1// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
2
3// Always enable asserts.
4#ifdef NDEBUG
5#undef NDEBUG
6#endif
7
8#include <assert.h>
9#include <stdlib.h>
10#include <signal.h>
11#include <unistd.h>
12#include <stdio.h>
13
14static bool signal_handler_ran = false;
15
16void do_nothing_signal_handler(int signum) {
17  write(1, "HANDLER\n", 8);
18  signal_handler_ran = true;
19}
20
21int main() {
22  const int kSignalToTest = SIGSYS;
23  assert(SIG_ERR != signal(kSignalToTest, do_nothing_signal_handler));
24  sigset_t empty_set;
25  assert(0 == sigemptyset(&empty_set));
26  sigset_t one_signal = empty_set;
27  assert(0 == sigaddset(&one_signal, kSignalToTest));
28  sigset_t old_set;
29  assert(0 == sigprocmask(SIG_BLOCK, &one_signal, &old_set));
30  raise(kSignalToTest);
31  assert(!signal_handler_ran);
32  sigset_t all_but_one;
33  assert(0 == sigfillset(&all_but_one));
34  assert(0 == sigdelset(&all_but_one, kSignalToTest));
35  sigsuspend(&all_but_one);
36  assert(signal_handler_ran);
37
38  // Restore the original set.
39  assert(0 == sigprocmask(SIG_SETMASK, &old_set, NULL));
40  printf("DONE");
41}
42
43// CHECK: HANDLER
44// CHECK: DONE
45