examples: add simple work_item example module

src/examples/work_item/WorkItemExample.cpp

@@ -0,0 +1,152 @@
+/****************************************************************************
+ *
+ *   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 "WorkItemExample.hpp"
+
+#include <drivers/drv_hrt.h>
+
+using namespace time_literals;
+
+WorkItemExample::WorkItemExample() :
+	ModuleParams(nullptr),
+	ScheduledWorkItem(MODULE_NAME, px4::wq_configurations::test1)
+{
+}
+
+WorkItemExample::~WorkItemExample()
+{
+	perf_free(_loop_perf);
+	perf_free(_loop_interval_perf);
+}
+
+bool WorkItemExample::init()
+{
+	ScheduleOnInterval(1000_us); // 1000 us interval, 1000 Hz rate
+
+	return true;
+}
+
+void WorkItemExample::Run()
+{
+	if (should_exit()) {
+		ScheduleClear();
+		exit_and_cleanup();
+		return;
+	}
+
+	perf_begin(_loop_perf);
+	perf_count(_loop_interval_perf);
+
+
+	// DO WORK
+
+
+
+	// Example
+	// grab latest accelerometer data
+	_sensor_accel_sub.update();
+	const sensor_accel_s &accel = _sensor_accel_sub.get();
+
+
+	// Example
+	// publish some data
+	orb_test_s data{};
+	data.timestamp = hrt_absolute_time();
+	data.val = accel.device_id;
+	_orb_test_pub.publish(data);
+
+
+
+
+	perf_end(_loop_perf);
+}
+
+int WorkItemExample::task_spawn(int argc, char *argv[])
+{
+	WorkItemExample *instance = new WorkItemExample();
+
+	if (instance) {
+		_object.store(instance);
+		_task_id = task_id_is_work_queue;
+
+		if (instance->init()) {
+			return PX4_OK;
+		}
+
+	} else {
+		PX4_ERR("alloc failed");
+	}
+
+	delete instance;
+	_object.store(nullptr);
+	_task_id = -1;
+
+	return PX4_ERROR;
+}
+
+int WorkItemExample::print_status()
+{
+	perf_print_counter(_loop_perf);
+	perf_print_counter(_loop_interval_perf);
+	return 0;
+}
+
+int WorkItemExample::custom_command(int argc, char *argv[])
+{
+	return print_usage("unknown command");
+}
+
+int WorkItemExample::print_usage(const char *reason)
+{
+	if (reason) {
+		PX4_WARN("%s\n", reason);
+	}
+
+	PRINT_MODULE_DESCRIPTION(
+		R"DESCR_STR(
+### Description
+Example of a simple module running out of a work queue.
+
+)DESCR_STR");
+
+	PRINT_MODULE_USAGE_NAME("work_item_example", "template");
+	PRINT_MODULE_USAGE_COMMAND("start");
+	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
+
+	return 0;
+}
+
+extern "C" __EXPORT int work_item_example_main(int argc, char *argv[])
+{
+	return WorkItemExample::main(argc, argv);
+}