зеркало из https://github.com/mozilla/gecko-dev.git
105 строки
3.2 KiB
C++
105 строки
3.2 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 "mozilla/RefPtr.h"
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#include "mozilla/ThreadSafeWeakPtr.h"
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using mozilla::SupportsThreadSafeWeakPtr;
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using mozilla::ThreadSafeWeakPtr;
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// To have a class C support weak pointers, inherit from SupportsThreadSafeWeakPtr<C>.
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class C : public SupportsThreadSafeWeakPtr<C>
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{
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public:
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MOZ_DECLARE_THREADSAFEWEAKREFERENCE_TYPENAME(C)
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MOZ_DECLARE_REFCOUNTED_TYPENAME(C)
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int mNum;
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C()
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: mNum(0)
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{}
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~C()
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{
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// Setting mNum in the destructor allows us to test against use-after-free below
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mNum = 0xDEAD;
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}
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void act() {}
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};
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int
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main()
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{
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RefPtr<C> c1 = new C;
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MOZ_RELEASE_ASSERT(c1->mNum == 0);
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// Get weak pointers to c1. The first time,
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// a reference-counted ThreadSafeWeakReference object is created that
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// can live beyond the lifetime of 'c1'. The ThreadSafeWeakReference
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// object will be notified of 'c1's destruction.
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ThreadSafeWeakPtr<C> w1(c1);
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{
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RefPtr<C> s1(w1);
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// Test a weak pointer for validity before using it.
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MOZ_RELEASE_ASSERT(s1);
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MOZ_RELEASE_ASSERT(s1 == c1);
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s1->mNum = 1;
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s1->act();
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}
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// Test taking another ThreadSafeWeakPtr<C> to c1
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ThreadSafeWeakPtr<C> w2(c1);
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{
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RefPtr<C> s2(w2);
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MOZ_RELEASE_ASSERT(s2);
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MOZ_RELEASE_ASSERT(s2 == c1);
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MOZ_RELEASE_ASSERT(w1 == s2);
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MOZ_RELEASE_ASSERT(s2->mNum == 1);
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}
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// Test that when a ThreadSafeWeakPtr is destroyed, it does not destroy the object that it points to,
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// and it does not affect other ThreadSafeWeakPtrs pointing to the same object (e.g. it does not
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// destroy the ThreadSafeWeakReference object).
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{
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ThreadSafeWeakPtr<C> w4local(c1);
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MOZ_RELEASE_ASSERT(w4local == c1);
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}
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// Now w4local has gone out of scope. If that had destroyed c1, then the following would fail
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// for sure (see C::~C()).
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MOZ_RELEASE_ASSERT(c1->mNum == 1);
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// Check that w4local going out of scope hasn't affected other ThreadSafeWeakPtr's pointing to c1
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MOZ_RELEASE_ASSERT(w1 == c1);
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MOZ_RELEASE_ASSERT(w2 == c1);
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// Now construct another C object and test changing what object a ThreadSafeWeakPtr points to
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RefPtr<C> c2 = new C;
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c2->mNum = 2;
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{
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RefPtr<C> s2(w2);
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MOZ_RELEASE_ASSERT(s2->mNum == 1); // w2 was pointing to c1
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}
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w2 = c2;
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{
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RefPtr<C> s2(w2);
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MOZ_RELEASE_ASSERT(s2);
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MOZ_RELEASE_ASSERT(s2 == c2);
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MOZ_RELEASE_ASSERT(s2 != c1);
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MOZ_RELEASE_ASSERT(w1 != s2);
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MOZ_RELEASE_ASSERT(s2->mNum == 2);
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}
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// Destroying the underlying object clears weak pointers to it.
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// It should not affect pointers that are not currently pointing to it.
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c1 = nullptr;
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MOZ_RELEASE_ASSERT(!bool(w1), "Deleting an object should clear ThreadSafeWeakPtr's to it.");
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MOZ_RELEASE_ASSERT(bool(w2), "Deleting an object should not clear ThreadSafeWeakPtr that are not pointing to it.");
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c2 = nullptr;
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MOZ_RELEASE_ASSERT(!bool(w2), "Deleting an object should clear ThreadSafeWeakPtr's to it.");
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}
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