Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!ames!apple!longway!std-unix
From: gwyn@brl.arpa (Doug Gwyn)
Newsgroups: comp.std.unix
Subject: Re: Another file handles question/comment
Message-ID: <379@longway.TIC.COM>
Date: 28 Aug 89 05:02:45 GMT
References: <378@longway.TIC.COM>
Sender: std-unix@longway.TIC.COM
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
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Approved: jsq@longway.tic.com (Moderator, John S. Quarterman)

From: gwyn@brl.arpa (Doug Gwyn)

In article <378@longway.TIC.COM> barry@PRC.Unisys.COM (Barry Traylor) writes:
>Within my development group there has been some debate about the file handle
>issue.  I believed the onus was on the implementation, but was convinced by
>associates, more imbued with the Unix tradition than myself, that that
>was not the case, that the onus was on the application.

Your associates are correct (as I interpret IEE Std 1003.1-1988).
The stuff about file handles is intended to allow the implementation
to NOT have to synchronize file descriptors with stdio streams and
vice-versa.  It is up to the application to take steps to assure
such synchronization when switching back and forth between multiple
handles on the same underlying open file description.

The intention is NOT to force extensive use of semaphores in the
library, quite the opposite.

Volume-Number: Volume 17, Number 10