Add a RT-Tasklist

1 files changed, 171 insertions, 0 deletions

diff --git a/libs/ardour/rt_tasklist.cc b/libs/ardour/rt_tasklist.cc
new file mode 100644
index 0000000000..db2a33015c
--- /dev/null
+++ b/libs/ardour/rt_tasklist.cc
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2017 Robin Gareus <robin@gareus.org>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+
+#include "pbd/pthread_utils.h"
+
+#include "ardour/audioengine.h"
+#include "ardour/debug.h"
+#include "ardour/rt_tasklist.h"
+#include "ardour/utils.h"
+
+#include "pbd/i18n.h"
+
+using namespace ARDOUR;
+
+RTTaskList::RTTaskList ()
+	: _threads_active (0)
+	, _task_run_sem ("rt_task_run", 0)
+	, _task_end_sem ("rt_task_done", 0)
+{
+	reset_thread_list ();
+}
+
+RTTaskList::~RTTaskList ()
+{
+	drop_threads ();
+}
+
+void
+RTTaskList::drop_threads ()
+{
+	Glib::Threads::Mutex::Lock pm (_process_mutex);
+	g_atomic_int_set (&_threads_active, 0);
+
+	uint32_t nt = _threads.size ();
+	for (uint32_t i = 0; i < nt; ++i) {
+		_task_run_sem.signal ();
+	}
+	for (std::vector<pthread_t>::const_iterator i = _threads.begin (); i != _threads.end (); ++i)
+	{
+		pthread_join (*i, NULL);
+	}
+	_threads.clear ();
+	_task_run_sem.reset ();
+	_task_end_sem.reset ();
+}
+
+/*static*/ void*
+RTTaskList::_thread_run (void *arg)
+{
+	RTTaskList *d = static_cast<RTTaskList *>(arg);
+	d->run ();
+	pthread_exit (0);
+	return 0;
+}
+
+void
+RTTaskList::reset_thread_list ()
+{
+	drop_threads ();
+
+	const uint32_t num_threads = how_many_dsp_threads ();
+	if (num_threads < 2) {
+		return;
+	}
+
+	Glib::Threads::Mutex::Lock pm (_process_mutex);
+
+	g_atomic_int_set (&_threads_active, 1);
+	for (uint32_t i = 0; i < num_threads; ++i) {
+		pthread_t thread_id;
+		size_t stacksize = 100000;
+		if (!AudioEngine::instance()->is_realtime ()
+		    ||
+		    pbd_realtime_pthread_create (PBD_SCHED_FIFO, -22, stacksize, &thread_id, _thread_run, this)) {
+			pthread_attr_t attr;
+			pthread_attr_init (&attr);
+			pthread_attr_setstacksize (&attr, stacksize);
+			if (pthread_create (&thread_id, &attr, _thread_run, this)) {
+				PBD::fatal << _("Cannot create thread for TaskList!") << endmsg;
+				/* NOT REACHED */
+			}
+			pthread_attr_destroy (&attr);
+		}
+		pbd_mach_set_realtime_policy (thread_id, 5. * 1e-5);
+		_threads.push_back (thread_id);
+	}
+}
+
+void
+RTTaskList::run ()
+{
+	Glib::Threads::Mutex::Lock tm (_tasklist_mutex, Glib::Threads::NOT_LOCK);
+	bool wait = true;
+
+	while (true) {
+		if (wait) {
+			_task_run_sem.wait ();
+		}
+
+		if (0 == g_atomic_int_get (&_threads_active)) {
+			_task_end_sem.signal ();
+			break;
+		}
+
+		wait = false;
+
+		boost::function<void ()> to_run;
+		tm.acquire ();
+		if (_tasklist.size () > 0) {
+			to_run = _tasklist.front();
+			_tasklist.pop_front ();
+		}
+		tm.release ();
+
+		if (!to_run.empty ()) {
+			to_run ();
+			continue;
+		}
+
+		if (!wait) {
+			_task_end_sem.signal ();
+		}
+
+		wait = true;
+	}
+}
+
+void
+RTTaskList::process (TaskList const& tl)
+{
+	Glib::Threads::Mutex::Lock pm (_process_mutex);
+	_tasklist = tl;
+	process_tasklist ();
+	_tasklist.clear ();
+}
+
+void
+RTTaskList::process_tasklist ()
+{
+	if (0 == g_atomic_int_get (&_threads_active) || _threads.size () == 0) {
+		for (TaskList::iterator i = _tasklist.begin (); i != _tasklist.end(); ++i) {
+			(*i)();
+		}
+		return;
+	}
+
+	uint32_t nt = std::min (_threads.size (), _tasklist.size ());
+
+	for (uint32_t i = 0; i < nt; ++i) {
+		_task_run_sem.signal ();
+	}
+	for (uint32_t i = 0; i < nt; ++i) {
+		_task_end_sem.wait ();
+	}
+}