start ch2.7

Author: laixintao

chapter2/07_Thread_synchronization_with_RLock.rst

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 使用RLock进行线程同步
 =====================
+
+

chapter2/box.py

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+import threading
+import time
+
+class Box(object):
+    lock = threading.RLock()
+
+    def __init__(self):
+        self.total_items = 0
+
+    def execute(self, n):
+        Box.lock.acquire()
+        self.total_items += n
+        Box.lock.release()
+
+    def add(self):
+        Box.lock.acquire()
+        self.execute(1)
+        Box.lock.release()
+
+    def remove(self):
+        Box.lock.acquire()
+        self.execute(-1)
+        Box.lock.release()
+
+## These two functions run n in separate
+## threads and call the Box's methods
+def adder(box, items):
+    while items > 0:
+        print("adding 1 item in the box")
+        box.add()
+        time.sleep(5)
+        items -= 1
+
+def remover(box, items):
+    while items > 0:
+        print("removing 1 item in the box")
+        box.remove()
+        time.sleep(5)
+        items -= 1
+ 
+## the main program build some
+## threads and make sure it works
+if __name__ == "__main__":
+    items = 5
+    print("putting %s items in the box " % items)
+    box = Box()
+    t1 = threading.Thread(target=adder, args=(box, items))
+    t2 = threading.Thread(target=remover, args=(box, items))
+    t1.start()
+    t2.start()
+
+    t1.join()
+    t2.join()
+    print("%s items still remain in the box " % box.total_items)