Script breaks out of function after sending a few packets

问题

I am writing a python program that sends packets for a specified amount of time.

The sending script:

import socket
import time
import networkparam
import ray

ray.init()

transformer_sending_time = 0
final_message_sent = False
@ray.remote
def send_message():
    """
    Sends an abnormal measurement to the specified ip address or port number given by the networkparam module
    Parameters
    ----------
    None, however we can consider the definitions in networkparam as the function args
    Returns
    ----------
    None
    """

    global transformer_sending_time
    global final_message_sent
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    ip = networkparam.ip
    port = networkparam.controller_port
    message = b"bait"
    seconds = 15
  
    end_time = time.time() + seconds
    while time.time() < end_time:
        sock.sendto(message, (ip, port))
        transformer_sending_time = time.time()

    print("done")
    final_message_sent = True

s = send_message.remote()

The receiving script:

import time
import socket
import networkparam

ip = networkparam.ip
controller_port = networkparam.controller_port
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind((ip,controller_port))

while True:
    data, addr = sock.recvfrom(1024)
    if not data:
        break
    print("received message: %s" % data)

I am expecting the sending script to run for the full 15 seconds and "done" to be printed. However, the sending script sends packets for approximately 2 seconds and then breaks out of the function and "done" never gets printed.

回答1:

ray.remote is a non-blocking operation. What's happening is your program is beginning the remote function call, then finishing. When it finishes, it tears down the ray cluster and ends the remote function.

You should add

s = send_message.remote()
ray.get(s)

The ray.get will try to get the return value of send_message (and return it), which means the program will have to wait for the remote function to finish.

来源：https://stackoverflow.com/questions/63539577/script-breaks-out-of-function-after-sending-a-few-packets

标签

python

sockets

while-loop

blocking

ray