summaryrefslogtreecommitdiffstats
path: root/src/corelib/kernel/qeventdispatcher_cf.mm
blob: 84223459685b4621ba104413eb0a2069eb69c777 (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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qeventdispatcher_cf_p.h"

#include <QtCore/qdebug.h>
#include <QtCore/qmetaobject.h>
#include <QtCore/qthread.h>
#include <QtCore/private/qcoreapplication_p.h>
#include <QtCore/private/qcore_unix_p.h>
#include <QtCore/private/qcore_mac_p.h>
#include <QtCore/private/qthread_p.h>

#include <limits>

#ifdef Q_OS_OSX
#  include <AppKit/NSApplication.h>
#else
#  include <UIKit/UIApplication.h>
#endif

QT_USE_NAMESPACE

@interface RunLoopModeTracker : NSObject {
    QStack<CFStringRef> m_runLoopModes;
}
@end

@implementation RunLoopModeTracker

- (id) init
{
    if (self = [super init]) {
        m_runLoopModes.push(kCFRunLoopDefaultMode);

        [[NSNotificationCenter defaultCenter]
            addObserver:self
            selector:@selector(receivedNotification:)
            name:nil
#ifdef Q_OS_OSX
            object:[NSApplication sharedApplication]];
#else
            object:[UIApplication sharedApplication]];
#endif
    }

    return self;
}

- (void) dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    [super dealloc];
}

static CFStringRef runLoopMode(NSDictionary *dictionary)
{
    for (NSString *key in dictionary) {
        if (CFStringHasSuffix((CFStringRef)key, CFSTR("RunLoopMode")))
            return (CFStringRef)[dictionary objectForKey: key];
    }

    return nil;
}

- (void) receivedNotification:(NSNotification *) notification
{
     if (CFStringHasSuffix((CFStringRef)notification.name, CFSTR("RunLoopModePushNotification"))) {
        if (CFStringRef mode = runLoopMode(notification.userInfo))
            m_runLoopModes.push(mode);
        else
            qWarning("Encountered run loop push notification without run loop mode!");

     } else if (CFStringHasSuffix((CFStringRef)notification.name, CFSTR("RunLoopModePopNotification"))) {
        CFStringRef mode = runLoopMode(notification.userInfo);
        if (CFStringCompare(mode, [self currentMode], 0) == kCFCompareEqualTo)
            m_runLoopModes.pop();
        else
            qWarning("Tried to pop run loop mode '%s' that was never pushed!", qPrintable(QCFString::toQString(mode)));

        Q_ASSERT(m_runLoopModes.size() >= 1);
     }
}

- (CFStringRef) currentMode
{
    return m_runLoopModes.top();
}

@end

QT_BEGIN_NAMESPACE

class RunLoopDebugger : public QObject
{
    Q_OBJECT

    Q_ENUMS(Activity)
    Q_ENUMS(Result)

public:

    #define Q_MIRROR_ENUM(name) name = name

    enum Activity {
        Q_MIRROR_ENUM(kCFRunLoopEntry),
        Q_MIRROR_ENUM(kCFRunLoopBeforeTimers),
        Q_MIRROR_ENUM(kCFRunLoopBeforeSources),
        Q_MIRROR_ENUM(kCFRunLoopBeforeWaiting),
        Q_MIRROR_ENUM(kCFRunLoopAfterWaiting),
        Q_MIRROR_ENUM(kCFRunLoopExit)
    };

    enum Result {
        Q_MIRROR_ENUM(kCFRunLoopRunFinished),
        Q_MIRROR_ENUM(kCFRunLoopRunStopped),
        Q_MIRROR_ENUM(kCFRunLoopRunTimedOut),
        Q_MIRROR_ENUM(kCFRunLoopRunHandledSource)
    };
};

#define Q_ENUM_PRINTER(enumName) \
    static const char* qPrintable##enumName(int value) \
    { \
        return RunLoopDebugger::staticMetaObject.enumerator(RunLoopDebugger::staticMetaObject.indexOfEnumerator(#enumName)).valueToKey(value); \
    }

Q_ENUM_PRINTER(Activity);
Q_ENUM_PRINTER(Result);

QDebug operator<<(QDebug s, timespec tv)
{
    s << tv.tv_sec << "." << qSetFieldWidth(9) << qSetPadChar(QChar(48)) << tv.tv_nsec << reset;
    return s;
}

