examples/threads/waitconditions/waitconditions.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/threads/waitconditions/waitconditions.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,126 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+//! [0]
+const int DataSize = 100000;
+const int BufferSize = 8192;
+char buffer[BufferSize];
+
+QWaitCondition bufferNotEmpty;
+QWaitCondition bufferNotFull;
+QMutex mutex;
+int numUsedBytes = 0;
+//! [0]
+
+//! [1]
+class Producer : public QThread
+//! [1] //! [2]
+{
+public:
+    void run();
+};
+
+void Producer::run()
+{
+    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
+    
+    for (int i = 0; i < DataSize; ++i) {
+        mutex.lock();
+        if (numUsedBytes == BufferSize)
+            bufferNotFull.wait(&mutex);
+        mutex.unlock();
+
+        buffer[i % BufferSize] = "ACGT"[(int)qrand() % 4];
+
+        mutex.lock();
+        ++numUsedBytes;
+        bufferNotEmpty.wakeAll();
+        mutex.unlock();
+    }
+}
+//! [2]
+
+//! [3]
+class Consumer : public QThread
+//! [3] //! [4]
+{
+public:
+    void run();
+};
+
+void Consumer::run()
+{
+    for (int i = 0; i < DataSize; ++i) {
+        mutex.lock();
+        if (numUsedBytes == 0)
+            bufferNotEmpty.wait(&mutex);
+        mutex.unlock();
+
+        fprintf(stderr, "%c", buffer[i % BufferSize]);
+
+        mutex.lock();
+        --numUsedBytes;
+        bufferNotFull.wakeAll();
+        mutex.unlock();
+    }
+    fprintf(stderr, "\n");
+}
+//! [4]
+
+//! [5]
+int main(int argc, char *argv[])
+//! [5] //! [6]
+{
+    QCoreApplication app(argc, argv);
+    Producer producer;
+    Consumer consumer;
+    producer.start();
+    consumer.start();
+    producer.wait();
+    consumer.wait();
+    return 0;
+}
+//! [6]