mirror of https://github.com/mkerrisk/man-pages
b892d64f4f
I also verified the behavior reported by Andrew Clayton
with the program below.
$ ./epoll_signalfd
PID of parent: 5661
PID of child: 5662
epoll_wait() returned 0
PID 5662: got signal 10
Successfully read signal, even though epoll_wait() didn't say FD was ready!
8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----
/* epoll_signalfd.c */
#include <sys/signalfd.h>
#include <signal.h>
#include <sys/epoll.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
} while (0)
static void
signalTest(int sfd, int epfd)
{
struct signalfd_siginfo fdsi;
struct epoll_event rev;
int ready;
ssize_t s;
usleep(50000);
ready = epoll_wait(epfd, &rev, 1, 0);
if (ready == -1)
errExit("epoll_wait");
printf("epoll_wait() returned %d\n", ready);
s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
if (s != sizeof(struct signalfd_siginfo))
errExit("read");
printf("PID %ld: got signal %d\n", (long) getpid(), fdsi.ssi_signo);
if (ready == 0 && s > 0)
printf("Successfully read signal, even though epoll_wait() "
"didn't say FD was ready!\n");
}
int
main(int argc, char *argv[])
{
struct epoll_event ev;
sigset_t mask;
int sfd, epfd;
sigfillset(&mask);
sigdelset(&mask, SIGINT);
if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
errExit("sigprocmask");
sfd = signalfd(-1, &mask, SFD_NONBLOCK);
if (sfd == -1)
errExit("signalfd");
epfd = epoll_create(5);
if (epfd == -1)
errExit("epoll_create");
ev.data.fd = sfd;
ev.events = EPOLLIN;
if (epoll_ctl(epfd, EPOLL_CTL_ADD, sfd, &ev) == -1)
errExit("epoll_ctl");
switch (fork()) {
case -1:
errExit("fork");
case 0:
printf("PID of child: %ld\n", (long) getpid());
raise(SIGUSR1);
signalTest(sfd, epfd);
break;
default:
printf("PID of parent: %ld\n", (long) getpid());
wait(NULL);
break;
}
exit(EXIT_SUCCESS);
}
8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----8x----
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
|
||
|---|---|---|
| man1 | ||
| man2 | ||
| man3 | ||
| man4 | ||
| man5 | ||
| man6 | ||
| man7 | ||
| man8 | ||
| scripts | ||
| CONTRIBUTING | ||
| Changes | ||
| Changes.old | ||
| Makefile | ||
| README | ||
| man-pages-5.03.Announce | ||
| man-pages-5.03.lsm | ||
README
This package contains Linux man pages for sections 1 through 8. Some more information is given in the 'man-pages-x.y.Announce' file. Installing and uninstalling =========================== "make install" will copy these man pages to /usr/share/man/man[1-8]. To install to a path different from /usr, use "make install prefix=/install/path". "make remove" or "make uninstall" will remove any man page in this distribution from its destination. Use with caution, and remember to use "prefix" if desired, as with the "install" target. "make" or "make all" will perform "make uninstall" followed by "make install". Man page overlap and duplication ================================ Note that sometimes these pages are duplicates of pages also distributed in other packages. This has been reported about: man page also found in ------------------------------------- resolver.3 bind-utils, bind9utils resolv.conf.5 " passwd.5 shadow, passwd mailaddr.7 ? Copyrights ========== See the 'man-pages-x.y.Announce' file. Homepage ======== For much more about the Linux man-pages project, see http://www.kernel.org/doc/man-pages/index.html.