Qt 4.8
Public Functions | Public Variables | Friends | List of all members
QThreadPoolPrivate Class Reference

#include <qthreadpool_p.h>

Inheritance diagram for QThreadPoolPrivate:
QObjectPrivate QObjectData

Public Functions

int activeThreadCount () const
 
void enqueueTask (QRunnable *task, int priority=0)
 
 QThreadPoolPrivate ()
 
void reset ()
 Makes all threads exit, waits for each thread to exit and deletes it. More...
 
bool startFrontRunnable ()
 Pulls a runnable from the front queue and runs it in the current thread. More...
 
void startThread (QRunnable *runnable=0)
 
void stealRunnable (QRunnable *)
 Searches for runnable in the queue, removes it from the queue and runs it if found. More...
 
bool tooManyThreadsActive () const
 
bool tryStart (QRunnable *task)
 
void tryToStartMoreThreads ()
 
bool waitForDone (int msecs=-1)
 
- Public Functions inherited from QObjectPrivate
void _q_reregisterTimers (void *pointer)
 
void addConnection (int signal, Connection *c)
 
void cleanConnectionLists ()
 
void connectNotify (const char *signal)
 
void deleteChildren ()
 
void disconnectNotify (const char *signal)
 
bool isSender (const QObject *receiver, const char *signal) const
 
bool isSignalConnected (uint signalIdx) const
 Returns true if the signal with index signal_index from object sender is connected. More...
 
void moveToThread_helper ()
 
 QObjectPrivate (int version=QObjectPrivateVersion)
 
QObjectList receiverList (const char *signal) const
 
QObjectList senderList () const
 
void setParent_helper (QObject *)
 
void setThreadData_helper (QThreadData *currentData, QThreadData *targetData)
 
int signalIndex (const char *signalName) const
 Returns the signal index used in the internal connectionLists vector. More...
 
virtual ~QObjectPrivate ()
 
- Public Functions inherited from QObjectData
virtual ~QObjectData ()=0
 

Public Variables

int activeThreads
 
QSet< QThreadPoolThread * > allThreads
 
QQueue< QThreadPoolThread * > expiredThreads
 
int expiryTimeout
 
bool isExiting
 
int maxThreadCount
 
QMutex mutex
 
QWaitCondition noActiveThreads
 
QList< QPair< QRunnable *, int > > queue
 
int reservedThreads
 
QQueue< QThreadPoolThread * > waitingThreads
 
- Public Variables inherited from QObjectPrivate
union {
   QObject *   currentChildBeingDeleted
 
   QAbstractDeclarativeData *   declarativeData
 
}; 
 
quint32 connectedSignals [2]
 
QObjectConnectionListVector * connectionLists
 
Sender * currentSender
 
QList< QPointer< QObject > > eventFilters
 
ExtraData * extraData
 
QString objectName
 
Connection * senders
 
QAtomicPointer< QtSharedPointer::ExternalRefCountData > sharedRefcount
 
QThreadData * threadData
 
void * unused
 
- Public Variables inherited from QObjectData
uint blockSig: 1
 
QObjectList children
 
uint hasGuards: 1
 
uint inEventHandler: 1
 
uint inThreadChangeEvent: 1
 
uint isWidget: 1
 
QMetaObject * metaObject
 
uint ownObjectName: 1
 
QObject * parent
 
uint pendTimer: 1
 
int postedEvents
 
QObject * q_ptr
 
uint receiveChildEvents: 1
 
uint sendChildEvents: 1
 
uint unused: 22
 
uint wasDeleted: 1
 

Friends

class QThreadPoolThread
 

Additional Inherited Members

- Public Types inherited from QObjectPrivate
typedef void(* StaticMetaCallFunction) (QObject *, QMetaObject::Call, int, void **)
 
- Static Public Functions inherited from QObjectPrivate
static void clearGuards (QObject *)
 
static QObjectPrivate * get (QObject *o)
 
static void resetCurrentSender (QObject *receiver, Sender *currentSender, Sender *previousSender)
 
static Sender * setCurrentSender (QObject *receiver, Sender *sender)
 
static void signalSignature (const QMetaMethod &signal, QVarLengthArray< char > *result)
 

Detailed Description

Definition at line 68 of file qthreadpool_p.h.

