-/* $Id$ */
-
/***
This file is part of avahi.
-
+
avahi is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
-
+
avahi is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
Public License for more details.
-
+
You should have received a copy of the GNU Lesser General Public
License along with avahi; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#include <assert.h>
#include <string.h>
#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
-#include <avahi-common/llist.h>
-#include <avahi-common/malloc.h>
-
+#include "llist.h"
+#include "malloc.h"
+#include "timeval.h"
#include "simple-watch.h"
struct AvahiWatch {
AvahiSimplePoll *simple_poll;
int dead;
+
int idx;
struct pollfd pollfd;
+
AvahiWatchCallback callback;
void *userdata;
AVAHI_LLIST_FIELDS(AvahiWatch, watches);
};
+struct AvahiTimeout {
+ AvahiSimplePoll *simple_poll;
+ int dead;
+
+ int enabled;
+ struct timeval expiry;
+
+ AvahiTimeoutCallback callback;
+ void *userdata;
+
+ AVAHI_LLIST_FIELDS(AvahiTimeout, timeouts);
+};
+
struct AvahiSimplePoll {
AvahiPoll api;
+ AvahiPollFunc poll_func;
+ void *poll_func_userdata;
struct pollfd* pollfds;
int n_pollfds, max_pollfds, rebuild_pollfds;
- struct timeval wakeup;
- int use_wakeup;
-
- int req_cleanup;
-
+ int watch_req_cleanup, timeout_req_cleanup;
int quit;
+ int events_valid;
int n_watches;
AVAHI_LLIST_HEAD(AvahiWatch, watches);
+ AVAHI_LLIST_HEAD(AvahiTimeout, timeouts);
+
+ int wakeup_pipe[2];
+ int wakeup_issued;
+
+ int prepared_timeout;
+
+ enum {
+ STATE_INIT,
+ STATE_PREPARING,
+ STATE_PREPARED,
+ STATE_RUNNING,
+ STATE_RAN,
+ STATE_DISPATCHING,
+ STATE_DISPATCHED,
+ STATE_QUIT,
+ STATE_FAILURE
+ } state;
};
-static AvahiWatch* watch_new(AvahiPoll *api, int fd, AvahiWatchEvent event, AvahiWatchCallback callback, void *userdata) {
+void avahi_simple_poll_wakeup(AvahiSimplePoll *s) {
+ char c = 'W';
+ assert(s);
+
+ write(s->wakeup_pipe[1], &c, sizeof(c));
+ s->wakeup_issued = 1;
+}
+
+static void clear_wakeup(AvahiSimplePoll *s) {
+ char c[10]; /* Read ten at a time */
+
+ if (!s->wakeup_issued)
+ return;
+
+ s->wakeup_issued = 0;
+
+ for(;;)
+ if (read(s->wakeup_pipe[0], &c, sizeof(c)) != sizeof(c))
+ break;
+}
+
+static int set_nonblock(int fd) {
+ int n;
+
+ assert(fd >= 0);
+
+ if ((n = fcntl(fd, F_GETFL)) < 0)
+ return -1;
+
+ if (n & O_NONBLOCK)
+ return 0;
+
+ return fcntl(fd, F_SETFL, n|O_NONBLOCK);
+}
+
+static AvahiWatch* watch_new(const AvahiPoll *api, int fd, AvahiWatchEvent event, AvahiWatchCallback callback, void *userdata) {
AvahiWatch *w;
AvahiSimplePoll *s;
-
+
assert(api);
assert(fd >= 0);
assert(callback);
if (!(w = avahi_new(AvahiWatch, 1)))
return NULL;
-
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(s);
+
w->simple_poll = s;
+ w->dead = 0;
+
w->pollfd.fd = fd;
w->pollfd.events = event;
+ w->pollfd.revents = 0;
+
w->callback = callback;
