
+	}
+	err = tx.Commit()
+	if err != ErrTxDone {
+		t.Errorf("expected %q from Commit; got %q", ErrTxDone, err)
+	}
+
+	tx, err = db.Begin()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = tx.Commit()
+	if err != nil {
+		t.Errorf("expected nil error from Commit; got %v", err)
+	}
+	err = tx.Rollback()
+	if err != ErrTxDone {
+		t.Errorf("expected %q from Rollback; got %q", ErrTxDone, err)
+	}
+}
+
 func TestStatementErrorAfterClose(t *testing.T) {
 	db := newTestDB(t, "people")
 	defer closeDB(t, db)
@@ -439,7 +786,7 @@ func TestStatementClose(t *testing.T) {
 		msg  string
 	}{
 		{&Stmt{stickyErr: want}, "stickyErr not propagated"},
-		{&Stmt{tx: &Tx{}, txsi: &driverStmt{&sync.Mutex{}, stubDriverStmt{want}}}, "driverStmt.Close() error not propagated"},
+		{&Stmt{tx: &Tx{}, txds: &driverStmt{Locker: &sync.Mutex{}, si: stubDriverStmt{want}}}, "driverStmt.Close() error not propagated"},
 	}
 	for _, test := range tests {
 		if err := test.stmt.Close(); err != want {
@@ -513,8 +860,8 @@ func TestExec(t *testing.T) {
 		{[]interface{}{7, 9}, ""},
 
 		// Invalid conversions:
-		{[]interface{}{"Brad", int64(0xFFFFFFFF)}, "sql: converting argument #1's type: sql/driver: value 4294967295 overflows int32"},
-		{[]interface{}{"Brad", "strconv fail"}, "sql: converting argument #1's type: sql/driver: value \"strconv fail\" can't be converted to int32"},
+		{[]interface{}{"Brad", int64(0xFFFFFFFF)}, "sql: converting argument $2 type: sql/driver: value 4294967295 overflows int32"},
+		{[]interface{}{"Brad", "strconv fail"}, `sql: converting argument $2 type: sql/driver: value "strconv fail" can't be converted to int32`},
 
 		// Wrong number of args:
 		{[]interface{}{}, "sql: expected 2 arguments, got 0"},
@@ -1159,17 +1506,19 @@ func TestMaxOpenConnsOnBusy(t *testing.T) {
 
 	db.SetMaxOpenConns(3)
 
-	conn0, err := db.conn(cachedOrNewConn)
+	ctx := context.Background()
+
+	conn0, err := db.conn(ctx, cachedOrNewConn)
 	if err != nil {
 		t.Fatalf("db open conn fail: %v", err)
 	}
 
-	conn1, err := db.conn(cachedOrNewConn)
+	conn1, err := db.conn(ctx, cachedOrNewConn)
 	if err != nil {
 		t.Fatalf("db open conn fail: %v", err)
 	}
 
-	conn2, err := db.conn(cachedOrNewConn)
+	conn2, err := db.conn(ctx, cachedOrNewConn)
 	if err != nil {
 		t.Fatalf("db open conn fail: %v", err)
 	}
@@ -1203,7 +1552,11 @@ func TestPendingConnsAfterErr(t *testing.T) {
 		tryOpen = maxOpen*2 + 2
 	)
 
-	db := newTestDB(t, "people")
+	// No queries will be run.
+	db, err := Open("test", fakeDBName)
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
 	defer closeDB(t, db)
 	defer func() {
 		for k, v := range db.lastPut {
@@ -1215,29 +1568,29 @@ func TestPendingConnsAfterErr(t *testing.T) {
 	db.SetMaxIdleConns(0)
 
 	errOffline := errors.New("db offline")
+
 	defer func() { setHookOpenErr(nil) }()
 
 	errs := make(chan error, tryOpen)
 
-	unblock := make(chan struct{})
+	var opening sync.WaitGroup
+	opening.Add(tryOpen)
+
 	setHookOpenErr(func() error {
-		<-unblock // block until all connections are in flight
+		// Wait for all connections to enqueue.
+		opening.Wait()
 		return errOffline
 	})
 
-	var opening sync.WaitGroup
-	opening.Add(tryOpen)
 	for i := 0; i < tryOpen; i++ {
 		go func() {
 			opening.Done() // signal one connection is in flight
-			_, err := db.Exec("INSERT|people|name=Julia,age=19")
+			_, err := db.Exec("will never run")
 			errs <- err
 		}()
 	}
 
-	opening.Wait()                    // wait for all workers to begin running
-	time.Sleep(10 * time.Millisecond) // make extra sure all workers are blocked
-	close(unblock)                    // let all workers proceed
+	opening.Wait() // wait for all workers to begin running
 
 	const timeout = 5 * time.Second
 	to := time.NewTimer(timeout)
@@ -1254,6 +1607,24 @@ func TestPendingConnsAfterErr(t *testing.T) {
 			t.Fatalf("orphaned connection request(s), still waiting after %v", timeout)
 		}
 	}
+
+	// Wait a reasonable time for the database to close all connections.
+	tick := time.NewTicker(3 * time.Millisecond)
+	defer tick.Stop()
+	for {
+		select {
+		case <-tick.C:
+			db.mu.Lock()
+			if db.numOpen == 0 {
+				db.mu.Unlock()
+				return
+			}
+			db.mu.Unlock()
+		case <-to.C:
+			// Closing the database will check for numOpen and fail the test.
+			return
+		}
+	}
 }
 
 func TestSingleOpenConn(t *testing.T) {
@@ -2236,6 +2607,54 @@ func TestIssue6081(t *testing.T) {
 	}
 }
 