Constructors and Destructors

◆ QThreadPoolPrivate()

QThreadPoolPrivate::QThreadPoolPrivate ( )

Definition at line 165 of file qthreadpool.cpp.

166  : isExiting(false),
167  expiryTimeout(30000),
168  maxThreadCount(qAbs(QThread::idealThreadCount())),
169  reservedThreads(0),
170  activeThreads(0)
171 { }
qAbs
Q_DECL_CONSTEXPR T qAbs(const T &t)
Definition: qglobal.h:1201
QThread::idealThreadCount
static int idealThreadCount()
Returns the ideal number of threads that can be run on the system.
Definition: qthread_unix.cpp:411

Functions

◆ activeThreadCount()

int QThreadPoolPrivate::activeThreadCount ( ) const

Definition at line 222 of file qthreadpool.cpp.

Referenced by tooManyThreadsActive(), and tryStart().

223 {
224  return (allThreads.count()
225  - expiredThreads.count()
226  - waitingThreads.count()
227  + reservedThreads);
228 }
QList::count
int count(const T &t) const
Returns the number of occurrences of value in the list.
Definition: qlist.h:891
QThreadPoolPrivate::expiredThreads
QQueue< QThreadPoolThread * > expiredThreads
Definition: qthreadpool_p.h:92
QSet::count
int count() const
Definition: qset.h:178
QThreadPoolPrivate::allThreads
QSet< QThreadPoolThread * > allThreads
Definition: qthreadpool_p.h:90
QThreadPoolPrivate::waitingThreads
QQueue< QThreadPoolThread * > waitingThreads
Definition: qthreadpool_p.h:91

◆ enqueueTask()

void QThreadPoolPrivate::enqueueTask ( QRunnable *  task,
int  priority = 0 
)

Definition at line 211 of file qthreadpool.cpp.

Referenced by tryStart().

212 {
213  if (runnable->autoDelete())
214  ++runnable->ref;
215 
216  // put it on the queue
217  QList<QPair<QRunnable *, int> >::iterator at =
218  qUpperBound(queue.begin(), queue.end(), priority);
219  queue.insert(at, qMakePair(runnable, priority));
220 }
qUpperBound
Q_OUTOFLINE_TEMPLATE RandomAccessIterator qUpperBound(RandomAccessIterator begin, RandomAccessIterator end, const T &value)
Definition: qalgorithms.h:262
at
#define at(className, varName)
Definition: qbuiltintypes.cpp:73
QList::begin
iterator begin()
Returns an STL-style iterator pointing to the first item in the list.
Definition: qlist.h:267
QList::insert
void insert(int i, const T &t)
Inserts value at index position i in the list.
Definition: qlist.h:575
QList::end
iterator end()
Returns an STL-style iterator pointing to the imaginary item after the last item in the list...
Definition: qlist.h:270
qMakePair
Q_OUTOFLINE_TEMPLATE QPair< T1, T2 > qMakePair(const T1 &x, const T2 &y)
Definition: qpair.h:102
QThreadPoolPrivate::queue
QList< QPair< QRunnable *, int > > queue
Definition: qthreadpool_p.h:93
QList
The QList class is a template class that provides lists.
Definition: qdatastream.h:62

◆ reset()

void QThreadPoolPrivate::reset ( )

Makes all threads exit, waits for each thread to exit and deletes it.

Warning
This function is not part of the public interface.

Definition at line 266 of file qthreadpool.cpp.

