Defect in XBD stdio.h

[don.cragun@xxxxxxx]

        Defect report from : Donald W. Cragun , Sun Microsystems, Inc.

(Please direct followup comments direct to austin-group-l@xxxxxx)

@ page 3251 line 11569-11570 section stdio.h objection {FOPEN_MAX}

Problem:

Edition of Specification (Year): 2004

Defect code :  3. Clarification required

{FOPEN_MAX} is a macro inherited from the C Standard used to
indicate the number of STDIO streams that can be open simultaneously.
It is stated to a number that the implementation guarantees can be
open.  But, since the C standard only knows about streams and
doesn't have any concept of underlying file descriptors;
implementations can't guarantee that applications won't use open()
to consume all file descriptors available to the process and,
therefore, can't guarantee that any particular number of STDIO
streams can be simultaneously open if all file descriptors are
otherwise in use.

The relationship between FOPEN_MAX and OPEN_MAX needs to be
clearly stated at least in rationale.

Action:

Change "None." in the APPLICATION USAGE section on P327, L11661 to:

    "Since STDIO streams use an underlying file descriptor to
     access the file associated with a stream, application
     writers need to be aware that {FOPEN_MAX} streams may
     not be available if file descriptors are being used to
     access files that are not associated with streams."