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-rw-r--r--avahi-common/simple-watch.c254
-rw-r--r--avahi-common/simple-watch.h19
-rw-r--r--avahi-common/watch-test.c7
3 files changed, 194 insertions, 86 deletions
diff --git a/avahi-common/simple-watch.c b/avahi-common/simple-watch.c
index 6872389..b8a1b82 100644
--- a/avahi-common/simple-watch.c
+++ b/avahi-common/simple-watch.c
@@ -29,6 +29,7 @@
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
+#include <stdio.h>
#include <avahi-common/llist.h>
#include <avahi-common/malloc.h>
@@ -64,6 +65,7 @@ struct AvahiTimeout {
struct AvahiSimplePoll {
AvahiPoll api;
AvahiPollFunc poll_func;
+ void *poll_func_userdata;
struct pollfd* pollfds;
int n_pollfds, max_pollfds, rebuild_pollfds;
@@ -77,18 +79,39 @@ struct AvahiSimplePoll {
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 void wakeup(AvahiSimplePoll *s) {
- char c = 'x';
+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;
@@ -121,6 +144,9 @@ static AvahiWatch* watch_new(const AvahiPoll *api, int fd, AvahiWatchEvent event
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;
@@ -131,22 +157,12 @@ static AvahiWatch* watch_new(const AvahiPoll *api, int fd, AvahiWatchEvent event
w->callback = callback;
w->userdata = userdata;
- 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++;
- wakeup(w->simple_poll);
-
return w;
}
@@ -154,6 +170,9 @@ static void watch_update(AvahiWatch *w, AvahiWatchEvent events) {
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) {
@@ -161,8 +180,6 @@ static void watch_update(AvahiWatch *w, AvahiWatchEvent events) {
w->simple_poll->pollfds[w->idx] = w->pollfd;
} else
w->simple_poll->rebuild_pollfds = 1;
-
- wakeup(w->simple_poll);
}
static AvahiWatchEvent watch_get_events(AvahiWatch *w) {
@@ -181,16 +198,7 @@ static void remove_pollfd(AvahiWatch *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) {
@@ -198,13 +206,14 @@ static void watch_free(AvahiWatch *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->watch_req_cleanup = 1;
-
- wakeup(w->simple_poll);
}
static void destroy_watch(AvahiWatch *w) {
@@ -245,6 +254,9 @@ static AvahiTimeout* timeout_new(const AvahiPoll *api, const struct timeval *tv,
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;
@@ -256,29 +268,29 @@ static AvahiTimeout* timeout_new(const AvahiPoll *api, const struct timeval *tv,
t->userdata = userdata;
AVAHI_LLIST_PREPEND(AvahiTimeout, timeouts, s->timeouts, t);
-
- wakeup(t->simple_poll);
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;
-
- wakeup(t->simple_poll);
}
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;
-
- wakeup(t->simple_poll);
}
@@ -331,7 +343,7 @@ AvahiSimplePoll *avahi_simple_poll_new(void) {
s->pollfds = NULL;
s->max_pollfds = s->n_pollfds = 0;
- s->rebuild_pollfds = 0;
+ s->rebuild_pollfds = 1;
s->quit = 0;
s->n_watches = 0;
s->events_valid = 0;
@@ -339,7 +351,13 @@ AvahiSimplePoll *avahi_simple_poll_new(void) {
s->watch_req_cleanup = 0;
s->timeout_req_cleanup = 0;
- avahi_simple_poll_set_func(s, NULL);
+ 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);
@@ -386,8 +404,10 @@ static int rebuild(AvahiSimplePoll *s) {
s->pollfds[0].fd = s->wakeup_pipe[0];
s->pollfds[0].events = POLLIN;
s->pollfds[0].revents = 0;
+
+ idx = 1;
- for (idx = 1, w = s->watches; w; w = w->watches_next) {
+ for (w = s->watches; w; w = w->watches_next) {
if(w->dead)
continue;
@@ -419,21 +439,22 @@ static AvahiTimeout* find_next_timeout(AvahiSimplePoll *s) {
return n;
}
-static int start_timeout_callback(AvahiTimeout *t) {
+static void timeout_callback(AvahiTimeout *t) {
assert(t);
assert(!t->dead);
assert(t->enabled);
t->enabled = 0;
t->callback(t, t->userdata);
- return 0;
}
-int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
- int r;
+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);
@@ -445,13 +466,17 @@ int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
cleanup_timeouts(s, 0);
/* Check whether a quit was requested */
- if (s->quit)
+ if (s->quit) {
+ s->state = STATE_QUIT;
return 1;
+ }
/* 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;
+ }
/* Calculate the wakeup time */
if ((next_timeout = find_next_timeout(s))) {
@@ -463,12 +488,9 @@ int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
next_timeout->expiry.tv_usec == 0) {
/* Just a shortcut so that we don't need to call gettimeofday() */
-
- /* The events poll() returned in the last call are now no longer valid */
- s->events_valid = 0;
- return start_timeout_callback(next_timeout);
+ timeout = 0;
+ goto finish;
}
-
gettimeofday(&now, NULL);
usec = avahi_timeval_diff(&next_timeout->expiry, &now);
@@ -476,9 +498,8 @@ int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
if (usec <= 0) {
/* Timeout elapsed */
- /* The events poll() returned in the last call are now no longer valid */
- s->events_valid = 0;
