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diff --git a/src/server/MessageContext.hpp b/src/server/MessageContext.hpp
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+++ b/src/server/MessageContext.hpp
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+/* This file is part of Ingen.
+ * Copyright 2007-2011 David Robillard <http://drobilla.net>
+ *
+ * Ingen 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.
+ *
+ * Ingen 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 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.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef INGEN_ENGINE_MESSAGECONTEXT_HPP
+#define INGEN_ENGINE_MESSAGECONTEXT_HPP
+
+#include <set>
+#include <glibmm/thread.h>
+#include "raul/Thread.hpp"
+#include "raul/Semaphore.hpp"
+#include "raul/AtomicPtr.hpp"
+#include "lv2/lv2plug.in/ns/ext/atom/atom.h"
+#include "Context.hpp"
+#include "ProcessContext.hpp"
+#include "ThreadManager.hpp"
+
+namespace Ingen {
+namespace Server {
+
+class NodeImpl;
+
+/** Context of a message_run() call.
+ *
+ * The message context is a non-hard-realtime thread used to execute things
+ * that can take too long to execute in an audio thread, and do sloppy timed
+ * event propagation and scheduling.  Interface to plugins via the
+ * LV2 contexts extension.
+ *
+ * \ingroup engine
+ */
+class MessageContext : public Context, public Raul::Thread
+{
+public:
+	explicit MessageContext(Engine& engine)
+		: Context(engine, MESSAGE)
+		, Raul::Thread("MessageContext")
+		, _sem(0)
+		, _requests(engine.event_queue_size())
+		, _end_time(0)
+	{
+		Thread::set_context(THREAD_MESSAGE);
+	}
+
+	/** Schedule a message context run at a certain time.
+	 * Safe to call from either process thread or pre-process thread.
+	 */
+	void run(NodeImpl* node, FrameTime time);
+
+protected:
+	struct Request {
+		Request(FrameTime t=0, NodeImpl* n=0) : time(t), node(n) {}
+		FrameTime time;
+		NodeImpl* node;
+	};
+
+public:
+	/** Signal the end of a cycle that has produced messages.
+	 * AUDIO THREAD ONLY.
+	 */
+	inline void signal(ProcessContext& context) {
+		ThreadManager::assert_thread(THREAD_PROCESS);
+		const Request cycle_end_request(context.end(), NULL);
+		_requests.write(sizeof(Request), &cycle_end_request);
+		_sem.post();
+	}
+
+	/** Return true iff requests are pending.  Safe from any thread. */
+	inline bool has_requests() const {
+		return _requests.read_space() >= sizeof(Request);
+	}
+
+protected:
+	/** Thread run method (wait for and execute requests from process thread */
+	void _run();
+
+	/** Execute a request (possibly enqueueing more requests) */
+	void execute(const Request& req);
+
+	Raul::Semaphore  _sem;
+	Raul::RingBuffer _requests;
+	Glib::Mutex      _mutex;
+	Glib::Cond       _cond;
+	Request          _non_rt_request;
+
+	struct RequestEarlier {
+		bool operator()(const Request& r1, const Request& r2) {
+			return r1.time < r2.time;
+		}
+	};
+
+	typedef std::set<Request, RequestEarlier> Queue;
+	Queue     _queue;
+	FrameTime _end_time;
+};
+
+} // namespace Server
+} // namespace Ingen
+
+#endif // INGEN_ENGINE_MESSAGECONTEXT_HPP
+