* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif /* HAVE_SYS_TIME_H */
-#ifdef HAVE_UNISTD_H
+#ifdef G_OS_UNIX
#include <unistd.h>
-#endif /* HAVE_UNISTD_H */
+#endif /* G_OS_UNIX */
#include <errno.h>
#include <string.h>
#include <windows.h>
#endif /* G_OS_WIN32 */
-#ifdef G_OS_BEOS
-#include <sys/socket.h>
-#include <sys/wait.h>
-#endif /* G_OS_BEOS */
+#include "glib_trace.h"
#include "gmain.h"
struct _GMainDispatch
{
gint depth;
- GSList *dispatching_sources; /* stack of current sources */
+ GSource *source;
};
#ifdef G_MAIN_POLL_DEBUG
static volatile int unix_signal_pending[NSIG];
static volatile int any_unix_signal_pending;
#endif
+static volatile guint unix_signal_refcount[NSIG];
/* Guards all the data below */
G_LOCK_DEFINE_STATIC (unix_signal_lock);
static GSList *unix_signal_watches;
static GSList *unix_child_watches;
-static GSourceFuncs g_unix_signal_funcs =
+GSourceFuncs g_unix_signal_funcs =
{
g_unix_signal_watch_prepare,
g_unix_signal_watch_check,
GSource *source;
GList *sl_iter;
GSourceList *list;
+ gint i;
g_return_if_fail (context != NULL);
g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
main_context_list = g_slist_remove (main_context_list, context);
G_UNLOCK (main_context_list);
+ /* Free pending dispatches */
+ for (i = 0; i < context->pending_dispatches->len; i++)
+ g_source_unref_internal (context->pending_dispatches->pdata[i], context, FALSE);
+
+ /* g_source_iter_next() assumes the context is locked. */
+ LOCK_CONTEXT (context);
g_source_iter_init (&iter, context, TRUE);
while (g_source_iter_next (&iter, &source))
{
source->context = NULL;
- g_source_destroy_internal (source, context, FALSE);
+ g_source_destroy_internal (source, context, TRUE);
}
+ UNLOCK_CONTEXT (context);
+
for (sl_iter = context->source_lists; sl_iter; sl_iter = sl_iter->next)
{
list = sl_iter->data;
* started in this thread to run under @context and deliver their
* results to its main loop, rather than running under the global
* default context in the main thread. Note that calling this function
- * changes the context returned by
- * g_main_context_get_thread_default(), <emphasis>not</emphasis> the
- * one returned by g_main_context_default(), so it does not affect the
- * context used by functions like g_idle_add().
+ * changes the context returned by g_main_context_get_thread_default(),
+ * not the one returned by g_main_context_default(), so it does not affect
+ * the context used by functions like g_idle_add().
*
* Normally you would call this function shortly after creating a new
* thread, passing it a #GMainContext which will be run by a
* operations that want to be able to be run in contexts other than
* the default one should call this method or
* g_main_context_ref_thread_default() to get a #GMainContext to add
- * their #GSource<!-- -->s to. (Note that even in single-threaded
+ * their #GSources to. (Note that even in single-threaded
* programs applications may sometimes want to temporarily push a
* non-default context, so it is not safe to assume that this will
* always return %NULL if you are running in the default thread.)
GUINT_TO_POINTER (source->source_id));
}
id = G_MAXUINT;
+ g_hash_table_add (context->overflow_used_source_ids, GUINT_TO_POINTER (id));
}
else if (context->overflow_used_source_ids == NULL)
{
static guint
g_source_attach_unlocked (GSource *source,
- GMainContext *context)
+ GMainContext *context,
+ gboolean do_wakeup)
{
GSList *tmp_list;
source->ref_count++;
source_add_to_context (source, context);
- tmp_list = source->poll_fds;
- while (tmp_list)
+ if (!SOURCE_BLOCKED (source))
{
- g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
- tmp_list = tmp_list->next;
- }
+ tmp_list = source->poll_fds;
+ while (tmp_list)
+ {
+ g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
+ tmp_list = tmp_list->next;
+ }
- for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
- g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
+ for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
+ g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
+ }
tmp_list = source->priv->child_sources;
while (tmp_list)
{
- g_source_attach_unlocked (tmp_list->data, context);
+ g_source_attach_unlocked (tmp_list->data, context, FALSE);
tmp_list = tmp_list->next;
}
+ /* If another thread has acquired the context, wake it up since it
+ * might be in poll() right now.
