DDS-XTypes 1.4b1 RTF Avatar
  1. OMG Issue

DDSXTY14 — Ambiguous definition and/or usage of PUSH(ORIGIN=0)

  • Key: DDSXTY14-73
  • Status: open  
  • Source: Real-Time Innovations ( Dr. Gerardo Pardo-Castellote, Ph.D.)
  • Summary:

    Note: This issue was filed by Sam Nosenzo in RTF 3. As the RTF 3 is already close it has been copied to RTF4

    The description of PUSH states:
    Pushes the specified XCDR stream variable VARIABLE
    into the stack and sets the current value to <newvalue>.
    The notation <?> indicates that the new value can be
    chosen by the implementation.
    This action is reverted by the POP() operation
    However the first serialization rule that writes the HEADER calls

    `PUSH(ORIGIN=0)` after writing the ENCHEADER, even though it's already been set to 0 on initialization. PUSH(ORIGIN=0) is also called after writing PL_CDR headers. I'm confused as to what this is supposed to mean. Based off of the current definition of PUSH I would be lead to believe that it truly does set the origin equal to 0. However looking at it's usage I would think that PUSH(ORIGIN=0) should mean that the origin is reset to where the current offset is, and based of of what I've seen in PL_CDRv1 messages with 8 byte members, this has been a correct assumption.
    Another confusing element around the usage of PUSH is that I don't see POP used anywhere in the Serialization rules.

  • Reported: DDS-XTypes 1.3b1 — Thu, 21 Mar 2024 03:48 GMT
  • Updated: Thu, 21 Mar 2024 03:49 GMT