--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Demo/threads/Generator.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,92 @@
+# Generator implementation using threads
+
+import sys
+import thread
+
+class Killed(Exception):
+    pass
+
+class Generator:
+    # Constructor
+    def __init__(self, func, args):
+        self.getlock = thread.allocate_lock()
+        self.putlock = thread.allocate_lock()
+        self.getlock.acquire()
+        self.putlock.acquire()
+        self.func = func
+        self.args = args
+        self.done = 0
+        self.killed = 0
+        thread.start_new_thread(self._start, ())
+
+    # Internal routine
+    def _start(self):
+        try:
+            self.putlock.acquire()
+            if not self.killed:
+                try:
+                    apply(self.func, (self,) + self.args)
+                except Killed:
+                    pass
+        finally:
+            if not self.killed:
+                self.done = 1
+                self.getlock.release()
+
+    # Called by producer for each value; raise Killed if no more needed
+    def put(self, value):
+        if self.killed:
+            raise TypeError, 'put() called on killed generator'
+        self.value = value
+        self.getlock.release()  # Resume consumer thread
+        self.putlock.acquire()  # Wait for next get() call
+        if self.killed:
+            raise Killed
+
+    # Called by producer to get next value; raise EOFError if no more
+    def get(self):
+        if self.killed:
+            raise TypeError, 'get() called on killed generator'
+        self.putlock.release()  # Resume producer thread
+        self.getlock.acquire()  # Wait for value to appear
+        if self.done:
+            raise EOFError  # Say there are no more values
+        return self.value
+
+    # Called by consumer if no more values wanted
+    def kill(self):
+        if self.killed:
+            raise TypeError, 'kill() called on killed generator'
+        self.killed = 1
+        self.putlock.release()
+
+    # Clone constructor
+    def clone(self):
+        return Generator(self.func, self.args)
+
+def pi(g):
+    k, a, b, a1, b1 = 2L, 4L, 1L, 12L, 4L
+    while 1:
+        # Next approximation
+        p, q, k = k*k, 2L*k+1L, k+1L
+        a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1
+        # Print common digits
+        d, d1 = a//b, a1//b1
+        while d == d1:
+            g.put(int(d))
+            a, a1 = 10L*(a%b), 10L*(a1%b1)
+            d, d1 = a//b, a1//b1
+
+def test():
+    g = Generator(pi, ())
+    g.kill()
+    g = Generator(pi, ())
+    for i in range(10): print g.get(),
+    print
+    h = g.clone()
+    g.kill()
+    while 1:
+        print h.get(),
+        sys.stdout.flush()
+
+test()