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From: Joshua Stewart <joshua.stewart@comcast.net>
To: linux-kernel@vger.kernel.org
Subject: A little explanation needed
Date: Sun, 22 Dec 2002 00:36:32 -0500	[thread overview]
Message-ID: <1040535392.1518.3.camel@localhost.localdomain> (raw)


Can anyone explain the purpose of this #define...

#define __cpu_raise_softirq(cpu, nr) do { softirq_pending(cpu) |= 1UL <<
(nr); } while (0)    // from interrupt.h

...versus the more "plain"...


#define __cpu_raise_softirq(cpu,nr) softirq_pending(cpu |= 1UL << (nr).

In otherwords, what's the use of a do{X}while(0) "loop" instead of just
X.  I'm not the world's best trained C programmer, so forgive me if I
sound stupid.

Josh



             reply	other threads:[~2002-12-22  5:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-12-22  5:36 Joshua Stewart [this message]
2002-12-22  5:35 ` A little explanation needed Greg KH
2002-12-22 21:07   ` Joshua Stewart
2002-12-22 20:12 ` DervishD

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