[英]Why is subclassing Thread so much slower than calling Thread?
我有Python 2.7代码,它发出1,000个请求来检查我当前的IP地址。 我用200线程和套接字编写了它。 代码使用两种方法执行相同的任务。 我找不到下面两个之间的任何差异,除了那个子类threading.Thread
#!/usr/bin/env python2.7
import sys, ssl, time, socket, threading
class Counter:
def __init__(self):
self._value = 0
self._LOCK = threading.Lock()
def increment(self):
with self._LOCK:
self._value += 1
return self._value
def pr(out):
sys.stdout.write('{}\n'.format(out))
sys.stdout.flush()
def recvAll(sock):
data = ''
BUF_SIZE = 1024
while True:
part = sock.recv(BUF_SIZE)
data += part
length = len(part)
if length < BUF_SIZE: break
return data
class Speed(threading.Thread):
_COUNTER = Counter()
def __init__(self):
super(Speed, self).__init__()
self.daemon = True
self._sock = ssl.wrap_socket(socket.socket(socket.AF_INET, socket.SOCK_STREAM))
self._sock.settimeout(5)
self._sock.connect(('checkip.amazonaws.com', 443))
self._request = 'GET / HTTP/1.1\r\n'
self._request += 'Host: checkip.amazonaws.com\r\n\r\n'
def run(self):
i = 0
while i < 5:
self._sock.write(self._request)
response = recvAll(self._sock)
if '200 OK' not in response: continue
count = Speed._COUNTER.increment()
pr('#{} - {}'.format(count, response))
i += 1
self._sock.close()
def speed():
sock = ssl.wrap_socket(socket.socket(socket.AF_INET, socket.SOCK_STREAM))
sock.settimeout(5)
sock.connect(('checkip.amazonaws.com', 443))
request = 'GET / HTTP/1.1\r\n'
request += 'Host: checkip.amazonaws.com\r\n\r\n'
i = 0
while i < 5:
sock.write(request)
response = recvAll(sock)
if '200 OK' not in response: continue
count = counter.increment()
pr('#{} - {}'.format(count, response))
i += 1
sock.close()
slow = False
if slow:
for _ in xrange(200):
thread = Speed()
thread.start()
else:
counter = Counter()
for _ in xrange(200):
thread = threading.Thread(target = speed)
thread.daemon = True
thread.start()
while threading.active_count() > 1: time.sleep(1)
我希望两者都有相似的速度。 但是,子类threading.Thread
的变化要慢很多很多。 任何想法为什么?
你的Thread
子类在__init__
做了太多的工作,它没有在新线程中执行。 因此,使用子类的版本最终会按顺序执行。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.