w->userdata = userdata;
- w->dead = 0;
- if (s->n_pollfds < s->max_pollfds) {
- /* If there's space for this pollfd, go on and allocate it */
- w->idx = s->n_pollfds++;
- s->pollfds[w->idx] = w->pollfd;
-
- } else {
- /* Unfortunately there's no place for this pollfd, so request a rebuild of the array */
- w->idx = -1;
- s->rebuild_pollfds = 1;
- }
+ w->idx = -1;
+ s->rebuild_pollfds = 1;
AVAHI_LLIST_PREPEND(AvahiWatch, watches, s->watches, w);
s->n_watches++;
assert(w);
assert(!w->dead);
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(w->simple_poll);
+
w->pollfd.events = events;
if (w->idx != -1) {
w->simple_poll->rebuild_pollfds = 1;
}
+static AvahiWatchEvent watch_get_events(AvahiWatch *w) {
+ assert(w);
+ assert(!w->dead);
+
+ if (w->idx != -1 && w->simple_poll->events_valid)
+ return w->simple_poll->pollfds[w->idx].revents;
+
+ return 0;
+}
+
static void remove_pollfd(AvahiWatch *w) {
assert(w);
if (w->idx == -1)
return;
-
- if (w->idx == w->simple_poll->n_pollfds-1) {
-
- /* This pollfd is at the end of the array, so we can easily cut it */
-
- assert(w->simple_poll->n_pollfds > 0);
- w->simple_poll->n_pollfds -= 1;
- } else
- /* Unfortunately this pollfd is in the middle of the array, so request a rebuild of it */
- w->simple_poll->rebuild_pollfds = 1;
+ w->simple_poll->rebuild_pollfds = 1;
}
static void watch_free(AvahiWatch *w) {
assert(w);
+
assert(!w->dead);
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(w->simple_poll);
+
remove_pollfd(w);
-
+
w->dead = 1;
w->simple_poll->n_watches --;
- w->simple_poll->req_cleanup = 1;
-}
-
-static void set_wakeup_time(AvahiPoll *api, const struct timeval *tv) {
- AvahiSimplePoll *s;
-
- assert(api);
- s = api->userdata;
-
- if (tv) {
- s->wakeup = *tv;
- s->use_wakeup = 1;
- } else
- s->use_wakeup = 0;
+ w->simple_poll->watch_req_cleanup = 1;
}
static void destroy_watch(AvahiWatch *w) {
if (!w->dead)
w->simple_poll->n_watches --;
-
+
avahi_free(w);
}
-static void cleanup(AvahiSimplePoll *s, int all) {
+static void cleanup_watches(AvahiSimplePoll *s, int all) {
AvahiWatch *w, *next;
assert(s);
destroy_watch(w);
}
- s->req_cleanup = 0;
+ s->timeout_req_cleanup = 0;
+}
+
+static AvahiTimeout* timeout_new(const AvahiPoll *api, const struct timeval *tv, AvahiTimeoutCallback callback, void *userdata) {
+ AvahiTimeout *t;
+ AvahiSimplePoll *s;
+
+ assert(api);
+ assert(callback);
+
+ s = api->userdata;
+ assert(s);
+
+ if (!(t = avahi_new(AvahiTimeout, 1)))
+ return NULL;
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(s);
+
+ t->simple_poll = s;
+ t->dead = 0;
+
+ if ((t->enabled = !!tv))
+ t->expiry = *tv;
+
+ t->callback = callback;
+ t->userdata = userdata;
+
+ AVAHI_LLIST_PREPEND(AvahiTimeout, timeouts, s->timeouts, t);
+ return t;
+}
+
+static void timeout_update(AvahiTimeout *t, const struct timeval *tv) {
+ assert(t);
