Extract BufferExchange, simplify threading.

firmware/common/buffer_exchange.cpp

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * 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, 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "buffer_exchange.hpp"
+
+BufferExchange* BufferExchange::obj { nullptr };
+
+BufferExchange::BufferExchange(
+	CaptureConfig* const config
+) : config { config }
+{
+	obj = this;
+	fifo_buffers_for_baseband = config->fifo_buffers_empty;
+	fifo_buffers_for_application = config->fifo_buffers_full;
+}
+
+BufferExchange::~BufferExchange() {
+	obj = nullptr;
+	fifo_buffers_for_baseband = nullptr;
+	fifo_buffers_for_application = nullptr;
+}
+
+StreamBuffer* BufferExchange::get(FIFO<StreamBuffer*>* fifo) {
+	while(true) {
+		StreamBuffer* p { nullptr };
+		fifo->out(p);
+		if( p ) {
+			return p;
+		}
+
+		chSysLock();
+		thread = chThdSelf();
+		chSchGoSleepS(THD_STATE_SUSPENDED);
+		chSysUnlock();
+	}
+}