mavlink: add class for command retransmission

This adds a class to allow for retransmission of outgoing commands. The sent commands are kept in a timestamped list to check if they are acked as required by the mavlink protocol. If they are not acked within a timeout, they can be retransmitted.
2026-10-23 14:33:33 +08:00 · 2017-07-08 11:52:23 +02:00
parent 9854fc0d84
commit af0107ae0a
7 changed files with 527 additions and 18 deletions
@@ -0,0 +1,125 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2017 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mavlink_command_sender.h
+ * Mavlink commands sender with support for retransmission.
+ *
+ * @author Julian Oes <julian@oes.ch>
+ */
+
+#pragma once
+
+#include <px4_tasks.h>
+#include <px4_sem.h>
+#include <drivers/drv_hrt.h>
+
+#include <uORB/topics/vehicle_command.h>
+#include <uORB/topics/vehicle_command_ack.h>
+
+#include "timestamped_list.h"
+#include "mavlink_bridge_header.h"
+#include <v2.0/mavlink_types.h>
+
+/**
+ * @class MavlinkCommandSender
+ */
+class MavlinkCommandSender
+{
+public:
+	/**
+	 * initialize: call this once on startup (this function is not thread-safe!)
+	 */
+	static void initialize();
+
+	static MavlinkCommandSender &instance();
+
+	/**
+	 * Send a command on a channel and keep it in a queue for retransmission.
+	 * thread-safe
+	 * @return 0 on success, <0 otherwise
+	 */
+	int handle_vehicle_command(struct vehicle_command_s &command, mavlink_channel_t channel);
+
+	/**
+	 * Check timeouts to verify if an commands need retransmission.
+	 * thread-safe
+	 */
+	void check_timeout(mavlink_channel_t channel);
+
+	/**
+	 * Handle mavlink command_ack.
+	 * thread-safe
+	 */
+	void handle_mavlink_command_ack(const mavlink_command_ack_t &ack, uint8_t from_sysid, uint8_t from_compid);
+
+private:
+	MavlinkCommandSender();
+
+	~MavlinkCommandSender();
+
+	static void lock()
+	{
+		do {} while (px4_sem_wait(&_lock) != 0);
+	}
+
+	static void unlock()
+	{
+		px4_sem_post(&_lock);
+	}
+
+
+	static bool _init;
+	static MavlinkCommandSender *_instance;
+
+	static px4_sem_t _lock;
+
+	// There are MAVLINK_COMM_0 to MAVLINK_COMM_3, so it should be 4.
+	static const unsigned MAX_MAVLINK_CHANNEL = 4;
+
+	typedef struct {
+		mavlink_command_long_t command = {};
+		hrt_abstime timestamp_us = 0;
+		hrt_abstime last_time_sent_us = 0;
+		int8_t num_sent_per_channel[MAX_MAVLINK_CHANNEL] = {-1, -1, -1, -1};
+	} command_item_t;
+
+	TimestampedList<command_item_t> _commands;
+
+	static const uint8_t RETRIES = 3;
+	static const uint64_t TIMEOUT_US = 500000;
+
+	/* do not allow copying or assigning this class */
+	MavlinkCommandSender(const MavlinkCommandSender &) = delete;
+	MavlinkCommandSender operator=(const MavlinkCommandSender &) = delete;
+};