PX4-Autopilot/platforms/common/px4_work_queue/WorkItem.cpp

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#include <px4_platform_common/px4_work_queue/WorkItem.hpp>

#include <px4_platform_common/px4_work_queue/WorkQueue.hpp>
#include <px4_platform_common/px4_work_queue/WorkQueueManager.hpp>

#include <px4_platform_common/log.h>
#include <px4_platform_common/posix.h>
#include <drivers/drv_hrt.h>

#include <pthread.h>

namespace px4
{

WorkItem::WorkItem(const char *name, const wq_config_t &config) :
	_item_name(name)
{
	if (!Init(config)) {
		PX4_ERR("init failed");
	}
}

WorkItem::WorkItem(const char *name, const WorkItem &work_item) :
	_item_name(name)
{
	px4::WorkQueue *wq = work_item._wq;

	if ((wq != nullptr) && wq->Attach(this)) {
		_wq = wq;
	}
}

WorkItem::~WorkItem()
{
	Deinit();
}

bool WorkItem::Init(const wq_config_t &config)
{
	// clear any existing first
	Deinit();

	px4::WorkQueue *wq = WorkQueueFindOrCreate(config);

	if ((wq != nullptr) && wq->Attach(this)) {
		_wq = wq;
		_time_first_run = 0;
		return true;
	}

	PX4_ERR("%s not available", config.name);
	return false;
}

void WorkItem::Deinit()
{
	// remove any currently queued work
	if (_wq != nullptr) {
		// prevent additional insertions
		px4::WorkQueue *wq_temp = _wq;
		_wq = nullptr;

		// remove any queued work
		wq_temp->Remove(this);

		// If Run() is already executing on the worker thread at this
		// moment, Remove was a no-op and Run() will still read/write
		// `this`. Wait for it to return before letting the owning
		// object's memory be torn down — otherwise a late
		// ScheduleDelayed from Run() writes into freed/reused memory
		// and corrupts the hrt callout queue.
		//
		// Skip the wait if we're being called from inside Run() on the
		// worker thread itself (e.g. should_exit() → ScheduleClear),
		// which would deadlock against our own flag.
		if (!pthread_equal(pthread_self(), wq_temp->runner_tid())) {
			while (_run_in_progress.load()) {
				px4_usleep(100);
			}
		}

		wq_temp->Detach(this);
	}
}

void WorkItem::ScheduleNow()
{
	if (_wq != nullptr) {
		_wq->Add(this);
	}
}

void WorkItem::ScheduleClear()
{
	if (_wq != nullptr) {
		_wq->Remove(this);
	}
}

float WorkItem::elapsed_time() const
{
	return hrt_elapsed_time(&_time_first_run) / 1e6f;
}

float WorkItem::average_rate() const
{
	const float rate = _run_count / elapsed_time();

	if ((_run_count > 1) && PX4_ISFINITE(rate)) {
		return rate;
	}

	return 0.f;
}

float WorkItem::average_interval() const
{
	const float rate = average_rate();
	const float interval = 1e6f / rate;

	if ((rate > FLT_EPSILON) && PX4_ISFINITE(interval)) {
		return roundf(interval);
	}

	return 0.f;
}

void WorkItem::print_run_status()
{
	PX4_INFO_RAW("%-29s %8.1f Hz %12.0f us\n", _item_name, (double)average_rate(), (double)average_interval());

	// reset statistics
	_run_count = 0;
}

} // namespace px4