PxMsgGetProtection()

Get protection mode of a message.

APPLIES TO

1.0.0

SYNOPSIS
PxAccessPerm_t PxMsgGetProtection (PxMsg_t msgid);
ARGUMENTS






msgid




Message object for which the protection mode is requested

















RETURN VALUES






    

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    Protection mode (NoAccessProtection, ReadProtection, WriteProtection, WRProtection)
    

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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










PxMsgGetProtection returns the protection mode for the data area of a given message object msgid. The following values are possible:














    

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    NoAccessProtection the caller has no access to the messages data area
    

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  • 

    ReadProtection the caller has read only access to the messages data area
    

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  • 

    WriteProtection the caller has write only access to the messages data area
    

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  • 

    WRProtection the caller has read and write access to the messages data area
    

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IMPLEMENTATION GUIDELINES
















Before call






    

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    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:
    

    

      

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      PxMsgIdIsValid() must be true.
      

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      PxMsgIdGet() must not be _PXIllegalObjId.
      

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

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After call






    

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    PxMsgGetProtection returns a value of type PxProtectType_t, which may have one of the following values (V):
    

    

      

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      NoAccessProtection neither read nor write access
      

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      ReadProtection read access
      

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      WriteProtection write access
      

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      WRProtection read and write access
      

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Best Practice






    

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    No restrictions.
    

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SEE ALSO











USAGE








#include "pxdef.h"

PxProtectType_t protType = PxMsgGetProtection(msgid);
switch (protType)
{
case NoAccessProtection:
	// Task has no permission to access message data
	break;
case ReadProtection:
	// Task has read-only permission to access message data
	break;
case WriteProtection:
	// Task has write-only permission to access message data
	break;
case WRProtection:
	// Task has read and write permission to access message data
	break;
}