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Don't release timer ids in event dispatcher code

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3rdparty event dispatchers are impossible to write without using the
internal API QAbstractEventDispatcherPrivate::releaseTimerId(). Fix
this by having each QObject keep track of its own timer ids, and
release them when they are no longer used. As a side effect, this
makes the QObjectData::pendTimer bit unnecessary.

This also removes the QObjectData::inThreadChangeEvent hack that the
event dispatchers used to avoid releasing timer ids when moving timers
to a new thread.

QBasicTimer becomes even more low-level. It cannot use
QObject::startTimer() anymore, since we do not have a way to call
QObject::killTimer() from QBasicTimer::stop(). QBasicTimer uses the
QAbstractEventDispatcher interface directly, and releases the timer id
explicitly as well when stopping the timer.

This change also fixes some rare timer id "leaks" when destroying or
stopping timers after a thread has exited and destroyed its event
dispatcher (the timer ids would never be released when no dispatcher
exists).

Globally destructed QObjects that have running timers may try to release
their timer ids after the timer id freelist has been destroyed. This
commit accomodates such objects by avoiding the null dereference in
QAbstractEventDispatcherPrivate::releaseTimerId().

Change-Id: I2d7cd8221fae441f3cf02b6c0b4bc16063834d00
Reviewed-by: David Faure <faure@kde.org>
Reviewed-by: Denis Dzyubenko <denis.dzyubenko@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
This commit is contained in:
Bradley T. Hughes 2011-12-20 11:38:35 +01:00 committed by Qt by Nokia
parent bd525a64d5
commit f821d6352e
9 changed files with 57 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/corelib/kernel/qabstracteventdispatcher.cpp
View File

@ -96,7 +96,10 @@ int QAbstractEventDispatcherPrivate::allocateTimerId()
void QAbstractEventDispatcherPrivate::releaseTimerId(int timerId)
{
timerIdFreeList()->release(timerId);
// this function may be called by a global destructor after
// timerIdFreeList() has been destructed
if (QtTimerIdFreeList *fl = timerIdFreeList())
fl->release(timerId);
}
/*!

26
src/corelib/kernel/qbasictimer.cpp
View File

@ -41,6 +41,7 @@
#include "qbasictimer.h"
#include "qabstracteventdispatcher.h"
#include "qabstracteventdispatcher_p.h"
QT_BEGIN_NAMESPACE
@ -114,9 +115,16 @@ QT_BEGIN_NAMESPACE
*/
void QBasicTimer::start(int msec, QObject *obj)
{
stop();
if (obj)
id = obj->startTimer(msec);
QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance();
if (!eventDispatcher)
return;
if (id) {
eventDispatcher->unregisterTimer(id);
QAbstractEventDispatcherPrivate::releaseTimerId(id);
}
id = 0;
if (obj)
id = eventDispatcher->registerTimer(msec, Qt::CoarseTimer, obj);
}
/*!
@ -132,9 +140,16 @@ void QBasicTimer::start(int msec, QObject *obj)
*/
void QBasicTimer::start(int msec, Qt::TimerType timerType, QObject *obj)
{
stop();
QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance();
if (!eventDispatcher)
return;
if (id) {
eventDispatcher->unregisterTimer(id);
QAbstractEventDispatcherPrivate::releaseTimerId(id);
}
id = 0;
if (obj)
id = obj->startTimer(msec, timerType);
id = eventDispatcher->registerTimer(msec, timerType, obj);
}
/*!
@ -148,6 +163,7 @@ void QBasicTimer::stop()
QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance();
if (eventDispatcher)
eventDispatcher->unregisterTimer(id);
QAbstractEventDispatcherPrivate::releaseTimerId(id);
}
id = 0;
}

