PxMsgSetProtection()

Set protection mode of a message.

APPLIES TO

8.2.0

SYNOPSIS
PxError_t PxMsgSetProtection (PxMsg_t msgid, PxProtectType_t protection);
ARGUMENTS






msgid




Message object for which the protection mode is changed


















protection




New protection mode for the message data

















RETURN VALUES






    

  • 

    PXROS error code
    

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ERROR CODES















PXERR_MSG_ILLMSG




The passed message handle is invalid








PXERR_MSG_ILLUSER




The calling task is not the user of the message








PXERR_PROT_PERMISSION




The calling task has no permission to change the protection








PXERR_MSG_ILLOWNER




The calling task is not the owner of the message








PXERR_PROT_ILL_HANDLE




Invalid pair number is given








PXERR_REQUEST_INVALID_PARAMETER




Request with invalid parameter









DESCRIPTION










PxMsgSetProtection sets the protection mode for the data area of a given message object msgid. The task has to be the owner (creator) of the message msgid! The following values are possible:














    

  • 

    NoAccessProtection, the caller has no access to the messages data area
    

    • 

  • 

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

    • 

  • 

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

    • 

  • 

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

    • 















The protection mode can only be changed if the caller has the appropriate permission. For example, the caller cannot set WriteProtection if it has no write access to the data area.






















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:
    

    

      

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      PxMsgIdIsValid() must be true.
      

      • 

    • 

      PxMsgIdGet() must not be _PXIllegalObjId.
      

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    • 

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

      • 

    

    

    • 

  • 

    protection must be of type PxProtectType_t and may have one of the following values (V):
    

    

      

    • 

      NoAccessProtection neither read nor write access
      

      • 

    • 

      ReadProtection read access
      

      • 

    • 

      WriteProtection write access
      

      • 

    • 

      WRProtection read and write access
      

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    • 



















After call






    

  • 

    The function returns PXERR_NOERROR if the message’s protection mode is changed. Any other return value describes an error, which has to be interpreted (C).
    

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Best Practice






    

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    No restrictions.
    

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SEE ALSO











USAGE








#include "pxdef.h"

PxError_t Err = PxMsgSetProtection(msgid, ReadPermission);

if (Err != PXERR_NOERROR) {
    // Report error
}