267 {
268  QMutexLocker locker(&mutex);
269  isExiting = true;
270 
271  do {
272  // make a copy of the set so that we can iterate without the lock
273  QSet<QThreadPoolThread *> allThreadsCopy = allThreads;
274  allThreads.clear();
275  locker.unlock();
276 
277  foreach (QThreadPoolThread *thread, allThreadsCopy) {
278  thread->runnableReady.wakeAll();
279  thread->wait();
280  delete thread;
281  }
282 
283  locker.relock();
284  // repeat until all newly arrived threads have also completed
285  } while (!allThreads.isEmpty());
286 
287  waitingThreads.clear();
288  expiredThreads.clear();
289 
290  isExiting = false;
291 }
QSet::isEmpty
bool isEmpty() const
Definition: qset.h:77
QThreadPoolPrivate::expiredThreads
QQueue< QThreadPoolThread * > expiredThreads
Definition: qthreadpool_p.h:92
QSet::clear
void clear()
Definition: qset.h:87
QList::clear
void clear()
Removes all items from the list.
Definition: qlist.h:764
QThreadPoolPrivate::allThreads
QSet< QThreadPoolThread * > allThreads
Definition: qthreadpool_p.h:90
QMutexLocker
The QMutexLocker class is a convenience class that simplifies locking and unlocking mutexes...
Definition: qmutex.h:101
QThread::wait
bool wait(unsigned long time=ULONG_MAX)
Blocks the thread until either of these conditions is met:
Definition: qthread_unix.cpp:706
QThreadPoolThread::runnableReady
QWaitCondition runnableReady
Definition: qthreadpool.cpp:71
QThreadPoolPrivate::waitingThreads
QQueue< QThreadPoolThread * > waitingThreads
Definition: qthreadpool_p.h:91

◆ startFrontRunnable()

bool QThreadPoolPrivate::startFrontRunnable ( )

Pulls a runnable from the front queue and runs it in the current thread.

Warning
This function is not part of the public interface. Blocks until the runnable has completed. Returns true if a runnable was found.

Definition at line 317 of file qthreadpool.cpp.

318 {
319  QMutexLocker locker(&mutex);
320  if (queue.isEmpty())
321  return false;
322 
323  QRunnable *runnable = queue.takeFirst().first;
324  const bool autoDelete = runnable->autoDelete();
325  bool del = autoDelete && !--runnable->ref;
326 
327  locker.unlock();
328  runnable->run();
329  locker.relock();
330 
331  if (del) {
332  delete runnable;
333  }
334 
335  return true;
336 }
QRunnable::run
virtual void run()=0
Implement this pure virtual function in your subclass.
QRunnable
The QRunnable class is the base class for all runnable objects.
Definition: qrunnable.h:52
QList::isEmpty
bool isEmpty() const
Returns true if the list contains no items; otherwise returns false.
Definition: qlist.h:152
QList::takeFirst
T takeFirst()
Removes the first item in the list and returns it.
Definition: qlist.h:489
QRunnable::ref
int ref
Definition: qrunnable.h:54
QMutexLocker
The QMutexLocker class is a convenience class that simplifies locking and unlocking mutexes...
Definition: qmutex.h:101
QRunnable::autoDelete
bool autoDelete() const
Returns true is auto-deletion is enabled; false otherwise.
Definition: qrunnable.h:66
QThreadPoolPrivate::queue
QList< QPair< QRunnable *, int > > queue
Definition: qthreadpool_p.h:93

◆ startThread()

void QThreadPoolPrivate::startThread ( QRunnable *  runnable = 0)
Warning
This function is not part of the public interface.

Definition at line 246 of file qthreadpool.cpp.

Referenced by tryStart().

247 {
248  QScopedPointer <QThreadPoolThread> thread(new QThreadPoolThread(this));
249  thread->setObjectName(QLatin1String("Thread (pooled)"));
250  allThreads.insert(thread.data());
251  ++activeThreads;
252 
253  if (runnable->autoDelete())
254  ++runnable->ref;
255  thread->runnable = runnable;
256  thread.take()->start();
257 }
QLatin1String
QLatin1String(DBUS_INTERFACE_DBUS))) Q_GLOBAL_STATIC_WITH_ARGS(QString
QScopedPointer
The QScopedPointer class stores a pointer to a dynamically allocated object, and deletes it upon dest...
Definition: qscopedpointer.h:87
QThreadPoolPrivate::QThreadPoolThread
friend class QThreadPoolThread
Definition: qthreadpool_p.h:71
QSet::insert
const_iterator insert(const T &value)
Definition: qset.h:179
QRunnable::ref
int ref
Definition: qrunnable.h:54
QThreadPoolPrivate::allThreads
QSet< QThreadPoolThread * > allThreads
Definition: qthreadpool_p.h:90
QRunnable::autoDelete
bool autoDelete() const
Returns true is auto-deletion is enabled; false otherwise.
Definition: qrunnable.h:66

◆ stealRunnable()

void QThreadPoolPrivate::stealRunnable ( QRunnable *  runnable)

Searches for runnable in the queue, removes it from the queue and runs it if found.

