mq_notify() was not setting errno on failures

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4133 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -2233,3 +2233,5 @@
 	  corresponding sans serif bold fonts.
 	* drivers/input/ads7843e.c and tsc2007.c:  Fix some errors in the poll
 	  setup error checking that was cloned into both drivers.
+	* sched/mq_notify.c:  Set errno appropriately on failures.  There are
+	  still severl message queue functions that do not set errno!

sched/mq_notify.c

@@ -1,7 +1,7 @@
 /************************************************************************
  * sched/mq_notify.c
  *
- *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,6 +42,8 @@
 #include <signal.h>
 #include <mqueue.h>
 #include <sched.h>
+#include <errno.h>
+
 #include "os_internal.h"
 #include "mq_internal.h"
 
@@ -95,7 +97,17 @@
  *      sigev_value - Value associated with the signal
  *
  * Return Value:
- *   None
+ *  On success mq_notify() returns 0; on error, -1 is returned, with
+ *  errno set to indicate the error.
+ *
+ *  EBADF The descriptor specified in mqdes is invalid. 
+ *  EBUSY Another process has already registered to receive notification
+ *    for this message queue. 
+ *  EINVAL sevp->sigev_notify is not one of the permitted values; or
+ *    sevp->sigev_notify is SIGEV_SIGNAL and sevp->sigev_signo is not a
+ *    valid signal number. 
+ *  ENOMEM
+ *    Insufficient memory.
  *
  * Assumptions:
  *
@@ -117,14 +129,21 @@ int mq_notify(mqd_t mqdes, const struct sigevent *notification)
 {
   _TCB   *rtcb;
   msgq_t *msgq;
-  int     ret = ERROR;
+  int     errval;
 
-  if (mqdes)
+  /* Was a valid message queue descriptor provided? */
+
+  if (!mqdes)
     {
-      sched_lock();
+      /* No.. return EBADF */
+
+      errval = EBADF;
+      goto errout;
+    }
 
   /* Get a pointer to the message queue */
 
+  sched_lock();
   msgq = mqdes->msgq;
 
   /* Get the current process ID */
@@ -135,19 +154,26 @@ int mq_notify(mqd_t mqdes, const struct sigevent *notification)
 
   if (!msgq->ntmqdes)
     {
-          /* No... Have we been asked to establish one?  Make
+      /* No... Have we been asked to establish one? */
-           * sure a good signal number has been provided
-           */
 
-          if (notification && GOOD_SIGNO(notification->sigev_signo))
+      if (notification)
         {
+          /* Yes... Was a valid signal number supplied? */
+
+          if (!GOOD_SIGNO(notification->sigev_signo))
+            {
+              /* No... Return EINVAL */
+
+              errval = EINVAL;
+              goto errout;
+            }
+
           /* Yes... Assign it to the current task. */
 
           msgq->ntvalue.sival_ptr = notification->sigev_value.sival_ptr;
           msgq->ntsigno           = notification->sigev_signo;
           msgq->ntpid             = rtcb->pid;
           msgq->ntmqdes           = mqdes;
-              ret                     = OK;
         }
     }
 
@@ -155,18 +181,32 @@ int mq_notify(mqd_t mqdes, const struct sigevent *notification)
    * Is it trying to remove it?
    */
 
-      else if ((msgq->ntpid == rtcb->pid) && (!notification))
+  else if ((msgq->ntpid != rtcb->pid) || (notification))
     {
-          /* Yes... Detach the notification */
+      /* This thread does not own the notification OR it is
+       * not trying to remove it.  Return EBUSY.
+       */
+
+      errval = EBUSY;
+      goto errout;
+    }
+  else
+    {
+      /* Yes, the notification belongs to this thread.  Allow the
+       * thread to detach the notification.
+       */
 
       msgq->ntpid             = INVALID_PROCESS_ID;
       msgq->ntsigno           = 0;
       msgq->ntvalue.sival_ptr = NULL;
       msgq->ntmqdes           = NULL;
-          ret                     = OK;
-        }
-      sched_unlock();
     }
 
-  return ret;
+  sched_unlock();
+  return OK;
+
+errout:
+  set_errno(errval);
+  sched_unlock();
+  return ERROR;
 }