sched/mqueue: configurable mqueue notification

Add a configuration to disable the mqueue notification mechanism

Signed-off-by: chao.an <anchao@xiaomi.com>

include/nuttx/mqueue.h

@@ -97,9 +97,11 @@ struct mqueue_inode_s
 #else
   uint16_t maxmsgsize;        /* Max size of message in message queue */
 #endif
+#ifndef CONFIG_DISABLE_MQUEUE_NOTIFICATION
   pid_t ntpid;                /* Notification: Receiving Task's PID */
   struct sigevent ntevent;    /* Notification description */
   struct sigwork_s ntwork;    /* Notification work */
+#endif
   FAR struct pollfd *fds[CONFIG_FS_MQUEUE_NPOLLWAITERS];
 };
 

sched/Kconfig

@@ -1585,6 +1585,12 @@ config MQ_MAXMSGSIZE
 		Message structures are allocated with a fixed payload size given by this
 		setting (does not include other message structure overhead.
 
+config DISABLE_MQUEUE_NOTIFICATION
+	bool "Disable POSIX message queue notification"
+	default DEFAULT_SMALL
+	---help---
+		Disable POSIX message queue notification
+
 endmenu # POSIX Message Queue Options
 
 config MODULE

sched/mqueue/mq_msgqalloc.c

@@ -98,7 +98,9 @@ int nxmq_alloc_msgq(FAR struct mq_attr *attr,
           msgq->maxmsgsize = MQ_MAX_BYTES;
         }
 
+#ifndef CONFIG_DISABLE_MQUEUE_NOTIFICATION
       msgq->ntpid = INVALID_PROCESS_ID;
+#endif
     }
   else
     {

sched/mqueue/mq_notify.c

@@ -94,6 +94,7 @@
 
 int mq_notify(mqd_t mqdes, FAR const struct sigevent *notification)
 {
+#ifndef CONFIG_DISABLE_MQUEUE_NOTIFICATION
   FAR struct mqueue_inode_s *msgq;
   FAR struct inode *inode;
   FAR struct file *filep;
@@ -189,4 +190,8 @@ errout:
 errout_without_lock:
   set_errno(errval);
   return ERROR;
+#else
+  set_errno(ENOSYS);
+  return ERROR;
+#endif
 }

sched/mqueue/mq_sndinternal.c

@@ -373,6 +373,7 @@ int nxmq_do_send(FAR struct mqueue_inode_s *msgq,
    * message queue
    */
 
+#ifndef CONFIG_DISABLE_MQUEUE_NOTIFICATION
   if (msgq->ntpid != INVALID_PROCESS_ID)
     {
       struct sigevent event;
@@ -393,6 +394,7 @@ int nxmq_do_send(FAR struct mqueue_inode_s *msgq,
       DEBUGVERIFY(nxsig_notification(pid, &event,
                                      SI_MESGQ, &msgq->ntwork));
     }
+#endif
 
   /* Check if any tasks are waiting for the MQ not empty event. */