Warning
This function is not part of the public interface. This function does not return until the runnable has completed.

Definition at line 347 of file qthreadpool.cpp.

348 {
349  if (runnable == 0 || queue.isEmpty())
350  return;
351  bool found = false;
352  {
353  QMutexLocker locker(&mutex);
354  QList<QPair<QRunnable *, int> >::iterator it = queue.begin();
355  QList<QPair<QRunnable *, int> >::iterator end = queue.end();
356 
357  while (it != end) {
358  if (it->first == runnable) {
359  found = true;
360  queue.erase(it);
361  break;
362  }
363  ++it;
364  }
365  }
366 
367  if (!found)
368  return;
369 
370  const bool autoDelete = runnable->autoDelete();
371  bool del = autoDelete && !--runnable->ref;
372 
373  runnable->run();
374 
375  if (del) {
376  delete runnable;
377  }
378 }
it
#define it(className, varName)
Definition: qbuiltintypes.cpp:95
QList::begin
iterator begin()
Returns an STL-style iterator pointing to the first item in the list.
Definition: qlist.h:267
QRunnable::run
virtual void run()=0
Implement this pure virtual function in your subclass.
QList::isEmpty
bool isEmpty() const
Returns true if the list contains no items; otherwise returns false.
Definition: qlist.h:152
QList::end
iterator end()
Returns an STL-style iterator pointing to the imaginary item after the last item in the list...
Definition: qlist.h:270
QRunnable::ref
int ref
Definition: qrunnable.h:54
QList::first
T & first()
Returns a reference to the first item in the list.
Definition: qlist.h:282
QList::erase
iterator erase(iterator pos)
Removes the item associated with the iterator pos from the list, and returns an iterator to the next ...
Definition: qlist.h:464
QMutexLocker
The QMutexLocker class is a convenience class that simplifies locking and unlocking mutexes...
Definition: qmutex.h:101
QRunnable::autoDelete
bool autoDelete() const
Returns true is auto-deletion is enabled; false otherwise.
Definition: qrunnable.h:66
end
static const KeyPair *const end
Definition: qt_cocoa_helpers_mac.mm:652
QThreadPoolPrivate::queue
QList< QPair< QRunnable *, int > > queue
Definition: qthreadpool_p.h:93
QList
The QList class is a template class that provides lists.
Definition: qdatastream.h:62

◆ tooManyThreadsActive()

bool QThreadPoolPrivate::tooManyThreadsActive ( ) const

Definition at line 237 of file qthreadpool.cpp.

Referenced by QThreadPoolThread::run().

238 {
239  const int activeThreadCount = this->activeThreadCount();
240  return activeThreadCount > maxThreadCount && (activeThreadCount - reservedThreads) > 1;
241 }
QThreadPoolPrivate::activeThreadCount
int activeThreadCount() const
Definition: qthreadpool.cpp:222

◆ tryStart()

bool QThreadPoolPrivate::tryStart ( QRunnable *  task)

Definition at line 173 of file qthreadpool.cpp.

Referenced by tryToStartMoreThreads().

