1 files changed, 127 insertions, 0 deletions
diff --git a/src/engine/EventSource.cpp b/src/engine/EventSource.cpp
new file mode 100644
index 00000000..0b8cb9dd
--- /dev/null
+++ b/src/engine/EventSource.cpp
@@ -0,0 +1,127 @@
+/* This file is part of Ingen.
+ * Copyright (C) 2008-2009 Dave 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
+ */
+
+#include <sys/mman.h>
+#include "EventSource.hpp"
+#include "QueuedEvent.hpp"
+#include "PostProcessor.hpp"
+#include "ThreadManager.hpp"
+#include "ProcessContext.hpp"
+
+using namespace std;
+
+namespace Ingen {
+
+
+EventSource::EventSource(size_t queue_size)
+	: _blocking_semaphore(0)
+{
+	Thread::set_context(THREAD_PRE_PROCESS);
+	assert(context() == THREAD_PRE_PROCESS);
+	set_name("EventSource");
+}
+
+
+EventSource::~EventSource()
+{
+	Thread::stop();
+}
+
+
+/** Push an unprepared event onto the queue.
+ */
+void
+EventSource::push_queued(QueuedEvent* const ev)
+{
+	assert(!ev->is_prepared());
+	Raul::List<Event*>::Node* node = new Raul::List<Event*>::Node(ev);
+	_events.push_back(node);
+	if (_prepared_back.get() == NULL)
+		_prepared_back = node;
+
+	whip();
+}
+
+
+/** Process all events for a cycle.
+ *
+ * Executed events will be pushed to @a dest.
+ */
+void
+EventSource::process(PostProcessor& dest, ProcessContext& context)
+{
+	assert(ThreadManager::current_thread_id() == THREAD_PROCESS);
+
+	if (_events.empty())
+		return;
+
+	/* Limit the maximum number of queued events to process per cycle.  This
+	 * makes the process callback (more) realtime-safe by preventing being
+	 * choked by events coming in faster than they can be processed.
+	 * FIXME: test this and figure out a good value */
+	const size_t MAX_QUEUED_EVENTS = context.nframes() / 32;
+
+	size_t num_events_processed = 0;
+
+	QueuedEvent*              ev       = (QueuedEvent*)_events.front();
+	Raul::List<Event*>::Node* new_head = _events.head();
+
+	while (ev && ev->is_prepared() && ev->time() < context.end()) {
+		ev->execute(context);
+		new_head = new_head->next();
+		if (++num_events_processed > MAX_QUEUED_EVENTS)
+			break;
+		ev = (new_head ? (QueuedEvent*)new_head->elem() : NULL);
+	}
+
+	if (num_events_processed > 0) {
+		Raul::List<Event*> front;
+		_events.chop_front(front, num_events_processed, new_head);
+		dest.append(&front);
+	}
+}
+
+
+/** Pre-process a single event */
+void
+EventSource::_whipped()
+{
+	Raul::List<Event*>::Node* pb = _prepared_back.get();
+	if (!pb)
+		return;
+
+	QueuedEvent* const ev = (QueuedEvent*)pb->elem();
+	assert(ev);
+	if (!ev)
+		return;
+
+	assert(!ev->is_prepared());
+	ev->pre_process();
+	assert(ev->is_prepared());
+
+	assert(_prepared_back.get() == pb);
+	_prepared_back = pb->next();
+
+	// If event was blocking, wait for event to being run through the
+	// process thread before preparing the next event
+	if (ev->is_blocking())
+		_blocking_semaphore.wait();
+}
+
+
+} // namespace Ingen
+