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