compiler-rt/test/tsan/fd_dup_norace.cpp

   1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
   2 #include <pthread.h>
   3 #include <stdio.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8
   9 int fds[2];
  10
  11 void *Thread1(void *x) {
  12   char buf;
  13   read(fds[0], &buf, 1);
  14   close(fds[0]);
  15   return 0;
  16 }
  17
  18 void *Thread2(void *x) {
  19   close(fds[1]);
  20   return 0;
  21 }
  22
  23 int main() {
  24   fds[0] = open("/dev/random", O_RDONLY);
  25   fds[1] = dup2(fds[0], 100);
  26   pthread_t t[2];
  27   pthread_create(&t[0], NULL, Thread1, NULL);
  28   pthread_create(&t[1], NULL, Thread2, NULL);
  29   pthread_join(t[0], NULL);
  30   pthread_join(t[1], NULL);
  31   fprintf(stderr, "OK\n");
  32 }
  33
  34 // CHECK-NOT: WARNING: ThreadSanitizer: data race