174 {
175  if (allThreads.isEmpty()) {
176  // always create at least one thread
177  startThread(task);
178  return true;
179  }
180 
181  // can't do anything if we're over the limit
182  if (activeThreadCount() >= maxThreadCount)
183  return false;
184 
185  if (waitingThreads.count() > 0) {
186  // recycle an available thread
187  enqueueTask(task);
188  waitingThreads.takeFirst()->runnableReady.wakeOne();
189  return true;
190  }
191 
192  if (!expiredThreads.isEmpty()) {
193  // restart an expired thread
194  QThreadPoolThread *thread = expiredThreads.dequeue();
195  Q_ASSERT(thread->runnable == 0);
196 
197  ++activeThreads;
198 
199  if (task->autoDelete())
200  ++task->ref;
201  thread->runnable = task;
202  thread->start();
203  return true;
204  }
205 
206  // start a new thread
207  startThread(task);
208  return true;
209 }
QThreadPoolThread::runnable
QRunnable * runnable
Definition: qthreadpool.cpp:73
QSet::isEmpty
bool isEmpty() const
Definition: qset.h:77
QList::count
int count(const T &t) const
Returns the number of occurrences of value in the list.
Definition: qlist.h:891
Q_ASSERT
#define Q_ASSERT(cond)
Definition: qglobal.h:1823
QList::isEmpty
bool isEmpty() const
Returns true if the list contains no items; otherwise returns false.
Definition: qlist.h:152
QThreadPoolPrivate::expiredThreads
QQueue< QThreadPoolThread * > expiredThreads
Definition: qthreadpool_p.h:92
QList::takeFirst
T takeFirst()
Removes the first item in the list and returns it.
Definition: qlist.h:489
QRunnable::ref
int ref
Definition: qrunnable.h:54
QThreadPoolPrivate::allThreads
QSet< QThreadPoolThread * > allThreads
Definition: qthreadpool_p.h:90
QThread::start
void start(Priority=InheritPriority)
Begins execution of the thread by calling run().
Definition: qthread_unix.cpp:583
QRunnable::autoDelete
bool autoDelete() const
Returns true is auto-deletion is enabled; false otherwise.
Definition: qrunnable.h:66
QThreadPoolPrivate::activeThreadCount
int activeThreadCount() const
Definition: qthreadpool.cpp:222
QThreadPoolPrivate::enqueueTask
void enqueueTask(QRunnable *task, int priority=0)
Definition: qthreadpool.cpp:211
QQueue::dequeue
T dequeue()
Removes the head item in the queue and returns it.
Definition: qqueue.h:61
QThreadPoolPrivate::startThread
void startThread(QRunnable *runnable=0)
Definition: qthreadpool.cpp:246
QThreadPoolPrivate::waitingThreads
QQueue< QThreadPoolThread * > waitingThreads
Definition: qthreadpool_p.h:91

◆ tryToStartMoreThreads()

void QThreadPoolPrivate::tryToStartMoreThreads ( )

Definition at line 230 of file qthreadpool.cpp.

231 {
232  // try to push tasks on the queue to any available threads
233  while (!queue.isEmpty() && tryStart(queue.first().first))
234  queue.removeFirst();
235 }
QList::isEmpty
bool isEmpty() const
Returns true if the list contains no items; otherwise returns false.
Definition: qlist.h:152
QList::removeFirst
void removeFirst()
Removes the first item in the list.
Definition: qlist.h:286
QList::first
T & first()
Returns a reference to the first item in the list.
Definition: qlist.h:282
QThreadPoolPrivate::queue
QList< QPair< QRunnable *, int > > queue
Definition: qthreadpool_p.h:93
QThreadPoolPrivate::tryStart
bool tryStart(QRunnable *task)
Definition: qthreadpool.cpp:173

◆ waitForDone()

bool QThreadPoolPrivate::waitForDone ( int  msecs = -1)

Definition at line 293 of file qthreadpool.cpp.