+ */
+ if (do_wakeup && context->owner && context->owner != G_THREAD_SELF)
+ g_wakeup_signal (context->wakeup);
+
return source->source_id;
}
g_return_val_if_fail (source->context == NULL, 0);
g_return_val_if_fail (!SOURCE_DESTROYED (source), 0);
+ TRACE (GLIB_MAIN_SOURCE_ATTACH (g_source_get_name (source)));
+
if (!context)
context = g_main_context_default ();
LOCK_CONTEXT (context);
- result = g_source_attach_unlocked (source, context);
-
- /* If another thread has acquired the context, wake it up since it
- * might be in poll() right now.
- */
- if (context->owner && context->owner != G_THREAD_SELF)
- g_wakeup_signal (context->wakeup);
+ result = g_source_attach_unlocked (source, context, TRUE);
UNLOCK_CONTEXT (context);
GMainContext *context,
gboolean have_lock)
{
+ TRACE (GLIB_MAIN_SOURCE_DESTROY (g_source_get_name (source)));
+
if (!have_lock)
LOCK_CONTEXT (context);
if (context)
{
+ g_source_attach_unlocked (child_source, context, TRUE);
UNLOCK_CONTEXT (context);
- g_source_attach (child_source, context);
}
}
* Dispatching the source does not reset the ready time. You should do
* so yourself, from the source dispatch function.
*
+ * Note that if you have a pair of sources where the ready time of one
+ * suggests that it will be delivered first but the priority for the
+ * other suggests that it would be delivered first, and the ready time
+ * for both sources is reached during the same main context iteration
+ * then the order of dispatch is undefined.
+ *
* Since: 2.36
**/
void
/**
* g_source_remove:
* @tag: the ID of the source to remove.
- *
- * Removes the source with the given id from the default main context.
- * The id of
- * a #GSource is given by g_source_get_id(), or will be returned by the
- * functions g_source_attach(), g_idle_add(), g_idle_add_full(),
- * g_timeout_add(), g_timeout_add_full(), g_child_watch_add(),
- * g_child_watch_add_full(), g_io_add_watch(), and g_io_add_watch_full().
+ *
+ * Removes the source with the given id from the default main context.
+ *
+ * The id of a #GSource is given by g_source_get_id(), or will be
+ * returned by the functions g_source_attach(), g_idle_add(),
+ * g_idle_add_full(), g_timeout_add(), g_timeout_add_full(),
+ * g_child_watch_add(), g_child_watch_add_full(), g_io_add_watch(), and
+ * g_io_add_watch_full().
*
* See also g_source_destroy(). You must use g_source_destroy() for sources
* added to a non-default main context.
*
- * Return value: %TRUE if the source was found and removed.
+ * It is a programmer error to attempt to remove a non-existent source.
+ *
+ * Return value: For historical reasons, this function always returns %TRUE
**/
gboolean
g_source_remove (guint tag)
{
GSource *source;
-
+
g_return_val_if_fail (tag > 0, FALSE);
source = g_main_context_find_source_by_id (NULL, tag);
if (source)
g_source_destroy (source);
+ else
+ g_critical ("Source ID %u was not found when attempting to remove it", tag);
return source != NULL;
}
* many things that the user could do. Instead, you can use the
* following techniques:
*
- * <orderedlist>
- * <listitem>
- * <para>
- * Use gtk_widget_set_sensitive() or modal dialogs to prevent
- * the user from interacting with elements while the main
- * loop is recursing.
- * </para>
- * </listitem>
- * <listitem>
- * <para>
- * Avoid main loop recursion in situations where you can't handle
- * arbitrary callbacks. Instead, structure your code so that you
- * simply return to the main loop and then get called again when
- * there is more work to do.
- * </para>
- * </listitem>
- * </orderedlist>
+ * 1. Use gtk_widget_set_sensitive() or modal dialogs to prevent
+ * the user from interacting with elements while the main
+ * loop is recursing.
+ *
+ * 2. Avoid main loop recursion in situations where you can't handle
+ * arbitrary callbacks. Instead, structure your code so that you
+ * simply return to the main loop and then get called again when
+ * there is more work to do.
