mirror of
https://github.com/mozilla/gecko-dev.git
synced 2025-10-31 08:18:54 +02:00
108 lines
3.4 KiB
C++
108 lines
3.4 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* 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/. */
|
|
|
|
/**
|
|
* DecodePool manages the threads used for decoding raster images.
|
|
*/
|
|
|
|
#ifndef mozilla_image_DecodePool_h
|
|
#define mozilla_image_DecodePool_h
|
|
|
|
#include "mozilla/Mutex.h"
|
|
#include "mozilla/StaticPtr.h"
|
|
#include "nsCOMArray.h"
|
|
#include "nsCOMPtr.h"
|
|
#include "nsIEventTarget.h"
|
|
#include "nsIObserver.h"
|
|
#include "mozilla/RefPtr.h"
|
|
#include "nsStringFwd.h"
|
|
|
|
class nsIThread;
|
|
class nsIThreadPool;
|
|
|
|
namespace mozilla {
|
|
namespace image {
|
|
|
|
class Decoder;
|
|
class DecodePoolImpl;
|
|
class IDecodingTask;
|
|
|
|
/**
|
|
* DecodePool is a singleton class that manages decoding of raster images. It
|
|
* owns a pool of image decoding threads that are used for asynchronous
|
|
* decoding.
|
|
*
|
|
* DecodePool allows callers to run a decoder, handling management of the
|
|
* decoder's lifecycle and whether it executes on the main thread,
|
|
* off-main-thread in the image decoding thread pool, or on some combination of
|
|
* the two.
|
|
*/
|
|
class DecodePool final : public nsIObserver {
|
|
public:
|
|
NS_DECL_THREADSAFE_ISUPPORTS
|
|
NS_DECL_NSIOBSERVER
|
|
|
|
/// Initializes the singleton instance. Should be called from the main thread.
|
|
static void Initialize();
|
|
|
|
/// Returns the singleton instance.
|
|
static DecodePool* Singleton();
|
|
|
|
/// @return the number of processor cores we have available. This is not the
|
|
/// same as the number of decoding threads we're actually using.
|
|
static uint32_t NumberOfCores();
|
|
|
|
/// True if the DecodePool is being shutdown. This may only be called by
|
|
/// threads from the pool to check if they should keep working or not.
|
|
static bool IsShuttingDown();
|
|
|
|
/// Ask the DecodePool to run @aTask asynchronously and return immediately.
|
|
void AsyncRun(IDecodingTask* aTask);
|
|
|
|
/**
|
|
* Run @aTask synchronously if the task would prefer it. It's up to the task
|
|
* itself to make this decision; @see IDecodingTask::ShouldPreferSyncRun(). If
|
|
* @aTask doesn't prefer it, just run @aTask asynchronously and return
|
|
* immediately.
|
|
* @return true if the task was run sync, false otherwise.
|
|
*/
|
|
bool SyncRunIfPreferred(IDecodingTask* aTask, const nsCString& aURI);
|
|
|
|
/**
|
|
* Run @aTask synchronously. This does not guarantee that @aTask will complete
|
|
* synchronously. If, for example, @aTask doesn't yet have the data it needs
|
|
* to run synchronously, it may recover by scheduling an async task to finish
|
|
* up the work when the remaining data is available.
|
|
*/
|
|
void SyncRunIfPossible(IDecodingTask* aTask, const nsCString& aURI);
|
|
|
|
/**
|
|
* Returns an event target interface to the DecodePool's I/O thread. Callers
|
|
* who want to deliver data to workers on the DecodePool can use this event
|
|
* target.
|
|
*
|
|
* @return An nsISerialEventTarget interface to the thread pool's I/O thread.
|
|
*/
|
|
already_AddRefed<nsISerialEventTarget> GetIOEventTarget();
|
|
|
|
private:
|
|
friend class DecodePoolWorker;
|
|
|
|
DecodePool();
|
|
virtual ~DecodePool();
|
|
|
|
static StaticRefPtr<DecodePool> sSingleton;
|
|
static uint32_t sNumCores;
|
|
bool mShuttingDown = false;
|
|
|
|
// mMutex protects mIOThread.
|
|
Mutex mMutex;
|
|
nsCOMPtr<nsIThread> mIOThread MOZ_GUARDED_BY(mMutex);
|
|
};
|
|
|
|
} // namespace image
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_image_DecodePool_h
|