mirror of
https://gitlab.gnome.org/GNOME/glib.git
synced 2024-11-14 21:36:13 +01:00
gmain: Avoid some lock/unlock dance during g_main_context_iterate
A context iteration we're doing lots of lock/unlocks and that's fine to give other threads contexts a chance to run, but we're doing it also just to call other functions that require locking, and this can be avoided. Other threads can still have a chance to run while releasing the ownership of the context.
This commit is contained in:
Marco Trevisan (Treviño)
parent
fe2de360de
commit
e7c2ead41b
198
glib/gmain.c
198
glib/gmain.c
@ -446,11 +446,25 @@ static void g_source_set_priority_unlocked (GSource *source,
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static void g_child_source_remove_internal (GSource *child_source,
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GMainContext *context);
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static void g_main_context_poll (GMainContext *context,
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gint timeout,
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gint priority,
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GPollFD *fds,
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gint n_fds);
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static gboolean g_main_context_acquire_unlocked (GMainContext *context);
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static void g_main_context_release_unlocked (GMainContext *context);
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static gboolean g_main_context_prepare_unlocked (GMainContext *context,
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gint *priority);
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static gint g_main_context_query_unlocked (GMainContext *context,
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gint max_priority,
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gint *timeout,
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GPollFD *fds,
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gint n_fds);
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static gboolean g_main_context_check_unlocked (GMainContext *context,
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gint max_priority,
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GPollFD *fds,
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gint n_fds);
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static void g_main_context_dispatch_unlocked (GMainContext *context);
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static void g_main_context_poll_unlocked (GMainContext *context,
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int timeout,
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int priority,
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GPollFD *fds,
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int n_fds);
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static void g_main_context_add_poll_unlocked (GMainContext *context,
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gint priority,
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GPollFD *fd);
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@ -3523,13 +3537,24 @@ gboolean
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g_main_context_acquire (GMainContext *context)
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{
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gboolean result = FALSE;
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GThread *self = G_THREAD_SELF;
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if (context == NULL)
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context = g_main_context_default ();
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LOCK_CONTEXT (context);
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result = g_main_context_acquire_unlocked (context);
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UNLOCK_CONTEXT (context);
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return result;
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}
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static gboolean
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g_main_context_acquire_unlocked (GMainContext *context)
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{
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GThread *self = G_THREAD_SELF;
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if (!context->owner)
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{
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context->owner = self;
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@ -3540,16 +3565,13 @@ g_main_context_acquire (GMainContext *context)
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if (context->owner == self)
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{
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context->owner_count++;
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result = TRUE;
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return TRUE;
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}
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else
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{
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TRACE (GLIB_MAIN_CONTEXT_ACQUIRE (context, FALSE /* failure */));
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return FALSE;
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}
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UNLOCK_CONTEXT (context);
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return result;
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}
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/**
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@ -3570,6 +3592,14 @@ g_main_context_release (GMainContext *context)
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LOCK_CONTEXT (context);
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g_main_context_release_unlocked (context);
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UNLOCK_CONTEXT (context);
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}
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static void
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g_main_context_release_unlocked (GMainContext *context)
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{
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context->owner_count--;
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if (context->owner_count == 0)
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{
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@ -3592,8 +3622,6 @@ g_main_context_release (GMainContext *context)
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g_mutex_unlock (waiter->mutex);
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}
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}
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UNLOCK_CONTEXT (context);
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}
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static gboolean
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@ -3706,24 +3734,36 @@ gboolean
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g_main_context_prepare (GMainContext *context,
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gint *priority)
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{
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guint i;
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gint n_ready = 0;
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gint current_priority = G_MAXINT;
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GSource *source;
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GSourceIter iter;
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gboolean ready;
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if (context == NULL)
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context = g_main_context_default ();
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LOCK_CONTEXT (context);
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ready = g_main_context_prepare_unlocked (context, priority);
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UNLOCK_CONTEXT (context);
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return ready;
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}
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static gboolean
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g_main_context_prepare_unlocked (GMainContext *context,
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gint *priority)
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{
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guint i;
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gint n_ready = 0;
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gint current_priority = G_MAXINT;
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GSource *source;
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GSourceIter iter;
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context->time_is_fresh = FALSE;
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if (context->in_check_or_prepare)
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{
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g_warning ("g_main_context_prepare() called recursively from within a source's check() or "
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"prepare() member.");
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UNLOCK_CONTEXT (context);
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return FALSE;
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}
