compiler-rt/test/tsan/fd_dup_race.cpp

   1 // RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
   2 #include "test.h"
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6
   7 // dup2(oldfd, newfd) races with close(newfd).
   8
   9 int fd;
  10
  11 void *Thread(void *x) {
  12   barrier_wait(&barrier);
  13   if (close(fd) == -1)
  14     exit(printf("close failed\n"));
  15   return 0;
  16 }
  17
  18 int main() {
  19   barrier_init(&barrier, 2);
  20   fd = open("/dev/random", O_RDONLY);
  21   int fd2 = open("/dev/random", O_RDONLY);
  22   if (fd == -1 || fd2 == -1)
  23     exit(printf("open failed\n"));
  24   pthread_t th;
  25   pthread_create(&th, 0, Thread, 0);
  26   if (dup2(fd2, fd) == -1)
  27     exit(printf("dup2 failed\n"));
  28   barrier_wait(&barrier);
  29   pthread_join(th, 0);
  30   fprintf(stderr, "DONE\n");
  31 }
  32
  33 // CHECK: WARNING: ThreadSanitizer: data race