зеркало из https://github.com/mozilla/gecko-dev.git
68 строки
2.1 KiB
C++
68 строки
2.1 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "nsISupportsImpl.h"
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#include "mozilla/Atomics.h"
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#include "nsThreadUtils.h"
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#include "gtest/gtest.h"
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using namespace mozilla;
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class nsThreadSafeAutoRefCntRunner final : public nsIRunnable
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{
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public:
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NS_DECL_THREADSAFE_ISUPPORTS
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NS_IMETHOD Run() final
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{
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for (int i = 0; i < 10000; i++) {
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if (++sRefCnt == 1) {
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sIncToOne++;
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}
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if (--sRefCnt == 0) {
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sDecToZero++;
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}
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}
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return NS_OK;
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}
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static ThreadSafeAutoRefCnt sRefCnt;
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static Atomic<uint32_t, Relaxed> sIncToOne;
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static Atomic<uint32_t, Relaxed> sDecToZero;
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private:
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~nsThreadSafeAutoRefCntRunner() {}
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};
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NS_IMPL_ISUPPORTS(nsThreadSafeAutoRefCntRunner, nsIRunnable)
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ThreadSafeAutoRefCnt nsThreadSafeAutoRefCntRunner::sRefCnt;
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Atomic<uint32_t, Relaxed> nsThreadSafeAutoRefCntRunner::sIncToOne(0);
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Atomic<uint32_t, Relaxed> nsThreadSafeAutoRefCntRunner::sDecToZero(0);
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// When a refcounted object is actually owned by a cache, we may not
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// want to release the object after last reference gets released. In
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// this pattern, the cache may rely on the balance of increment to one
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// and decrement to zero, so that it can maintain a counter for GC.
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TEST(AutoRefCnt, ThreadSafeAutoRefCntBalance)
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{
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static const size_t kThreadCount = 4;
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nsCOMPtr<nsIThread> threads[kThreadCount];
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for (size_t i = 0; i < kThreadCount; i++) {
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nsresult rv = NS_NewThread(getter_AddRefs(threads[i]),
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new nsThreadSafeAutoRefCntRunner);
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EXPECT_TRUE(NS_SUCCEEDED(rv));
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}
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for (size_t i = 0; i < kThreadCount; i++) {
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threads[i]->Shutdown();
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}
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EXPECT_EQ(nsThreadSafeAutoRefCntRunner::sRefCnt, nsrefcnt(0));
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EXPECT_EQ(nsThreadSafeAutoRefCntRunner::sIncToOne,
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nsThreadSafeAutoRefCntRunner::sDecToZero);
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}
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