uORB: Added a new uorb_shutdown function that is called during normal shutdown procedures. It will only

call into a new UORB COMMUNICATOR ICHANNEL shutdown interface if it has been configured, otherwise it
does nothing. This allows ICHANNEL implementations to pass on a shutdown indication to a remote processor.
Implemented the shutdown interface in the muorb module for VOXL flight controllers.

platforms/common/apps.cpp.in

@@ -2,6 +2,7 @@
 #include <px4_platform_common/time.h>
 #include <px4_platform_common/posix.h>
 #include <px4_platform_common/log.h>
+#include <uORB/uORB.h>
 
 #include "apps.h"
 
@@ -43,6 +44,7 @@ void list_builtins(apps_map_type &apps)
 int shutdown_main(int argc, char *argv[])
 {
 	printf("Exiting NOW.\n");
+	uorb_shutdown();
 	system_exit(0);
 }
 

platforms/common/shutdown.cpp

@@ -49,6 +49,7 @@
 
 #include <px4_platform_common/external_reset_lockout.h>
 #include <px4_platform_common/log.h>
+#include <uORB/uORB.h>
 
 #include <stdint.h>
 #include <errno.h>
@@ -173,6 +174,8 @@ static void shutdown_worker(void *arg)
 	const bool delay_elapsed = (now > shutdown_time_us);
 
 	if (delay_elapsed && ((done && shutdown_lock_counter == 0) || (now > (shutdown_time_us + shutdown_timeout_us)))) {
+		uorb_shutdown();
+
 		if (shutdown_args & SHUTDOWN_ARG_REBOOT) {
 #if defined(CONFIG_BOARDCTL_RESET)
 			PX4_INFO_RAW("Reboot NOW.");

platforms/common/uORB/uORB.cpp

@@ -51,6 +51,7 @@
 #include <sys/boardctl.h>
 #endif
 
+
 static uORB::DeviceMaster *g_dev = nullptr;
 
 int uorb_start(void)
@@ -113,6 +114,18 @@ int uorb_top(char **topic_filter, int num_filters)
 	return OK;
 }
 
+void uorb_shutdown(void)
+{
+#ifdef CONFIG_ORB_COMMUNICATOR
+	uORBCommunicator::IChannel *ch = uORB::Manager::get_instance()->get_uorb_communicator();
+
+	if (ch) {
+		ch->shutdown();
+	}
+
+#endif /* CONFIG_ORB_COMMUNICATOR */
+}
+
 orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data)
 {
 	return uORB::Manager::get_instance()->orb_advertise(meta, data);

platforms/common/uORB/uORB.h

@@ -121,6 +121,7 @@ __BEGIN_DECLS
 int uorb_start(void);
 int uorb_status(void);
 int uorb_top(char **topic_filter, int num_filters);
+void uorb_shutdown(void);
 
 /**
  * ORB topic advertiser handle.

platforms/common/uORB/uORBCommunicator.hpp

@@ -129,6 +129,22 @@ public:
 
 	virtual int16_t send_message(const char *messageName, int32_t length, uint8_t *data) = 0;
 
+
+	//=========================================================================
+	//     INTERFACES FOR Lifecycle messages
+	//=========================================================================
+
+	/**
+	 * @brief Interface to notify the remote entity of a shutdown.
+	 *
+	 * @return
+	 * 	0 = success; This means the shutdown is successfully sent to the receiver
+	 * 		Note: This does not mean that the receiver has received it.
+	 *  otherwise = failure.
+	 */
+
+	virtual int16_t shutdown() { return 0; }
+
 };
 
 /**

platforms/posix/src/px4/common/main.cpp

@@ -73,6 +73,7 @@
 #include <px4_platform_common/getopt.h>
 #include <px4_platform_common/tasks.h>
 #include <px4_platform_common/posix.h>
+#include <uORB/uORB.h>
 
 #include "apps.h"
 #include "px4_daemon/client.h"
@@ -505,6 +506,7 @@ void sig_int_handler(int sig_num)
 	fflush(stdout);
 	printf("\nPX4 Exiting...\n");
 	fflush(stdout);
+	uorb_shutdown();
 	px4_daemon::Pxh::stop();
 	_exit_requested = true;
 }

src/modules/muorb/apps/muorb_main.cpp

@@ -58,7 +58,9 @@ muorb_init()
 	if (channel && channel->Initialize(enable_debug)) {
 		uORB::Manager::get_instance()->set_uorb_communicator(channel);
 
-		if (channel->Test()) { return OK; }
+		if (channel->Test()) {
+			return OK;
+		}
 	}
 
 	return -EINVAL;

src/modules/muorb/apps/uORBAppsProtobufChannel.cpp

@@ -291,6 +291,20 @@ int16_t uORB::AppsProtobufChannel::register_handler(uORBCommunicator::IChannelRx
 	return 0;
 }
 
+int16_t uORB::AppsProtobufChannel::shutdown()
+{
+	if (_ShutdownRequested) {
+		return 0;
+	}
+
+	_ShutdownRequested = true;
+
+	PX4_ERR("Sending kill command to SLPI!!!");
+	fc_sensor_kill_slpi();
+	sleep(1);
+	return 0;
+}
+
 int16_t uORB::AppsProtobufChannel::send_message(const char *messageName, int length, uint8_t *data)
 {
 	// This is done to slow down high rate debug messages.

src/modules/muorb/apps/uORBAppsProtobufChannel.hpp

@@ -147,6 +147,16 @@ public:
 	 */
 	int16_t send_message(const char *messageName, int length, uint8_t *data);
 
+	/**
+	 * @brief Interface to notify the remote entity of a shutdown.
+	 *
+	 * @return
+	 * 	0 = success; This means the shutdown is successfully sent to the receiver
+	 * 		Note: This does not mean that the receiver has received it.
+	 *  otherwise = failure.
+	 */
+	int16_t shutdown();
+
 	/**
 	 * @brief Interface to test the functions of the protobuf channel.
 	 *
@@ -169,6 +179,7 @@ private:
 	static bool                                 _Debug;
 
 	bool                                        _Initialized;
+	bool                                        _ShutdownRequested{false};
 	uint32_t                                    _MessageCounter;
 
 private: