Commit 5ad7893b authored by Allison Karlitskaya's avatar Allison Karlitskaya

gmain: Remove dispatching source stack

This stack exists only to answer the question of "what is the currently
dispatching source" and is handled in a way that makes it very clear
that we don't need to be using a linked list at all...

Just store the GSource directly.

Independently discovered (and same solution) by Phillip Susi.

https://bugzilla.gnome.org/show_bug.cgi?id=709113
parent 4e9e7d0c
......@@ -217,7 +217,7 @@ typedef struct _GMainDispatch GMainDispatch;
struct _GMainDispatch
{
gint depth;
GSList *dispatching_sources; /* stack of current sources */
GSource *source;
};
#ifdef G_MAIN_POLL_DEBUG
......@@ -2853,7 +2853,7 @@ GSource *
g_main_current_source (void)
{
GMainDispatch *dispatch = get_dispatch ();
return dispatch->dispatching_sources ? dispatch->dispatching_sources->data : NULL;
return dispatch->source;
}
/**
......@@ -3029,7 +3029,7 @@ g_main_dispatch (GMainContext *context)
gboolean (*dispatch) (GSource *,
GSourceFunc,
gpointer);
GSList current_source_link;
GSource *prev_source;
dispatch = source->source_funcs->dispatch;
cb_funcs = source->callback_funcs;
......@@ -3049,26 +3049,17 @@ g_main_dispatch (GMainContext *context)
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 = &current_source_link;
need_destroy = ! dispatch (source,
callback,
user_data);
g_assert (current->dispatching_sources == &current_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->depth++;
need_destroy = !(* dispatch) (source, callback, user_data);
current->source = prev_source;
current->depth--;
if (cb_funcs)
cb_funcs->unref (cb_data);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment