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udevd: ppoll() -> epoll + signalfd

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This commit is contained in:
Kay Sievers 2011-04-18 02:14:24 +02:00
parent 1d843b7d68
commit 82063a88d1
2 changed files with 75 additions and 53 deletions
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2
TODO
View File

@ -1,5 +1,3 @@
- get rid of select()
- use signalfd instead of ppoll()
- remove deprecated trigger --type=failed logic

126
udev/udevd.c
View File

@ -85,7 +85,6 @@ static sigset_t orig_sigmask;
static UDEV_LIST(event_list);
static UDEV_LIST(worker_list);
static bool udev_exit;
static volatile sig_atomic_t worker_exit;
enum event_state {
EVENT_UNDEF,
@ -168,18 +167,6 @@ static void event_queue_delete(struct event *event, bool export)
free(event);
}
static void event_sig_handler(int signum)
{
switch (signum) {
case SIGALRM:
_exit(1);
break;
case SIGTERM:
worker_exit = true;
break;
}
}
static struct worker *worker_ref(struct worker *worker)
{
worker->refcount++;
@ -220,7 +207,6 @@ static void worker_new(struct event *event)
struct worker *worker;
struct udev_monitor *worker_monitor;
pid_t pid;
struct sigaction act;
/* listen for new events */
worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
@ -242,12 +228,11 @@ static void worker_new(struct event *event)
pid = fork();
switch (pid) {
case 0: {
sigset_t sigmask;
struct udev_device *dev;
struct pollfd pmon = {
.fd = udev_monitor_get_fd(worker_monitor),
.events = POLLIN,
};
struct udev_device *dev = NULL;
int fd_monitor;
struct epoll_event ep_signal, ep_monitor;
sigset_t mask;
int rc = EXIT_SUCCESS;
/* move initial device from queue */
dev = event->dev;
@ -265,25 +250,41 @@ static void worker_new(struct event *event)
udev_log_close();
udev_log_init("udevd-work");
/* set signal handlers */
memset(&act, 0x00, sizeof(act));
act.sa_handler = event_sig_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
sigaction(SIGTERM, &act, NULL);
sigaction(SIGALRM, &act, NULL);
sigfillset(&mask);
fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
if (fd_signal < 0) {
err(udev, "error creating signalfd %m\n");
rc = 2;
goto out;
}
/* unblock SIGALRM */
sigfillset(&sigmask);
sigdelset(&sigmask, SIGALRM);
sigprocmask(SIG_SETMASK, &sigmask, NULL);
/* SIGTERM is unblocked in ppoll() */
sigdelset(&sigmask, SIGTERM);
fd_ep = epoll_create1(EPOLL_CLOEXEC);
if (fd_ep < 0) {
err(udev, "error creating epoll fd: %m\n");
rc = 3;
goto out;
}
memset(&ep_signal, 0, sizeof(struct epoll_event));
ep_signal.events = EPOLLIN;
ep_signal.data.fd = fd_signal;
fd_monitor = udev_monitor_get_fd(worker_monitor);
memset(&ep_monitor, 0, sizeof(struct epoll_event));
ep_monitor.events = EPOLLIN;
ep_monitor.data.fd = fd_monitor;
if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
err(udev, "fail to add fds to epoll: %m\n");
rc = 4;
goto out;
}
/* request TERM signal if parent exits */
prctl(PR_SET_PDEATHSIG, SIGTERM);
do {
for (;;) {
struct udev_event *udev_event;
struct worker_message msg = {};
int err;
@ -291,8 +292,10 @@ static void worker_new(struct event *event)
info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
udev_event = udev_event_new(dev);
if (udev_event == NULL)
_exit(3);
if (udev_event == NULL) {
rc = 5;
goto out;
}
/* set timeout to prevent hanging processes */
alarm(UDEV_EVENT_TIMEOUT);
@ -334,29 +337,50 @@ static void worker_new(struct event *event)
udev_device_unref(dev);
dev = NULL;
/* wait for more device messages or signal from udevd */
while (!worker_exit) {
/* wait for more device messages from main udevd, or term signal */
while (dev == NULL) {
struct epoll_event ev[4];
int fdcount;
int i;
fdcount = ppoll(&pmon, 1, NULL, &sigmask);
fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
if (fdcount < 0)
continue;
if (pmon.revents & POLLIN) {
dev = udev_monitor_receive_device(worker_monitor);
if (dev != NULL)
break;
for (i = 0; i < fdcount; i++) {
if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
dev = udev_monitor_receive_device(worker_monitor);
} else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
struct signalfd_siginfo fdsi;
ssize_t size;
size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
if (size != sizeof(struct signalfd_siginfo))
continue;
switch (fdsi.ssi_signo) {
case SIGTERM:
goto out;
case SIGALRM:
rc = EXIT_FAILURE;
goto out;
}
}
}
}
} while (dev != NULL);
}
out:
udev_device_unref(dev);
if (fd_signal >= 0)
close(fd_signal);
if (fd_ep >= 0)
close(fd_ep);
close(fd_inotify);
close(worker_watch[WRITE_END]);
udev_rules_unref(rules);
udev_monitor_unref(worker_monitor);
udev_unref(udev);
udev_log_close();
exit(EXIT_SUCCESS);
exit(rc);
}
case -1:
udev_monitor_unref(worker_monitor);
@ -1455,18 +1479,18 @@ int main(int argc, char *argv[])
/* block and listen to all signals on signalfd */
sigfillset(&mask);
sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
fd_signal = signalfd(-1, &mask, SFD_CLOEXEC);
fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
if (fd_signal < 0) {
fprintf(stderr, "error getting signalfd\n");
err(udev, "error getting signalfd\n");
fprintf(stderr, "error creating signalfd\n");
err(udev, "error creating signalfd\n");
rc = 5;
goto exit;
}
/* unnamed socket from workers to the main daemon */
if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
fprintf(stderr, "error getting socketpair\n");
err(udev, "error getting socketpair\n");
fprintf(stderr, "error creating socketpair\n");
err(udev, "error creating socketpair\n");
rc = 6;
goto exit;
}