diff options
| author | Peter Harris <pharris@opentext.com> | 2012-08-16 11:59:14 -0400 |
|---|---|---|
| committer | Peter Harris <pharris@opentext.com> | 2012-09-18 11:42:23 -0400 |
| commit | 08cc068ead7b8e678cdb119b38ada5261d5cc3ea (patch) | |
| tree | 10884817653262c3c3af3273e0f8b4f3b749bebe | |
| parent | ff53285ae3f604e9f2cc5f4837255220459b5e44 (diff) | |
Allow xcb_send_request with >MAX_IOV iovecs
This allows an application to do a scatter/gather operation on a large
image buffer to avoid the extra memcpy.
Use autoconf to use UIO_MAXIOV where IOV_MAX is not available (and the
POSIX minimum of 16 where neither are available).
Reviewed-by: Uli Schlachter <psychon@znc.in>
Signed-off-by: Peter Harris <pharris@opentext.com>
| -rw-r--r-- | configure.ac | 7 | ||||
| -rw-r--r-- | src/xcb_conn.c | 7 |
2 files changed, 13 insertions, 1 deletions
diff --git a/configure.ac b/configure.ac index d6b9531..3f44b53 100644 --- a/configure.ac +++ b/configure.ac @@ -117,6 +117,13 @@ dnl check for support for Solaris Trusted Extensions AC_CHECK_HEADERS([tsol/label.h]) AC_CHECK_FUNCS([is_system_labeled]) +dnl check for IOV_MAX, and fall back to UIO_MAXIOV on BSDish systems +AC_CHECK_DECL([IOV_MAX], [], + [AC_CHECK_DECL([UIO_MAXIOV], [AC_DEFINE([IOV_MAX], [UIO_MAXIOV])], + [AC_DEFINE([IOV_MAX], [16], [Define if not provided by <limits.h>])], + [[#include <sys/uio.h>]])], + [[#include <limits.h>]]) + xcbincludedir='${includedir}/xcb' AC_SUBST(xcbincludedir) diff --git a/src/xcb_conn.c b/src/xcb_conn.c index 7979491..e01d566 100644 --- a/src/xcb_conn.c +++ b/src/xcb_conn.c @@ -36,6 +36,7 @@ #include <stdlib.h> #include <fcntl.h> #include <errno.h> +#include <limits.h> #include "xcb.h" #include "xcbint.h" @@ -209,7 +210,11 @@ static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count) i++; } #else - n = writev(c->fd, *vector, *count); + n = *count; + if (n > IOV_MAX) + n = IOV_MAX; + + n = writev(c->fd, *vector, n); if(n < 0 && errno == EAGAIN) return 1; #endif /* _WIN32 */ |