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/****************************************************************************
*
* Copyright (c) 2014, 2015 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_orb_subscription.cpp
* uORB subscription implementation.
*
* @author Anton Babushkin <anton.babushkin@me.com>
* @author Lorenz Meier <lorenz@px4.io>
*/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <uORB/uORB.h>
#include <stdio.h>
#include "mavlink_orb_subscription.h"
MavlinkOrbSubscription::MavlinkOrbSubscription(const orb_id_t topic, int instance) :
next(nullptr),
_topic(topic),
_instance(instance),
_fd(orb_subscribe_multi(_topic, instance)),
_published(false)
{
}
MavlinkOrbSubscription::~MavlinkOrbSubscription()
{
close(_fd);
}
orb_id_t
MavlinkOrbSubscription::get_topic() const
{
return _topic;
}
int
MavlinkOrbSubscription::get_instance() const
{
return _instance;
}
bool
MavlinkOrbSubscription::update(uint64_t *time, void* data)
{
// TODO this is NOT atomic operation, we can get data newer than time
// if topic was published between orb_stat and orb_copy calls.
uint64_t time_topic;
if (orb_stat(_fd, &time_topic)) {
/* error getting last topic publication time */
time_topic = 0;
}
if (orb_copy(_topic, _fd, data)) {
/* error copying topic data */
memset(data, 0, _topic->o_size);
return false;
} else {
/* data copied successfully */
_published = true;
if (time_topic != *time) {
*time = time_topic;
return true;
} else {
return false;
}
}
}
bool
MavlinkOrbSubscription::update(void* data)
{
return !orb_copy(_topic, _fd, data);
}
bool
MavlinkOrbSubscription::is_published()
{
if (_published) {
return true;
}
bool updated;
orb_check(_fd, &updated);
if (updated) {
_published = true;
}
return _published;
}
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