Messages in this thread | | | Subject | Re: select implementation not POSIX compliant? | From | Steven Dake <> | Date | Wed, 11 Aug 2004 14:57:29 -0700 |
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You will find poll works as you desire but select does not. I recommend porting to poll anyway; select sucks bad. You might even try out epoll in 2.6.
Thanks Good luck
On Wed, 2004-08-11 at 12:40, Alex Riesen wrote: > On linux-kernel, Nick Palmer wrote: > > I am working on porting some software from Solaris to Linux 2.6.7. I > > have run into a problem with the interaction of select and/or > > recvmsg and close in our multi-threaded application. The application > > expects that a close call on a socket that another thread is > > blocking in select and/or recvmsg on will cause select and/or > > recvmsg to return with an error. Linux does not seem to do this. (I > > also verified that the same issue exists in Linux 2.4.25, just to be > > sure it wasn't introduced in 2.6 in case you were wondering.) > > It works always for stream sockets and does not at all (even with > shutdown, even using poll(2) or read(2) instead of select) for dgram > sockets. > > What domain (inet, local) are your sockets in? > What type (stream, dgram)? > > There will probably be a problem anyway with changing the behaviour: > there surely is lots of code, which start complaining about select and > poll finishing "unexpectedly". > > I used this to check: > > #include <unistd.h> > #include <stdio.h> > #include <stdlib.h> > #include <sys/socket.h> > #include <sys/wait.h> > #include <netinet/in.h> > #include <fcntl.h> > > int main(int argc, char* argv[]) > { > int status; > int fds[2]; > fd_set set; > #if 0 > puts("stream"); > if ( socketpair(PF_LOCAL, SOCK_STREAM, 0, fds) < 0 ) > #else > puts("dgram"); > if ( socketpair(PF_LOCAL, SOCK_DGRAM, 0, fds) < 0 ) > #endif > { > perror("socketpair"); > exit(1); > } > fcntl(fds[0], F_SETFL, fcntl(fds[0], F_GETFL) | O_NONBLOCK); > fcntl(fds[1], F_SETFL, fcntl(fds[1], F_GETFL) | O_NONBLOCK); > switch ( fork() ) > { > case 0: > sleep(1); > close(fds[0]); > shutdown(fds[1], SHUT_RD); > close(fds[1]); > exit(0); > break; > case -1: > perror("fork"); > exit(1); > } > close(fds[1]); > FD_ZERO(&set); > FD_SET(fds[0], &set); > select(fds[0] + 1, &set, NULL, NULL, 0); > wait(&status); > return 0; > } > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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