Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretations for IEEE Std 1003.1™-2001 IEEE Standard for Information Technology - Portable Operating System Interface (POSIX®)

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Interpretation Request #34
Topic: SIGPOLL XSR option Relevant Sections: XBD signal.h

STREAMS support is optional and interfaces directly related to streams are shaded [XSR] throughout the standard. For example, stropts.h, isastream, getmsg, getpmsg, ioctl, putmsg, putpmsg, fattach, fdetach are all shaded [XSR]. SIGPOLL is defined in signal.h Aside from signal.h, SIGPOLL is only ever discussed in XSR related text. Since the SIGPOLL signal is only used by the above STREAMS interfaces, we think it should be shaded [XSR] in signal.h. Currently SIGPOLL is [XSI]. SIGPOLL references in signal.h should be shaded [XSR].

Interpretation Response
The standards states the requirements for SIGPOLL to be supported as part of the XSI option, and conforming implementations must conform to this. However, concerns have been raised about this which are being referred to the sponsor.

Rationale for Interpretation
The semantics of SIGPOLL are only specified with functionality in the XSR option.