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@ -3736,7 +3776,6 @@ g_main_context_prepare (GMainContext *context,
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if (dispatch)
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g_main_dispatch (context, ¤t_time);
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UNLOCK_CONTEXT (context);
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return TRUE;
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}
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#endif
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@ -3854,8 +3893,6 @@ g_main_context_prepare (GMainContext *context,
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g_source_iter_clear (&iter);
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TRACE (GLIB_MAIN_CONTEXT_AFTER_PREPARE (context, current_priority, n_ready));
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UNLOCK_CONTEXT (context);
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if (priority)
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*priority = current_priority;
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@ -3893,14 +3930,30 @@ g_main_context_query (GMainContext *context,
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gint n_fds)
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{
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gint n_poll;
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GPollRec *pollrec, *lastpollrec;
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gushort events;
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if (context == NULL)
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context = g_main_context_default ();
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LOCK_CONTEXT (context);
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n_poll = g_main_context_query_unlocked (context, max_priority, timeout, fds, n_fds);
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UNLOCK_CONTEXT (context);
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return n_poll;
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}
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static gint
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g_main_context_query_unlocked (GMainContext *context,
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gint max_priority,
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gint *timeout,
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GPollFD *fds,
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gint n_fds)
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{
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gint n_poll;
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GPollRec *pollrec, *lastpollrec;
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gushort events;
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TRACE (GLIB_MAIN_CONTEXT_BEFORE_QUERY (context, max_priority));
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/* fds is filled sequentially from poll_records. Since poll_records
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@ -3957,8 +4010,6 @@ g_main_context_query (GMainContext *context,
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TRACE (GLIB_MAIN_CONTEXT_AFTER_QUERY (context, context->timeout,
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fds, n_poll));
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UNLOCK_CONTEXT (context);
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return n_poll;
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}
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@ -3989,6 +4040,23 @@ g_main_context_check (GMainContext *context,
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gint max_priority,
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GPollFD *fds,
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gint n_fds)
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{
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gboolean ready;
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LOCK_CONTEXT (context);
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ready = g_main_context_check_unlocked (context, max_priority, fds, n_fds);
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UNLOCK_CONTEXT (context);
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return ready;
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}
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static gboolean
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g_main_context_check_unlocked (GMainContext *context,
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gint max_priority,
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GPollFD *fds,
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gint n_fds)
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{
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GSource *source;
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GSourceIter iter;
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@ -3999,13 +4067,10 @@ g_main_context_check (GMainContext *context,
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if (context == NULL)
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context = g_main_context_default ();
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LOCK_CONTEXT (context);
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if (context->in_check_or_prepare)
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{
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g_warning ("g_main_context_check() called recursively from within a source's check() or "
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"prepare() member.");
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UNLOCK_CONTEXT (context);
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return FALSE;
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}
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@ -4031,7 +4096,6 @@ g_main_context_check (GMainContext *context,
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{
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TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, 0));
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UNLOCK_CONTEXT (context);
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return FALSE;
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}
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@ -4167,8 +4231,6 @@ g_main_context_check (GMainContext *context,
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TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, n_ready));
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UNLOCK_CONTEXT (context);
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return n_ready > 0;
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}
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@ -4193,6 +4255,14 @@ g_main_context_dispatch (GMainContext *context)
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LOCK_CONTEXT (context);
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g_main_context_dispatch_unlocked (context);
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UNLOCK_CONTEXT (context);
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}
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static void
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g_main_context_dispatch_unlocked (GMainContext *context)
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{
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TRACE (GLIB_MAIN_CONTEXT_BEFORE_DISPATCH (context));
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if (context->pending_dispatches->len > 0)
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@ -4201,16 +4271,14 @@ g_main_context_dispatch (GMainContext *context)
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}
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TRACE (GLIB_MAIN_CONTEXT_AFTER_DISPATCH (context));
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UNLOCK_CONTEXT (context);
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}
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/* HOLDS context lock */
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static gboolean
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g_main_context_iterate (GMainContext *context,
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gboolean block,
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gboolean dispatch,
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GThread *self)
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g_main_context_iterate_unlocked (GMainContext *context,
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gboolean block,
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gboolean dispatch,
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GThread *self)
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{
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gint max_priority = 0;
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gint timeout;
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@ -4219,16 +4287,12 @@ g_main_context_iterate (GMainContext *context,
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GPollFD *fds = NULL;
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gint64 begin_time_nsec G_GNUC_UNUSED;
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UNLOCK_CONTEXT (context);
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begin_time_nsec = G_TRACE_CURRENT_TIME;
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if (!g_main_context_acquire (context))
