X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fpbd%2Fevent_loop.cc;h=b6888f0f7d09b0c9e0e96dccc9f17814f476ce9d;hb=c046b7c9d36d54600907565271a8ea2ceb004300;hp=e95a938d63d65c7d1fe1bd998a76618a4931c82e;hpb=f14a33e492ee45599fcb20087bdd32a1698a6803;p=ardour.git

diff --git a/libs/pbd/event_loop.cc b/libs/pbd/event_loop.cc
index e95a938d63..b6888f0f7d 100644
--- a/libs/pbd/event_loop.cc
+++ b/libs/pbd/event_loop.cc
@@ -1,14 +1,32 @@
-#include <iostream>
+/*
+    Copyright (C) 2012 Paul Davis 
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
 #include "pbd/event_loop.h"
 #include "pbd/stacktrace.h"
 
 using namespace PBD;
 using namespace std;
 
-Glib::StaticPrivate<EventLoop> EventLoop::thread_event_loop;
-
 static void do_not_delete_the_loop_pointer (void*) { }
 
+Glib::Threads::Private<EventLoop> EventLoop::thread_event_loop (do_not_delete_the_loop_pointer); 
+
 EventLoop* 
 EventLoop::get_event_loop_for_thread() {
 	return thread_event_loop.get ();
@@ -17,34 +35,46 @@ EventLoop::get_event_loop_for_thread() {
 void 
 EventLoop::set_event_loop_for_thread (EventLoop* loop) 
 {
-	thread_event_loop.set (loop, do_not_delete_the_loop_pointer); 
+	thread_event_loop.set (loop);
 }
 
-/** Called when a sigc::trackable that was connected to using the invalidator() macro
- *  is destroyed.
- */
 void* 
 EventLoop::invalidate_request (void* data)
 {
         InvalidationRecord* ir = (InvalidationRecord*) data;
 
+	/* Some of the requests queued with an EventLoop may involve functors
+	 * that make method calls to objects whose lifetime is shorter
+	 * than the EventLoop's. We do not want to make those calls if the
+	 * object involve has been destroyed. To prevent this, we 
+	 * provide a way to invalidate those requests when the object is
+	 * destroyed.
+	 *
+	 * An object was passed to __invalidator() which added a callback to
+	 * EventLoop::invalidate_request() to its "notify when destroyed"
+	 * list. __invalidator() returned an InvalidationRecord that has been
+	 * to passed to this function as data.
+	 *
+	 * The object is currently being destroyed and so we want to
+	 * mark all requests involving this object that are queued with
+	 * any EventLoop as invalid. 
+	 *
+	 * As of April 2012, we are usign sigc::trackable as the base object
+	 * used to queue calls to ::invalidate_request() to be made upon
+	 * destruction, via its ::add_destroy_notify_callback() API. This is
+	 * not necessarily ideal, but it is very close to precisely what we
+	 * want, and many of the objects we want to do this with already
+	 * inherit (indirectly) from sigc::trackable.
+	 */
+	
         if (ir->event_loop) {
-                Glib::Mutex::Lock lm (ir->event_loop->slot_invalidation_mutex());
-                if (ir->request) {
-                        cerr << "Object deleted had outstanding event loop request, IR created @ "
-                             << ir->file << ':' << ir->line
-                             << endl;
-                        ir->request->valid = false;
-                        ir->request->invalidation = 0;
-                } else {
-                        cerr << "No queued request associated with object deletion from "
-                             << ir->file << ':' << ir->line
-                             << endl;
-                        
-                }
-
-                delete ir;
-        }
+		Glib::Threads::Mutex::Lock lm (ir->event_loop->slot_invalidation_mutex());
+		for (list<BaseRequestObject*>::iterator i = ir->requests.begin(); i != ir->requests.end(); ++i) {
+			(*i)->valid = false;
+			(*i)->invalidation = 0;
+		}
+		delete ir;
+        } 
 
         return 0;
 }