1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 // UNSUPPORTED: ios
3
4 #include <pthread.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <unistd.h>
8 #include <sys/types.h>
9
10 int fds[2];
11 int X;
12
Thread1(void * x)13 void *Thread1(void *x) {
14 X = 42;
15 write(fds[1], "a", 1);
16 return NULL;
17 }
18
Thread2(void * x)19 void *Thread2(void *x) {
20 char buf;
21 while (read(fds[0], &buf, 1) != 1) {
22 }
23 X = 43;
24 return NULL;
25 }
26
main()27 int main() {
28 pipe(fds);
29 int pid = vfork();
30 if (pid < 0) {
31 fprintf(stderr, "FAIL to vfork\n");
32 exit(1);
33 }
34 if (pid == 0) { // child
35 // Closing of fds must not affect parent process.
36 // Strictly saying this is undefined behavior, because vfork child is not
37 // allowed to call any functions other than exec/exit. But this is what
38 // openjdk does.
39 close(fds[0]);
40 close(fds[1]);
41 _exit(0);
42 }
43 pthread_t t[2];
44 pthread_create(&t[0], NULL, Thread1, NULL);
45 pthread_create(&t[1], NULL, Thread2, NULL);
46 pthread_join(t[0], NULL);
47 pthread_join(t[1], NULL);
48 fprintf(stderr, "DONE\n");
49 }
50
51 // CHECK-NOT: WARNING: ThreadSanitizer: data race
52 // CHECK-NOT: FAIL to vfork
53 // CHECK: DONE
54