利用 Thread Sanitizer 工具检查数据竞争的问题
例子
#include <pthread.h>
int Global;
void *Thread1(void *x) {
Global = 42;
return x;
}
int main(void) {
pthread_t t;
pthread_create(&t, NULL, Thread1, NULL);
Global = 43;
pthread_join(t, NULL);
return Global;
}
技巧
gcc 从4.8版本起，集成了Address Sanitizer工具，可以用来检查数据竞争的问题（编译时指定“-fsanitize=thread -fPIE -pie”）。以上面程序为例：
gcc -fsanitize=thread -fPIE -pie -g -o a a.c -lpthread
执行a程序：
[root@localhost nan]# ./a
==================
WARNING: ThreadSanitizer: data race (pid=14545)
Write of size 4 at 0x7f055b4802b0 by thread T1:
#0 Thread1 /home/nan/a.c:4 (a+0x000000000a87)
Previous write of size 4 at 0x7f055b4802b0 by main thread:
#0 main /home/nan/a.c:10 (a+0x000000000ae8)
Location is global 'Global' of size 4 at 0x7f055b4802b0 (a+0x0000002012b0)
Thread T1 (tid=14547, running) created by main thread at:
#0 pthread_create /opt/gcc-4.9.2/src/gcc-4.9.2/libsanitizer/tsan/tsan_interceptors.cc:877 (libtsan.so.0+0x00000004aa83)
#1 main /home/nan/a.c:9 (a+0x000000000ad9)
SUMMARY: ThreadSanitizer: data race /home/nan/a.c:4 Thread1
==================
ThreadSanitizer: reported 1 warnings
可以看到，执行程序时检测出了对Global变量的竞争访问。
详情参见gcc 手册
贡献者
nanxiao
