test/tsan/fork_deadlock.cc

   1 // RUN: %clangxx_tsan -O1 %s -o %t && TSAN_OPTIONS="atexit_sleep_ms=50" %run %t 2>&1 | FileCheck %s
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <errno.h>
   5 #include <pthread.h>
   6 #include <unistd.h>
   7 #include <sys/types.h>
   8 #include <sys/wait.h>
   9
  10 int counter;
  11
  12 static void *incrementer(void *p) {
  13   for (;;)
  14     __sync_fetch_and_add(&counter, 1);
  15   return 0;
  16 }
  17
  18 static void *watchdog(void *p) {
  19   sleep(100);
  20   fprintf(stderr, "timed out after 100 seconds\n");
  21   exit(1);
  22   return 0;
  23 }
  24
  25 int main() {
  26   pthread_t th1, th2;
  27   pthread_create(&th1, 0, incrementer, 0);
  28   pthread_create(&th2, 0, watchdog, 0);
  29   for (int i = 0; i < 10; i++) {
  30     switch (fork()) {
  31     default:  // parent
  32       while (wait(0) < 0) {}
  33       fprintf(stderr, ".");
  34       break;
  35     case 0:  // child
  36       __sync_fetch_and_add(&counter, 1);
  37       exit(0);
  38       break;
  39     case -1:  // error
  40       fprintf(stderr, "failed to fork (%d)\n", errno);
  41       exit(1);
  42     }
  43   }
  44   fprintf(stderr, "OK\n");
  45 }
  46
  47 // CHECK: OK
  48