X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-common%2Fsimple-watch.c;h=8df18dd7737236b2f3fa0956d025d912cfcd90c1;hb=d133b188f257ac505b66a69ddf58165e8eeb73ca;hp=acc092378010bfe2a46434e3789d06c7b4d79fd8;hpb=5d047523c87ba11aad8c384f7ffde25b4dd746ed;p=catta

diff --git a/avahi-common/simple-watch.c b/avahi-common/simple-watch.c
index acc0923..8df18dd 100644
--- a/avahi-common/simple-watch.c
+++ b/avahi-common/simple-watch.c
@@ -1,18 +1,16 @@
-/* $Id$ */
-
 /***
   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
@@ -27,44 +25,114 @@
 #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);
@@ -74,24 +142,22 @@ static AvahiWatch* watch_new(AvahiPoll *api, int fd, AvahiWatchEvent event, Avah
 
     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++;
@@ -103,6 +169,9 @@ 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) {
@@ -112,46 +181,38 @@ static void watch_update(AvahiWatch *w, AvahiWatchEvent events) {
         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) {
@@ -162,11 +223,11 @@ 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);
 
@@ -177,7 +238,81 @@ static void cleanup(AvahiSimplePoll *s, int all) {
             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) {
@@ -185,21 +320,46 @@ 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;
 }
@@ -207,32 +367,46 @@ AvahiSimplePoll *avahi_simple_poll_new(void) {
 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;
@@ -242,83 +416,234 @@ static int rebuild(AvahiSimplePoll *s) {
     }
 
     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;
+}