1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 #include <pthread.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <unistd.h>
6 #include <sys/types.h>
7
8 int fds[2];
9 int X;
10
Thread1(void * x)11 void *Thread1(void *x) {
12 X = 42;
13 write(fds[1], "a", 1);
14 return NULL;
15 }
16
Thread2(void * x)17 void *Thread2(void *x) {
18 char buf;
19 while (read(fds[0], &buf, 1) != 1) {
20 }
21 X = 43;
22 return NULL;
23 }
24
main()25 int main() {
26 pipe(fds);
27 int pid = vfork();
28 if (pid < 0) {
29 fprintf(stderr, "FAIL to vfork\n");
30 exit(1);
31 }
32 if (pid == 0) { // child
33 // Closing of fds must not affect parent process.
34 // Strictly saying this is undefined behavior, because vfork child is not
35 // allowed to call any functions other than exec/exit. But this is what
36 // openjdk does.
37 close(fds[0]);
38 close(fds[1]);
39 _exit(0);
40 }
41 pthread_t t[2];
42 pthread_create(&t[0], NULL, Thread1, NULL);
43 pthread_create(&t[1], NULL, Thread2, NULL);
44 pthread_join(t[0], NULL);
45 pthread_join(t[1], NULL);
46 fprintf(stderr, "DONE\n");
47 }
48
49 // CHECK-NOT: WARNING: ThreadSanitizer: data race
50 // CHECK-NOT: FAIL to vfork
51 // CHECK: DONE
52