2001-08-09 Joel Sherrill <joel@OARcorp.com>

	* c/src/exec/itron/src/snd_mbx.c, c/src/exec/itron/src/tsnd_mbf.c
	c/src/exec/posix/src/mqueuesendsupp.c,
	c/src/exec/rtems/src/msgqsubmit.c,
	c/src/exec/score/include/rtems/score/coremsg.h,
	c/src/exec/score/inline/rtems/score/coremsg.inl,
	c/src/exec/score/src/coremsgsubmit.c: Unblocking message queue
	operations should NOT use _Thread_Executing for return status
	since it is permissible to invoke message send operations from
	an ISR.  This was reported by Suvrat Gupta <suvrat@utstar.com>.

7 files changed, 57 insertions, 43 deletions

diff --git a/c/src/exec/itron/src/snd_mbx.c b/c/src/exec/itron/src/snd_mbx.c
index e02714465e..db1f0ee5ae 100644
--- a/c/src/exec/itron/src/snd_mbx.c
+++ b/c/src/exec/itron/src/snd_mbx.c
@@ -29,6 +29,7 @@ ER snd_msg(
   Objects_Locations                location;
   unsigned32                       message_priority;
   void                            *message_contents;
+  CORE_message_queue_Status        msg_status;
 
   if ( !pk_msg )
     return E_PAR;
@@ -46,7 +47,7 @@ ER snd_msg(
         message_priority = CORE_MESSAGE_QUEUE_SEND_REQUEST;
 
       message_contents = pk_msg;
-      _CORE_message_queue_Submit(
+      msg_status = _CORE_message_queue_Submit(
         &the_mailbox->message_queue,
         &message_contents,
         sizeof(T_MSG *),
@@ -60,8 +61,6 @@ ER snd_msg(
   }
 
   _ITRON_return_errorno( 
-     _ITRON_Mailbox_Translate_core_message_queue_return_code(
-          _Thread_Executing->Wait.return_code
-     )
+     _ITRON_Mailbox_Translate_core_message_queue_return_code( msg_status )
   );
 }
diff --git a/c/src/exec/itron/src/tsnd_mbf.c b/c/src/exec/itron/src/tsnd_mbf.c
index 0ed3b4f90e..5a4e4cb1b2 100644
--- a/c/src/exec/itron/src/tsnd_mbf.c
+++ b/c/src/exec/itron/src/tsnd_mbf.c
@@ -33,6 +33,7 @@ ER tsnd_mbf(
   Objects_Locations              location;
   Watchdog_Interval              interval;
   boolean                        wait;
+  CORE_message_queue_Status      msg_status;
 
   if (msgsz <= 0 || !msg)
     return E_PAR;
@@ -57,7 +58,7 @@ ER tsnd_mbf(
 
     case OBJECTS_LOCAL:
       /* XXX Submit needs to take into account blocking */
-      _CORE_message_queue_Submit(
+      msg_status = _CORE_message_queue_Submit(
         &the_message_buffer->message_queue,
         msg,
         msgsz,
@@ -69,7 +70,7 @@ ER tsnd_mbf(
       );
       _Thread_Enable_dispatch();
       return _ITRON_Message_buffer_Translate_core_message_buffer_return_code(
-          _Thread_Executing->Wait.return_code
+          msg_status
       );
     }
 
diff --git a/c/src/exec/posix/src/mqueuesendsupp.c b/c/src/exec/posix/src/mqueuesendsupp.c
index f456758c83..9615244583 100644
--- a/c/src/exec/posix/src/mqueuesendsupp.c
+++ b/c/src/exec/posix/src/mqueuesendsupp.c
@@ -44,6 +44,7 @@ int _POSIX_Message_queue_Send_support(
 {
   register POSIX_Message_queue_Control *the_mq;
   Objects_Locations                     location;
+  CORE_message_queue_Status             msg_status;
 
   /*
    * Validate the priority.
@@ -70,7 +71,7 @@ int _POSIX_Message_queue_Send_support(
         set_errno_and_return_minus_one( EBADF );
       }
 
-      _CORE_message_queue_Submit(
+      msg_status = _CORE_message_queue_Submit(
         &the_mq->Message_queue,
         (void *) msg_ptr,
         msg_len,
@@ -86,12 +87,12 @@ int _POSIX_Message_queue_Send_support(
       );
 