+ assert(!t->dead);
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(t->simple_poll);
+
+ if ((t->enabled = !!tv))
+ t->expiry = *tv;
+}
+
+static void timeout_free(AvahiTimeout *t) {
+ assert(t);
+ assert(!t->dead);
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(t->simple_poll);
+
+ t->dead = 1;
+ t->simple_poll->timeout_req_cleanup = 1;
+}
+
+
+static void destroy_timeout(AvahiTimeout *t) {
+ assert(t);
+
+ AVAHI_LLIST_REMOVE(AvahiTimeout, timeouts, t->simple_poll->timeouts, t);
+
+ avahi_free(t);
+}
+
+static void cleanup_timeouts(AvahiSimplePoll *s, int all) {
+ AvahiTimeout *t, *next;
+ assert(s);
+
+ for (t = s->timeouts; t; t = next) {
+ next = t->timeouts_next;
+
+ if (all || t->dead)
+ destroy_timeout(t);
+ }
+
+ s->timeout_req_cleanup = 0;
}
AvahiSimplePoll *avahi_simple_poll_new(void) {
if (!(s = avahi_new(AvahiSimplePoll, 1)))
return NULL;
-
+
+ if (pipe(s->wakeup_pipe) < 0) {
+ avahi_free(s);
+ return NULL;
+ }
+
+ set_nonblock(s->wakeup_pipe[0]);
+ set_nonblock(s->wakeup_pipe[1]);
+
s->api.userdata = s;
+
s->api.watch_new = watch_new;
s->api.watch_free = watch_free;
s->api.watch_update = watch_update;
- s->api.set_wakeup_time = set_wakeup_time;
+ s->api.watch_get_events = watch_get_events;
+
+ s->api.timeout_new = timeout_new;
+ s->api.timeout_free = timeout_free;
+ s->api.timeout_update = timeout_update;
+
s->pollfds = NULL;
s->max_pollfds = s->n_pollfds = 0;
- s->use_wakeup = 0;
- s->rebuild_pollfds = 0;
+ s->rebuild_pollfds = 1;
s->quit = 0;
s->n_watches = 0;
- s->req_cleanup = 0;
+ s->events_valid = 0;
+
+ s->watch_req_cleanup = 0;
+ s->timeout_req_cleanup = 0;
+
+ s->prepared_timeout = 0;
+
+ s->state = STATE_INIT;
+
+ s->wakeup_issued = 0;
+
+ avahi_simple_poll_set_func(s, NULL, NULL);
AVAHI_LLIST_HEAD_INIT(AvahiWatch, s->watches);
+ AVAHI_LLIST_HEAD_INIT(AvahiTimeout, s->timeouts);
return s;
}
void avahi_simple_poll_free(AvahiSimplePoll *s) {
assert(s);
- cleanup(s, 1);
-
+ cleanup_timeouts(s, 1);
+ cleanup_watches(s, 1);
assert(s->n_watches == 0);
-
+
avahi_free(s->pollfds);
+
+ if (s->wakeup_pipe[0] >= 0)
+ close(s->wakeup_pipe[0]);
+
+ if (s->wakeup_pipe[1] >= 0)
+ close(s->wakeup_pipe[1]);
+
avahi_free(s);
}
static int rebuild(AvahiSimplePoll *s) {
AvahiWatch *w;
int idx;
-
+
assert(s);
- if (s->n_watches > s->max_pollfds) {
+ if (s->n_watches+1 > s->max_pollfds) {
struct pollfd *n;
s->max_pollfds = s->n_watches + 10;
-
+
if (!(n = avahi_realloc(s->pollfds, sizeof(struct pollfd) * s->max_pollfds)))
return -1;
s->pollfds = n;
}
- for (idx = 0, w = s->watches; w; w = w->watches_next) {
+
+ s->pollfds[0].fd = s->wakeup_pipe[0];
+ s->pollfds[0].events = POLLIN;
+ s->pollfds[0].revents = 0;
+
+ idx = 1;
+
+ for (w = s->watches; w; w = w->watches_next) {
if(w->dead)
continue;
}
s->n_pollfds = idx;
-
+ s->events_valid = 0;
s->rebuild_pollfds = 0;
return 0;
}
