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c3618a0b1b
When we shutdown the decode pool threads, it does not do a simple join with the main thread. It will actually process the main thread event loop, which can cause a bad series of events. The refresh tick could still be running and advancing our animated images, causing the animated decoders to continue running, which in turn prevents the decoder threads from finishing shutting down, and the main thread from joining them. Now we check on each frame whether or not the decoder should just stop decoding more frames because the decode pool has started shutdown. If it has, it will stop immediately.
111 lines
3.4 KiB
C++
111 lines
3.4 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/**
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* DecodePool manages the threads used for decoding raster images.
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*/
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#ifndef mozilla_image_DecodePool_h
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#define mozilla_image_DecodePool_h
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#include "mozilla/Mutex.h"
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#include "mozilla/StaticPtr.h"
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#include "nsCOMArray.h"
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#include "nsCOMPtr.h"
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#include "nsIEventTarget.h"
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#include "nsIObserver.h"
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#include "mozilla/RefPtr.h"
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#include "nsStringFwd.h"
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class nsIThread;
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class nsIThreadPool;
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namespace mozilla {
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namespace image {
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class Decoder;
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class DecodePoolImpl;
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class IDecodingTask;
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/**
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* DecodePool is a singleton class that manages decoding of raster images. It
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* owns a pool of image decoding threads that are used for asynchronous
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* decoding.
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*
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* DecodePool allows callers to run a decoder, handling management of the
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* decoder's lifecycle and whether it executes on the main thread,
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* off-main-thread in the image decoding thread pool, or on some combination of
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* the two.
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*/
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class DecodePool final : public nsIObserver
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{
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public:
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NS_DECL_THREADSAFE_ISUPPORTS
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NS_DECL_NSIOBSERVER
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/// Initializes the singleton instance. Should be called from the main thread.
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static void Initialize();
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/// Returns the singleton instance.
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static DecodePool* Singleton();
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/// @return the number of processor cores we have available. This is not the
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/// same as the number of decoding threads we're actually using.
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static uint32_t NumberOfCores();
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/// True if the DecodePool is being shutdown. This may only be called by
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/// threads from the pool to check if they should keep working or not.
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bool IsShuttingDown() const;
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/// Ask the DecodePool to run @aTask asynchronously and return immediately.
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void AsyncRun(IDecodingTask* aTask);
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/**
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* Run @aTask synchronously if the task would prefer it. It's up to the task
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* itself to make this decision; @see IDecodingTask::ShouldPreferSyncRun(). If
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* @aTask doesn't prefer it, just run @aTask asynchronously and return
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* immediately.
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* @return true if the task was run sync, false otherwise.
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*/
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bool SyncRunIfPreferred(IDecodingTask* aTask, const nsCString& aURI);
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/**
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* Run @aTask synchronously. This does not guarantee that @aTask will complete
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* synchronously. If, for example, @aTask doesn't yet have the data it needs to
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* run synchronously, it may recover by scheduling an async task to finish up
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* the work when the remaining data is available.
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*/
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void SyncRunIfPossible(IDecodingTask* aTask, const nsCString& aURI);
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/**
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* Returns an event target interface to the DecodePool's I/O thread. Callers
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* who want to deliver data to workers on the DecodePool can use this event
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* target.
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*
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* @return An nsIEventTarget interface to the thread pool's I/O thread.
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*/
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already_AddRefed<nsIEventTarget> GetIOEventTarget();
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private:
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friend class DecodePoolWorker;
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DecodePool();
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virtual ~DecodePool();
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static StaticRefPtr<DecodePool> sSingleton;
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static uint32_t sNumCores;
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RefPtr<DecodePoolImpl> mImpl;
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// mMutex protects mIOThread.
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Mutex mMutex;
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nsCOMPtr<nsIThread> mIOThread;
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};
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} // namespace image
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} // namespace mozilla
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#endif // mozilla_image_DecodePool_h
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