зеркало из https://github.com/mozilla/gecko-dev.git
83 строки
2.0 KiB
C++
83 строки
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set sw=2 ts=8 et ft=cpp : */
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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 file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "mozilla/Assertions.h"
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#include "mozilla/Logging.h"
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#include "mozilla/ShmemPool.h"
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#include "mozilla/Move.h"
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namespace mozilla {
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ShmemPool::ShmemPool(size_t aPoolSize)
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: mMutex("mozilla::ShmemPool"),
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mPoolFree(aPoolSize)
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#ifdef DEBUG
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,mMaxPoolUse(0)
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#endif
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{
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mShmemPool.SetLength(aPoolSize);
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}
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mozilla::ShmemBuffer ShmemPool::GetIfAvailable(size_t aSize)
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{
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MutexAutoLock lock(mMutex);
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// Pool is empty, don't block caller.
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if (mPoolFree == 0) {
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// This isn't initialized, so will be understood as an error.
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return ShmemBuffer();
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}
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ShmemBuffer& res = mShmemPool[mPoolFree - 1];
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if (!res.mInitialized) {
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LOG(("No free preallocated Shmem"));
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return ShmemBuffer();
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}
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MOZ_ASSERT(res.mShmem.IsWritable(), "Pool in Shmem is not writable?");
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if (res.mShmem.Size<uint8_t>() < aSize) {
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LOG(("Free Shmem but not of the right size"));
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return ShmemBuffer();
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}
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mPoolFree--;
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#ifdef DEBUG
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size_t poolUse = mShmemPool.Length() - mPoolFree;
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if (poolUse > mMaxPoolUse) {
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mMaxPoolUse = poolUse;
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LOG(("Maximum ShmemPool use increased: %zu buffers", mMaxPoolUse));
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}
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#endif
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return Move(res);
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}
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void ShmemPool::Put(ShmemBuffer&& aShmem)
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{
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MutexAutoLock lock(mMutex);
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MOZ_ASSERT(mPoolFree < mShmemPool.Length());
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mShmemPool[mPoolFree] = Move(aShmem);
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mPoolFree++;
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#ifdef DEBUG
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size_t poolUse = mShmemPool.Length() - mPoolFree;
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if (poolUse > 0) {
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LOG_VERBOSE(("ShmemPool usage reduced to %zu buffers", poolUse));
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}
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#endif
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}
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ShmemPool::~ShmemPool()
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{
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#ifdef DEBUG
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for (size_t i = 0; i < mShmemPool.Length(); i++) {
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MOZ_ASSERT(!mShmemPool[i].Valid());
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}
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#endif
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}
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} // namespace mozilla
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