diff options
Diffstat (limited to 'src/corelib/concurrent/qthreadpool.cpp')
| -rw-r--r-- | src/corelib/concurrent/qthreadpool.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/corelib/concurrent/qthreadpool.cpp b/src/corelib/concurrent/qthreadpool.cpp index 8913b56..eea6331 100644 --- a/src/corelib/concurrent/qthreadpool.cpp +++ b/src/corelib/concurrent/qthreadpool.cpp @@ -1,7 +1,7 @@ /**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). -** Contact: Qt Software Information (qt-info@nokia.com) +** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QtCore module of the Qt Toolkit. ** @@ -34,7 +34,7 @@ ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you are unsure which license is appropriate for your use, please -** contact the sales department at qt-sales@nokia.com. +** contact the sales department at http://www.qtsoftware.com/contact. ** $QT_END_LICENSE$ ** ****************************************************************************/ @@ -222,6 +222,8 @@ void QThreadPoolPrivate::enqueueTask(QRunnable *runnable, int priority) int QThreadPoolPrivate::activeThreadCount() const { + // To improve scalability this function is called without holding + // the mutex lock -- keep it thread-safe. return (allThreads.count() - expiredThreads.count() - waitingThreads @@ -481,6 +483,12 @@ bool QThreadPool::tryStart(QRunnable *runnable) return false; Q_D(QThreadPool); + + // To improve scalability perform a check on the thread count + // before locking the mutex. + if (d->allThreads.isEmpty() == false && d->activeThreadCount() >= d->maxThreadCount) + return false; + QMutexLocker locker(&d->mutex); return d->tryStart(runnable); } @@ -527,7 +535,6 @@ void QThreadPool::setExpiryTimeout(int expiryTimeout) int QThreadPool::maxThreadCount() const { Q_D(const QThreadPool); - QMutexLocker locker(&d->mutex); return d->maxThreadCount; } @@ -556,7 +563,6 @@ void QThreadPool::setMaxThreadCount(int maxThreadCount) int QThreadPool::activeThreadCount() const { Q_D(const QThreadPool); - QMutexLocker locker(&d->mutex); return d->activeThreadCount(); } |