#if DEBUG_EVENT_DISPATCHER
uint g_eventDispatcherIndentationLevel = 0;
#endif

static const CFTimeInterval kCFTimeIntervalMinimum = 0;
static const CFTimeInterval kCFTimeIntervalDistantFuture = std::numeric_limits<CFTimeInterval>::max();

#pragma mark - Class definition

QEventDispatcherCoreFoundation::QEventDispatcherCoreFoundation(QObject *parent)
    : QAbstractEventDispatcher(parent)
    , m_processEvents(QEventLoop::EventLoopExec)
    , m_postedEventsRunLoopSource(this, &QEventDispatcherCoreFoundation::processPostedEvents)
    , m_runLoopActivityObserver(this, &QEventDispatcherCoreFoundation::handleRunLoopActivity,
#if DEBUG_EVENT_DISPATCHER
        kCFRunLoopAllActivities
#else
        kCFRunLoopBeforeWaiting | kCFRunLoopAfterWaiting
#endif
    )
    , m_runLoopModeTracker([[RunLoopModeTracker alloc] init])
    , m_runLoopTimer(0)
    , m_blockedRunLoopTimer(0)
    , m_overdueTimerScheduled(false)
{
    m_cfSocketNotifier.setHostEventDispatcher(this);

    m_postedEventsRunLoopSource.addToMode(kCFRunLoopCommonModes);
    m_runLoopActivityObserver.addToMode(kCFRunLoopCommonModes);
}

QEventDispatcherCoreFoundation::~QEventDispatcherCoreFoundation()
{
    invalidateTimer();
    qDeleteAll(m_timerInfoList);

    m_cfSocketNotifier.removeSocketNotifiers();
}

/*!
    Processes all pending events that match \a flags until there are no
    more events to process. Returns \c true if pending events were handled;
    otherwise returns \c false.

    Note:

      - All events are considered equal. This function should process
        both system/native events (that we may or may not care about),
        as well as Qt-events (posted events and timers).

      - The function should not return until all queued/available events
        have been processed. If the WaitForMoreEvents is set, the
        function should wait only if there were no events ready,
        and _then_ process all newly queued/available events.

    These notes apply to other function in this class as well, such as
    hasPendingEvents().
*/
bool QEventDispatcherCoreFoundation::processEvents(QEventLoop::ProcessEventsFlags flags)
{
    bool eventsProcessed = false;

    if (flags & (QEventLoop::ExcludeUserInputEvents | QEventLoop::ExcludeSocketNotifiers))
        qWarning() << "processEvents() flags" << flags << "not supported on iOS";

    qEventDispatcherDebug() << "Entering with " << flags; qIndent();

    if (m_blockedRunLoopTimer) {
        Q_ASSERT(m_blockedRunLoopTimer == m_runLoopTimer);

        qEventDispatcherDebug() << "Recursing from blocked timer " << m_blockedRunLoopTimer;
        m_runLoopTimer = 0; // Unset current timer to force creation of new timer
        updateTimers();
    }

    if (m_processEvents.deferredWakeUp) {
        // We may be processing events recursivly as a result of processing a posted event,
        // in which case we need to signal the run-loop source so that this iteration of
        // processEvents will take care of the newly posted events.
        m_postedEventsRunLoopSource.signal();
        m_processEvents.deferredWakeUp = false;

        qEventDispatcherDebug() << "Processed deferred wake-up";
    }

    // The documentation states that this signal is emitted after the event
    // loop returns from a function that could block, which is not the case
    // here, but all the other event dispatchers emit awake at the start of
    // processEvents, and the QEventLoop auto-test has an explicit check for
    // this behavior, so we assume it's for a good reason and do it as well.
    emit awake();

    ProcessEventsState previousState = m_processEvents;
    m_processEvents = ProcessEventsState(flags);

    bool returnAfterSingleSourceHandled = !(m_processEvents.flags & QEventLoop::EventLoopExec);

    Q_FOREVER {
        CFStringRef mode = [m_runLoopModeTracker currentMode];

        CFTimeInterval duration = (m_processEvents.flags & QEventLoop::WaitForMoreEvents) ?
            kCFTimeIntervalDistantFuture : kCFTimeIntervalMinimum;

        qEventDispatcherDebug() << "Calling CFRunLoopRunInMode = " << qPrintable(QCFString::toQString(mode))
            << " for " << duration << " ms, processing single source = " << returnAfterSingleSourceHandled; qIndent();

