我在使用cPython进行线程时遇到同步问题。我有两个文件,我解析它们并返回所需的结果。但是,下面的代码奇怪地起作用,并且返回三次而不是两次,并且按照我将它们放入队列的顺序不返回。下面的代码:python多线程同步
import Queue
import threading
from HtmlDoc import Document
OUT_LIST = []
class Threader(threading.Thread):
"""
Start threading
"""
def __init__(self, queue, out_queue):
threading.Thread.__init__(self)
self.queue = queue
self.out_queue = out_queue
def run(self):
while True:
if self.queue.qsize() == 0: break
path, host = self.queue.get()
f = open(path, "r")
source = f.read()
f.close()
self.out_queue.put((source, host))
self.queue.task_done()
class Processor(threading.Thread):
"""
Process threading
"""
def __init__(self, out_queue):
self.out_queue = out_queue
self.l_first = []
self.f_append = self.l_first.append
self.l_second = []
self.s_append = self.l_second.append
threading.Thread.__init__(self)
def first(self, doc):
# some code to to retrieve the text desired, this works 100% I tested it manually
def second(self, doc):
# some code to to retrieve the text desired, this works 100% I tested it manually
def run(self):
while True:
if self.out_queue.qsize() == 0: break
doc, host = self.out_queue.get()
if host == "first":
self.first(doc)
elif host == "second":
self.second(doc)
OUT_LIST.extend(self.l_first + self.l_second)
self.out_queue.task_done()
def main():
queue = Queue.Queue()
out_queue = Queue.Queue()
queue.put(("...first.html", "first"))
queue.put(("...second.html", "second"))
qsize = queue.qsize()
for i in range(qsize):
t = Threader(queue, out_queue)
t.setDaemon(True)
t.start()
for i in range(qsize):
dt = Processor(out_queue)
dt.setDaemon(True)
dt.start()
queue.join()
out_queue.join()
print '<br />'.join(OUT_LIST)
main()
现在,当我打印,我想打印的“第一”首先,然后的“第二”内容的内容。谁能帮我?
注:我是线程,因为实际上我将不得不一次连接超过10个地方并检索其结果。我相信线程是完成这样的任务的最合适的方式
由于过度使用同步问题以及在需要在多台服务器上运行脚本时可能具有较高的平行度级别,因此我优先考虑多线程的多进程。 – varela
I/O绑定的线程很少受GIL和上下文切换影响。线程比进程消耗更少的资源,在这种情况下,这看起来很好。 – Martin