我用python写了一个epoll包装器,它工作得很好,但最近我发现性能不太适合发送大包。我仔细查看了代码,发现实际上有很多错误
Traceback (most recent call last):
File "/Users/dawn/Documents/workspace/work/dev/server/sandbox/single_point/tcp_epoll.py", line 231, in send_now
num_bytes = self.sock.send(self.response)
error: [Errno 35] Resource temporarily unavailable
之前按照文件所说的那样静音,所以我的发送功能是这样完成的:
def send_now(self):
'''send message at once'''
st = time.time()
times = 0
while self.response != '':
try:
num_bytes = self.sock.send(self.response)
l.info('msg wrote %s %d : %r size %r',self.ip,self.port,self.response[:num_bytes],num_bytes)
self.response = self.response[num_bytes:]
except socket.error,e:
if e[0] in (errno.EWOULDBLOCK,errno.EAGAIN):
#here I printed it, but I silent it in normal days
#print 'would block, again %r',tb.format_exc()
break
else:
l.warning('%r %r socket error %r',self.ip,self.port,tb.format_exc())
#must break or cause dead loop
break
except:
#other exceptions
l.warning('%r %r msg write error %r',self.ip,self.port,tb.format_exc())
break
times += 1
et = time.time()
我在谷歌上搜索了一下,说这是由于临时网络缓冲区用完造成的那么,我如何手动有效地检测这个错误,而不是进入异常阶段呢?
因为这会导致很长时间来引发/处理异常。
使用select
查看套接字是否已准备好进行读取或写入。