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From: williams@sp14.csrd.uiuc.edu (Peter Lawrence Williams)
Newsgroups: comp.sys.sgi
Subject: locks
Summary: locks
Keywords: locks
Message-ID: <1990Oct9.151517.18350@csrd.uiuc.edu>
Date: 9 Oct 90 15:15:17 GMT
Sender: news@csrd.uiuc.edu (news)
Distribution: comp.sys.sgi
Organization: UIUC Center for Supercomputing Research and Development
Lines: 18


I need a lot of locks for a program I'm developing, and plan on using
multiplexed locks.  The following are some questions which I couldn`t 
find answers to in the man pages or ulock.h.

I'd like to know how to determine whether a particular SGI machine has
soft or hard locks.  Also how much memory in the shared area is required 
per soft lock.  u_locks.h say there can be a maximum of 4096 hard locks
per share group, so I'm going to create exactly 4096 locks and assume
that my code should then be portable across machines regardless of whether
they have soft or hard lock capability.  I am assuming that 4096 soft locks 
will fit in the default 64K shared area.

Any pointers to example code using u_locks.h?

Thank you,
Peter Williams
williams@csrd.uiuc.edu