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if (!g_main_context_acquire_unlocked (context))
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{
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gboolean got_ownership;
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LOCK_CONTEXT (context);
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if (!block)
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return FALSE;
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@ -4239,8 +4303,6 @@ g_main_context_iterate (GMainContext *context,
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if (!got_ownership)
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return FALSE;
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}
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else
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LOCK_CONTEXT (context);
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if (!context->cached_poll_array)
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{
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@ -4251,38 +4313,33 @@ g_main_context_iterate (GMainContext *context,
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allocated_nfds = context->cached_poll_array_size;
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fds = context->cached_poll_array;
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UNLOCK_CONTEXT (context);
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g_main_context_prepare (context, &max_priority);
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g_main_context_prepare_unlocked (context, &max_priority);
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while ((nfds = g_main_context_query (context, max_priority, &timeout, fds,
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allocated_nfds)) > allocated_nfds)
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while ((nfds = g_main_context_query_unlocked (
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context, max_priority, &timeout, fds,
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allocated_nfds)) > allocated_nfds)
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{
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LOCK_CONTEXT (context);
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g_free (fds);
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context->cached_poll_array_size = allocated_nfds = nfds;
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context->cached_poll_array = fds = g_new (GPollFD, nfds);
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UNLOCK_CONTEXT (context);
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}
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if (!block)
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timeout = 0;
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g_main_context_poll (context, timeout, max_priority, fds, nfds);
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g_main_context_poll_unlocked (context, timeout, max_priority, fds, nfds);
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some_ready = g_main_context_check (context, max_priority, fds, nfds);
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some_ready = g_main_context_check_unlocked (context, max_priority, fds, nfds);
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if (dispatch)
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g_main_context_dispatch (context);
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g_main_context_dispatch_unlocked (context);
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g_main_context_release (context);
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g_main_context_release_unlocked (context);
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g_trace_mark (begin_time_nsec, G_TRACE_CURRENT_TIME - begin_time_nsec,
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"GLib", "g_main_context_iterate",
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"Context %p, %s ⇒ %s", context, block ? "blocking" : "non-blocking", some_ready ? "dispatched" : "nothing");
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LOCK_CONTEXT (context);
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return some_ready;
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}
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@ -4304,7 +4361,7 @@ g_main_context_pending (GMainContext *context)
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context = g_main_context_default();
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LOCK_CONTEXT (context);
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retval = g_main_context_iterate (context, FALSE, FALSE, G_THREAD_SELF);
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retval = g_main_context_iterate_unlocked (context, FALSE, FALSE, G_THREAD_SELF);
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UNLOCK_CONTEXT (context);
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return retval;
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@ -4340,7 +4397,7 @@ g_main_context_iteration (GMainContext *context, gboolean may_block)
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context = g_main_context_default();
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LOCK_CONTEXT (context);
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retval = g_main_context_iterate (context, may_block, TRUE, G_THREAD_SELF);
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retval = g_main_context_iterate_unlocked (context, may_block, TRUE, G_THREAD_SELF);
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UNLOCK_CONTEXT (context);
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return retval;
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@ -4476,7 +4533,7 @@ g_main_loop_run (GMainLoop *loop)
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g_atomic_int_set (&loop->is_running, TRUE);
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while (g_atomic_int_get (&loop->is_running))
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g_main_context_iterate (loop->context, TRUE, TRUE, self);
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g_main_context_iterate_unlocked (loop->context, TRUE, TRUE, self);
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UNLOCK_CONTEXT (loop->context);
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@ -4548,11 +4605,11 @@ g_main_loop_get_context (GMainLoop *loop)
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/* HOLDS: context's lock */
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static void
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g_main_context_poll (GMainContext *context,
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gint timeout,
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gint priority,
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GPollFD *fds,
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gint n_fds)
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g_main_context_poll_unlocked (GMainContext *context,
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int timeout,
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int priority,
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GPollFD *fds,
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int n_fds)
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{
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#ifdef G_MAIN_POLL_DEBUG
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GTimer *poll_timer;
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@ -4575,13 +4632,12 @@ g_main_context_poll (GMainContext *context,
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poll_timer = g_timer_new ();
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}
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#endif
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LOCK_CONTEXT (context);
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poll_func = context->poll_func;
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UNLOCK_CONTEXT (context);
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ret = (*poll_func) (fds, n_fds, timeout);
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LOCK_CONTEXT (context);
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errsv = errno;
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if (ret < 0 && errsv != EINTR)
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{
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@ -4596,8 +4652,6 @@ g_main_context_poll (GMainContext *context,
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#ifdef G_MAIN_POLL_DEBUG
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if (_g_main_poll_debug)
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{
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LOCK_CONTEXT (context);
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g_print ("g_main_poll(%d) timeout: %d - elapsed %12.10f seconds",
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n_fds,
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timeout,
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@ -4634,8 +4688,6 @@ g_main_context_poll (GMainContext *context,
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pollrec = pollrec->next;
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}
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g_print ("\n");
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UNLOCK_CONTEXT (context);
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}
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#endif
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} /* if (n_fds || timeout != 0) */
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