1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | 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 
14 static bool signal_handler_ran = false;
15 
do_nothing_signal_handler(int signum)16 void do_nothing_signal_handler(int signum) {
17   write(1, "HANDLER\n", 8);
18   signal_handler_ran = true;
19 }
20 
main()21 int 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\n");
41 }
42 
43 // CHECK: HANDLER
44 // CHECK: DONE
45