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