8
src/corelib/kernel/qeventdispatcher_win.cpp
View File

@ -548,12 +548,8 @@ void QEventDispatcherWin32Private::registerTimer(WinTimerInfo *t)
qErrnoWarning("QEventDispatcherWin32::registerTimer: Failed to create a timer");
}
void QEventDispatcherWin32Private::unregisterTimer(WinTimerInfo *t, bool closingDown)
void QEventDispatcherWin32Private::unregisterTimer(WinTimerInfo *t)
{
// mark timer as unused
if (!QObjectPrivate::get(t->obj)->inThreadChangeEvent && !closingDown)
QAbstractEventDispatcherPrivate::releaseTimerId(t->timerId);
if (t->interval == 0) {
QCoreApplicationPrivate::removePostedTimerEvent(t->dispatcher, t->timerId);
} else if (t->fastTimerId != 0) {
@ -1051,7 +1047,7 @@ void QEventDispatcherWin32::closingDown()
// clean up any timers
for (int i = 0; i < d->timerVec.count(); ++i)
d->unregisterTimer(d->timerVec.at(i), true);
d->unregisterTimer(d->timerVec.at(i));
d->timerVec.clear();
d->timerDict.clear();

2
src/corelib/kernel/qeventdispatcher_win_p.h
View File

@ -161,7 +161,7 @@ public:
WinTimerVec timerVec;
WinTimerDict timerDict;
void registerTimer(WinTimerInfo *t);
void unregisterTimer(WinTimerInfo *t, bool closingDown = false);
void unregisterTimer(WinTimerInfo *t);
void sendTimerEvent(int timerId);
// socket notifiers

39
src/corelib/kernel/qobject.cpp
View File

@ -44,6 +44,7 @@
#include "qmetaobject_p.h"
#include "qabstracteventdispatcher.h"
#include "qabstracteventdispatcher_p.h"
#include "qcoreapplication.h"
#include "qcoreapplication_p.h"
#include "qvariant.h"
@ -162,7 +163,6 @@ QObjectPrivate::QObjectPrivate(int version)
q_ptr = 0;
parent = 0; // no parent yet. It is set by setParent()
isWidget = false; // assume not a widget object
pendTimer = false; // no timers yet
blockSig = false; // not blocking signals
wasDeleted = false; // double-delete catcher
isDeletingChildren = false; // set by deleteChildren()
@ -171,17 +171,20 @@ QObjectPrivate::QObjectPrivate(int version)
postedEvents = 0;
extraData = 0;
connectedSignals[0] = connectedSignals[1] = 0;
inThreadChangeEvent = false;
metaObject = 0;
isWindow = false;
}
QObjectPrivate::~QObjectPrivate()
{
if (pendTimer) {
if (!runningTimers.isEmpty()) {
// unregister pending timers
if (threadData->eventDispatcher)
threadData->eventDispatcher->unregisterTimers(q_ptr);
// release the timer ids back to the pool
for (int i = 0; i < runningTimers.size(); ++i)
QAbstractEventDispatcherPrivate::releaseTimerId(runningTimers.at(i));
}
if (postedEvents)
@ -1019,11 +1022,8 @@ bool QObject::event(QEvent *e)
if (eventDispatcher) {
QList<QAbstractEventDispatcher::TimerInfo> timers = eventDispatcher->registeredTimers(this);
if (!timers.isEmpty()) {
// set inThreadChangeEvent to true to tell the dispatcher not to release out timer ids
// back to the pool (since the timer ids are moving to a new thread).
d->inThreadChangeEvent = true;
// do not to release our timer ids back to the pool (since the timer ids are moving to a new thread).
eventDispatcher->unregisterTimers(this);
d->inThreadChangeEvent = false;
QMetaObject::invokeMethod(this, "_q_reregisterTimers", Qt::QueuedConnection,
Q_ARG(void*, (new QList<QAbstractEventDispatcher::TimerInfo>(timers))));
}
@ -1382,13 +1382,13 @@ int QObject::startTimer(int interval, Qt::TimerType timerType)
return 0;
}
d->pendTimer = true; // set timer flag
if (!d->threadData->eventDispatcher) {
qWarning("QObject::startTimer: QTimer can only be used with threads started with QThread");
return 0;
}
return d->threadData->eventDispatcher->registerTimer(interval, timerType, this);
int timerId = d->threadData->eventDispatcher->registerTimer(interval, timerType, this);
d->runningTimers.append(timerId);
return timerId;
}
/*!
@ -1403,8 +1403,23 @@ int QObject::startTimer(int interval, Qt::TimerType timerType)
void QObject::killTimer(int id)
{
Q_D(QObject);
if (d->threadData->eventDispatcher)
d->threadData->eventDispatcher->unregisterTimer(id);
if (id) {
int at = d->runningTimers.indexOf(id);
if (at == -1) {
// timer isn't owned by this object
qWarning("QObject::killTimer(): Error: timer id %d is not valid for object %p (%s), timer has not been killed",
id,
this,
qPrintable(objectName()));
return;
}
if (d->threadData->eventDispatcher)
d->threadData->eventDispatcher->unregisterTimer(id);
d->runningTimers.remove(at);
QAbstractEventDispatcherPrivate::releaseTimerId(id);
}
}

