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From: vijay@nixdorf2.osf.org (Vijay Kumar)
Newsgroups: comp.os.mach
Subject: Synchronization in MACH
Keywords: MACH
Message-ID: <19061@paperboy.OSF.ORG>
Date: 18 Feb 91 17:01:45 GMT
Sender: news@OSF.ORG
Reply-To: vijay@nixdorf2.osf.org (Vijay Kumar)
Organization: OSF
Lines: 19

Hi,

Recently I was reading an article about MACH and I noticed that MACH
doesn't provide
an synchronization mechanism between threads like semaphores on System
V. The only
synchronization mechanism provided is via MACH IPC and threads have to
implement
their own ways of synchronization perhaps using thread scheduling
facilities like:
thread_suspend(), thread_wait() and thread_resume(). Does someone know
exactly why
semaphores are not supported in MACH? There's some good reason, I hope. 

For designing databases which heavily depend on synchronization
mechanisms provided
by the underlying os, it would be really helpful.

Vijay