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// RUN: %clang_tsan %s -o %t -undefined dynamic_lookup
// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not='ThreadSanitizer'
#include "dispatch/dispatch.h"
#include <stdio.h>
// Allow compilation with pre-macOS 10.14 (and aligned) SDKs
API_AVAILABLE(macos(10.14), ios(12.0), tvos(12.0), watchos(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW
void dispatch_async_and_wait(dispatch_queue_t queue,
DISPATCH_NOESCAPE dispatch_block_t block);
long global;
int main() {
// Guard execution on pre-macOS 10.14 (and aligned) platforms
if (dispatch_async_and_wait == NULL) {
fprintf(stderr, "Done.\n");
return 0;
}
dispatch_queue_t q = dispatch_queue_create("my.queue", DISPATCH_QUEUE_SERIAL);
dispatch_semaphore_t s = dispatch_semaphore_create(0);
// Force queue to context switch onto separate thread.
dispatch_async(q, ^{
dispatch_semaphore_wait(s, DISPATCH_TIME_FOREVER);
});
dispatch_semaphore_signal(s);
global++;
dispatch_async_and_wait(q, ^{
// The queue continues to execute on separate thread. This would cause a
// race if we had used `dispatch_async()` without the `_and_wait` part.
global++;
});
global++;
fprintf(stderr, "Done.\n");
return 0;
}
// CHECK: Done.
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