px4_getpid: return the taskmap index instead of pthread_self()

this makes it consistent with other functions, like px4_task_spawn_cmd()
and px4_task_kill()

src/modules/mavlink/mavlink_receiver.cpp

@@ -2079,7 +2079,7 @@ MavlinkReceiver::receive_thread(void *arg)
 	{
 		char thread_name[24];
 		sprintf(thread_name, "mavlink_rcv_if%d", _mavlink->get_instance_id());
-		px4_prctl(PR_SET_NAME, thread_name, getpid());
+		px4_prctl(PR_SET_NAME, thread_name, px4_getpid());
 	}
 
 	const int timeout = 500;

src/modules/uORB/uORBDevices.hpp

@@ -232,7 +232,7 @@ private:
 					We allow one publisher to have an open file descriptor at the same time. */
 	bool    _IsRemoteSubscriberPresent;
 #else
-	unsigned long     _publisher; /**< if nonzero, current publisher. Only used inside the advertise call.
+	px4_task_t     _publisher; /**< if nonzero, current publisher. Only used inside the advertise call.
 					We allow one publisher to have an open file descriptor at the same time. */
 #endif
 	int32_t _subscriber_count;

src/platforms/posix/px4_layer/px4_posix_tasks.cpp

@@ -387,9 +387,21 @@ bool px4_task_is_running(const char *taskname)
 	return false;
 }
 
-unsigned long px4_getpid()
+px4_task_t px4_getpid()
 {
-	return (unsigned long)pthread_self();
+	pthread_t pid = pthread_self();
+	px4_task_t ret = -1;
+
+	pthread_mutex_lock(&task_mutex);
+
+	for (int i = 0; i < PX4_MAX_TASKS; i++) {
+		if (taskmap[i].isused && taskmap[i].pid == pid) {
+			ret = i;
+		}
+	}
+
+	pthread_mutex_unlock(&task_mutex);
+	return ret;
 }
 
 const char *px4_get_taskname()
@@ -410,7 +422,7 @@ const char *px4_get_taskname()
 	return prog_name;
 }
 
-int px4_prctl(int option, const char *arg2, unsigned pid)
+int px4_prctl(int option, const char *arg2, px4_task_t pid)
 {
 	int rv;
 

src/platforms/px4_posix.h

@@ -109,7 +109,7 @@ __EXPORT int		px4_ioctl(int fd, int cmd, unsigned long arg);
 __EXPORT int		px4_poll(px4_pollfd_struct_t *fds, nfds_t nfds, int timeout);
 __EXPORT int		px4_fsync(int fd);
 __EXPORT int		px4_access(const char *pathname, int mode);
-__EXPORT unsigned long	px4_getpid(void);
+__EXPORT px4_task_t	px4_getpid(void);
 
 __EXPORT void		px4_enable_sim_lockstep(void);
 __EXPORT void		px4_sim_start_delay(void);

src/platforms/px4_tasks.h

@@ -131,7 +131,7 @@ __EXPORT bool px4_task_is_running(const char *taskname);
 
 #ifdef __PX4_POSIX
 /** set process (and thread) options */
-__EXPORT int px4_prctl(int option, const char *arg2, unsigned pid);
+__EXPORT int px4_prctl(int option, const char *arg2, px4_task_t pid);
 #endif
 
 /** return the name of the current task */

src/platforms/qurt/px4_layer/px4_qurt_tasks.cpp

@@ -326,7 +326,7 @@ void px4_show_tasks()
 
 }
 
-unsigned long px4_getpid()
+px4_task_t px4_getpid()
 {
 	pthread_t pid = pthread_self();
 //
@@ -340,10 +340,6 @@ unsigned long px4_getpid()
 		}
 	}
 
-#ifndef __PX4_QURT
-	// XXX This doesn't seem to be working on QURT
-	PX4_ERR("px4_getpid() called from unknown thread context!");
-#endif
 	return ~0;
 }
 
@@ -386,7 +382,7 @@ int px4_sem_timedwait(px4_sem_t *sem, const struct timespec *ts)
 	return 0;
 }
 
-int px4_prctl(int option, const char *arg2, unsigned pid)
+int px4_prctl(int option, const char *arg2, px4_task_t pid)
 {
 	int rv;