import threading
def tryfinally(finallyf):
u"returns a decorator that adds try/finally behavior with given no-argument call in the finally"
print "tryfinally"
def decorator(callable):
print "decorator"
def execute(*args, **kwargs):
print "execute1"
try: result = callable(*args, **kwargs)
finally: finallyf()
return result
return execute
return decorator
def usinglock(lock):
u"returns a decorator whose argument will acquire the given lock while executing"
print "usinglock"
def decorator(function):
print "decorator"
body = tryfinally(lock.release)(function)
def execute(*args, **kwargs):
print "execute"
lock.acquire()
return body(*args, **kwargs)
return execute
return decorator
def synchronized(function):
u"decorator; only one thread can enter the decorated function at a time; recursion is OK"
print "synchronized"
return usinglock(threading.RLock())(function)
@synchronized
def foo(*args):
print "Only one thread can enter this function at a time"
if __name__=="__main__":
foo(123)
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