From 77845f601912c0237fb40a19d401ca64bac542b1 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 14 Dec 2016 22:19:33 +0100
Subject: Atomically to invalidate request

Yet another slightly overkill approach, but it /may/ explain crashes.
---
 libs/pbd/pbd/abstract_ui.cc |  6 +++---
 libs/pbd/pbd/event_loop.h   | 14 +++++++++-----
 2 files changed, 12 insertions(+), 8 deletions(-)

(limited to 'libs/pbd/pbd')

diff --git a/libs/pbd/pbd/abstract_ui.cc b/libs/pbd/pbd/abstract_ui.cc
index 330e6ddc59..db63c3f96d 100644
--- a/libs/pbd/pbd/abstract_ui.cc
+++ b/libs/pbd/pbd/abstract_ui.cc
@@ -168,7 +168,7 @@ AbstractUI<RequestObject>::get_request (RequestType rt)
 		DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated per-thread request of type %2, caller %3\n", event_loop_name(), rt, pthread_name()));
 
 		vec.buf[0]->type = rt;
-		vec.buf[0]->valid = true;
+		vec.buf[0]->validate ();
 		return vec.buf[0];
 	}
 
@@ -218,7 +218,7 @@ AbstractUI<RequestObject>::handle_ui_requests ()
 			if (vec.len[0] == 0) {
 				break;
 			} else {
-				if (vec.buf[0]->valid) {
+				if (vec.buf[0]->valid ()) {
 					/* We first need to remove the event from the list.
 					 * If the event results in object destruction, PBD::EventLoop::invalidate_request
 					 * will delete the invalidation record (aka buf[0]), so we cannot use it after calling do_request
@@ -327,7 +327,7 @@ AbstractUI<RequestObject>::handle_ui_requests ()
 			}
 		}
 
-		if (!req->valid) {
+		if (!req->valid ()) {
 			DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 handling invalid heap request, type %3, deleting\n", event_loop_name(), pthread_name(), req->type));
 			delete req;
 			continue;
diff --git a/libs/pbd/pbd/event_loop.h b/libs/pbd/pbd/event_loop.h
index f7765cb792..ce2040084c 100644
--- a/libs/pbd/pbd/event_loop.h
+++ b/libs/pbd/pbd/event_loop.h
@@ -67,12 +67,16 @@ class LIBPBD_API EventLoop
         static void* invalidate_request (void* data);
 
 	struct BaseRequestObject {
-	    RequestType             type;
-            bool                    valid;
-            InvalidationRecord*     invalidation;
-	    boost::function<void()> the_slot;
+		RequestType             type;
+		gint                    _valid;
+		InvalidationRecord*     invalidation;
+		boost::function<void()> the_slot;
 
-            BaseRequestObject() : valid (true), invalidation (0) {}
+		BaseRequestObject() : _valid (0), invalidation (0) {}
+
+		void validate () { g_atomic_int_set (&_valid, 1); }
+		void invalidate () { g_atomic_int_set (&_valid, 0); }
+		bool valid () { return g_atomic_int_get (&_valid) == 1; }
 	};
 
 	virtual void call_slot (InvalidationRecord*, const boost::function<void()>&) = 0;
-- 
cgit v1.2.3