Date: Thu, 19 Mar 2009 11:23:44 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-current@freebsd.org, barney_cordoba@yahoo.com Cc: Julian Elischer <julian@elischer.org>, current@freebsd.org Subject: Re: Is there a delay which yields? Message-ID: <200903191123.45006.jhb@freebsd.org> In-Reply-To: <808304.73330.qm@web63904.mail.re1.yahoo.com> References: <808304.73330.qm@web63904.mail.re1.yahoo.com>
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On Sunday 15 March 2009 2:43:18 pm Barney Cordoba wrote: > > --- On Sun, 3/15/09, Julian Elischer <julian@elischer.org> wrote: > > > From: Julian Elischer <julian@elischer.org> > > Subject: Re: Is there a delay which yields? > > To: barney_cordoba@yahoo.com > > Cc: current@freebsd.org > > Date: Sunday, March 15, 2009, 1:16 PM > > Barney Cordoba wrote: > > > I'd expect DELAY to yield till timeout but a task > > with a delay loop just > > > runs to 100% usage. Is there a function which can > > yield exectution for > > > a set amount of time (without having to use a timer)? > > > > DELAY is designe for use early in the boot when thre are no > > timers. > > it is only occasionally used for cases during normal > > operation. > > > > how would a thread know how long it has been away if no > > timer is used? > > > I guess I mean a sleep. > > Also, this is a kernel driver. I have a device > which requires a toggle with a 10ms delay between pulses. I hate to > tie up the cpu for 10ms with a delay. Sort of like the following: > > write_pulse(); > delay(10000); > write_pulse(); Use pause(9). -- John Baldwin
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