internal/race: add package

Factor out duplicated race thunks from sync, syscall net
and fmt packages into a separate package and use it.

Fixes #8593

Change-Id: I156869c50946277809f6b509463752e7f7d28cdb
Reviewed-on: https://go-review.googlesource.com/14870
Reviewed-by: Brad Fitzpatrick <[email protected]>
Run-TryBot: Dmitry Vyukov <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: dvyukov

src/cmd/dist/deps.go

@@ -7,6 +7,7 @@ package fmt_test
 import (
 	"bytes"
 	. "fmt"
+	"internal/race"
 	"io"
 	"math"
 	"reflect"
@@ -982,7 +983,7 @@ func TestCountMallocs(t *testing.T) {
 		t.Skip("skipping malloc count in short mode")
 	case runtime.GOMAXPROCS(0) > 1:
 		t.Skip("skipping; GOMAXPROCS>1")
-	case raceenabled:
+	case race.Enabled:
 		t.Skip("skipping malloc count under race detector")
 	}
 	for _, mt := range mallocTest {

src/fmt/fmt_test.go

@@ -39,9 +39,10 @@ var pkgDeps = map[string][]string{
 	"runtime":                 {"unsafe", "runtime/internal/atomic", "runtime/internal/sys"},
 	"runtime/internal/sys":    {},
 	"runtime/internal/atomic": {"unsafe", "runtime/internal/sys"},
-	"sync":        {"runtime", "sync/atomic", "unsafe"},
-	"sync/atomic": {"unsafe"},
-	"unsafe":      {},
+	"internal/race":           {"runtime", "unsafe"},
+	"sync":                    {"internal/race", "runtime", "sync/atomic", "unsafe"},
+	"sync/atomic":             {"unsafe"},
+	"unsafe":                  {},
 
 	"L0": {
 		"errors",
@@ -131,7 +132,7 @@ var pkgDeps = map[string][]string{
 	// End of linear dependency definitions.
 
 	// Operating system access.
-	"syscall":                           {"L0", "unicode/utf16"},
+	"syscall":                           {"L0", "internal/race", "unicode/utf16"},
 	"internal/syscall/unix":             {"L0", "syscall"},
 	"internal/syscall/windows":          {"L0", "syscall"},
 	"internal/syscall/windows/registry": {"L0", "syscall", "unicode/utf16"},
@@ -278,7 +279,7 @@ var pkgDeps = map[string][]string{
 	// Basic networking.
 	// Because net must be used by any package that wants to
 	// do networking portably, it must have a small dependency set: just L0+basic os.
-	"net": {"L0", "CGO", "math/rand", "os", "sort", "syscall", "time", "internal/syscall/windows", "internal/singleflight"},
+	"net": {"L0", "CGO", "math/rand", "os", "sort", "syscall", "time", "internal/syscall/windows", "internal/singleflight", "internal/race"},
 
 	// NET enables use of basic network-related packages.
 	"NET": {

src/fmt/norace_test.go

@@ -0,0 +1,11 @@
+// Copyright 2015 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 race contains helper functions for manually instrumenting code for the race detector.
+
+The runtime package intentionally exports these functions only in the race build;
+this package exports them unconditionally but without the "race" build tag they are no-ops.
+*/
+package race

src/fmt/race_test.go

@@ -0,0 +1,40 @@
+// Copyright 2015 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.
+
+// +build !race
+
+package race
+
+import (
+	"unsafe"
+)
+
+const Enabled = false
+
+func Acquire(addr unsafe.Pointer) {
+}
+
+func Release(addr unsafe.Pointer) {
+}
+
+func ReleaseMerge(addr unsafe.Pointer) {
+}
+
+func Disable() {
+}
+
+func Enable() {
+}
+
+func Read(addr unsafe.Pointer) {
+}
+
+func Write(addr unsafe.Pointer) {
+}
+
+func ReadRange(addr unsafe.Pointer, len int) {
+}
+
+func WriteRange(addr unsafe.Pointer, len int) {
+}

src/go/build/deps_test.go

@@ -0,0 +1,50 @@
+// Copyright 2015 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.
+
+// +build race
+
+package race
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+const Enabled = true
+
+func Acquire(addr unsafe.Pointer) {
+	runtime.RaceAcquire(addr)
+}
+
+func Release(addr unsafe.Pointer) {
+	runtime.RaceRelease(addr)
+}
+
+func ReleaseMerge(addr unsafe.Pointer) {
+	runtime.RaceReleaseMerge(addr)
+}
+
+func Disable() {
+	runtime.RaceDisable()
+}
+
+func Enable() {
+	runtime.RaceEnable()
+}
+
+func Read(addr unsafe.Pointer) {
+	runtime.RaceRead(addr)
+}
+
+func Write(addr unsafe.Pointer) {
+	runtime.RaceWrite(addr)
+}
+
+func ReadRange(addr unsafe.Pointer, len int) {
+	runtime.RaceReadRange(addr, len)
+}
+
+func WriteRange(addr unsafe.Pointer, len int) {
+	runtime.RaceWriteRange(addr, len)
+}

