1 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 
3 // Test that a signal is not delivered when it is blocked.
4 
5 #include "test.h"
6 #include <semaphore.h>
7 #include <signal.h>
8 #include <errno.h>
9 
10 int stop;
11 sig_atomic_t signal_blocked;
12 
handler(int signum)13 void handler(int signum) {
14   if (signal_blocked) {
15     fprintf(stderr, "signal arrived when blocked\n");
16     exit(1);
17   }
18 }
19 
thread(void * arg)20 void *thread(void *arg) {
21   sigset_t myset;
22   sigemptyset(&myset);
23   sigaddset(&myset, SIGUSR1);
24   while (!__atomic_load_n(&stop, __ATOMIC_RELAXED)) {
25     usleep(1);
26     if (pthread_sigmask(SIG_BLOCK, &myset, 0)) {
27       fprintf(stderr, "pthread_sigmask failed %d\n", errno);
28       exit(1);
29     }
30     signal_blocked = 1;
31     usleep(1);
32     signal_blocked = 0;
33     if (pthread_sigmask(SIG_UNBLOCK, &myset, 0)) {
34       fprintf(stderr, "pthread_sigmask failed %d\n", errno);
35       exit(1);
36     }
37   }
38   return 0;
39 }
40 
main(int argc,char ** argv)41 int main(int argc, char** argv) {
42   struct sigaction act = {};
43   act.sa_handler = &handler;
44   if (sigaction(SIGUSR1, &act, 0)) {
45     fprintf(stderr, "sigaction failed %d\n", errno);
46     return 1;
47   }
48   pthread_t th;
49   pthread_create(&th, 0, thread, 0);
50   for (int i = 0; i < 100000; i++)
51     pthread_kill(th, SIGUSR1);
52   __atomic_store_n(&stop, 1, __ATOMIC_RELAXED);
53   pthread_join(th, 0);
54   fprintf(stderr, "DONE\n");
55   return 0;
56 }
57 
58 // CHECK-NOT: ThreadSanitizer CHECK
59 // CHECK-NOT: WARNING: ThreadSanitizer:
60 // CHECK: DONE
61