compiler-rt/test/tsan/libdispatch/once.c

   1 // RUN: %clang_tsan %s -o %t
   2 // RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not='ThreadSanitizer'
   3
   4 #include <dispatch/dispatch.h>
   5
   6 #include "../test.h"
   7
   8 static const long kNumThreads = 4;
   9
  10 long global;
  11 long global2;
  12
  13 static dispatch_once_t once_token;
  14 static dispatch_once_t once_token2;
  15
  16 void f(void *a) {
  17   global2 = 42;
  18   usleep(100000);
  19 }
  20
  21 void *Thread(void *a) {
  22   barrier_wait(&barrier);
  23
  24   dispatch_once(&once_token, ^{
  25     global = 42;
  26     usleep(100000);
  27   });
  28   long x = global;
  29
  30   dispatch_once_f(&once_token2, NULL, f);
  31   long x2 = global2;
  32
  33   fprintf(stderr, "global = %ld\n", x);
  34   fprintf(stderr, "global2 = %ld\n", x2);
  35   return 0;
  36 }
  37
  38 int main() {
  39   fprintf(stderr, "Hello world.\n");
  40   barrier_init(&barrier, kNumThreads);
  41
  42   pthread_t t[kNumThreads];
  43   for (int i = 0; i < kNumThreads; i++) {
  44     pthread_create(&t[i], 0, Thread, 0);
  45   }
  46   for (int i = 0; i < kNumThreads; i++) {
  47     pthread_join(t[i], 0);
  48   }
  49
  50   fprintf(stderr, "Done.\n");
  51 }
  52
  53 // CHECK: Hello world.
  54 // CHECK: Done.