gecko-dev/dom/media/systemservices/MediaSystemResourceClient.h

95 строки
2.7 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */
#if !defined(MediaSystemResourceClient_h_)
#define MediaSystemResourceClient_h_
#include "MediaSystemResourceManager.h"
#include "MediaSystemResourceTypes.h"
#include "mozilla/Atomics.h"
#include "mozilla/media/MediaSystemResourceTypes.h"
#include "mozilla/Monitor.h"
#include "mozilla/nsRefPtr.h"
namespace mozilla {
class MediaSystemResourceManager;
/**
* This is a base class for listener callbacks.
* This callback is invoked when the media system resource reservation state
* is changed.
*/
class MediaSystemResourceReservationListener {
public:
virtual void ResourceReserved() = 0;
virtual void ResourceReserveFailed() = 0;
};
/**
* MediaSystemResourceClient is used to reserve a media system resource
* like hw decoder. When system has a limitation of a media resource,
* use this class to mediate use rights of the resource.
*/
class MediaSystemResourceClient
{
public:
// Enumeration for the valid decoding states
enum ResourceState {
RESOURCE_STATE_START,
RESOURCE_STATE_WAITING,
RESOURCE_STATE_ACQUIRED,
RESOURCE_STATE_NOT_ACQUIRED,
RESOURCE_STATE_END
};
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaSystemResourceClient)
explicit MediaSystemResourceClient(MediaSystemResourceType aReourceType);
bool SetListener(MediaSystemResourceReservationListener* aListener);
// Try to acquire media resource asynchronously.
// If the resource is used by others, wait until acquired.
void Acquire();
// Try to acquire media resource synchronously. If the resource is not immediately
// available, fail to acquire it.
// return false if resource is not acquired.
// return true if resource is acquired.
//
// This function should not be called on ImageBridge thread.
// It should be used only for compatibility with legacy code.
bool AcquireSyncNoWait();
void ReleaseResource();
private:
~MediaSystemResourceClient();
nsRefPtr<MediaSystemResourceManager> mManager;
const MediaSystemResourceType mResourceType;
const uint32_t mId;
// Modified only by MediaSystemResourceManager.
// Accessed and modified with MediaSystemResourceManager::mReentrantMonitor held.
MediaSystemResourceReservationListener* mListener;
ResourceState mResourceState;
bool mIsSync;
ReentrantMonitor* mAcquireSyncWaitMonitor;
bool* mAcquireSyncWaitDone;
static mozilla::Atomic<uint32_t> sSerialCounter;
friend class MediaSystemResourceManager;
};
} // namespace mozilla
#endif