+// TestIssue18429 attempts to stress rolling back the transaction from a
+// context cancel while simultaneously calling Tx.Rollback. Rolling back from a
+// context happens concurrently so tx.rollback and tx.Commit must guard against
+// double entry.
+//
+// In the test, a context is canceled while the query is in process so
+// the internal rollback will run concurrently with the explicitly called
+// Tx.Rollback.
+func TestIssue18429(t *testing.T) {
+	db := newTestDB(t, "people")
+	defer closeDB(t, db)
+
+	ctx := context.Background()
+	sem := make(chan bool, 20)
+	var wg sync.WaitGroup
+
+	const milliWait = 30
+
+	for i := 0; i < 100; i++ {
+		sem <- true
+		wg.Add(1)
+		go func() {
+			defer func() {
+				<-sem
+				wg.Done()
+			}()
+			qwait := (time.Duration(rand.Intn(milliWait)) * time.Millisecond).String()
+
+			ctx, cancel := context.WithTimeout(ctx, time.Duration(rand.Intn(milliWait))*time.Millisecond)
+			defer cancel()
+
+			tx, err := db.BeginTx(ctx, nil)
+			if err != nil {
+				return
+			}
+			rows, err := tx.QueryContext(ctx, "WAIT|"+qwait+"|SELECT|people|name|")
+			if rows != nil {
+				rows.Close()
+			}
+			// This call will race with the context cancel rollback to complete
+			// if the rollback itself isn't guarded.
+			tx.Rollback()
+		}()
+	}
+	wg.Wait()
+	time.Sleep(milliWait * 3 * time.Millisecond)
+}
+
 func TestConcurrency(t *testing.T) {
 	doConcurrentTest(t, new(concurrentDBQueryTest))
 	doConcurrentTest(t, new(concurrentDBExecTest))
@@ -2279,7 +2698,8 @@ func TestConnectionLeak(t *testing.T) {
 	go func() {
 		r, err := db.Query("SELECT|people|name|")
 		if err != nil {
-			t.Fatal(err)
+			t.Error(err)
+			return
 		}
 		r.Close()
 		wg.Done()
@@ -2299,6 +2719,97 @@ func TestConnectionLeak(t *testing.T) {
 	wg.Wait()
 }
 
+// badConn implements a bad driver.Conn, for TestBadDriver.
+// The Exec method panics.
+type badConn struct{}
+
+func (bc badConn) Prepare(query string) (driver.Stmt, error) {
+	return nil, errors.New("badConn Prepare")
+}
+
+func (bc badConn) Close() error {
+	return nil
+}
+
+func (bc badConn) Begin() (driver.Tx, error) {
+	return nil, errors.New("badConn Begin")
+}
+
+func (bc badConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	panic("badConn.Exec")
+}
+
+// badDriver is a driver.Driver that uses badConn.
+type badDriver struct{}
+
+func (bd badDriver) Open(name string) (driver.Conn, error) {
+	return badConn{}, nil
+}
+
+// Issue 15901.
+func TestBadDriver(t *testing.T) {
+	Register("bad", badDriver{})
+	db, err := Open("bad", "ignored")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if r := recover(); r == nil {
+			t.Error("expected panic")
+		} else {
+			if want := "badConn.Exec"; r.(string) != want {
+				t.Errorf("panic was %v, expected %v", r, want)
+			}
+		}
+	}()
+	defer db.Close()
+	db.Exec("ignored")
+}
+
+type pingDriver struct {
+	fails bool
+}
+
+type pingConn struct {
+	badConn
+	driver *pingDriver
+}
+
+var pingError = errors.New("Ping failed")
+
+func (pc pingConn) Ping(ctx context.Context) error {
+	if pc.driver.fails {
+		return pingError
+	}
+	return nil
+}
+
+var _ driver.Pinger = pingConn{}
+
+func (pd *pingDriver) Open(name string) (driver.Conn, error) {
+	return pingConn{driver: pd}, nil
+}
+
+func TestPing(t *testing.T) {
+	driver := &pingDriver{}
+	Register("ping", driver)
+
+	db, err := Open("ping", "ignored")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := db.Ping(); err != nil {
+		t.Errorf("err was %#v, expected nil", err)
+		return
+	}
+
+	driver.fails = true
+	if err := db.Ping(); err != pingError {
+		t.Errorf("err was %#v, expected pingError", err)
+	}
+}
+
 func BenchmarkConcurrentDBExec(b *testing.B) {
 	b.ReportAllocs()
 	ct := new(concurrentDBExecTest)