PxMsgGetSender()

Return the sender TaskId of the message.

APPLIES TO

8.2.0

SYNOPSIS
PxTask_t PxMsgGetSender (PxMsg_t msgid);
ARGUMENTS






msgid




The message object

















RETURN VALUES






    

  • 

    Message sender
    

    • 







ERROR CODES















PXERR_MSG_ILLMSG




msgid is not a valid object id








PXERR_MSG_ILLUSER




The calling task is not user of this message









DESCRIPTION










PxMsgGetSender returns the message’s sender. If the message has been sent by a handler the previous user of the message is returned.






















IMPLEMENTATION GUIDELINES
















Before call






    

  • 

    msgid must be a valid message object, requested via PxMsgRequest…​ or PxMsgEnvelop…​ or received by a PxMsgReceive…​ call (V). This id may be checked with one of the following macros:
    

    

      

    • 

      PxMsgIdIsValid() must be true.
      

      • 

    • 

      PxMsgIdGet() must not be _PXIllegalObjId.
      

      • 

    • 

      PxMsgIdError() must be PXERR_NOERROR otherwise the returned error code has to be interpreted (C).
      

      • 

    

    

    • 



















After call






    

  • 

    The returned value is the task object id of type PxTask_t. This id may be checked with one of the following macros:
    

    

      

    • 

      PxTaskIdIsValid() must be true.
      

      • 

    • 

      PxTaskIdGet() must not be _PXIllegalObjId.
      

      • 

    • 

      PxTaskIdError() must be PXERR_NOERROR otherwise the returned error code has to be interpreted (C).
      

      • 

    

    

    • 

  • 

    Additionally the task object may be checked with PxTaskCheck() (F).
    

    • 



















Best Practice






    

  • 

    No restrictions.
    

    • 






























SEE ALSO











USAGE








#include "pxdef.h"

PxTask_t msgOwner = PxMsgGetSender(msgid);

if (msgOwner.error == PXERR_NOERROR)
{
	if (msgOwner.id != _PXIllegalObjId)
	{
		// The msgOwner contains the task ID of the sender
	}
	else
	{
		// Cannot get the message sender because
		// the calling task is not the message user
	}
}
else
{
	// The message handle is invalid (msgOwner.error == PXERR_MSG_ILLMSG)
}