*
* Return value: The main loop recursion level in the current thread
- **/
+ */
int
g_main_depth (void)
{
g_main_current_source (void)
{
GMainDispatch *dispatch = get_dispatch ();
- return dispatch->dispatching_sources ? dispatch->dispatching_sources->data : NULL;
+ return dispatch->source;
}
/**
* {
* SomeWidget *self = data;
*
- * GDK_THREADS_ENTER (<!-- -->);
- * /<!-- -->* do stuff with self *<!-- -->/
+ * GDK_THREADS_ENTER ();
+ * /* do stuff with self */
* self->idle_id = 0;
- * GDK_THREADS_LEAVE (<!-- -->);
+ * GDK_THREADS_LEAVE ();
*
* return G_SOURCE_REMOVE;
* }
* GDK_THREADS_ENTER ();
* if (!g_source_is_destroyed (g_main_current_source ()))
* {
- * /<!-- -->* do stuff with self *<!-- -->/
+ * /* do stuff with self */
* }
* GDK_THREADS_LEAVE ();
*
source->flags |= G_SOURCE_BLOCKED;
- tmp_list = source->poll_fds;
- while (tmp_list)
+ if (source->context)
{
- g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
- tmp_list = tmp_list->next;
- }
+ tmp_list = source->poll_fds;
+ while (tmp_list)
+ {
+ g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
+ tmp_list = tmp_list->next;
+ }
- for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
- g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
+ for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
+ g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
+ }
if (source->priv && source->priv->child_sources)
{
gboolean (*dispatch) (GSource *,
GSourceFunc,
gpointer);
- GSList current_source_link;
+ GSource *prev_source;
dispatch = source->source_funcs->dispatch;
cb_funcs = source->callback_funcs;
UNLOCK_CONTEXT (context);
- current->depth++;
- /* The on-stack allocation of the GSList is unconventional, but
- * we know that the lifetime of the link is bounded to this
- * function as the link is kept in a thread specific list and
- * not manipulated outside of this function and its descendants.
- * Avoiding the overhead of a g_slist_alloc() is useful as many
- * applications do little more than dispatch events.
- *
- * This is a performance hack - do not revert to g_slist_prepend()!
- */
- current_source_link.data = source;
- current_source_link.next = current->dispatching_sources;
- current->dispatching_sources = ¤t_source_link;
- need_destroy = ! dispatch (source,
- callback,
- user_data);
- g_assert (current->dispatching_sources == ¤t_source_link);
- current->dispatching_sources = current_source_link.next;
- current->depth--;
-
+ /* These operations are safe because 'current' is thread-local
+ * and not modified from anywhere but this function.
+ */
+ prev_source = current->source;
+ current->source = source;
+ current->depth++;
+
+ TRACE( GLIB_MAIN_BEFORE_DISPATCH (g_source_get_name (source)));
+ need_destroy = !(* dispatch) (source, callback, user_data);
+ TRACE( GLIB_MAIN_AFTER_DISPATCH (g_source_get_name (source)));
+
+ current->source = prev_source;
+ current->depth--;
+
if (cb_funcs)
cb_funcs->unref (cb_data);
* g_main_context_wakeup:
* @context: a #GMainContext
*
- * If @context is currently waiting in a poll(), interrupt
- * the poll(), and continue the iteration process.
+ * If @context is currently blocking in g_main_context_iteration()
+ * waiting for a source to become ready, cause it to stop blocking
+ * and return. Otherwise, cause the next invocation of
+ * g_main_context_iteration() to return without blocking.
+ *
+ * This API is useful for low-level control over #GMainContext; for
+ * example, integrating it with main loop implementations such as
+ * #GMainLoop.
+ *
+ * Another related use for this function is when implementing a main
+ * loop with a termination condition, computed from multiple threads:
+ *
+ * |[
+ * #define NUM_TASKS 10
+ * static volatile gint tasks_remaining = NUM_TASKS;
+ * ...
+ *
+ * while (g_atomic_int_get (&tasks_remaining) != 0)
+ * g_main_context_iteration (NULL, TRUE);
+ * ]|
+ *
+ * Then in a thread:
+ * |[
+ * perform_work();
+ *
+ * if (g_atomic_int_dec_and_test (&tasks_remaining))
+ * g_main_context_wakeup (NULL);
+ * ]|
**/
void
g_main_context_wakeup (GMainContext *context)
}
static void
-dispatch_unix_signals (void)
+dispatch_unix_signals_unlocked (void)
{
+ gboolean pending[NSIG];
GSList *node;
+ gint i;
/* clear this first incase another one arrives while we're processing */
any_unix_signal_pending = FALSE;
- G_LOCK(unix_signal_lock);
+ /* We atomically test/clear the bit from the global array in case
+ * other signals arrive while we are dispatching.
+ *
+ * We then can safely use our own array below without worrying about
+ * races.
+ */
+ for (i = 0; i < NSIG; i++)
+ {
+ /* Be very careful with (the volatile) unix_signal_pending.
