From: Nick Garnett <nickg@ecoscentric.com>
To: "wyb" <wyb@topsec.com.cn>
Cc: <ecos-discuss@sources.redhat.com>
Subject: Re: [ECOS] exit() and lock()
Date: Fri, 23 Apr 2004 14:13:00 -0000 [thread overview]
Message-ID: <m3pt9yg8lp.fsf@miso.calivar.com> (raw)
In-Reply-To: <019f01c4292c$5bb5d6c0$1a0fa8c0@codingman>
"wyb" <wyb@topsec.com.cn> writes:
> I'm reading the ECOS source code, and confused by Cyg_Thread::exit()
> calling lock() on entry, but not calling unlock() before return
> (Althrough it never return)
>
> Can anybody help me? thanks
The last thing it does is call Cyg_Scheduler::reschedule(). This
causes the current thread to lose control of the CPU without
decrementing the scheduler lock.
The scheduler lock is effectively a per-thread value, so when the
context switches to another thread, the lock will be set to that
thread's lock value. It simply doesn't matter that the exited thread
has a non-zero lock value, it will never be rescheduled.
--
Nick Garnett eCos Kernel Architect
http://www.ecoscentric.com The eCos and RedBoot experts
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
prev parent reply other threads:[~2004-04-23 12:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-23 13:17 wyb
2004-04-23 14:13 ` Nick Garnett [this message]
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