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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /dom/media/systemservices/ShmemPool.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'dom/media/systemservices/ShmemPool.cpp')
-rw-r--r--dom/media/systemservices/ShmemPool.cpp82
1 files changed, 82 insertions, 0 deletions
diff --git a/dom/media/systemservices/ShmemPool.cpp b/dom/media/systemservices/ShmemPool.cpp
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+++ b/dom/media/systemservices/ShmemPool.cpp
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+/* -*- 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/Assertions.h"
+#include "mozilla/Logging.h"
+#include "mozilla/ShmemPool.h"
+#include "mozilla/Move.h"
+
+namespace mozilla {
+
+ShmemPool::ShmemPool(size_t aPoolSize)
+ : mMutex("mozilla::ShmemPool"),
+ mPoolFree(aPoolSize)
+#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) {
+ // This isn't initialized, so will be understood as an error.
+ return ShmemBuffer();
+ }
+
+ ShmemBuffer& res = mShmemPool[mPoolFree - 1];
+
+ if (!res.mInitialized) {
+ LOG(("No free preallocated Shmem"));
+ return ShmemBuffer();
+ }
+
+ MOZ_ASSERT(res.mShmem.IsWritable(), "Pool in Shmem is not writable?");
+
+ if (res.mShmem.Size<char>() < aSize) {
+ 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;
+ LOG(("Maximum ShmemPool use increased: %d buffers", mMaxPoolUse));
+ }
+#endif
+ return Move(res);
+}
+
+void ShmemPool::Put(ShmemBuffer&& aShmem)
+{
+ MutexAutoLock lock(mMutex);
+ MOZ_ASSERT(mPoolFree < mShmemPool.Length());
+ mShmemPool[mPoolFree] = Move(aShmem);
+ mPoolFree++;
+#ifdef DEBUG
+ size_t poolUse = mShmemPool.Length() - mPoolFree;
+ if (poolUse > 0) {
+ LOG(("ShmemPool usage reduced to %d buffers", poolUse));
+ }
+#endif
+}
+
+ShmemPool::~ShmemPool()
+{
+#ifdef DEBUG
+ for (size_t i = 0; i < mShmemPool.Length(); i++) {
+ MOZ_ASSERT(!mShmemPool[i].Valid());
+ }
+#endif
+}
+
+} // namespace mozilla