compiler-rt/test/tsan/fd_stdout_race.cpp

   1 // RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
   2 #include "test.h"
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6
   7 int X;
   8
   9 void *Thread1(void *x) {
  10   barrier_wait(&barrier);
  11   int f = open("/dev/random", O_RDONLY);
  12   char buf;
  13   read(f, &buf, 1);
  14   close(f);
  15   X = 42;
  16   return NULL;
  17 }
  18
  19 void *Thread2(void *x) {
  20   X = 43;
  21   write(STDOUT_FILENO, "a", 1);
  22   barrier_wait(&barrier);
  23   return NULL;
  24 }
  25
  26 int main() {
  27   barrier_init(&barrier, 2);
  28   pthread_t t[2];
  29   pthread_create(&t[0], NULL, Thread1, NULL);
  30   pthread_create(&t[1], NULL, Thread2, NULL);
  31   pthread_join(t[0], NULL);
  32   pthread_join(t[1], NULL);
  33 }
  34
  35 // CHECK: WARNING: ThreadSanitizer: data race
  36 // CHECK:   Write of size 4
  37 // CHECK:     #0 Thread1
  38 // CHECK:   Previous write of size 4
  39 // CHECK:     #0 Thread2
  40
  41