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5fd1d453a9
This change moves us away from NSPR primitives for our primary synchronization primitives. We're still using PRMonitor for ReentrantMonitor, however. The benefits of this change: * Slightly faster, as we don't have to deal with some of NSPR's overhead; * Smaller datatypes. On POSIX platforms in particular, PRLock is enormous. PRCondVar also has some unnecessary overhead. * Less dynamic memory allocation. Out of necessity, Mutex and CondVar allocated the NSPR data structures they needed, which lead to unnecessary checks for failure. While sizeof(Mutex) and sizeof(CondVar) may get bigger, since they're embedding structures now, the total memory usage should be less. * Less NSPR usage. This shouldn't need any explanation.
137 lines
2.8 KiB
C++
137 lines
2.8 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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#ifndef mozilla_CondVar_h
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#define mozilla_CondVar_h
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#include "mozilla/BlockingResourceBase.h"
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#include "mozilla/PlatformConditionVariable.h"
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#include "mozilla/Mutex.h"
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#ifdef MOZILLA_INTERNAL_API
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#include "GeckoProfiler.h"
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#endif //MOZILLA_INTERNAL_API
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namespace mozilla {
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/**
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* CondVar
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* Vanilla condition variable. Please don't use this unless you have a
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* compelling reason --- Monitor provides a simpler API.
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*/
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class CondVar : BlockingResourceBase
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{
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public:
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/**
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* CondVar
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*
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* The CALLER owns |aLock|.
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*
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* @param aLock A Mutex to associate with this condition variable.
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* @param aName A name which can reference this monitor
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* @returns If failure, nullptr.
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* If success, a valid Monitor* which must be destroyed
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* by Monitor::DestroyMonitor()
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**/
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CondVar(Mutex& aLock, const char* aName)
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: BlockingResourceBase(aName, eCondVar)
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, mLock(&aLock)
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{
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MOZ_COUNT_CTOR(CondVar);
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}
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/**
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* ~CondVar
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* Clean up after this CondVar, but NOT its associated Mutex.
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**/
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~CondVar()
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{
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MOZ_COUNT_DTOR(CondVar);
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}
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#ifndef DEBUG
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/**
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* Wait
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* @see prcvar.h
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**/
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nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT)
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{
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#ifdef MOZILLA_INTERNAL_API
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GeckoProfilerThreadSleepRAII sleep;
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#endif //MOZILLA_INTERNAL_API
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if (aInterval == PR_INTERVAL_NO_TIMEOUT) {
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mImpl.wait(*mLock);
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} else {
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mImpl.wait_for(*mLock, TimeDuration::FromMilliseconds(double(aInterval)));
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}
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return NS_OK;
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}
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#else
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nsresult Wait(PRIntervalTime aInterval = PR_INTERVAL_NO_TIMEOUT);
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#endif // ifndef DEBUG
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/**
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* Notify
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* @see prcvar.h
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**/
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nsresult Notify()
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{
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mImpl.notify_one();
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return NS_OK;
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}
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/**
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* NotifyAll
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* @see prcvar.h
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**/
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nsresult NotifyAll()
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{
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mImpl.notify_all();
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return NS_OK;
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}
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#ifdef DEBUG
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/**
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* AssertCurrentThreadOwnsMutex
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* @see Mutex::AssertCurrentThreadOwns
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**/
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void AssertCurrentThreadOwnsMutex()
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{
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mLock->AssertCurrentThreadOwns();
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}
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/**
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* AssertNotCurrentThreadOwnsMutex
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* @see Mutex::AssertNotCurrentThreadOwns
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**/
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void AssertNotCurrentThreadOwnsMutex()
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{
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mLock->AssertNotCurrentThreadOwns();
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}
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#else
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void AssertCurrentThreadOwnsMutex() {}
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void AssertNotCurrentThreadOwnsMutex() {}
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#endif // ifdef DEBUG
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private:
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CondVar();
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CondVar(const CondVar&) = delete;
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CondVar& operator=(const CondVar&) = delete;
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Mutex* mLock;
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detail::ConditionVariableImpl mImpl;
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};
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} // namespace mozilla
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#endif // ifndef mozilla_CondVar_h
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