src/internal/race/doc.go

@@ -5,6 +5,7 @@
 package net
 
 import (
+	"internal/race"
 	"os"
 	"runtime"
 	"sync"
@@ -461,8 +462,8 @@ func (fd *netFD) Read(buf []byte) (int, error) {
 	n, err := rsrv.ExecIO(o, "WSARecv", func(o *operation) error {
 		return syscall.WSARecv(o.fd.sysfd, &o.buf, 1, &o.qty, &o.flags, &o.o, nil)
 	})
-	if raceenabled {
-		raceAcquire(unsafe.Pointer(&ioSync))
+	if race.Enabled {
+		race.Acquire(unsafe.Pointer(&ioSync))
 	}
 	err = fd.eofError(n, err)
 	if _, ok := err.(syscall.Errno); ok {
@@ -504,8 +505,8 @@ func (fd *netFD) Write(buf []byte) (int, error) {
 		return 0, err
 	}
 	defer fd.writeUnlock()
-	if raceenabled {
-		raceReleaseMerge(unsafe.Pointer(&ioSync))
+	if race.Enabled {
+		race.ReleaseMerge(unsafe.Pointer(&ioSync))
 	}
 	o := &fd.wop
 	o.InitBuf(buf)

src/internal/race/norace.go

@@ -5,6 +5,7 @@
 package sync
 
 import (
+	"internal/race"
 	"sync/atomic"
 	"unsafe"
 )
@@ -51,12 +52,12 @@ func NewCond(l Locker) *Cond {
 //
 func (c *Cond) Wait() {
 	c.checker.check()
-	if raceenabled {
-		raceDisable()
+	if race.Enabled {
+		race.Disable()
 	}
 	atomic.AddUint32(&c.waiters, 1)
-	if raceenabled {
-		raceEnable()
+	if race.Enabled {
+		race.Enable()
 	}
 	c.L.Unlock()
 	runtime_Syncsemacquire(&c.sema)
@@ -81,14 +82,14 @@ func (c *Cond) Broadcast() {
 
 func (c *Cond) signalImpl(all bool) {
 	c.checker.check()
-	if raceenabled {
-		raceDisable()
+	if race.Enabled {
+		race.Disable()
 	}
 	for {
 		old := atomic.LoadUint32(&c.waiters)
 		if old == 0 {
-			if raceenabled {
-				raceEnable()
+			if race.Enabled {
+				race.Enable()
 			}
 			return
 		}
@@ -97,8 +98,8 @@ func (c *Cond) signalImpl(all bool) {
 			new = 0
 		}
 		if atomic.CompareAndSwapUint32(&c.waiters, old, new) {
-			if raceenabled {
-				raceEnable()
+			if race.Enabled {
+				race.Enable()
 			}
 			runtime_Syncsemrelease(&c.sema, old-new)
 			return

src/internal/race/race.go

@@ -7,5 +7,3 @@ package sync
 // Export for testing.
 var Runtime_Semacquire = runtime_Semacquire
 var Runtime_Semrelease = runtime_Semrelease
-
-const RaceEnabled = raceenabled

src/net/fd_windows.go

@@ -11,6 +11,7 @@
 package sync
 
 import (
+	"internal/race"
 	"sync/atomic"
 	"unsafe"
 )
@@ -41,8 +42,8 @@ const (
 func (m *Mutex) Lock() {
 	// Fast path: grab unlocked mutex.
 	if atomic.CompareAndSwapInt32(&m.state, 0, mutexLocked) {
-		if raceenabled {
-			raceAcquire(unsafe.Pointer(m))
+		if race.Enabled {
+			race.Acquire(unsafe.Pointer(m))
 		}
 		return
 	}
@@ -85,8 +86,8 @@ func (m *Mutex) Lock() {
 		}
 	}
 
-	if raceenabled {
-		raceAcquire(unsafe.Pointer(m))
+	if race.Enabled {
+		race.Acquire(unsafe.Pointer(m))
 	}
 }
 
@@ -97,9 +98,9 @@ func (m *Mutex) Lock() {
 // It is allowed for one goroutine to lock a Mutex and then
 // arrange for another goroutine to unlock it.
 func (m *Mutex) Unlock() {
-	if raceenabled {
+	if race.Enabled {
 		_ = m.state
-		raceRelease(unsafe.Pointer(m))
+		race.Release(unsafe.Pointer(m))
 	}
 
 	// Fast path: drop lock bit.

src/net/race.go

@@ -5,6 +5,7 @@
 package sync
 
 import (
+	"internal/race"
 	"runtime"
 	"sync/atomic"
 	"unsafe"
@@ -59,7 +60,7 @@ type poolLocal struct {
 
 // Put adds x to the pool.
 func (p *Pool) Put(x interface{}) {
-	if raceenabled {
+	if race.Enabled {
 		// Under race detector the Pool degenerates into no-op.
 		// It's conforming, simple and does not introduce excessive
 		// happens-before edges between unrelated goroutines.
@@ -91,7 +92,7 @@ func (p *Pool) Put(x interface{}) {
 // If Get would otherwise return nil and p.New is non-nil, Get returns
 // the result of calling p.New.
 func (p *Pool) Get() interface{} {
-	if raceenabled {
+	if race.Enabled {
 		if p.New != nil {
 			return p.New()
 		}