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Last update: 30 March,1998

								1003.1c-95  #38

 _____________________________________________________________________________

	Interpretation Number:	XXXX
	Topic:               mutex
	Relevant Sections:   2.2.2.68

Interpretation Request: (Defect Report)
-----------------------

	From: Andrew Josey (on behalf of the X/Open Base working group)

Part 1. Interpretation Request for:
   IEEE Std 1003.1c-1995 as contained in:
   ISO/IEC 9945-1:1996(E), ANSI/IEEE Std. 1003.1, 1996 Edition.
   Subsection 2.2.2.68, Page 20, Line 308.

Question:
Why does a mutex only allow multiple threads to serialize their access to
"shared data"? A mutex may be used to provide mutual exclusion among threads
trying to access any sort of shared resource. For example, several threads
may occasionally need to utilize a single hardware co-processor, and may
serialize access to that resource with a mutex even though it isn't "shared
data".

Suggested Correction:
Change the phrase "shared data" to "shared resources".

Interpretation response
------------------------
The part of the definition cited is informative in scope and does not
require any restrictions on conforming applications.  The proposed
change may add some additional clarity and will be referred to the
sponsor for consideration.  


Rationale
-------------
The wording of the particular sentence is neither binding upon the
application, nor is it constrained by the interface, and it is not
testable by a conformance test.  Changing 'data' to 'resources' may help
someone inexperienced in this area but does not seem to make a
significant improvement in the standard. 

Forwarded to Interpretations group: Dec 9 1996
Proposed resolution: Jan 29 1997
Finalised: Feb 20 1997