From: Grant Edwards <grant.b.edwards@gmail.com>
To: ecos-discuss@ecos.sourceware.org
Subject: [ECOS] How to know if scheduler has started?
Date: Thu, 31 Oct 2013 16:25:00 -0000 [thread overview]
Message-ID: <l4u08n$cap$1@ger.gmane.org> (raw)
This question has come up many times in the past 10-12 years, but I've
never seen a real answer:
How do you tell if the scheduler has been started?
Specifically, how do you know when it's safe to attempt to lock a mutex?
Several people have suggested this snippet:
scheduler_running = cyg_thread_self() != cyg_thread_idle_thread();
That seems to work when called from cyg_user_start() and from normal
threads, but it doesn't work when called from initialization code in
a device driver.
So, I'll ask again:
how does one write code that knows to lock/unlock a mutex when called
from a normal user thread but not attempt the lock/unlock whcn called
from initialization code in cyg_user_start() or a device driver?
The function does not get called from ISR/DSR contexts: it is only
called during initialization (before the scheduler is started) and
from normal user threads.
OTOH, are you are allowed to lock/unlock mutexes from initialization
code? Maybe I'm misremembering, but I thought that was forbidden?
--
Grant Edwards grant.b.edwards Yow! I was born in a
at Hostess Cupcake factory
gmail.com before the sexual
revolution!
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
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next reply other threads:[~2013-10-31 16:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-31 16:25 Grant Edwards [this message]
2013-11-01 17:04 ` Nick Garnett
2013-11-02 16:26 ` [ECOS] " Grant Edwards
-- strict thread matches above, loose matches on Subject: below --
2003-09-17 14:49 [ECOS] " Grant Edwards
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