recv未按預期工作。 我發送10個字節(通過wireshark驗證),recv只獲取第一個字節並放棄其餘(直到下一個sendto)。 這是一個多播的東西?我很確定我用單播UDP做了同樣的事情,並且沒有問題。Python recv多播返回一個字節
這裏是我的示例代碼:
import struct, socket, multiprocessing, time
MCAST_PORT = 62950
MCAST_GRP = '239.0.0.13'
def _Rx(self, RXsock, Queue):
print "Receiver started"
while True:
# State machine goes here to parse header and recv (<msglen>) bytes.
print "Waiting Rx char...", RXsock
char = RXsock.recv(1) # Blocks here after first byte ("1") ???
print "Rx", hex(ord(char))
TXsock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
TXsock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
RXsock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
RXsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
RXsock.bind((MCAST_GRP, MCAST_PORT))
mreq = struct.pack("4sl", socket.inet_aton(MCAST_GRP), socket.INADDR_ANY)
RXsock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
RxQueue = multiprocessing.Queue()
receiver = multiprocessing.Process(target=_Rx, args=(None, RXsock, RxQueue))
receiver.daemon = True
receiver.start()
TXsock.sendto("09123456789", (MCAST_GRP, MCAST_PORT))
time.sleep(3)
也許相關:http://stackoverflow.com/questions/2862071/how-large-should-my-recv-buffer-be-when-calling-recv-in-the-socket-library(因爲它的數據報) – Caramiriel