使用线程池

需要你的主线程把处理任务托付给一个工作线程池

Queue.Queue是用来协调工作线程池的最简单和最有效率的方法。因为它已经有了全局变量的保护（加锁和解锁）

#-*-coding:utf-8-*-
import threading, Queue, time, sys
#global varialbes
Qin = Queue.Queue()
Qout = Queue.Queue()
Qerr = Queue.Queue()

Pool = [ ]
def report_error():
    '''put error information into Qerr to report the error'''
    Qerr.put(sys.exc_info()[:2])
def get_all_from_queue(Q):
    '''acquire all items of Queue Q ,no need to wait'''
    try:
        while True:
            yield Q.get_nowait()
    except Queue.Empty:
        raise StopIteration

def do_work_from_queue():
    ''' workthread acquire little job and loops working'''
    while True:
        command, item = Qin.get()
        if command == 'stop':
            break
        try:
        #simulate the job of working
            if command == 'process':
                result = 'new' + item
            else:
                raise ValueError ,'Unknown command %r' %command
        except:
            #it's right to except unconditionally,because we report all the mistakes
            report_error()
        else:
            Qout.put(result)

def make_and_start_thread_pool(number_of_threads_in_pool=5, daemons=True):
    '''create a pool has N threads, and make them daemon and start'''
    for i in range(number_of_threads_in_pool):
        new_thread = threading.Thread(target = do_work_from_queue)
        new_thread.setDaemon(daemons)
        Pool.append(new_thread)
        new_thread.start()

def request_work(data, command = 'process'):
    '''requesting work as if tuple(command, data)'''
    Qin.put((command, data))

def get_result():
    return Qout.get()

def show_all_results():
    for result in get_all_from_queue(Qout):
        print 'Result:', result

def show_all_errors():
    for etyp, err in get_all_from_queue(Qerr):
        print 'Error:', etyp, err

def stop_and_free_thread_pool():
    #sequence is important,first of all, let all the threads stop
    for i in range(len(Pool)):
        request_work(None,'stop')
    #wait every thread stop
    for existing_thread in Pool:
        existing_thread.join()
    #clean thread pool
    del Pool[:]



for i in ('_ba', '_be', '_bo'):
    request_work(i)
make_and_start_thread_pool()
stop_and_free_thread_pool()
show_all_results()
show_all_errors()

运行效果：

Result: new_ba
Result: new_be
Result: new_bo