From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- widget/nsBaseAppShell.h | 135 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 widget/nsBaseAppShell.h (limited to 'widget/nsBaseAppShell.h') diff --git a/widget/nsBaseAppShell.h b/widget/nsBaseAppShell.h new file mode 100644 index 0000000000..4ee9e3d2e7 --- /dev/null +++ b/widget/nsBaseAppShell.h @@ -0,0 +1,135 @@ +/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */ +/* 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/. */ + +#ifndef nsBaseAppShell_h__ +#define nsBaseAppShell_h__ + +#include "mozilla/Atomics.h" +#include "nsIAppShell.h" +#include "nsIThreadInternal.h" +#include "nsIObserver.h" +#include "nsIRunnable.h" +#include "nsCOMPtr.h" +#include "nsTArray.h" +#include "prinrval.h" + +/** + * A singleton that manages the UI thread's event queue. Subclass this class + * to enable platform-specific event queue support. + */ +class nsBaseAppShell : public nsIAppShell, public nsIThreadObserver, + public nsIObserver +{ +public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIAPPSHELL + + NS_DECL_NSITHREADOBSERVER + NS_DECL_NSIOBSERVER + + nsBaseAppShell(); + +protected: + virtual ~nsBaseAppShell(); + + /** + * This method is called by subclasses when the app shell singleton is + * instantiated. + */ + nsresult Init(); + + /** + * Called by subclasses from a native event. See ScheduleNativeEventCallback. + */ + void NativeEventCallback(); + + /** + * Make a decision as to whether or not NativeEventCallback will + * trigger gecko event processing when there are pending gecko + * events. + */ + virtual void DoProcessMoreGeckoEvents(); + + /** + * Implemented by subclasses. Invoke NativeEventCallback from a native + * event. This method may be called on any thread. + */ + virtual void ScheduleNativeEventCallback() = 0; + + /** + * Implemented by subclasses. Process the next native event. Only wait for + * the next native event if mayWait is true. This method is only called on + * the main application thread. + * + * @param mayWait + * If "true", then this method may wait if necessary for the next available + * native event. DispatchNativeEvent may be called to unblock a call to + * ProcessNextNativeEvent that is waiting. + * @return + * This method returns "true" if a native event was processed. + */ + virtual bool ProcessNextNativeEvent(bool mayWait) = 0; + + int32_t mSuspendNativeCount; + uint32_t mEventloopNestingLevel; + +private: + bool DoProcessNextNativeEvent(bool mayWait); + + bool DispatchDummyEvent(nsIThread* target); + + void IncrementEventloopNestingLevel(); + void DecrementEventloopNestingLevel(); + + nsCOMPtr mDummyEvent; + /** + * mBlockedWait points back to a slot that controls the wait loop in + * an outer OnProcessNextEvent invocation. Nested calls always set + * it to false to unblock an outer loop, since all events may + * have been consumed by the inner event loop(s). + */ + bool *mBlockedWait; + int32_t mFavorPerf; + mozilla::Atomic mNativeEventPending; + PRIntervalTime mStarvationDelay; + PRIntervalTime mSwitchTime; + PRIntervalTime mLastNativeEventTime; + enum EventloopNestingState { + eEventloopNone, // top level thread execution + eEventloopXPCOM, // innermost native event loop is ProcessNextNativeEvent + eEventloopOther // innermost native event loop is a native library/plugin etc + }; + EventloopNestingState mEventloopNestingState; + bool mRunning; + bool mExiting; + /** + * mBlockNativeEvent blocks the appshell from processing native events. + * It is set to true while a nested native event loop (eEventloopOther) + * is processing gecko events in NativeEventCallback(), thus queuing up + * native events until we return to that loop (bug 420148). + * We force mBlockNativeEvent to false in case handling one of the gecko + * events spins up a nested XPCOM event loop (eg. modal window) which would + * otherwise lead to a "deadlock" where native events aren't processed at all. + */ + bool mBlockNativeEvent; + /** + * Tracks whether we have processed any gecko events in NativeEventCallback so + * that we can avoid erroneously entering a blocking loop waiting for gecko + * events to show up during OnProcessNextEvent. This is required because on + * OS X ProcessGeckoEvents may be invoked inside the context of + * ProcessNextNativeEvent and may result in NativeEventCallback being invoked + * and in turn invoking NS_ProcessPendingEvents. Because + * ProcessNextNativeEvent may be invoked prior to the NS_HasPendingEvents + * waiting loop, this is the only way to make the loop aware that events may + * have been processed. + * + * This variable is set to false in OnProcessNextEvent prior to the first + * call to DoProcessNextNativeEvent. It is set to true by + * NativeEventCallback after calling NS_ProcessPendingEvents. + */ + bool mProcessedGeckoEvents; +}; + +#endif // nsBaseAppShell_h__ -- cgit v1.2.3