Date: Sun, 23 Dec 2007 17:55:39 GMT From: Robert Watson <rwatson@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 131480 for review Message-ID: <200712231755.lBNHtdMp058811@repoman.freebsd.org>
next in thread | raw e-mail | index | archive | help
http://perforce.freebsd.org/chv.cgi?CH=131480 Change 131480 by rwatson@rwatson_cinnamon on 2007/12/23 17:55:33 Add a comment before BPF buffers are either read or zero-copy rotated to explain what's going on. Affected files ... .. //depot/projects/zcopybpf/src/contrib/libpcap/pcap-bpf.c#12 edit Differences ... ==== //depot/projects/zcopybpf/src/contrib/libpcap/pcap-bpf.c#12 (text+ko) ==== @@ -284,6 +284,14 @@ } cc = p->cc; if (p->cc == 0) { + /* + * When reading without zero-copy from a file descriptor, we + * use a single buffer and return a length of data in the + * buffer. With zero-copy, we update the p->buffer pointer + * to point at whatever underlying buffer contains the next + * data and update cc to reflect the data found in the + * buffer. + */ #ifdef BIOCSETBUFMODE if (p->zerocopy) { if (p->buffer != NULL)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200712231755.lBNHtdMp058811>