-int avahi_simple_poll_iterate(AvahiSimplePoll *s, int block) {
- int timeout, r, ret = 0;
+static AvahiTimeout* find_next_timeout(AvahiSimplePoll *s) {
+ AvahiTimeout *t, *n = NULL;
assert(s);
- if (s->quit)
+ for (t = s->timeouts; t; t = t->timeouts_next) {
+
+ if (t->dead || !t->enabled)
+ continue;
+
+ if (!n || avahi_timeval_compare(&t->expiry, &n->expiry) < 0)
+ n = t;
+ }
+
+ return n;
+}
+
+static void timeout_callback(AvahiTimeout *t) {
+ assert(t);
+ assert(!t->dead);
+ assert(t->enabled);
+
+ t->enabled = 0;
+ t->callback(t, t->userdata);
+}
+
+int avahi_simple_poll_prepare(AvahiSimplePoll *s, int timeout) {
+ AvahiTimeout *next_timeout;
+
+ assert(s);
+ assert(s->state == STATE_INIT || s->state == STATE_DISPATCHED || s->state == STATE_FAILURE);
+ s->state = STATE_PREPARING;
+
+ /* Clear pending wakeup requests */
+ clear_wakeup(s);
+
+ /* Cleanup things first */
+ if (s->watch_req_cleanup)
+ cleanup_watches(s, 0);
+
+ if (s->timeout_req_cleanup)
+ cleanup_timeouts(s, 0);
+
+ /* Check whether a quit was requested */
+ if (s->quit) {
+ s->state = STATE_QUIT;
return 1;
+ }
- if (s->req_cleanup)
- cleanup(s, 0);
-
+ /* Do we need to rebuild our array of pollfds? */
if (s->rebuild_pollfds)
- if (rebuild(s) < 0)
+ if (rebuild(s) < 0) {
+ s->state = STATE_FAILURE;
return -1;
+ }
- if (block) {
- if (s->use_wakeup) {
- struct timeval now;
- AvahiUsec usec;
+ /* Calculate the wakeup time */
+ if ((next_timeout = find_next_timeout(s))) {
+ struct timeval now;
+ int t;
+ AvahiUsec usec;
- gettimeofday(&now, NULL);
+ if (next_timeout->expiry.tv_sec == 0 &&
+ next_timeout->expiry.tv_usec == 0) {
- usec = avahi_timeval_diff(&s->wakeup, &now);
-
- timeout = usec <= 0 ? 0 : (int) (usec / 1000);
- } else
- timeout = -1;
- } else
- timeout = 0;
+ /* Just a shortcut so that we don't need to call gettimeofday() */
+ timeout = 0;
+ goto finish;
+ }
- if ((r = poll(s->pollfds, s->n_pollfds, timeout)) < 0)
- return -1;
+ gettimeofday(&now, NULL);
+ usec = avahi_timeval_diff(&next_timeout->expiry, &now);
+
+ if (usec <= 0) {
+ /* Timeout elapsed */
+
+ timeout = 0;
+ goto finish;
+ }
+
+ /* Calculate sleep time. We add 1ms because otherwise we'd
+ * wake up too early most of the time */
+ t = (int) (usec / 1000) + 1;
+
+ if (timeout < 0 || timeout > t)
+ timeout = t;
+ }
+
+finish:
+ s->prepared_timeout = timeout;
+ s->state = STATE_PREPARED;
+ return 0;
+}
+
+int avahi_simple_poll_run(AvahiSimplePoll *s) {
+ assert(s);
+ assert(s->state == STATE_PREPARED || s->state == STATE_FAILURE);
+
+ s->state = STATE_RUNNING;
- else if (r > 0) {
- AvahiWatch *w;
+ for (;;) {
+ errno = 0;
- for (w = s->watches; w; w = w->watches_next) {
+ if (s->poll_func(s->pollfds, s->n_pollfds, s->prepared_timeout, s->poll_func_userdata) < 0) {
- if (w->dead)
+ if (errno == EINTR)
continue;
- assert(w->idx >= 0);
- assert(w->idx < s->n_pollfds);