       _Thread_Enable_dispatch();
-      if ( !_Thread_Executing->Wait.return_code )
+      if ( !msg_status )
         return 0;
 
       set_errno_and_return_minus_one(
         _POSIX_Message_queue_Translate_core_message_queue_return_code(
-          _Thread_Executing->Wait.return_code
+          msg_status 
         )
       );
   }
diff --git a/c/src/exec/rtems/src/msgqsubmit.c b/c/src/exec/rtems/src/msgqsubmit.c
index 16f1c50266..5cca0ae5dd 100644
--- a/c/src/exec/rtems/src/msgqsubmit.c
+++ b/c/src/exec/rtems/src/msgqsubmit.c
@@ -61,6 +61,7 @@ rtems_status_code _Message_queue_Submit(
 {
   register Message_queue_Control  *the_message_queue;
   Objects_Locations                location;
+  CORE_message_queue_Status        msg_status;
 
   the_message_queue = _Message_queue_Get( id, &location );
   switch ( location )
@@ -97,7 +98,7 @@ rtems_status_code _Message_queue_Submit(
     case OBJECTS_LOCAL:
       switch ( submit_type ) {
         case MESSAGE_QUEUE_SEND_REQUEST:
-          _CORE_message_queue_Send(
+          msg_status = _CORE_message_queue_Send(
             &the_message_queue->message_queue,
             buffer,
             size,
@@ -112,7 +113,7 @@ rtems_status_code _Message_queue_Submit(
           );
           break;
         case MESSAGE_QUEUE_URGENT_REQUEST:
-          _CORE_message_queue_Urgent(
+          msg_status = _CORE_message_queue_Urgent(
             &the_message_queue->message_queue,
             buffer,
             size,
@@ -131,9 +132,8 @@ rtems_status_code _Message_queue_Submit(
       }
 
       _Thread_Enable_dispatch();
-      return _Message_queue_Translate_core_message_queue_return_code(
-        _Thread_Executing->Wait.return_code
-      );
+      return
+        _Message_queue_Translate_core_message_queue_return_code( msg_status );
           
   }
   return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */
diff --git a/c/src/exec/score/include/rtems/score/coremsg.h b/c/src/exec/score/include/rtems/score/coremsg.h
index 818b1e8c18..0036db0f81 100644
--- a/c/src/exec/score/include/rtems/score/coremsg.h
+++ b/c/src/exec/score/include/rtems/score/coremsg.h
@@ -239,7 +239,7 @@ CORE_message_queue_Status _CORE_message_queue_Broadcast(
  *
  */
  
-void _CORE_message_queue_Submit(
+CORE_message_queue_Status _CORE_message_queue_Submit(
   CORE_message_queue_Control                *the_message_queue,
   void                                      *buffer,
   unsigned32                                 size,
diff --git a/c/src/exec/score/inline/rtems/score/coremsg.inl b/c/src/exec/score/inline/rtems/score/coremsg.inl
index 7356ce9537..2f6fe5e877 100644
--- a/c/src/exec/score/inline/rtems/score/coremsg.inl
+++ b/c/src/exec/score/inline/rtems/score/coremsg.inl
@@ -27,7 +27,7 @@
  *  This routine sends a message to the end of the specified message queue.
  */
  
-RTEMS_INLINE_ROUTINE void _CORE_message_queue_Send(
+RTEMS_INLINE_ROUTINE CORE_message_queue_Status _CORE_message_queue_Send(
   CORE_message_queue_Control                *the_message_queue,
   void                                      *buffer,
   unsigned32                                 size,
@@ -37,7 +37,7 @@ RTEMS_INLINE_ROUTINE void _CORE_message_queue_Send(
   Watchdog_Interval                          timeout
 )
 {
-  _CORE_message_queue_Submit(
+  return _CORE_message_queue_Submit(
     the_message_queue,
     buffer,
     size,
@@ -62,7 +62,7 @@ RTEMS_INLINE_ROUTINE void _CORE_message_queue_Send(
  *  This routine sends a message to the front of the specified message queue.
  */
  
