blob: 44f4821798d61ef20922966fb7dfc6a28fe84b88 [file] [log] [blame]
* Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <stddef.h>
#include <list>
#include "api/scoped_refptr.h"
#include "api/video/i420_buffer.h"
#include "rtc_base/race_checker.h"
#include "rtc_base/ref_counted_object.h"
namespace webrtc {
// Simple buffer pool to avoid unnecessary allocations of I420Buffer objects.
// The pool manages the memory of the I420Buffer returned from CreateBuffer.
// When the I420Buffer is destructed, the memory is returned to the pool for use
// by subsequent calls to CreateBuffer. If the resolution passed to CreateBuffer
// changes, old buffers will be purged from the pool.
// Note that CreateBuffer will crash if more than kMaxNumberOfFramesBeforeCrash
// are created. This is to prevent memory leaks where frames are not returned.
class I420BufferPool {
explicit I420BufferPool(bool zero_initialize);
I420BufferPool(bool zero_initialze, size_t max_number_of_buffers);
// Returns a buffer from the pool. If no suitable buffer exist in the pool
// and there are less than |max_number_of_buffers| pending, a buffer is
// created. Returns null otherwise.
rtc::scoped_refptr<I420Buffer> CreateBuffer(int width, int height);
// Returns a buffer from the pool with the explicitly specified stride.
rtc::scoped_refptr<I420Buffer> CreateBuffer(int width,
int height,
int stride_y,
int stride_u,
int stride_v);
// Changes the max amount of buffers in the pool to the new value.
// Returns true if change was successful and false if the amount of already
// allocated buffers is bigger than new value.
bool Resize(size_t max_number_of_buffers);
// Clears buffers_ and detaches the thread checker so that it can be reused
// later from another thread.
void Release();
// Explicitly use a RefCountedObject to get access to HasOneRef,
// needed by the pool to check exclusive access.
using PooledI420Buffer = rtc::RefCountedObject<I420Buffer>;
rtc::RaceChecker race_checker_;
std::list<rtc::scoped_refptr<PooledI420Buffer>> buffers_;
// If true, newly allocated buffers are zero-initialized. Note that recycled
// buffers are not zero'd before reuse. This is required of buffers used by
// FFmpeg according to, which only requires it for the
// initial allocation (as shown by FFmpeg's own buffer allocation code). It
// has to do with "Use-of-uninitialized-value" on "Linux_msan_chrome".
const bool zero_initialize_;
// Max number of buffers this pool can have pending.
size_t max_number_of_buffers_;
} // namespace webrtc