blob: fabc0e188afe43e99e1020e037468616ff29a0b7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/* -*- 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();
/**
* Called by subclasses. Reset the internal timezone when the user's system
* timezone changes.
*/
static void OnSystemTimezoneChange();
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<nsIRunnable> 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;
mozilla::Atomic<bool> mNativeEventPending;
PRIntervalTime mGeckoTaskBurstStartTime;
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__
|