        SInt32 result = CFRunLoopRunInMode(mode, duration, returnAfterSingleSourceHandled);

        qUnIndent(); qEventDispatcherDebug() << "result = " << qPrintableResult(result);

        eventsProcessed |= (result == kCFRunLoopRunHandledSource
                            || m_processEvents.processedPostedEvents
                            || m_processEvents.processedTimers);

        if (result == kCFRunLoopRunFinished) {
            // This should only happen at application shutdown, as the main runloop
            // will presumably always have sources registered.
            break;
        } else if (m_processEvents.wasInterrupted) {

            if (m_processEvents.flags & QEventLoop::EventLoopExec) {
                Q_ASSERT(result == kCFRunLoopRunStopped);

                // The runloop was potentially stopped (interrupted) by us, as a response to
                // a Qt event loop being asked to exit. We check that the topmost eventloop
                // is still supposed to keep going and return if not. Note that the runloop
                // might get stopped as a result of a non-top eventloop being asked to exit,
                // in which case we continue running the top event loop until that is asked
                // to exit, and then unwind back to the previous event loop which will break
                // immediately, since it has already been exited.

                QEventLoop *currentEventLoop = QThreadData::current()->eventLoops.top();
                Q_ASSERT(currentEventLoop);

                if (!currentEventLoop->isRunning()) {
                    qEventDispatcherDebug() << "Top level event loop was exited";
                    break;
                } else {
                    qEventDispatcherDebug() << "Top level event loop still running, making another pass";
                }
            } else {
                // We were called manually, through processEvents(), and should stop processing
                // events, even if we didn't finish processing all the queued events.
                qEventDispatcherDebug() << "Top level processEvents was interrupted";
                break;
            }
        }

        if (m_processEvents.flags & QEventLoop::EventLoopExec) {
            // We were called from QEventLoop's exec(), which blocks until the event
            // loop is asked to exit by calling processEvents repeatedly. Instead of
            // re-entering this method again and again from QEventLoop, we can block
            // here,  one lever closer to CFRunLoopRunInMode, by running the native
            // event loop again and again until we're interrupted by QEventLoop.
            continue;
        } else {
            // We were called 'manually', through processEvents()

            if (result == kCFRunLoopRunHandledSource) {
                // We processed one or more sources, but there might still be other
                // sources that did not get a chance to process events, so we need
                // to do another pass.

                // But we should only wait for more events the first time
                m_processEvents.flags &= ~QEventLoop::WaitForMoreEvents;
                continue;

            } else if (m_overdueTimerScheduled && !m_processEvents.processedTimers) {
                // CFRunLoopRunInMode does not guarantee that a scheduled timer with a fire
                // date in the past (overdue) will fire on the next run loop pass. The Qt
                // APIs on the other hand document eg. zero-interval timers to always be
                // handled after processing all available window-system events.
                qEventDispatcherDebug() << "Manually processing timers due to overdue timer";
                processTimers(0);
                eventsProcessed = true;
            }
        }

        break;
    }

    if (m_blockedRunLoopTimer) {
        invalidateTimer();
        m_runLoopTimer = m_blockedRunLoopTimer;
    }

    if (m_processEvents.deferredUpdateTimers)
        updateTimers();

    if (m_processEvents.deferredWakeUp) {
        m_postedEventsRunLoopSource.signal();
        qEventDispatcherDebug() << "Processed deferred wake-up";
    }

    bool wasInterrupted = m_processEvents.wasInterrupted;

    // Restore state of previous processEvents() call
    m_processEvents = previousState;

    if (wasInterrupted) {
        // The current processEvents run has been interrupted, but there may still be
        // others below it (eg, in the case of nested event loops). We need to trigger
        // another interrupt so that the parent processEvents call has a chance to check
        // if it should continue.
        qEventDispatcherDebug() << "Forwarding interrupt in case of nested processEvents";
        interrupt();
    }

    qEventDispatcherDebug() << "Returning with eventsProcessed = " << eventsProcessed; qUnIndent();

    return eventsProcessed;
}

bool QEventDispatcherCoreFoundation::processPostedEvents()
{
    if (m_processEvents.processedPostedEvents && !(m_processEvents.flags & QEventLoop::EventLoopExec)) {
        qEventDispatcherDebug() << "Already processed events this pass";
        return false;
    }

    m_processEvents.processedPostedEvents = true;

    qEventDispatcherDebug() << "Sending posted events for " << m_processEvents.flags; qIndent();
    QCoreApplication::sendPostedEvents();
    qUnIndent();

    return true;
}

void QEventDispatcherCoreFoundation::processTimers(CFRunLoopTimerRef timer)
{
    if (m_processEvents.processedTimers && !(m_processEvents.flags & QEventLoop::EventLoopExec)) {
        qEventDispatcherDebug() << "Already processed timers this pass";
        m_processEvents.deferredUpdateTimers = true;
        return;
    }

    qEventDispatcherDebug() << "CFRunLoopTimer " << timer << " fired, activating Qt timers"; qIndent();