4
src/corelib/kernel/qobject.h
View File

@ -96,15 +96,13 @@ public:
QObjectList children;
uint isWidget : 1;
uint pendTimer : 1;
uint blockSig : 1;
uint wasDeleted : 1;
uint isDeletingChildren : 1;
uint sendChildEvents : 1;
uint receiveChildEvents : 1;
uint inThreadChangeEvent : 1;
uint isWindow : 1; //for QWindow
uint unused : 23;
uint unused : 25;
int postedEvents;
QMetaObject *metaObject; // assert dynamic
};

1
src/corelib/kernel/qobject_p.h
View File

@ -198,6 +198,7 @@ public:
Sender *currentSender; // object currently activating the object
mutable quint32 connectedSignals[2];
QVector<int> runningTimers;
QList<QPointer<QObject> > eventFilters;
union {
QObject *currentChildBeingDeleted;

10
src/corelib/kernel/qtimerinfo_unix.cpp
View File

@ -266,11 +266,6 @@ bool QTimerInfoList::unregisterTimer(int timerId)
firstTimerInfo = 0;
if (t->activateRef)
*(t->activateRef) = 0;
// release the timer id
if (!QObjectPrivate::get(t->obj)->inThreadChangeEvent)
QAbstractEventDispatcherPrivate::releaseTimerId(timerId);
delete t;
return true;
}
@ -292,11 +287,6 @@ bool QTimerInfoList::unregisterTimers(QObject *object)
firstTimerInfo = 0;
if (t->activateRef)
*(t->activateRef) = 0;
// release the timer id
if (!QObjectPrivate::get(t->obj)->inThreadChangeEvent)
QAbstractEventDispatcherPrivate::releaseTimerId(t->id);
delete t;
// move back one so that we don't skip the new current item
--i;

4
src/plugins/platforms/cocoa/qcocoaeventdispatcher.mm
View File

@ -190,8 +190,6 @@ bool QCocoaEventDispatcher::unregisterTimer(int identifier)
if (timerInfo == 0)
return false;
if (!QObjectPrivate::get(timerInfo->obj)->inThreadChangeEvent)
QAbstractEventDispatcherPrivate::releaseTimerId(identifier);
CFRunLoopTimerInvalidate(timerInfo->runLoopTimer);
CFRelease(timerInfo->runLoopTimer);
delete timerInfo;
@ -217,8 +215,6 @@ bool QCocoaEventDispatcher::unregisterTimers(QObject *obj)
if (timerInfo->obj != obj) {
++it;
} else {
if (!QObjectPrivate::get(timerInfo->obj)->inThreadChangeEvent)
QAbstractEventDispatcherPrivate::releaseTimerId(timerInfo->id);
CFRunLoopTimerInvalidate(timerInfo->runLoopTimer);
CFRelease(timerInfo->runLoopTimer);
delete timerInfo;