From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Larmour To: Rafael Rodríguez Velilla Cc: ecos Subject: Re: [ECOS] About Cyg_Scheduler::unlock_inner Date: Tue, 22 May 2001 13:50:00 -0000 Message-id: <3B0AD0F4.E14617C3@redhat.com> References: <3B0ABE79.A4CA4B8B@tid.es> X-SW-Source: 2001-05/msg00368.html Rafael Rodríguez Velilla wrote: > > I'm working with eCos 1.3.1 and I have a question about > Cyg_Scheduler::unlock_inner. > > This method is only called when calling Cyg_Scheduler::unlock with > sched_lock=1; (so it should become 0) > I have seen in the code that it first calls any pending DSR (if there > is any) and then it checks if there's a new thread that reclaims the > CPU. > Why is the context of the new thread restored before decrementing > sched_lock? You can't be in the process of switching the context when there's a chance the system could be rescheduled again (e.g. due to a new interrupt). > Why is not the new thread run with the scheduler unlocked? Once it is restored, it unlocks the scheduler almost straight away. Jifl -- Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062 Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine