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widget/xpwidgets/nsBaseAppShell.h@b8a032363ba2 (annotated)

widget/xpwidgets/nsBaseAppShell.h

Thu, 22 Jan 2015 13:21:57 +0100

author

Michael Schloh von Bennewitz <michael@schloh.com>

date

Thu, 22 Jan 2015 13:21:57 +0100

branch

TOR_BUG_9701

changeset 15

b8a032363ba2

permissions

-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

michael@0	1	/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
michael@0	2	/* This Source Code Form is subject to the terms of the Mozilla Public
michael@0	3	* License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0	4	* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0	5
michael@0	6	#ifndef nsBaseAppShell_h__
michael@0	7	#define nsBaseAppShell_h__
michael@0	8
michael@0	9	#include "mozilla/Atomics.h"
michael@0	10	#include "nsIAppShell.h"
michael@0	11	#include "nsIThreadInternal.h"
michael@0	12	#include "nsIObserver.h"
michael@0	13	#include "nsIRunnable.h"
michael@0	14	#include "nsCOMPtr.h"
michael@0	15	#include "nsTArray.h"
michael@0	16	#include "prinrval.h"
michael@0	17
michael@0	18	/**
michael@0	19	* A singleton that manages the UI thread's event queue. Subclass this class
michael@0	20	* to enable platform-specific event queue support.
michael@0	21	*/
michael@0	22	class nsBaseAppShell : public nsIAppShell, public nsIThreadObserver,
michael@0	23	public nsIObserver
michael@0	24	{
michael@0	25	public:
michael@0	26	NS_DECL_THREADSAFE_ISUPPORTS
michael@0	27	NS_DECL_NSIAPPSHELL
michael@0	28	NS_DECL_NSITHREADOBSERVER
michael@0	29	NS_DECL_NSIOBSERVER
michael@0	30
michael@0	31	nsBaseAppShell();
michael@0	32
michael@0	33	protected:
michael@0	34	virtual ~nsBaseAppShell();
michael@0	35
michael@0	36	/**
michael@0	37	* This method is called by subclasses when the app shell singleton is
michael@0	38	* instantiated.
michael@0	39	*/
michael@0	40	nsresult Init();
michael@0	41
michael@0	42	/**
michael@0	43	* Called by subclasses from a native event. See ScheduleNativeEventCallback.
michael@0	44	*/
michael@0	45	void NativeEventCallback();
michael@0	46
michael@0	47	/**
michael@0	48	* Make a decision as to whether or not NativeEventCallback will
michael@0	49	* trigger gecko event processing when there are pending gecko
michael@0	50	* events.
michael@0	51	*/
michael@0	52	virtual void DoProcessMoreGeckoEvents();
michael@0	53
michael@0	54	/**
michael@0	55	* Implemented by subclasses. Invoke NativeEventCallback from a native
michael@0	56	* event. This method may be called on any thread.
michael@0	57	*/
michael@0	58	virtual void ScheduleNativeEventCallback() = 0;
michael@0	59
michael@0	60	/**
michael@0	61	* Implemented by subclasses. Process the next native event. Only wait for
michael@0	62	* the next native event if mayWait is true. This method is only called on
michael@0	63	* the main application thread.
michael@0	64	*
michael@0	65	* @param mayWait
michael@0	66	* If "true", then this method may wait if necessary for the next available
michael@0	67	* native event. DispatchNativeEvent may be called to unblock a call to
michael@0	68	* ProcessNextNativeEvent that is waiting.
michael@0	69	* @return
michael@0	70	* This method returns "true" if a native event was processed.
michael@0	71	*/
michael@0	72	virtual bool ProcessNextNativeEvent(bool mayWait) = 0;
michael@0	73
michael@0	74	int32_t mSuspendNativeCount;
michael@0	75	uint32_t mEventloopNestingLevel;
michael@0	76
michael@0	77	private:
michael@0	78	bool DoProcessNextNativeEvent(bool mayWait, uint32_t recursionDepth);
michael@0	79
michael@0	80	bool DispatchDummyEvent(nsIThread* target);
michael@0	81
michael@0	82	void IncrementEventloopNestingLevel();
michael@0	83	void DecrementEventloopNestingLevel();
michael@0	84
michael@0	85	/**
michael@0	86	* Runs all synchronous sections which are queued up in mSyncSections.
michael@0	87	*/
michael@0	88	void RunSyncSectionsInternal(bool stable, uint32_t threadRecursionLevel);
michael@0	89
