1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/widget/xpwidgets/nsBaseAppShell.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,167 @@
1.4 +/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsBaseAppShell_h__
1.10 +#define nsBaseAppShell_h__
1.11 +
1.12 +#include "mozilla/Atomics.h"
1.13 +#include "nsIAppShell.h"
1.14 +#include "nsIThreadInternal.h"
1.15 +#include "nsIObserver.h"
1.16 +#include "nsIRunnable.h"
1.17 +#include "nsCOMPtr.h"
1.18 +#include "nsTArray.h"
1.19 +#include "prinrval.h"
1.20 +
1.21 +/**
1.22 + * A singleton that manages the UI thread's event queue. Subclass this class
1.23 + * to enable platform-specific event queue support.
1.24 + */
1.25 +class nsBaseAppShell : public nsIAppShell, public nsIThreadObserver,
1.26 + public nsIObserver
1.27 +{
1.28 +public:
1.29 + NS_DECL_THREADSAFE_ISUPPORTS
1.30 + NS_DECL_NSIAPPSHELL
1.31 + NS_DECL_NSITHREADOBSERVER
1.32 + NS_DECL_NSIOBSERVER
1.33 +
1.34 + nsBaseAppShell();
1.35 +
1.36 +protected:
1.37 + virtual ~nsBaseAppShell();
1.38 +
1.39 + /**
1.40 + * This method is called by subclasses when the app shell singleton is
1.41 + * instantiated.
1.42 + */
1.43 + nsresult Init();
1.44 +
1.45 + /**
1.46 + * Called by subclasses from a native event. See ScheduleNativeEventCallback.
1.47 + */
1.48 + void NativeEventCallback();
1.49 +
1.50 + /**
1.51 + * Make a decision as to whether or not NativeEventCallback will
1.52 + * trigger gecko event processing when there are pending gecko
1.53 + * events.
1.54 + */
1.55 + virtual void DoProcessMoreGeckoEvents();
1.56 +
1.57 + /**
1.58 + * Implemented by subclasses. Invoke NativeEventCallback from a native
1.59 + * event. This method may be called on any thread.
1.60 + */
1.61 + virtual void ScheduleNativeEventCallback() = 0;
1.62 +
1.63 + /**
1.64 + * Implemented by subclasses. Process the next native event. Only wait for
1.65 + * the next native event if mayWait is true. This method is only called on
1.66 + * the main application thread.
1.67 + *
1.68 + * @param mayWait
1.69 + * If "true", then this method may wait if necessary for the next available
1.70 + * native event. DispatchNativeEvent may be called to unblock a call to
1.71 + * ProcessNextNativeEvent that is waiting.
1.72 + * @return
1.73 + * This method returns "true" if a native event was processed.
1.74 + */
1.75 + virtual bool ProcessNextNativeEvent(bool mayWait) = 0;
1.76 +
1.77 + int32_t mSuspendNativeCount;
1.78 + uint32_t mEventloopNestingLevel;
1.79 +
1.80 +private:
1.81 + bool DoProcessNextNativeEvent(bool mayWait, uint32_t recursionDepth);
1.82 +
1.83 + bool DispatchDummyEvent(nsIThread* target);
1.84 +
1.85 + void IncrementEventloopNestingLevel();
1.86 + void DecrementEventloopNestingLevel();
1.87 +
1.88 + /**
1.89 + * Runs all synchronous sections which are queued up in mSyncSections.
1.90 + */
1.91 + void RunSyncSectionsInternal(bool stable, uint32_t threadRecursionLevel);
1.92 +
1.93 + void RunSyncSections(bool stable, uint32_t threadRecursionLevel)
1.94 + {
1.95 + if (!mSyncSections.IsEmpty()) {
1.96 + RunSyncSectionsInternal(stable, threadRecursionLevel);
1.97 + }
1.98 + }
1.99 +
1.100 + void ScheduleSyncSection(nsIRunnable* runnable, bool stable);
1.101 +
1.102 + struct SyncSection {
1.103 + SyncSection()
1.104 + : mStable(false), mEventloopNestingLevel(0), mThreadRecursionLevel(0)
1.105 + { }
1.106 +
1.107 + void Forget(SyncSection* other) {
1.108 + other->mStable = mStable;
1.109 + other->mEventloopNestingLevel = mEventloopNestingLevel;
1.110 + other->mThreadRecursionLevel = mThreadRecursionLevel;
1.111 + other->mRunnable = mRunnable.forget();
1.112 + }
1.113 +
1.114 + bool mStable;
1.115 + uint32_t mEventloopNestingLevel;
1.116 + uint32_t mThreadRecursionLevel;
1.117 + nsCOMPtr<nsIRunnable> mRunnable;
1.118 + };
1.119 +
1.120 + nsCOMPtr<nsIRunnable> mDummyEvent;
1.121 + /**
1.122 + * mBlockedWait points back to a slot that controls the wait loop in
1.123 + * an outer OnProcessNextEvent invocation. Nested calls always set
1.124 + * it to false to unblock an outer loop, since all events may
1.125 + * have been consumed by the inner event loop(s).
1.126 + */
1.127 + bool *mBlockedWait;
1.128 + int32_t mFavorPerf;
1.129 + mozilla::Atomic<bool> mNativeEventPending;
1.130 + PRIntervalTime mStarvationDelay;
1.131 + PRIntervalTime mSwitchTime;
1.132 + PRIntervalTime mLastNativeEventTime;
1.133 + enum EventloopNestingState {
1.134 + eEventloopNone, // top level thread execution
1.135 + eEventloopXPCOM, // innermost native event loop is ProcessNextNativeEvent
1.136 + eEventloopOther // innermost native event loop is a native library/plugin etc
1.137 + };
1.138 + EventloopNestingState mEventloopNestingState;
1.139 + nsTArray<SyncSection> mSyncSections;
1.140 + bool mRunning;
1.141 + bool mExiting;
1.142 + /**
1.143 + * mBlockNativeEvent blocks the appshell from processing native events.
1.144 + * It is set to true while a nested native event loop (eEventloopOther)
1.145 + * is processing gecko events in NativeEventCallback(), thus queuing up
1.146 + * native events until we return to that loop (bug 420148).
1.147 + * We force mBlockNativeEvent to false in case handling one of the gecko
1.148 + * events spins up a nested XPCOM event loop (eg. modal window) which would
1.149 + * otherwise lead to a "deadlock" where native events aren't processed at all.
1.150 + */
1.151 + bool mBlockNativeEvent;
1.152 + /**
1.153 + * Tracks whether we have processed any gecko events in NativeEventCallback so
1.154 + * that we can avoid erroneously entering a blocking loop waiting for gecko
1.155 + * events to show up during OnProcessNextEvent. This is required because on
1.156 + * OS X ProcessGeckoEvents may be invoked inside the context of
1.157 + * ProcessNextNativeEvent and may result in NativeEventCallback being invoked
1.158 + * and in turn invoking NS_ProcessPendingEvents. Because
1.159 + * ProcessNextNativeEvent may be invoked prior to the NS_HasPendingEvents
1.160 + * waiting loop, this is the only way to make the loop aware that events may
1.161 + * have been processed.
1.162 + *
1.163 + * This variable is set to false in OnProcessNextEvent prior to the first
1.164 + * call to DoProcessNextNativeEvent. It is set to true by
1.165 + * NativeEventCallback after calling NS_ProcessPendingEvents.
1.166 + */
1.167 + bool mProcessedGeckoEvents;
1.168 +};
1.169 +
1.170 +#endif // nsBaseAppShell_h__
