libgo/misc/cgo/testsanitizers/src/tsan6.go

   1 // Copyright 2016 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package main
   6
   7 // Check that writes to Go allocated memory, with Go synchronization,
   8 // do not look like a race.
   9
  10 /*
  11 #cgo CFLAGS: -fsanitize=thread
  12 #cgo LDFLAGS: -fsanitize=thread
  13
  14 void f(char *p) {
  15         *p = 1;
  16 }
  17 */
  18 import "C"
  19
  20 import (
  21         "runtime"
  22         "sync"
  23 )
  24
  25 func main() {
  26         var wg sync.WaitGroup
  27         var mu sync.Mutex
  28         c := make(chan []C.char, 100)
  29         for i := 0; i < 10; i++ {
  30                 wg.Add(2)
  31                 go func() {
  32                         defer wg.Done()
  33                         for i := 0; i < 100; i++ {
  34                                 c <- make([]C.char, 4096)
  35                                 runtime.Gosched()
  36                         }
  37                 }()
  38                 go func() {
  39                         defer wg.Done()
  40                         for i := 0; i < 100; i++ {
  41                                 p := &(<-c)[0]
  42                                 mu.Lock()
  43                                 C.f(p)
  44                                 mu.Unlock()
  45                         }
  46                 }()
  47         }
  48         wg.Wait()
  49 }