1 files changed, 203 insertions, 0 deletions
diff --git a/examples3/semaphore.py b/examples3/semaphore.py
new file mode 100755
index 0000000..ac8b231
--- /dev/null
+++ b/examples3/semaphore.py
@@ -0,0 +1,203 @@
+#!/usr/bin/env python
+#
+# A port of the semaphore example from Qt.
+
+
+import sys
+
+# Check if thread support was enabled.
+try:
+    from qt import QThread
+except:
+    print "Thread support not enabled"
+    sys.exit(1)
+
+from qt import *
+
+
+# The semaphore instances.
+yellowSem = None
+greenSem = None
+
+
+class YellowThread(QThread):
+    def __init__(self,o):
+        QThread.__init__(self)
+
+        self.receiver = o
+        self.stopped = 0
+        self.mutex = QMutex()
+
+    def run(self):
+        global yellowSem, greenSem
+
+        for i in range(20):
+            yellowSem += 1
+
+            event = QCustomEvent(12345)
+            event.setData(QString("Yellow!"))
+            QThread.postEvent(self.receiver,event)
+            self.msleep(200);
+
+            greenSem -= 1
+
+            self.mutex.lock()
+            if self.stopped:
+                self.stopped = 0
+                self.mutex.unlock()
+                break
+
+            self.mutex.unlock()
+
+        yellowSem += 1
+
+        event = QCustomEvent(12346)
+        event.setData(QString("Yellow!"))
+        QThread.postEvent(self.receiver,event)
+
+        greenSem -= 1
+
+    def stop(self):
+        self.mutex.lock()
+        self.stopped = 1
+        self.mutex.unlock()
+
+
+class GreenThread(QThread):
+    def __init__(self,o):
+        QThread.__init__(self)
+
+        self.receiver = o
+        self.stopped = 0
+        self.mutex = QMutex()
+
+    def run(self):
+        global yellowSem, greenSem
+
+        for i in range(20):
+            greenSem += 1
+
+            event = QCustomEvent(12345)
+            event.setData(QString("Green!"))
+            QThread.postEvent(self.receiver,event)
+            self.msleep(200)
+
+            yellowSem -= 1
+
+            self.mutex.lock()
+            if self.stopped:
+                self.stopped = 0
+                self.mutex.unlock()
+                break
+
+            self.mutex.unlock()
+
+        greenSem += 1
+
+        event = QCustomEvent(12346)
+        event.setData(QString("Green!"))
+        QThread.postEvent(self.receiver,event)
+        self.msleep(10)
+
+        yellowSem -= 1
+
+    def stop(self):
+        self.mutex.lock()
+        self.stopped = 1
+        self.mutex.unlock()
+
+
+class SemaphoreExample(QWidget):
+    def __init__(self):
+        QWidget.__init__(self)
+
+        self.yellowThread = YellowThread(self)
+        self.greenThread = GreenThread(self)
+
+        global yellowSem, greenSem
+        yellowSem = QSemaphore(1)
+        greenSem = QSemaphore(1)
+
+        self.button = QPushButton("&Ignition!",self)
+        self.connect(self.button,SIGNAL("clicked()"),self.startExample)
+
+        self.mlineedit = QMultiLineEdit(self)
+        self.label = QLabel(self)
+
+        vbox = QVBoxLayout(self,5)
+        vbox.addWidget(self.button)
+        vbox.addWidget(self.mlineedit)
+        vbox.addWidget(self.label)
+
+    def __del__(self):
+        stopYellow = self.yellowThread.running()
+        stopGreen = self.greenThread.running()
+
+        if stopYellow:
+            self.yellowThread.stop()
+
+        if self.greenThread.running():
+            self.greenThread.stop()
+
+        if stopYellow:
+            self.yellowThread.wait()
+
+        if stopGreen:
+            self.greenThread.wait()
+
+        global yellowSem, greenSem
+        yellowSem = None
+        greenSem = None
+
+    def startExample(self):
+        if self.yellowThread.running() or self.greenThread.running():
+            QMessageBox.information(self,"Sorry",
+                "The threads have not completed yet, and must finish before "
+                "they can be started again.")
+
+            return
+
+        self.mlineedit.clear()
+
+        global yellowSem
+
+        while yellowSem.available() < yellowSem.total():
+            yellowSem -= 1
+
+        yellowSem += 1
+
+        self.yellowThread.start()
+        self.greenThread.start()
+
+    def customEvent(self,event):
+        if event.type() == 12345:
+            s = event.data()
+
+            self.mlineedit.append(s)
+
+            if s.latin1() == "Green!":
+                self.label.setEraseColor(Qt.green)
+            else:
+                self.label.setEraseColor(Qt.yellow)
+
+            self.label.setText(s)
+
+            del s
+        elif event.type() == 12346:
+            s = event.data()
+
+            QMessageBox.information(self,s.latin1() + " - Finished",
+                "The thread creating the \"" + s.latin1() +
+                "\" events has finished.")
+
+            del s
+        else:
+            print "Unknown custom event type:", event.type()
+
+
+app = QApplication(sys.argv)
+se = SemaphoreExample()
+app.setMainWidget(se)
+se.show()
+
+sys.exit(app.exec_loop())