px4-firmware/platforms/common/events.cpp

71 lines
2.8 KiB
C++

/****************************************************************************
*
* Copyright (c) 2020 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.
*
****************************************************************************/
#include <pthread.h>
#include <drivers/drv_hrt.h>
#include <px4_platform_common/posix.h>
#include <px4_platform_common/events.h>
#include <uORB/uORB.h>
static orb_advert_t orb_event_pub = nullptr;
static pthread_mutex_t publish_event_mutex = PTHREAD_MUTEX_INITIALIZER;
static uint16_t event_sequence{events::initial_event_sequence};
namespace events
{
void send(EventType &event)
{
event.timestamp = hrt_absolute_time();
// We need some synchronization here because:
// - modifying orb_event_pub
// - the update of event_sequence needs to be atomic
// - we need to ensure ordering of the sequence numbers: the sequence we set here
// has to be the one published next.
pthread_mutex_lock(&publish_event_mutex);
event.event_sequence = ++event_sequence; // Set the sequence here so we're able to detect uORB queue overflows
if (orb_event_pub != nullptr) {
orb_publish(ORB_ID(event), orb_event_pub, &event);
} else {
orb_event_pub = orb_advertise_queue(ORB_ID(event), &event, event_s::ORB_QUEUE_LENGTH);
}
pthread_mutex_unlock(&publish_event_mutex);
}
} /* namespace events */