diff options
Diffstat (limited to 'avahi-common/thread-watch.c')
| -rw-r--r-- | avahi-common/thread-watch.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/avahi-common/thread-watch.c b/avahi-common/thread-watch.c new file mode 100644 index 0000000..27a0835 --- /dev/null +++ b/avahi-common/thread-watch.c @@ -0,0 +1,186 @@ +/* $Id$ */ + +/*** + 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 + USA. +***/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <sys/poll.h> +#include <assert.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <stdio.h> +#include <pthread.h> +#include <signal.h> + +#include "llist.h" +#include "malloc.h" +#include "timeval.h" +#include "simple-watch.h" +#include "thread-watch.h" + +struct AvahiThreadedPoll { + AvahiSimplePoll *simple_poll; + pthread_t thread_id; + pthread_mutex_t mutex; + int thread_running; + int retval; +}; + +static int poll_func(struct pollfd *ufds, unsigned int nfds, int timeout, void *userdata) { + pthread_mutex_t *mutex = userdata; + int r; + + /* Before entering poll() we unlock the mutex, so that + * avahi_simple_poll_quit() can succeed from another thread. */ + + pthread_mutex_unlock(mutex); + r = poll(ufds, nfds, timeout); + pthread_mutex_lock(mutex); + + return r; +} + +static void* thread(void *userdata){ + AvahiThreadedPoll *p = userdata; + sigset_t mask; + + /* Make sure that signals are delivered to the main thread */ + sigfillset(&mask); + pthread_sigmask(SIG_BLOCK, &mask, NULL); + + pthread_mutex_lock(&p->mutex); + p->retval = avahi_simple_poll_loop(p->simple_poll); + pthread_mutex_unlock(&p->mutex); + + return NULL; +} + +AvahiThreadedPoll *avahi_threaded_poll_new(void) { + AvahiThreadedPoll *p; + + if (!(p = avahi_new(AvahiThreadedPoll, 1))) + goto fail; /* OOM */ + + if (!(p->simple_poll = avahi_simple_poll_new())) + goto fail; + + pthread_mutex_init(&p->mutex, NULL); + + avahi_simple_poll_set_func(p->simple_poll, poll_func, &p->mutex); + + p->thread_running = 0; + + return p; + +fail: + if (p) { + if (p->simple_poll) { + avahi_simple_poll_free(p->simple_poll); + pthread_mutex_destroy(&p->mutex); + } + + avahi_free(p); + } + + return NULL; +} + +void avahi_threaded_poll_free(AvahiThreadedPoll *p) { + assert(p); + + /* Make sure that this function is not called from the helper thread */ + assert(!p->thread_running || !pthread_equal(pthread_self(), p->thread_id)); + + if (p->thread_running) + avahi_threaded_poll_quit(p); + + if (p->simple_poll) + avahi_simple_poll_free(p->simple_poll); + + pthread_mutex_destroy(&p->mutex); + avahi_free(p); +} + +const AvahiPoll* avahi_threaded_poll_get(AvahiThreadedPoll *p) { + assert(p); + + return avahi_simple_poll_get(p->simple_poll); +} + +int avahi_threaded_poll_start(AvahiThreadedPoll *p) { + assert(p); + + assert(!p->thread_running); + + if (pthread_create(&p->thread_id, NULL, thread, p) < 0) + return -1; + + return 0; +} + +int avahi_threaded_poll_stop(AvahiThreadedPoll *p) { + assert(p); + + if (!p->thread_running) + return -1; + + /* Make sure that this function is not called from the helper thread */ + assert(!pthread_equal(pthread_self(), p->thread_id)); + + pthread_mutex_lock(&p->mutex); + avahi_simple_poll_quit(p->simple_poll); + pthread_mutex_unlock(&p->mutex); + + pthread_join(p->thread_id, NULL); + p->thread_running = 0; + + return p->retval; +} + +void avahi_threaded_poll_quit(AvahiThreadedPoll *p) { + assert(p); + + /* Make sure that this function is called from the helper thread */ + assert(pthread_equal(pthread_self(), p->thread_id)); + + avahi_simple_poll_quit(p->simple_poll); +} + +void avahi_threaded_poll_lock(AvahiThreadedPoll *p) { + assert(p); + + /* Make sure that this function is not called from the helper thread */ + assert(!p->thread_running || !pthread_equal(pthread_self(), p->thread_id)); + + pthread_mutex_lock(&p->mutex); +} + +void avahi_threaded_poll_unlock(AvahiThreadedPoll *p) { + assert(p); + + /* Make sure that this function is not called from the helper thread */ + assert(!p->thread_running || !pthread_equal(pthread_self(), p->thread_id)); + + pthread_mutex_unlock(&p->mutex); +} |