michael@0	90	void RunSyncSections(bool stable, uint32_t threadRecursionLevel)
michael@0	91	{
michael@0	92	if (!mSyncSections.IsEmpty()) {
michael@0	93	RunSyncSectionsInternal(stable, threadRecursionLevel);
michael@0	94	}
michael@0	95	}
michael@0	96
michael@0	97	void ScheduleSyncSection(nsIRunnable* runnable, bool stable);
michael@0	98
michael@0	99	struct SyncSection {
michael@0	100	SyncSection()
michael@0	101	: mStable(false), mEventloopNestingLevel(0), mThreadRecursionLevel(0)
michael@0	102	{ }
michael@0	103
michael@0	104	void Forget(SyncSection* other) {
michael@0	105	other->mStable = mStable;
michael@0	106	other->mEventloopNestingLevel = mEventloopNestingLevel;
michael@0	107	other->mThreadRecursionLevel = mThreadRecursionLevel;
michael@0	108	other->mRunnable = mRunnable.forget();
michael@0	109	}
michael@0	110
michael@0	111	bool mStable;
michael@0	112	uint32_t mEventloopNestingLevel;
michael@0	113	uint32_t mThreadRecursionLevel;
michael@0	114	nsCOMPtr<nsIRunnable> mRunnable;
michael@0	115	};
michael@0	116
michael@0	117	nsCOMPtr<nsIRunnable> mDummyEvent;
michael@0	118	/**
michael@0	119	* mBlockedWait points back to a slot that controls the wait loop in
michael@0	120	* an outer OnProcessNextEvent invocation. Nested calls always set
michael@0	121	* it to false to unblock an outer loop, since all events may
michael@0	122	* have been consumed by the inner event loop(s).
michael@0	123	*/
michael@0	124	bool *mBlockedWait;
michael@0	125	int32_t mFavorPerf;
michael@0	126	mozilla::Atomic<bool> mNativeEventPending;
michael@0	127	PRIntervalTime mStarvationDelay;
michael@0	128	PRIntervalTime mSwitchTime;
michael@0	129	PRIntervalTime mLastNativeEventTime;
michael@0	130	enum EventloopNestingState {
michael@0	131	eEventloopNone, // top level thread execution
michael@0	132	eEventloopXPCOM, // innermost native event loop is ProcessNextNativeEvent
michael@0	133	eEventloopOther // innermost native event loop is a native library/plugin etc
michael@0	134	};
michael@0	135	EventloopNestingState mEventloopNestingState;
michael@0	136	nsTArray<SyncSection> mSyncSections;
michael@0	137	bool mRunning;
michael@0	138	bool mExiting;
michael@0	139	/**
michael@0	140	* mBlockNativeEvent blocks the appshell from processing native events.
michael@0	141	* It is set to true while a nested native event loop (eEventloopOther)
michael@0	142	* is processing gecko events in NativeEventCallback(), thus queuing up
michael@0	143	* native events until we return to that loop (bug 420148).
michael@0	144	* We force mBlockNativeEvent to false in case handling one of the gecko
michael@0	145	* events spins up a nested XPCOM event loop (eg. modal window) which would
michael@0	146	* otherwise lead to a "deadlock" where native events aren't processed at all.
michael@0	147	*/
michael@0	148	bool mBlockNativeEvent;
michael@0	149	/**
michael@0	150	* Tracks whether we have processed any gecko events in NativeEventCallback so
michael@0	151	* that we can avoid erroneously entering a blocking loop waiting for gecko
michael@0	152	* events to show up during OnProcessNextEvent. This is required because on
michael@0	153	* OS X ProcessGeckoEvents may be invoked inside the context of
michael@0	154	* ProcessNextNativeEvent and may result in NativeEventCallback being invoked
michael@0	155	* and in turn invoking NS_ProcessPendingEvents. Because
michael@0	156	* ProcessNextNativeEvent may be invoked prior to the NS_HasPendingEvents
michael@0	157	* waiting loop, this is the only way to make the loop aware that events may
michael@0	158	* have been processed.
michael@0	159	*
michael@0	160	* This variable is set to false in OnProcessNextEvent prior to the first
michael@0	161	* call to DoProcessNextNativeEvent. It is set to true by
michael@0	162	* NativeEventCallback after calling NS_ProcessPendingEvents.
michael@0	163	*/
michael@0	164	bool mProcessedGeckoEvents;
michael@0	165	};
michael@0	166
michael@0	167	#endif // nsBaseAppShell_h__