    // Activating Qt timers might recurse into processEvents() if a timer-callback
    // brings up a new event-loop or tries to processes events manually. Although
    // a CFRunLoop can recurse inside its callbacks, a single CFRunLoopTimer can
    // not. So, for each recursion into processEvents() from a timer-callback we
    // need to set up a new timer-source. Instead of doing it preemtivly each
    // time we activate Qt timers, we set a flag here, and let processEvents()
    // decide whether or not it needs to bring up a new timer source.

    // We may have multiple recused timers, so keep track of the previous blocked timer
    CFRunLoopTimerRef previouslyBlockedRunLoopTimer = m_blockedRunLoopTimer;

    m_blockedRunLoopTimer = timer;
    m_timerInfoList.activateTimers();
    m_blockedRunLoopTimer = previouslyBlockedRunLoopTimer;
    m_processEvents.processedTimers = true;

    qUnIndent();

    // Now that the timer source is unblocked we may need to schedule it again
    updateTimers();
}

void QEventDispatcherCoreFoundation::handleRunLoopActivity(CFRunLoopActivity activity)
{
    qEventDispatcherDebug() << qPrintableActivity(activity);

    switch (activity) {
    case kCFRunLoopBeforeWaiting:
        if (m_processEvents.processedTimers
                && !(m_processEvents.flags & QEventLoop::EventLoopExec)
                && m_processEvents.flags & QEventLoop::WaitForMoreEvents) {
            // CoreFoundation does not treat a timer as a reason to exit CFRunLoopRunInMode
            // when asked to only process a single source, so we risk waiting a long time for
            // a 'proper' source to fire (typically a system source that we don't control).
            // To fix this we do an explicit interrupt after processing our timer, so that
            // processEvents() gets a chance to re-evaluate the state of things.
            interrupt();
        }
        emit aboutToBlock();
        break;
    case kCFRunLoopAfterWaiting:
        emit awake();
        break;
#if DEBUG_EVENT_DISPATCHER
    case kCFRunLoopEntry:
    case kCFRunLoopBeforeTimers:
    case kCFRunLoopBeforeSources:
    case kCFRunLoopExit:
        break;
#endif
    default:
        Q_UNREACHABLE();
    }
}

bool QEventDispatcherCoreFoundation::hasPendingEvents()
{
    // There doesn't seem to be any API on iOS to peek into the other sources
    // to figure out if there are pending non-Qt events. As a workaround, we
    // assume that if the run-loop is currently blocking and waiting for a
    // source to signal then there are no system-events pending. If this
    // function is called from the main thread then the second clause
    // of the condition will always be true, as the run loop is
    // never waiting in that case. The function would be more aptly named
    // 'maybeHasPendingEvents' in our case.

    extern uint qGlobalPostedEventsCount();
    return qGlobalPostedEventsCount() || !CFRunLoopIsWaiting(CFRunLoopGetMain());
}

void QEventDispatcherCoreFoundation::wakeUp()
{
    if (m_processEvents.processedPostedEvents && !(m_processEvents.flags & QEventLoop::EventLoopExec)) {
        // A manual processEvents call should only result in processing the events posted
        // up until then. Any newly posted events as result of processing existing posted
        // events should be handled in the next call to processEvents(). Since we're using
        // a run-loop source to process our posted events we need to prevent it from being
        // signaled as a result of posting new events, otherwise we end up in an infinite
        // loop. We do however need to signal the source at some point, so that the newly
        // posted event gets processed on the next processEvents() call, so we flag the
        // need to do a deferred wake-up.
        m_processEvents.deferredWakeUp = true;
        qEventDispatcherDebug() << "Already processed posted events, deferring wakeUp";
        return;
    }

    m_postedEventsRunLoopSource.signal();
    CFRunLoopWakeUp(CFRunLoopGetMain());

    qEventDispatcherDebug() << "Signaled posted event run-loop source";
}

void QEventDispatcherCoreFoundation::interrupt()
{
    qEventDispatcherDebug() << "Marking current processEvent as interrupted";
    m_processEvents.wasInterrupted = true;
    CFRunLoopStop(CFRunLoopGetMain());
}

void QEventDispatcherCoreFoundation::flush()
{
    // X11 only.
}

#pragma mark - Socket notifiers

void QEventDispatcherCoreFoundation::registerSocketNotifier(QSocketNotifier *notifier)
{
    m_cfSocketNotifier.registerSocketNotifier(notifier);
}

void QEventDispatcherCoreFoundation::unregisterSocketNotifier(QSocketNotifier *notifier)
{
    m_cfSocketNotifier.unregisterSocketNotifier(notifier);
}