-RTEMS_INLINE_ROUTINE void _CORE_message_queue_Urgent(
+RTEMS_INLINE_ROUTINE CORE_message_queue_Status _CORE_message_queue_Urgent(
   CORE_message_queue_Control                *the_message_queue,
   void                                      *buffer,
   unsigned32                                 size,
@@ -72,7 +72,7 @@ RTEMS_INLINE_ROUTINE void _CORE_message_queue_Urgent(
   Watchdog_Interval                          timeout
 )
 {
-  _CORE_message_queue_Submit(
+  return _CORE_message_queue_Submit(
     the_message_queue,
     buffer,
     size,
diff --git a/c/src/exec/score/src/coremsgsubmit.c b/c/src/exec/score/src/coremsgsubmit.c
index 6829351c18..94398db4c0 100644
--- a/c/src/exec/score/src/coremsgsubmit.c
+++ b/c/src/exec/score/src/coremsgsubmit.c
@@ -53,7 +53,7 @@
  *    error code                    - if unsuccessful
  */
 
-void _CORE_message_queue_Submit(
+CORE_message_queue_Status _CORE_message_queue_Submit(
   CORE_message_queue_Control                *the_message_queue,
   void                                      *buffer,
   unsigned32                                 size,
@@ -67,14 +67,9 @@ void _CORE_message_queue_Submit(
   ISR_Level                            level;
   CORE_message_queue_Buffer_control   *the_message;
   Thread_Control                      *the_thread;
-  Thread_Control                      *executing;
-
-  _Thread_Executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
 
   if ( size > the_message_queue->maximum_message_size ) {
-    _Thread_Executing->Wait.return_code =
-       CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE;
-    return;
+    return CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE;
   }
 
   /*
@@ -96,7 +91,7 @@ void _CORE_message_queue_Submit(
       if ( !_Objects_Is_local_id( the_thread->Object.id ) )
         (*api_message_queue_mp_support) ( the_thread, id );
 #endif
-      return;
+      return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
     }
   }
 
@@ -114,10 +109,9 @@ void _CORE_message_queue_Submit(
     /*
      *  NOTE: If the system is consistent, this error should never occur.
      */
+
     if ( !the_message ) {
-      _Thread_Executing->Wait.return_code =
-          CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
-      return;
+      return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
     }
 
     _CORE_message_queue_Copy_buffer(
@@ -133,7 +127,7 @@ void _CORE_message_queue_Submit(
        the_message,
        submit_type
     );
-    return;
+    return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
   }
 
   /*
@@ -143,20 +137,39 @@ void _CORE_message_queue_Submit(
    */
 
   if ( !wait ) {
-    _Thread_Executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_TOO_MANY;
-    return;
+    return CORE_MESSAGE_QUEUE_STATUS_TOO_MANY;
+  }
+
+  /*
+   *  Do NOT block on a send if the caller is in an ISR.  It is
+   *  deadly to block in an ISR.
+   */
+
+  if ( _ISR_Is_in_progress() ) {
+    return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
   }
 
-  executing = _Thread_Executing;
+  /*
+   *  WARNING!! executing should NOT be used prior to this point.
+   *  Thus the unusual choice to open a new scope and declare 
+   *  it as a variable.  Doing this emphasizes how dangerous it
+   *  would be to use this variable prior to here.
+   */
+
+  { 
+    Thread_Control  *executing = _Thread_Executing;
+
+    _ISR_Disable( level );
+    _Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue );
+    executing->Wait.queue              = &the_message_queue->Wait_queue;
+    executing->Wait.id                 = id;
+    executing->Wait.return_argument    = (void *)buffer;
+    executing->Wait.return_argument_1  = (void *)size;
+    executing->Wait.count              = submit_type;
+    _ISR_Enable( level );
 
-  _ISR_Disable( level );
-  _Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue );
-  executing->Wait.queue              = &the_message_queue->Wait_queue;
-  executing->Wait.id                 = id;
-  executing->Wait.return_argument    = (void *)buffer;
-  executing->Wait.return_argument_1  = (void *)size;
-  executing->Wait.count              = submit_type;
-  _ISR_Enable( level );
+    _Thread_queue_Enqueue( &the_message_queue->Wait_queue, timeout );
+  }
 
-  _Thread_queue_Enqueue( &the_message_queue->Wait_queue, timeout );
+  return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
 }