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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Tasking Techniques - Opinions?
Date: 1997/06/07
Message-ID: <dewar.865692193@merv>#1/1
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Organization: New York University
Newsgroups: comp.lang.ada
Date: 1997-06-07T00:00:00+00:00
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Jon says

<<> Absolutely true.  However, do be aware that protected types have
> significant overhead -- not as much as task rendezvous, but on the
> order of ten times a procedure call.
 
I find this surprising. On what do you base this 10X figure?
>>

surprisingly low? or suprisingly high? The difference will vary widely. If
taking the necessary lock requires a kernel call, as it does when running
over some OS's, then the factor of 10 will be wildly optimistic. Protected
types were designed to be efficient on bare hardware, their implementation
over operating stystems is often disappointingly inefficient.