compiler-rt/test/tsan/libdispatch/apply-race.c

   1 // RUN: %clang_tsan %s -o %t
   2 // RUN: %deflake %run %t 2>&1 | FileCheck %s
   3
   4 #include <dispatch/dispatch.h>
   5
   6 #include "../test.h"
   7
   8 long global;
   9
  10 int main(int argc, const char *argv[]) {
  11   barrier_init(&barrier, 2);
  12   fprintf(stderr, "start\n");
  13
  14   // Warm up GCD (workaround for macOS Sierra where dispatch_apply might run single-threaded).
  15   dispatch_sync(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ });
  16
  17   dispatch_queue_t q = dispatch_queue_create("my.queue", DISPATCH_QUEUE_CONCURRENT);
  18   dispatch_apply(2, q, ^(size_t i) {
  19     global = i;
  20     barrier_wait(&barrier);
  21   });
  22
  23   fprintf(stderr, "done\n");
  24   return 0;
  25 }
  26
  27 // CHECK: start
  28 // CHECK: WARNING: ThreadSanitizer: data race
  29 // CHECK: Location is global 'global'
  30 // CHECK: done