worker and HRT threads for Qurt platform (#20739)

* Getting work manager and hrt threads ready for Qurt platform

platforms/common/include/px4_platform_common/posix.h

@@ -104,6 +104,13 @@ typedef struct {
 // Qurt has no fsync implementation so need to declare one here
 // and then define a fake one in the Qurt platform code.
 void fsync(int fd);
+// Qurt doesn't have a way to set the scheduler policy. It is always, essentially,
+// SCHED_FIFO. So have to add a fake function for the code that tries to set it.
+#include <pthread.h>
+__EXPORT int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);
+// Qurt POSIX implementation doesn't define the SIGCONT signal so we just map it
+// to a reasonable alternative
+#define SIGCONT SIGALRM
 #endif
 
 __EXPORT int 		px4_open(const char *path, int flags, ...);

platforms/common/px4_work_queue/WorkQueueManager.cpp

@@ -267,9 +267,7 @@ WorkQueueManagerRun(int, char **)
 			// create new work queue
 
 			// stack size
-#if defined(__PX4_QURT)
-			const size_t stacksize = math::max(8 * 1024, PX4_STACK_ADJUSTED(wq->stacksize));
-#elif defined(__PX4_NUTTX)
+#if defined(__PX4_NUTTX) || defined(__PX4_QURT)
 			const size_t stacksize = math::max(PTHREAD_STACK_MIN, PX4_STACK_ADJUSTED(wq->stacksize));
 #elif defined(__PX4_POSIX)
 			// On posix system , the desired stacksize round to the nearest multiplier of the system pagesize
@@ -304,8 +302,6 @@ WorkQueueManagerRun(int, char **)
 				PX4_ERR("getting sched param for %s failed (%i)", wq->name, ret_getschedparam);
 			}
 
-#ifndef __PX4_QURT
-
 			// schedule policy FIFO
 			int ret_setschedpolicy = pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
 
@@ -313,8 +309,6 @@ WorkQueueManagerRun(int, char **)
 				PX4_ERR("failed to set sched policy SCHED_FIFO (%i)", ret_setschedpolicy);
 			}
 
-#endif // ! QuRT
-
 			// priority
 			param.sched_priority = sched_priority;
 			int ret_setschedparam = pthread_attr_setschedparam(&attr, &param);

platforms/common/work_queue/hrt_thread.c

@@ -293,4 +293,3 @@ void hrt_work_queue_init(void)
 	signal(SIGCONT, _sighandler);
 #endif
 }
-