294 {
295  QMutexLocker locker(&mutex);
296  if (msecs < 0) {
297  while (!(queue.isEmpty() && activeThreads == 0))
298  noActiveThreads.wait(locker.mutex());
299  } else {
300  QElapsedTimer timer;
301  timer.start();
302  int t;
303  while (!(queue.isEmpty() && activeThreads == 0) &&
304  ((t = msecs - timer.elapsed()) > 0))
305  noActiveThreads.wait(locker.mutex(), t);
306  }
307  return queue.isEmpty() && activeThreads == 0;
308 }
timer
EventLoopTimerRef timer
Definition: qapplication_mac.mm:881
QElapsedTimer
The QElapsedTimer class provides a fast way to calculate elapsed times.
Definition: qelapsedtimer.h:53
QElapsedTimer::elapsed
qint64 elapsed() const
Returns the number of milliseconds since this QElapsedTimer was last started.
Definition: qelapsedtimer_generic.cpp:132
QList::isEmpty
bool isEmpty() const
Returns true if the list contains no items; otherwise returns false.
Definition: qlist.h:152
QWaitCondition::wait
bool wait(QMutex *mutex, unsigned long time=ULONG_MAX)
Definition: qwaitcondition_unix.cpp:145
QMutexLocker
The QMutexLocker class is a convenience class that simplifies locking and unlocking mutexes...
Definition: qmutex.h:101
QThreadPoolPrivate::noActiveThreads
QWaitCondition noActiveThreads
Definition: qthreadpool_p.h:94
QElapsedTimer::start
void start()
Starts this timer.
Definition: qelapsedtimer_generic.cpp:79
QThreadPoolPrivate::queue
QList< QPair< QRunnable *, int > > queue
Definition: qthreadpool_p.h:93

Friends and Related Functions

◆ QThreadPoolThread

friend class QThreadPoolThread
friend

Definition at line 71 of file qthreadpool_p.h.

Referenced by startThread().

Properties

◆ activeThreads

int QThreadPoolPrivate::activeThreads

Definition at line 100 of file qthreadpool_p.h.

Referenced by QThreadPoolThread::registerThreadInactive(), QThreadPoolThread::run(), startThread(), tryStart(), and waitForDone().

◆ allThreads

QSet<QThreadPoolThread *> QThreadPoolPrivate::allThreads

Definition at line 90 of file qthreadpool_p.h.

Referenced by activeThreadCount(), reset(), startThread(), and tryStart().

◆ expiredThreads

QQueue<QThreadPoolThread *> QThreadPoolPrivate::expiredThreads

Definition at line 92 of file qthreadpool_p.h.

Referenced by activeThreadCount(), reset(), QThreadPoolThread::run(), and tryStart().

◆ expiryTimeout

int QThreadPoolPrivate::expiryTimeout

Definition at line 97 of file qthreadpool_p.h.

Referenced by QThreadPoolThread::run().

◆ isExiting

bool QThreadPoolPrivate::isExiting

Definition at line 96 of file qthreadpool_p.h.

Referenced by reset(), and QThreadPoolThread::run().

◆ maxThreadCount

int QThreadPoolPrivate::maxThreadCount

Definition at line 98 of file qthreadpool_p.h.

Referenced by tooManyThreadsActive(), and tryStart().

◆ mutex

QMutex QThreadPoolPrivate::mutex
mutable

Definition at line 89 of file qthreadpool_p.h.

Referenced by reset(), QThreadPoolThread::run(), startFrontRunnable(), stealRunnable(), and waitForDone().

◆ noActiveThreads

QWaitCondition QThreadPoolPrivate::noActiveThreads

Definition at line 94 of file qthreadpool_p.h.

Referenced by QThreadPoolThread::registerThreadInactive(), and waitForDone().

◆ queue

QList<QPair<QRunnable *, int> > QThreadPoolPrivate::queue

Definition at line 93 of file qthreadpool_p.h.

Referenced by enqueueTask(), QThreadPoolThread::run(), startFrontRunnable(), stealRunnable(), tryToStartMoreThreads(), and waitForDone().

◆ reservedThreads

int QThreadPoolPrivate::reservedThreads

Definition at line 99 of file qthreadpool_p.h.

Referenced by activeThreadCount(), and tooManyThreadsActive().

◆ waitingThreads

QQueue<QThreadPoolThread *> QThreadPoolPrivate::waitingThreads

Definition at line 91 of file qthreadpool_p.h.

Referenced by activeThreadCount(), reset(), QThreadPoolThread::run(), and tryStart().

The documentation for this class was generated from the following files:
Qt 4.8 Source Code Browser