1// Copyright 2015 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 5package main 6 7// This program produced false race reports when run under the C/C++ 8// ThreadSanitizer, as it did not understand the synchronization in 9// the Go code. 10 11/* 12#cgo CFLAGS: -fsanitize=thread 13#cgo LDFLAGS: -fsanitize=thread 14 15extern void GoRun(void); 16 17// Yes, you can have definitions if you use //export, as long as they are weak. 18 19int val __attribute__ ((weak)); 20 21int run(void) __attribute__ ((weak)); 22 23int run() { 24 val = 1; 25 GoRun(); 26 return val; 27} 28 29void setVal(int) __attribute__ ((weak)); 30 31void setVal(int i) { 32 val = i; 33} 34*/ 35import "C" 36 37import "runtime" 38 39//export GoRun 40func GoRun() { 41 runtime.LockOSThread() 42 c := make(chan bool) 43 go func() { 44 runtime.LockOSThread() 45 C.setVal(2) 46 c <- true 47 }() 48 <-c 49} 50 51func main() { 52 if v := C.run(); v != 2 { 53 panic(v) 54 } 55} 56