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GP89提到了一个很好的解决方案。使用队列将写入任务发送到对文件具有唯一写入权限的专用进程。其他所有工人均具有只读访问权限。这将消除冲突。这是一个使用apply_async的示例，但它也适用于map：
import multiprocessing as mpimport timefn = 'c:/temp/temp.txt'def worker(arg, q): '''stupidly simulates long running process''' start = time.clock() s = 'this is a test' txt = s for i in range(200000): txt += s done = time.clock() - start with open(fn, 'rb') as f: size = len(f.read()) res = 'Process' + str(arg), str(size), done q.put(res) return resdef listener(q): '''listens for messages on the q, writes to file. ''' with open(fn, 'w') as f: while 1: m = q.get() if m == 'kill': f.write('killed') break f.write(str(m) + 'n') f.flush()def main(): #must use Manager queue here, or will not work manager = mp.Manager() q = manager.Queue() pool = mp.Pool(mp.cpu_count() + 2) #put listener to work first watcher = pool.apply_async(listener, (q,)) #fire off workers jobs = [] for i in range(80): job = pool.apply_async(worker, (i, q)) jobs.append(job) # collect results from the workers through the pool result queue for job in jobs: job.get() #now we are done, kill the listener q.put('kill') pool.close() pool.join()if __name__ == "__main__": main()
