From 024d857f0dc239726cc8c042e8b9296e8886af7d Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Thu, 26 Jul 2012 16:38:44 +0000
Subject: Fix post processor ordering to be correctly monotonic between both
 pre-processed events and notifications.

git-svn-id: http://svn.drobilla.net/lad/trunk/ingen@4560 a436a847-0d15-0410-975c-d299462d15a1
---
 src/server/Context.cpp       |  9 +++++++--
 src/server/Context.hpp       |  2 +-
 src/server/PostProcessor.cpp | 30 ++++++++++++++----------------
 3 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/src/server/Context.cpp b/src/server/Context.cpp
index 0f7555a4..745b849f 100644
--- a/src/server/Context.cpp
+++ b/src/server/Context.cpp
@@ -33,10 +33,11 @@ struct Notification
 	                    LV2_URID           k = 0,
 	                    uint32_t           s = 0,
 	                    Raul::Atom::TypeID t = 0)
-		: port(p), key(k), size(s), type(t)
+		: port(p), time(f), key(k), size(s), type(t)
 	{}
 
 	PortImpl*          port;
+	FrameTime          time;
 	LV2_URID           key;
 	uint32_t           size;
 	Raul::Atom::TypeID type;
@@ -74,11 +75,15 @@ Context::notify(LV2_URID           key,
 }
 
 void
-Context::emit_notifications()
+Context::emit_notifications(FrameTime end)
 {
 	const uint32_t read_space = _event_sink.read_space();
 	Notification   note;
 	for (uint32_t i = 0; i < read_space; i += sizeof(note)) {
+		if (_event_sink.peek(sizeof(note), &note) != sizeof(note) ||
+		    note.time >= end) {
+			return;
+		}
 		if (_event_sink.read(sizeof(note), &note) == sizeof(note)) {
 			Raul::Atom value = _engine.world()->forge().alloc(
 				note.size, note.type, NULL);
diff --git a/src/server/Context.hpp b/src/server/Context.hpp
index bd740504..caebd7a4 100644
--- a/src/server/Context.hpp
+++ b/src/server/Context.hpp
@@ -62,7 +62,7 @@ public:
 	            const void*        body = NULL);
 
 	/** Emit pending notifications in some other non-realtime thread. */
-	void emit_notifications();
+	void emit_notifications(FrameTime end);
 
 	inline ID id() const { return _id; }
 
diff --git a/src/server/PostProcessor.cpp b/src/server/PostProcessor.cpp
index 16b0317d..984f69b5 100644
--- a/src/server/PostProcessor.cpp
+++ b/src/server/PostProcessor.cpp
@@ -54,34 +54,32 @@ PostProcessor::append(ProcessContext& context, Event* first, Event* last)
 void
 PostProcessor::process()
 {
-	const FrameTime end_time = _max_time.get();
+	const FrameTime end_time = _max_time.get() + 1;
 
-	/* FIXME: The order here is a bit tricky: if the normal events are
-	 * processed first, then a deleted port may still have a pending
-	 * broadcast event which will segfault if executed afterwards.
-	 * If it's the other way around, broadcasts will be sent for
-	 * ports the client doesn't even know about yet... */
-
-	/* FIXME: process events from all threads if parallel */
-
-	/* Process audio thread generated events */
-	_engine.process_context().emit_notifications();
+	// To avoid a race, we only process up to tail and never write to _tail
+	Event* const tail = _tail.get();
 
-	/* Process normal events */
 	Event* ev = _head.get();
 	if (!ev) {
 		return;
 	}
 
-	Event* const tail = _tail.get();
-	_head = (Event*)tail->next();
-	while (ev && ev->time() <= end_time) {
+	while (ev->time() < end_time) {
 		Event* const next = (Event*)ev->next();
+
+		// Process audio thread notifications up until this event's time
+		_engine.process_context().emit_notifications(ev->time());
+
+		// Process and delete this event
 		ev->post_process();
 		delete ev;
-		if (ev == tail) {
+
+		if (ev == tail || next->time() >= end_time) {
+			// Reached end, update _head
+			_head = next;
 			break;
 		}
+
 		ev = next;
 	}
 }
-- 
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