Stack Overflow
Stack Overflow

Questions tagged [recvmmsg]

7 questions
9
votes
3 answers

How do I get the size of the msg_control buffer for recvmsg?

when using recvmsg I use MSG_TRUNC and MSG_PEEK like so: msgLen = recvmsg(fd, &hdr, MSG_PEEK | MSG_TRUNC) this gives me the size of the buffer to allocate for the next message my question is how do I get the size of the buffer I should allocate for…
user3076936
  • 169
  • 13
5
votes
0 answers

recvmmsg/recv/recvfrom blocks under high load

We have an application on Centos 6 that calls recvmmsg() on a multicast address to read 1024 UDP packets at a time. When we run multiple instances of this application on the same box (all listening to the same traffic), sometimes this call will…
Tars AC
  • 79
  • 2
1
vote
1 answer

Linux C sockets - recvmsg - getting source ifindex

I'm opening a RAW socket in Linux and reading all messages. recvmsg(mysock, &msg, 0); I'm traversing on all cmsg on that msg buffer and I get only one. for (c = CMSG_FIRSTHDR(&msg); c; c = CMSG_NXTHDR(&msg, c)) { How can I extract the ifindex…
User121212
  • 35
  • 5
1
vote
2 answers

Reading multiple UDP messages without polling

I would like to use the recvmmsg call to read multiple UDP messages from ONE single socket at once. I'm reading data from a single multicast group. When I read TCP data, I usually use poll/select with a non-blocking socket (and timeout) to be…
Abruzzo Forte e Gentile
  • 14,423
  • 28
  • 99
  • 173
0
votes
0 answers

process hangs on socket recvmsg call while receiving complete mmapped memory block

I have a server process (C program)which does mmap for a physical memory of size around 70MB and when I'm sending this entire memory block over socket to a client process, My socket send api returns success but client keeps waiting for the message…
Rushi Kurhade
  • 1
0
votes
1 answer

MPI_Send getting stuck when executing with different nodes

I have a very simple MPI program where node 0 sends a character to node 1, but the send and receive are getting stuck whenever I use two or more different machines. The program works fine when I use several processes in only one machine. It seems to…
Matheus Mendonça
  • 21
  • 6
0
votes
0 answers

recvmmsg remains blocked on CTRL-C

I am using recvmmsg to read from a blocking UDP socket out of a mutlicast group. In the man pages of that API I noted that the errors messages don't mention EINTR so it looks like that api cannot catch when a signal has been received. I tested and…
Abruzzo Forte e Gentile
  • 14,423
  • 28
  • 99
  • 173