1// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2// UNSUPPORTED: darwin
3#include <pthread.h>
4#include <stdio.h>
5#include <stdlib.h>
6#include <signal.h>
7#include <sys/types.h>
8#include <sys/time.h>
9#include <unistd.h>
10#include <errno.h>
11
12volatile int X;
13int stop;
14
15static void handler(int sig) {
16  (void)sig;
17  if (X != 0)
18    printf("bad");
19}
20
21static void* busy(void *p) {
22  while (__atomic_load_n(&stop, __ATOMIC_RELAXED) == 0) {
23  }
24  return 0;
25}
26
27static void* reset(void *p) {
28  struct sigaction act = {};
29  for (int i = 0; i < 1000000; i++) {
30    act.sa_handler = &handler;
31    if (sigaction(SIGPROF, &act, 0)) {
32      perror("sigaction");
33      exit(1);
34    }
35    act.sa_handler = SIG_IGN;
36    if (sigaction(SIGPROF, &act, 0)) {
37      perror("sigaction");
38      exit(1);
39    }
40  }
41  return 0;
42}
43
44int main() {
45  struct sigaction act = {};
46  act.sa_handler = SIG_IGN;
47  if (sigaction(SIGPROF, &act, 0)) {
48    perror("sigaction");
49    exit(1);
50  }
51
52  itimerval t;
53  t.it_value.tv_sec = 0;
54  t.it_value.tv_usec = 10;
55  t.it_interval = t.it_value;
56  if (setitimer(ITIMER_PROF, &t, 0)) {
57    perror("setitimer");
58    exit(1);
59  }
60
61  pthread_t th[2];
62  pthread_create(&th[0], 0, busy, 0);
63  pthread_create(&th[1], 0, reset, 0);
64
65  pthread_join(th[1], 0);
66  __atomic_store_n(&stop, 1, __ATOMIC_RELAXED);
67  pthread_join(th[0], 0);
68
69  fprintf(stderr, "DONE\n");
70  return 0;
71}
72
73// CHECK-NOT: WARNING: ThreadSanitizer:
74// CHECK: DONE
75// CHECK-NOT: WARNING: ThreadSanitizer:
76