+ s->state = STATE_FAILURE;
+ return -1;
+ }
+
+ break;
+ }
+
+ /* The poll events are now valid again */
+ s->events_valid = 1;
+
+ /* Update state */
+ s->state = STATE_RAN;
+ return 0;
+}
+
+int avahi_simple_poll_dispatch(AvahiSimplePoll *s) {
+ AvahiTimeout *next_timeout;
+ AvahiWatch *w;
+
+ assert(s);
+ assert(s->state == STATE_RAN);
+ s->state = STATE_DISPATCHING;
+
+ /* We execute only on callback in every iteration */
- if (s->pollfds[w->idx].revents > 0)
- w->callback(w, w->pollfd.fd, s->pollfds[w->idx].revents, w->userdata);
+ /* Check whether the wakeup time has been reached now */
+ if ((next_timeout = find_next_timeout(s))) {
- if (s->quit) {
- ret = 1;
- goto finish;
- }
+ if (next_timeout->expiry.tv_sec == 0 && next_timeout->expiry.tv_usec == 0) {
+
+ /* Just a shortcut so that we don't need to call gettimeofday() */
+ timeout_callback(next_timeout);
+ goto finish;
+ }
+
+ if (avahi_age(&next_timeout->expiry) >= 0) {
+
+ /* Timeout elapsed */
+ timeout_callback(next_timeout);
+ goto finish;
}
}
- ret = 0;
+ /* Look for some kind of I/O event */
+ for (w = s->watches; w; w = w->watches_next) {
+
+ if (w->dead)
+ continue;
+
+ assert(w->idx >= 0);
+ assert(w->idx < s->n_pollfds);
+
+ if (s->pollfds[w->idx].revents != 0) {
+ w->callback(w, w->pollfd.fd, s->pollfds[w->idx].revents, w->userdata);
+ goto finish;
+ }
+ }
finish:
- if (s->req_cleanup)
- cleanup(s, 0);
-
- return ret;
+ s->state = STATE_DISPATCHED;
+ return 0;
}
-void avahi_simple_poll_quit(AvahiSimplePoll *w) {
- assert(w);
+int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
+ int r;
+
+ if ((r = avahi_simple_poll_prepare(s, timeout)) != 0)
+ return r;
- w->quit = 1;
+ if ((r = avahi_simple_poll_run(s)) != 0)
+ return r;
+
+ if ((r = avahi_simple_poll_dispatch(s)) != 0)
+ return r;
+
+ return 0;
}
-AvahiPoll* avahi_simple_poll_get(AvahiSimplePoll *s) {
+void avahi_simple_poll_quit(AvahiSimplePoll *s) {
assert(s);
-
+
+ s->quit = 1;
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(s);
+}
+
+const AvahiPoll* avahi_simple_poll_get(AvahiSimplePoll *s) {
+ assert(s);
+
return &s->api;
}
+
+static int system_poll(struct pollfd *ufds, unsigned int nfds, int timeout, AVAHI_GCC_UNUSED void *userdata) {
+ return poll(ufds, nfds, timeout);
+}
+
+void avahi_simple_poll_set_func(AvahiSimplePoll *s, AvahiPollFunc func, void *userdata) {
+ assert(s);
+
+ s->poll_func = func ? func : system_poll;
+ s->poll_func_userdata = func ? userdata : NULL;
+
+ /* If there is a background thread running the poll() for us, tell it to exit the poll() */
+ avahi_simple_poll_wakeup(s);
+}
+
+int avahi_simple_poll_loop(AvahiSimplePoll *s) {
+ int r;
+
+ assert(s);
+
+ for (;;)
+ if ((r = avahi_simple_poll_iterate(s, -1)) != 0)
+ if (r >= 0 || errno != EINTR)
+ return r;
+}
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