使用Python廣播和接收數據

Question

我試圖播放一些數據並使用python接收數據。 這是我想出的代碼。

from socket import * 
import threading 

class PingerThread (threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 

    def run (self): 
     print 'start thread' 
     cs = socket(AF_INET, SOCK_DGRAM) 
     cs.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) 
     cs.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) 
     cs.sendto('This is a test', ('192.168.65.255', 4499)) 

a = PingerThread() 
a.start() 

cs = socket(AF_INET, SOCK_DGRAM) 
data = cs.recvfrom(1024) # <-- waiting forever 

但是，代碼似乎永遠在cs.recvfrom(1024)等待。什麼可能是錯誤的？

Answer 1

您的線程可能會在之前發送其數據您開始收聽。

添加一個循環，你的線程停止問題

from socket import * 
import threading 
import time 

class PingerThread (threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 

    def run (self): 
     for i in range(10): 
      print 'start thread' 
      cs = socket(AF_INET, SOCK_DGRAM) 
      cs.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) 
      cs.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) 
      cs.sendto('This is a test', ('192.168.1.3', 4499)) 
      time.sleep(1) 

a = PingerThread() 
a.start() 


cs = socket(AF_INET, SOCK_DGRAM) 
try: 
    cs.bind(('192.168.1.3', 4499)) 
except: 
    print 'failed to bind' 
    cs.close() 
    raise 
    cs.blocking(0) 
data = cs.recvfrom(1024) # <-- waiting forever 
print data 

Answer 2

有在代碼中的三個問題。

1. 該監聽器沒有任何約束力。
2. 打開的插座未關閉。
3. 有時，線程產生得如此之快以至於偵聽器只是錯過了廣播數據。

這是修改後的工作代碼。

from socket import * 
import time 
import threading 

port = 4490 
class PingerThread (threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 

    def run (self): 
     print 'start thread' 
     cs = socket(AF_INET, SOCK_DGRAM) 
     cs.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) 
     cs.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) 

     time.sleep(0.1) # issue 3 solved 
     cs.sendto('This is a test', ('192.168.65.255', port)) 

a = PingerThread() 
a.start() 

cs = socket(AF_INET, SOCK_DGRAM) 
try: 
    cs.bind(('192.168.65.255', port)) # issue 1 solved 
except: 
    print 'failed to bind' 
    cs.close() 
    raise 
    cs.blocking(0) 

data = cs.recvfrom(20) 
print data 
cs.close() # issue 2 solved