+ *
+ * We must ensure that it's not possible that we clear it without
+ * handling the signal. We therefore must ensure that our pending
+ * array has a field set (ie: we will do something about the
+ * signal) before we clear the item in unix_signal_pending.
+ *
+ * Note specifically: we must check _our_ array.
+ */
+ pending[i] = unix_signal_pending[i];
+ if (pending[i])
+ unix_signal_pending[i] = FALSE;
+ }
/* handle GChildWatchSource instances */
- if (unix_signal_pending[SIGCHLD])
+ if (pending[SIGCHLD])
{
- unix_signal_pending[SIGCHLD] = FALSE;
-
/* The only way we can do this is to scan all of the children.
*
* The docs promise that we will not reap children that we are not
if (!source->pending)
{
- if (unix_signal_pending[source->signum])
+ if (pending[source->signum])
{
- unix_signal_pending[source->signum] = FALSE;
source->pending = TRUE;
wake_source ((GSource *) source);
}
}
+}
+
+static void
+dispatch_unix_signals (void)
+{
+ G_LOCK(unix_signal_lock);
+ dispatch_unix_signals_unlocked ();
G_UNLOCK(unix_signal_lock);
}
}
static void
-ensure_unix_signal_handler_installed_unlocked (int signum)
+ref_unix_signal_handler_unlocked (int signum)
{
- static sigset_t installed_signal_mask;
- static gboolean initialized;
- struct sigaction action;
-
- if (!initialized)
+ /* Ensure we have the worker context */
+ g_get_worker_context ();
+ unix_signal_refcount[signum]++;
+ if (unix_signal_refcount[signum] == 1)
{
- sigemptyset (&installed_signal_mask);
- g_get_worker_context ();
- initialized = TRUE;
+ struct sigaction action;
+ action.sa_handler = g_unix_signal_handler;
+ sigemptyset (&action.sa_mask);
+#ifdef SA_RESTART
+ action.sa_flags = SA_RESTART | SA_NOCLDSTOP;
+#else
+ action.sa_flags = SA_NOCLDSTOP;
+#endif
+ sigaction (signum, &action, NULL);
}
+}
- if (sigismember (&installed_signal_mask, signum))
- return;
-
- sigaddset (&installed_signal_mask, signum);
-
- action.sa_handler = g_unix_signal_handler;
- sigemptyset (&action.sa_mask);
- action.sa_flags = SA_RESTART | SA_NOCLDSTOP;
- sigaction (signum, &action, NULL);
+static void
+unref_unix_signal_handler_unlocked (int signum)
+{
+ unix_signal_refcount[signum]--;
+ if (unix_signal_refcount[signum] == 0)
+ {
+ struct sigaction action;
+ memset (&action, 0, sizeof (action));
+ action.sa_handler = SIG_DFL;
+ sigemptyset (&action.sa_mask);
+ sigaction (signum, &action, NULL);
+ }
}
GSource *
unix_signal_source->pending = FALSE;
G_LOCK (unix_signal_lock);
- ensure_unix_signal_handler_installed_unlocked (signum);
+ ref_unix_signal_handler_unlocked (signum);
unix_signal_watches = g_slist_prepend (unix_signal_watches, unix_signal_source);
- if (unix_signal_pending[signum])
- unix_signal_source->pending = TRUE;
- unix_signal_pending[signum] = FALSE;
+ dispatch_unix_signals_unlocked ();
G_UNLOCK (unix_signal_lock);
return source;
static void
g_unix_signal_watch_finalize (GSource *source)
{
+ GUnixSignalWatchSource *unix_signal_source;
+
+ unix_signal_source = (GUnixSignalWatchSource *) source;
+
G_LOCK (unix_signal_lock);
+ unref_unix_signal_handler_unlocked (unix_signal_source->signum);
unix_signal_watches = g_slist_remove (unix_signal_watches, source);
G_UNLOCK (unix_signal_lock);
}
{
G_LOCK (unix_signal_lock);
unix_child_watches = g_slist_remove (unix_child_watches, source);
+ unref_unix_signal_handler_unlocked (SIGCHLD);
G_UNLOCK (unix_signal_lock);
}
g_source_add_poll (source, &child_watch_source->poll);
#else /* G_OS_WIN32 */
G_LOCK (unix_signal_lock);
- ensure_unix_signal_handler_installed_unlocked (SIGCHLD);
+ ref_unix_signal_handler_unlocked (SIGCHLD);
unix_child_watches = g_slist_prepend (unix_child_watches, child_watch_source);
if (waitpid (pid, &child_watch_source->child_status, WNOHANG) > 0)
child_watch_source->child_exited = TRUE;