зеркало из https://github.com/mozilla/gecko-dev.git
100 строки
2.5 KiB
C++
100 строки
2.5 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set sw=2 ts=8 et ft=cpp : */
|
|
/* 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 "mozilla/ShmemPool.h"
|
|
|
|
#include <utility>
|
|
|
|
#include "mozilla/Assertions.h"
|
|
#include "mozilla/Logging.h"
|
|
|
|
mozilla::LazyLogModule sShmemPoolLog("ShmemPool");
|
|
|
|
#define SHMEMPOOL_LOG_VERBOSE(args) \
|
|
MOZ_LOG(sShmemPoolLog, mozilla::LogLevel::Verbose, args)
|
|
|
|
namespace mozilla {
|
|
|
|
ShmemPool::ShmemPool(size_t aPoolSize, PoolType aPoolType)
|
|
: mPoolType(aPoolType),
|
|
mMutex("mozilla::ShmemPool"),
|
|
mPoolFree(aPoolSize),
|
|
mErrorLogged(false)
|
|
#ifdef DEBUG
|
|
,
|
|
mMaxPoolUse(0)
|
|
#endif
|
|
{
|
|
mShmemPool.SetLength(aPoolSize);
|
|
}
|
|
|
|
mozilla::ShmemBuffer ShmemPool::GetIfAvailable(size_t aSize) {
|
|
MutexAutoLock lock(mMutex);
|
|
|
|
// Pool is empty, don't block caller.
|
|
if (mPoolFree == 0) {
|
|
if (!mErrorLogged) {
|
|
// log "out of pool" once as error to avoid log spam
|
|
mErrorLogged = true;
|
|
SHMEMPOOL_LOG_ERROR(
|
|
("ShmemPool is empty, future occurrences "
|
|
"will be logged as warnings"));
|
|
} else {
|
|
SHMEMPOOL_LOG_WARN(("ShmemPool is empty"));
|
|
}
|
|
// This isn't initialized, so will be understood as an error.
|
|
return ShmemBuffer();
|
|
}
|
|
|
|
ShmemBuffer& res = mShmemPool[mPoolFree - 1];
|
|
|
|
if (!res.mInitialized) {
|
|
SHMEMPOOL_LOG(("No free preallocated Shmem"));
|
|
return ShmemBuffer();
|
|
}
|
|
|
|
MOZ_ASSERT(res.mShmem.IsWritable(), "Pool in Shmem is not writable?");
|
|
|
|
if (res.mShmem.Size<uint8_t>() < aSize) {
|
|
SHMEMPOOL_LOG(("Free Shmem but not of the right size"));
|
|
return ShmemBuffer();
|
|
}
|
|
|
|
mPoolFree--;
|
|
#ifdef DEBUG
|
|
size_t poolUse = mShmemPool.Length() - mPoolFree;
|
|
if (poolUse > mMaxPoolUse) {
|
|
mMaxPoolUse = poolUse;
|
|
SHMEMPOOL_LOG(
|
|
("Maximum ShmemPool use increased: %zu buffers", mMaxPoolUse));
|
|
}
|
|
#endif
|
|
return std::move(res);
|
|
}
|
|
|
|
void ShmemPool::Put(ShmemBuffer&& aShmem) {
|
|
MutexAutoLock lock(mMutex);
|
|
MOZ_ASSERT(mPoolFree < mShmemPool.Length());
|
|
mShmemPool[mPoolFree] = std::move(aShmem);
|
|
mPoolFree++;
|
|
#ifdef DEBUG
|
|
size_t poolUse = mShmemPool.Length() - mPoolFree;
|
|
if (poolUse > 0) {
|
|
SHMEMPOOL_LOG_VERBOSE(("ShmemPool usage reduced to %zu buffers", poolUse));
|
|
}
|
|
#endif
|
|
}
|
|
|
|
ShmemPool::~ShmemPool() {
|
|
#ifdef DEBUG
|
|
for (size_t i = 0; i < mShmemPool.Length(); i++) {
|
|
MOZ_ASSERT(!mShmemPool[i].Valid());
|
|
}
|
|
#endif
|
|
}
|
|
|
|
} // namespace mozilla
|