code review 6610064: race: syscall changes

src/pkg/syscall/syscall_windows.go

 // Copyright 2009 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.
 
 // Windows system calls.
 
 package syscall
 
 import (
         "unicode/utf16"
@@ skipping 249 matching lines @@
 func Read(fd Handle, p []byte) (n int, err error) {
         var done uint32
         e := ReadFile(fd, p, &done, nil)
         if e != nil {
                 if e == ERROR_BROKEN_PIPE {
                         // NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
                         return 0, nil
                 }
                 return 0, e
         }
+        if raceenabled {
+                raceAcquire(unsafe.Pointer(&ioSync))
+        }
         return int(done), nil
 }
 
 func Write(fd Handle, p []byte) (n int, err error) {
+        if raceenabled {
+                raceReleaseMerge(unsafe.Pointer(&ioSync))
+        }
         var done uint32
         e := WriteFile(fd, p, &done, nil)
         if e != nil {
                 return 0, e
         }
         return int(done), nil
 }
+
+var ioSync int64
 
 func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
         var w uint32
         switch whence {
         case 0:
                 w = FILE_BEGIN
         case 1:
                 w = FILE_CURRENT
         case 2:
                 w = FILE_END
@@ skipping 496 matching lines @@
 
 func (s Signal) String() string {
         if 0 <= s && int(s) < len(signals) {
                 str := signals[s]
                 if str != "" {
                         return str
                 }
         }
         return "signal " + itoa(int(s))
 }