How to set timeout on python's socket recv method?

问题

I need to set timeout on python's socket recv method. How to do it?

回答1:

The typical approach is to use select() to wait until data is available or until the timeout occurs. Only call recv() when data is actually available. To be safe, we also set the socket to non-blocking mode to guarantee that recv() will never block indefinitely. select() can also be used to wait on more than one socket at a time.

import select

mysocket.setblocking(0)

ready = select.select([mysocket], [], [], timeout_in_seconds)
if ready[0]:
    data = mysocket.recv(4096)

If you have a lot of open file descriptors, poll() is a more efficient alternative to select().

Another option is to set a timeout for all operations on the socket using socket.settimeout(), but I see that you've explicitly rejected that solution in another answer.

回答2:

there's socket.settimeout()

回答3:

As mentioned both select.select() and socket.settimeout() will work.

Note you might need to call settimeout twice for your needs, e.g.

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("",0))
sock.listen(1)
# accept can throw socket.timeout
sock.settimeout(5.0)
conn, addr = sock.accept()

# recv can throw socket.timeout
conn.settimeout(5.0)
conn.recv(1024)

回答4:

You could set timeout before receiving the response and after having received the response set it back to None:

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

sock.settimeout(5.0)
data = sock.recv(1024)
sock.settimeout(None)

回答5:

The timeout that you are looking for is the connection socket's timeout not the primary socket's, if you implement the server side. In other words, there is another timeout for the connection socket object, which is the output of socket.accept() method. Therefore:

sock.listen(1)
connection, client_address = sock.accept()
connection.settimeout(5)    # This is the one that affects recv() method.
connection.gettimeout()     # This should result 5
sock.gettimeout()           # This outputs None when not set previously, if I remember correctly.

If you implement the client side, it would be simple.

sock.connect(server_address)
sock.settimeout(3)

回答6:

As mentioned in previous replies, you can use something like: .settimeout() For example:

import socket

s = socket.socket()

s.settimeout(1) # Sets the socket to timeout after 1 second of no activity

host, port = "somehost", 4444
s.connect((host, port))

s.send("Hello World!\r\n")

try:
    rec = s.recv(100) # try to receive 100 bytes
except socket.timeout: # fail after 1 second of no activity
    print("Didn't receive data! [Timeout]")
finally:
    s.close()

I hope this helps!!

回答7:

You can use socket.settimeout() which accepts a integer argument representing number of seconds. For example, socket.settimeout(1) will set the timeout to 1 second

回答8:

try this it uses the underlying C.

timeval = struct.pack('ll', 2, 100)
s.setsockopt(socket.SOL_SOCKET, socket.SO_RCVTIMEO, timeval)

回答9:

#! /usr/bin/python3.6

# -*- coding: utf-8 -*-
import socket
import time
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
s.settimeout(5)
PORT = 10801

s.bind(('', PORT))
print('Listening for broadcast at ', s.getsockname())
BUFFER_SIZE = 4096
while True:
    try:
        data, address = s.recvfrom(BUFFER_SIZE)
    except socket.timeout:
        print("Didn't receive data! [Timeout 5s]")
        continue

来源：https://stackoverflow.com/questions/2719017/how-to-set-timeout-on-pythons-socket-recv-method

标签

python

sockets

timeout