Messages in this thread | | | Date | Fri, 22 Nov 2013 09:53:52 -0800 | Subject | disappearing listen()ed SO_REUSEPORT sockets across fork() when using epoll | From | Shawn Landden <> |
| |
Hello, when running the attached program on 3.12 child processes are missing a socket fd opened, set with SO_REUSEPORT, listen()ed to, and added to epoll_ctl().
This is the output I get when pointing "wget http://localhost:5555/" at the attached program:
main PID 31591 PID 31634 started PID 31634 accept()ed connection PID 31635 started PID 31636 started PID 31635 accept() failed: Bad file descriptor PID 31636 accept() failed: Bad file descriptor PID 31634 accept()ed connection PID 31634 accept()ed connection PID 31634 accept()ed connection PID 31634 accept()ed connection
While I would expect something like:
main PID 31591 PID 31634 started PID 31634 accept()ed connection PID 31635 started PID 31636 started PID 31635 accept()ed connection PID 31636 accept()ed connection
-more new processes, but inversely proportional to number of listening processes -accept() always returns successfully
--
--- Shawn Landden +1 360 389 3001 (SMS preferred) #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <stdlib.h> #include <string.h> #include <sys/epoll.h>
int main( int argc, char *argv[]) { int sockfd, epollfd, acceptfd, portno; struct epoll_event event = {EPOLLIN, NULL}, gotevent; char buffer[256]; struct sockaddr_in serv_addr; int n; pid_t pid;
printf("main PID %d\n", getpid());
memset((char *) &serv_addr, 0, sizeof(serv_addr)); portno = 5555; serv_addr.sin_family = AF_INET; serv_addr.sin_addr.s_addr = INADDR_ANY; serv_addr.sin_port = htons(portno); if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) return printf("socket() failed: %m\n");
int optval = 1; if ((setsockopt(sockfd, SOL_SOCKET, SO_REUSEPORT, &optval, sizeof(optval))) < 0) return printf("setsockopt() failed: %m");
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) return printf("bind() failed: %m\n");
if (listen(sockfd, SOMAXCONN) < 0) return printf("listen() failed: %m\n"); if ((epollfd = epoll_create1(0)) < 0) return printf("epoll_create1() failed: %m\n"); if (epoll_ctl(epollfd, EPOLL_CTL_ADD, sockfd, &event) < 0) return printf("epoll_ctl() failed: %m\n"); while (1) { if (epoll_wait(epollfd, &gotevent, 1, -1) != 1) return printf("epoll_wait() failed: %m\n");
pid = fork(); if (pid == 0) { printf("PID %d started\n", getpid()); while(1) { struct sockaddr_in cli_addr; socklen_t cli_size = sizeof cli_addr;
if ((acceptfd = accept(sockfd, (struct sockaddr *)&cli_addr, &cli_size)) < 0) { printf("PID %d accept() failed: %m\n", getpid()); sleep(60); return 1; }
printf("PID %d accept()ed connection\n", getpid());
if (close(acceptfd) < 0) return printf("close() failed: %m\n"); } } close(sockfd); } }
| |