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Re: [ecos] synchronization level of cyg_drv_cond_broadcast
- To: Schmidt Henning Larsen <HenningLS at danfoss dot com>
- Subject: Re: [ECOS] [ecos] synchronization level of cyg_drv_cond_broadcast
- From: Jonathan Larmour <jlarmour at redhat dot com>
- Date: Tue, 30 Oct 2001 14:20:42 +0000
- Cc: "Ecos-Discuss (E-mail)" <ecos-discuss at sources dot redhat dot com>
- Organization: Red Hat UK Ltd.
- References: <829F632D2F25D411B6920008C716F831025B80ED@dd01-e01.drives.danfoss.dk>
Schmidt Henning Larsen wrote:
>
> > >
> > > Hi
> > >
> > > Why is the syncronization level of cyg_drv_cond_broadcast: DSR.
> > > I meen it's a nonblocking call !?
> >
> > You mean you expect to use it in an ISR too? The answer is no
> > as it might
> > corrupt kernel structures that are only protected by a DSR
> > lock, not by
> > disabling interrupts. This is entirely intentional.
>
> Ok thanks.
> How about cyg_semaphore_post() can I use that in a ISR.
No, you can't use anything like that in an ISR. Either use a DSR, or manage
some shared state yourself and disable interrupts around the accesses to
it. DSRs are meant to be the mechanism to synchronise between threads and
interrupts.
Jifl
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