gecko-dev/image/DecodePool.h
Nicholas Nethercote 58786e1ea7 Bug 1375392 - Tweak the PROFILER_LABEL* macros. r=mstange.
This patch makes the following changes to the macros.

- Removes PROFILER_LABEL_FUNC. It's only suitable for use in functions outside
  classes, due to PROFILER_FUNCTION_NAME not getting class names, and it was
  mostly misused.

- Removes PROFILER_FUNCTION_NAME. It's no longer used, and __func__ is
  universally available now anyway.

- Combines the first two string literal arguments of PROFILER_LABEL and
  PROFILER_LABEL_DYNAMIC into a single argument. There was no good reason for
  them to be separate, and it forced a '::' in the label, which isn't always
  appropriate. Also, the meaning of the "name_space" argument was interpreted
  in an interesting variety of ways.

- Adds an "AUTO_" prefix to PROFILER_LABEL and PROFILER_LABEL_DYNAMIC, to make
  it clearer they construct RAII objects rather than just being function calls.
  (I myself have screwed up the scoping because of this in the past.)

- Fills in the 'js::ProfileEntry::Category::' qualifier within the macro, so
  the caller doesn't need to. This makes a *lot* more of the uses fit onto a
  single line.

The patch also makes the following changes to the macro uses (beyond those
required by the changes described above).

- Fixes a bunch of labels that had gotten out of sync with the name of the
  class and/or function that encloses them.

- Removes a useless PROFILER_LABEL use within a trivial scope in
  EventStateManager::DispatchMouseOrPointerEvent(). It clearly wasn't serving
  any useful purpose. It also serves as extra evidence that the AUTO_ prefix is
  a good idea.

- Tweaks DecodePool::SyncRunIf{Preferred,Possible} so that the labelling is
  done within them, instead of at their callsites, because that's a more
  standard way of doing things.

--HG--
extra : rebase_source : 318d1bc6fc1425a94aacbf489dd46e4f83211de4
2017-06-22 17:08:53 +10:00

108 lines
3.2 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 : 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();
/// 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 nsIEventTarget interface to the thread pool's I/O thread.
*/
already_AddRefed<nsIEventTarget> GetIOEventTarget();
private:
friend class DecodePoolWorker;
DecodePool();
virtual ~DecodePool();
static StaticRefPtr<DecodePool> sSingleton;
static uint32_t sNumCores;
RefPtr<DecodePoolImpl> mImpl;
// mMutex protects mThreads and mIOThread.
Mutex mMutex;
nsTArray<nsCOMPtr<nsIThread>> mThreads;
nsCOMPtr<nsIThread> mIOThread;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_DecodePool_h