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changeset 4434:80df7b82d3c9 stable-1.0

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Merge r4336: Microoptimization of sendfile(2) usage under FreeBSD. FreeBSD kernel checks headers/trailers pointer against NULL, not corresponding count. Passing NULL if there are no headers/trailers helps to avoid unneeded work in kernel, as well as unexpected 0 bytes GIO in traces.
author Maxim Dounin <mdounin@mdounin.ru>
date Sun, 05 Feb 2012 12:42:36 +0000
parents dfb04ceb266f
children 3b9be99122b6
files src/os/unix/ngx_freebsd_sendfile_chain.c
diffstat 1 files changed, 7 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -246,9 +246,14 @@ ngx_freebsd_sendfile_chain(ngx_connectio
                 }
             }
 
-            hdtr.headers = (struct iovec *) header.elts;
+            /*
+             * sendfile() does unneeded work if sf_hdtr's count is 0,
+             * but corresponding pointer is not NULL
+             */
+
+            hdtr.headers = header.nelts ? (struct iovec *) header.elts: NULL;
             hdtr.hdr_cnt = header.nelts;
-            hdtr.trailers = (struct iovec *) trailer.elts;
+            hdtr.trailers = trailer.nelts ? (struct iovec *) trailer.elts: NULL;
             hdtr.trl_cnt = trailer.nelts;
 
             /*