Merge pull request #199 from ReinierNL/update_demo23_v2

Updates for demo 23

Author: pyscripter

Demos/Demo23/Unit1.dfm

@@ -26,7 +26,7 @@ object Form1: TForm1
     Font.Name = 'Consolas'
     Font.Style = []
     Lines.Strings = (
-      'import threading'
+      'import threading_test'
       'import sys'
       'try:'
       '  count = int(sys.argv[1])'
@@ -35,7 +35,7 @@ object Form1: TForm1
       ''
       'for i in range(count):'
       '  print ("**** Pass", i)'
-      '  threading._test()'
+      '  threading_test._test()'
       'print ("**** Done.")')
     ParentFont = False
     ScrollBars = ssBoth

Demos/Demo23/threading_test.py

@@ -0,0 +1,96 @@
+from threading import *
+from collections import deque
+from time import sleep
+
+def _test():
+
+    class BoundedQueue():
+
+        def __init__(self, limit):
+            self.mon = RLock()
+            self.rc = Condition(self.mon)
+            self.wc = Condition(self.mon)
+            self.limit = limit
+            self.queue = deque()
+
+        def put(self, item):
+            self.mon.acquire()
+            while len(self.queue) >= self.limit:
+                self._note("put(%s): queue full", item)
+                self.wc.wait()
+            self.queue.append(item)
+            self._note("put(%s): appended, length now %d",
+                       item, len(self.queue))
+            self.rc.notify()
+            self.mon.release()
+
+        def get(self):
+            self.mon.acquire()
+            while not self.queue:
+                self._note("get(): queue empty")
+                self.rc.wait()
+            item = self.queue.popleft()
+            self._note("get(): got %s, %d left", item, len(self.queue))
+            self.wc.notify()
+            self.mon.release()
+            return item
+
+        def _note(self, format, *args):
+            format = format % args
+            ident = get_ident()
+            try:
+                name = current_thread().name
+            except KeyError:
+                name = "<OS thread %d>" % ident
+            format = "%s: %s" % (name, format)
+            print(format)
+
+    class ProducerThread(Thread):
+
+        def __init__(self, queue, quota):
+            Thread.__init__(self, name="Producer")
+            self.queue = queue
+            self.quota = quota
+
+        def run(self):
+            from random import random
+            counter = 0
+            while counter < self.quota:
+                counter = counter + 1
+                self.queue.put("%s.%d" % (self.name, counter))
+                sleep(random() * 0.00001)
+
+
+    class ConsumerThread(Thread):
+
+        def __init__(self, queue, count):
+            Thread.__init__(self, name="Consumer")
+            self.queue = queue
+            self.count = count
+
+        def run(self):
+            while self.count > 0:
+                item = self.queue.get()
+                print(item)
+                self.count = self.count - 1
+
+    NP = 3
+    QL = 4
+    NI = 5
+
+    Q = BoundedQueue(QL)
+    P = []
+    for i in range(NP):
+        t = ProducerThread(Q, NI)
+        t.name = ("Producer-%d" % (i+1))
+        P.append(t)
+    C = ConsumerThread(Q, NI*NP)
+    for t in P:
+        t.start()
+        sleep(0.000001)
+    C.start()
+    for t in P:
+        t.join()
+    C.join()
+
+_test()