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Description:
This recipe gives access to the Sync class.
Objects created by the Sync class are meant to
be used when trying to syncronize the execution
of two or more threads. See z_service.py for more
a simple example of how Sync objects can be used.
Source: Text Source
'''Support module for syncronizing threads.
This module allows access to the Sync class which can
allow automatic sycronization across several threads.'''
__version__ = 1.1
import thread
class Sync:
'Sync(threads) -> new syncronizer object'
def __init__(self, threads):
'x.__init__(...) initializes x'
self.__threads = threads
self.__count = 0
self.__main = thread.allocate_lock()
self.__exit = thread.allocate_lock()
self.__exit.acquire()
def sync(self):
'Automatically syncronizes threads.'
self.__main.acquire()
self.__count += 1
if self.__count < self.__threads:
self.__main.release()
else:
self.__exit.release()
self.__exit.acquire()
self.__count -= 1
if self.__count > 0:
self.__exit.release()
else:
self.__main.release()
if __name__ == '__main__':
import sys
print 'Content-Type: text/plain'
print
print file(sys.argv[0]).read()
Discussion:
The following code gives one example of how Sync objects can be used.
import os
import random
import sync
import time
SLOTS = 10
def reader(slots):
while True:
if os.name == 'nt':
os.system('cls')
elif os.name == 'posix':
os.system('clear')
print str(slots)[1:-1]
def writer(slots, index, sleep):
while True:
if not random.randrange(100000):
sleep.sync()
time.sleep(5)
slots[index] = (slots[index] + 1) % 10
def main():
slots = [0] * SLOTS
sleep = sync.Sync(SLOTS)
sync.thread.start_new_thread(reader, (slots,))
for index in range(SLOTS):
sync.thread.start_new_thread(writer, (slots, index, sleep))
sync.Sync(2).sync()
if __name__ == '__main__':
main()
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