Date: Sat, 02 Dec 1995 21:36:30 -0500 From: Robert Withrow <witr@rwwa.com> To: freebsd-hackers@FreeBSD.ORG Subject: Proper way to determine non-blocking status... Message-ID: <199512030236.VAA11976@spooky.rwwa.com>
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Even though it seems like it is almost never done by
existing driver code, would I be correct in assuming that
the *right* way to determine if a device read is allowed to
sleep or not is the following?
int xxread(dev_t dev, struct uio *uio, int ioflag)
{
if (ioflag & IO_NDELAY) {
/* Can't block here */
return EWOULDBLOCK;
} else { /* Otherwise try again */
/* Can sleep here */
...
}
}
-----------------------------------------------------------------------------
Robert Withrow, Tel: +1 617 598 4480, Fax: +1 617 598 4430 Net: witr@rwwa.COM
R.W. Withrow Associates, 319 Lynnway Suite 201, Lynn MA 01901 USA
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