Date: Sun, 23 Nov 2008 00:20:51 +0000 (UTC) From: Kip Macy <kmacy@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r185193 - head/sys/sys Message-ID: <200811230020.mAN0KpYQ033357@svn.freebsd.org>
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Author: kmacy Date: Sun Nov 23 00:20:51 2008 New Revision: 185193 URL: http://svn.freebsd.org/changeset/base/185193 Log: buf_ring_peek should return NULL if the ring is empty rather than whatever happened to be at cons_tail last time it was in use Modified: head/sys/sys/buf_ring.h Modified: head/sys/sys/buf_ring.h ============================================================================== --- head/sys/sys/buf_ring.h Sun Nov 23 00:16:10 2008 (r185192) +++ head/sys/sys/buf_ring.h Sun Nov 23 00:20:51 2008 (r185193) @@ -216,7 +216,10 @@ buf_ring_peek(struct buf_ring *br) panic("lock not held on single consumer dequeue"); #endif mb(); - return (br->br_ring[br->br_cons_tail]); + if (br->br_cons_head == br->br_prod_tail) + return (NULL); + + return (br->br_ring[br->br_cons_head]); } static __inline int
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