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From: mickey@axis.fr (Michael Dance)
Newsgroups: comp.sys.ibm.pc
Subject: Re: OS/2 programmer's model
Message-ID: <299@axis.fr>
Date: Sat, 12-Sep-87 14:42:50 EDT
Article-I.D.: axis.299
Posted: Sat Sep 12 14:42:50 1987
Date-Received: Tue, 15-Sep-87 01:47:38 EDT
References: <371@micropen>
Organization: Sharc Informatique
Lines: 26
Keywords: OS/2 UNIX-like MSDOS
Summary: OS/2 vs UNIX: msg queues


It has been said that OS/2 message queues are the same (functionally)
as UNIX message queues but (according to Byte) OS/2 queues are
only readable by the process that created them (or perhaps the user
who created them - maybe someone can clarify this) which is
not the same as UNIX that allows message queues to be read and written
by many processes and many users (the UNIX queues have read and write
bits set at creation time in the same way as files). Arbitration
between such prcesses can be random (first come first serve) or
by the use of message types.

For example UNIX message queues can be used as bidirectional 'pipes'
by the processes at both ends of the 'pipe' by judicious use of
message types, this is not possible with OS/2 (as described by Byte)

This is not an terrible problem in the sense it can be worked around
but if it exists in UNIX people will use it (I already have)
so moving UNIX code to OS/2 may not be very simple - especially as
UNIX has virtually no multi-process debugging tools, whether OS/2
will have such tools is yet to be seen (they are difficult to conceive
in a non-deterministic system let alone implement).

PS /2 is an IBM trademark
   3/2 is an arithmetic expression yielding 1 in integer arithmetic
   surely used by someone in a programming book as such an example
   Can IBM copyright something already published?