- return start_timeout_callback(next_timeout);
+ timeout = 0;
+ goto finish;
}
/* Calculate sleep time. We add 1ms because otherwise we'd
@@ -489,44 +510,96 @@ int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
timeout = t;
}
- if ((r = s->poll_func(s->pollfds, s->n_pollfds, timeout)) < 0)
- return -1;
+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_RUNNING;
+
+ if (s->prepared_timeout != 0) {
+
+ if (s->poll_func(s->pollfds, s->n_pollfds, s->prepared_timeout, s->poll_func_userdata) < 0) {
+ s->state = STATE_FAILURE;
+ return -1;
+ }
+
+ /* The poll events are now valid again */
+ s->events_valid = 1;
+ } else
+ s->events_valid = 0;
+
+ /* Update state */
+ s->state = STATE_RAN;
+ return 0;
+}
+
+int avahi_simple_poll_dispatch(AvahiSimplePoll *s) {
+ AvahiTimeout *next_timeout;
+ AvahiWatch *w;
- /* The pollf events are now valid again */
- s->events_valid = 1;
+ assert(s);
+ assert(s->state == STATE_RAN);
+ s->state = STATE_DISPATCHING;
+ /* We execute only on callback in every iteration */
+
/* Check whether the wakeup time has been reached now */
if ((next_timeout = find_next_timeout(s))) {
- struct timeval now;
- gettimeofday(&now, NULL);
+ 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) {
- if (avahi_timeval_compare(&next_timeout->expiry, &now) <= 0)
- /* Time elapsed */
- return start_timeout_callback(next_timeout);
+ /* Timeout elapsed */
+ timeout_callback(next_timeout);
+ goto finish;
+ }
}
-
- if (r > 0) {
- AvahiWatch *w;
- /* Look for some kind of I/O event */
+ /* 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;
+ }
+ }
- for (w = s->watches; w; w = w->watches_next) {
+finish:
- if (w->dead)
- continue;
+ s->state = STATE_DISPATCHED;
+ return 0;
+}
- assert(w->idx >= 0);
- assert(w->idx < s->n_pollfds);
+int avahi_simple_poll_iterate(AvahiSimplePoll *s, int timeout) {
+ int r;
- if (s->pollfds[w->idx].revents > 0) {
- /* We execute only on callback in every iteration */
- w->callback(w, w->pollfd.fd, s->pollfds[w->idx].revents, w->userdata);
- return 0;
- }
- }
- }
+ if ((r = avahi_simple_poll_prepare(s, timeout)) != 0)
+ return r;
+
+ if ((r = avahi_simple_poll_run(s)) != 0)
+ return r;
+ if ((r = avahi_simple_poll_dispatch(s)) != 0)
+ return r;
+
return 0;
}
@@ -534,7 +607,9 @@ void avahi_simple_poll_quit(AvahiSimplePoll *s) {
assert(s);
s->quit = 1;
- wakeup(s);
+
+ /* 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) {
@@ -543,9 +618,26 @@ const AvahiPoll* avahi_simple_poll_get(AvahiSimplePoll *s) {
return &s->api;
}
-void avahi_simple_poll_set_func(AvahiSimplePoll *s, AvahiPollFunc func) {
+static int system_poll(struct pollfd *ufds, unsigned int nfds, int timeout, 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 : (AvahiPollFunc) poll;
- wakeup(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)
+ return r;
}
diff --git a/avahi-common/simple-watch.h b/avahi-common/simple-watch.h
index c8234f2..0833570 100644
--- a/avahi-common/simple-watch.h
+++ b/avahi-common/simple-watch.h
@@ -65,10 +65,25 @@ int avahi_simple_poll_iterate(AvahiSimplePoll *s, int sleep_time);
void avahi_simple_poll_quit(AvahiSimplePoll *s);
/** Prototype for a poll() type function */
-typedef int (*AvahiPollFunc)(struct pollfd *ufds, unsigned int nfds, int timeout);
+typedef int (*AvahiPollFunc)(struct pollfd *ufds, unsigned int nfds, int timeout, void *userdata);
/** Replace the internally used poll() function. By default the system's poll() will be used */
-void avahi_simple_poll_set_func(AvahiSimplePoll *s, AvahiPollFunc func);
+void avahi_simple_poll_set_func(AvahiSimplePoll *s, AvahiPollFunc func, void *userdata);
+
+/** The first stage of avahi_simple_poll_iterate(), use this function only if you know what you do */
+int avahi_simple_poll_prepare(AvahiSimplePoll *s, int timeout);
+
+/** The second stage of avahi_simple_poll_iterate(), use this function only if you know what you do */
+int avahi_simple_poll_run(AvahiSimplePoll *s);
+
+/** The third and final stage of avahi_simple_poll_iterate(), use this function only if you know what you do */
+int avahi_simple_poll_dispatch(AvahiSimplePoll *s);
+
+/** Call avahi_simple_poll_iterate() in a loop and return if it returns non-zero */
+int avahi_simple_poll_loop(AvahiSimplePoll *s);
+
+/** Wakeup the main loop. (for threaded environments) */
+void avahi_simple_poll_wakeup(AvahiSimplePoll *s);
#ifndef DOXYGEN_SHOULD_SKIP_THIS
AVAHI_C_DECL_END
diff --git a/avahi-common/watch-test.c b/avahi-common/watch-test.c
index ffb2149..921a8f7 100644
--- a/avahi-common/watch-test.c
+++ b/avahi-common/watch-test.c
@@ -78,9 +78,10 @@ int main(int argc, char *argv[]) {
api->timeout_new(api, &tv, wakeup, NULL);
/* Our main loop */
- for (;;)
- if (avahi_simple_poll_iterate(simple_poll, -1) != 0)
- break;
+ avahi_simple_poll_loop(simple_poll);
+
+
+ avahi_simple_poll_free(simple_poll);
return 0;
}