#pragma mark - Timers

void QEventDispatcherCoreFoundation::registerTimer(int timerId, int interval, Qt::TimerType timerType, QObject *object)
{
    qEventDispatcherDebug() << "id = " << timerId << ", interval = " << interval
        << ", type = " << timerType << ", object = " << object;

    Q_ASSERT(timerId > 0 && interval >= 0 && object);
    Q_ASSERT(object->thread() == thread() && thread() == QThread::currentThread());

    m_timerInfoList.registerTimer(timerId, interval, timerType, object);
    updateTimers();
}

bool QEventDispatcherCoreFoundation::unregisterTimer(int timerId)
{
    Q_ASSERT(timerId > 0);
    Q_ASSERT(thread() == QThread::currentThread());

    bool returnValue = m_timerInfoList.unregisterTimer(timerId);

    qEventDispatcherDebug() << "id = " << timerId << ", timers left: " << m_timerInfoList.size();

    updateTimers();
    return returnValue;
}

bool QEventDispatcherCoreFoundation::unregisterTimers(QObject *object)
{
    Q_ASSERT(object && object->thread() == thread() && thread() == QThread::currentThread());

    bool returnValue = m_timerInfoList.unregisterTimers(object);

    qEventDispatcherDebug() << "object = " << object << ", timers left: " << m_timerInfoList.size();

    updateTimers();
    return returnValue;
}

QList<QAbstractEventDispatcher::TimerInfo> QEventDispatcherCoreFoundation::registeredTimers(QObject *object) const
{
    Q_ASSERT(object);
    return m_timerInfoList.registeredTimers(object);
}

int QEventDispatcherCoreFoundation::remainingTime(int timerId)
{
    Q_ASSERT(timerId > 0);
    return m_timerInfoList.timerRemainingTime(timerId);
}

static double timespecToSeconds(const timespec &spec)
{
    static double nanosecondsPerSecond = 1.0 * 1000 * 1000 * 1000;
    return spec.tv_sec + (spec.tv_nsec / nanosecondsPerSecond);
}

void QEventDispatcherCoreFoundation::updateTimers()
{
    if (m_timerInfoList.size() > 0) {
        // We have Qt timers registered, so create or reschedule CF timer to match

        timespec tv = { -1, -1 };
        CFAbsoluteTime timeToFire = m_timerInfoList.timerWait(tv) ?
            // We have a timer ready to fire right now, or some time in the future
            CFAbsoluteTimeGetCurrent() + timespecToSeconds(tv)
            // We have timers, but they are all currently blocked by callbacks
            : kCFTimeIntervalDistantFuture;

        if (!m_runLoopTimer) {
            m_runLoopTimer = CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault,
                timeToFire, kCFTimeIntervalDistantFuture, 0, 0, ^(CFRunLoopTimerRef timer) {
                processTimers(timer);
            });

            CFRunLoopAddTimer(CFRunLoopGetMain(), m_runLoopTimer, kCFRunLoopCommonModes);
            qEventDispatcherDebug() << "Created new CFRunLoopTimer " << m_runLoopTimer;

        } else {
            CFRunLoopTimerSetNextFireDate(m_runLoopTimer, timeToFire);
            qEventDispatcherDebug() << "Re-scheduled CFRunLoopTimer " << m_runLoopTimer;
        }

        m_overdueTimerScheduled = !timespecToSeconds(tv);

        qEventDispatcherDebug() << "Next timeout in " << tv << " seconds";

    } else {
        // No Qt timers are registered, so make sure we're not running any CF timers
        invalidateTimer();

        m_overdueTimerScheduled = false;
    }
}

void QEventDispatcherCoreFoundation::invalidateTimer()
{
    if (!m_runLoopTimer || (m_runLoopTimer == m_blockedRunLoopTimer))
        return;

    CFRunLoopTimerInvalidate(m_runLoopTimer);
    qEventDispatcherDebug() << "Invalidated CFRunLoopTimer " << m_runLoopTimer;

    CFRelease(m_runLoopTimer);
    m_runLoopTimer = 0;
}

#include "qeventdispatcher_cf.moc"
#include "moc_qeventdispatcher_cf_p.cpp"

QT_END_NAMESPACE