diff options
| author | Peter Harris <git@peter.is-a-geek.org> | 2012-08-12 13:28:36 -0400 |
|---|---|---|
| committer | Peter Harris <pharris@opentext.com> | 2012-08-15 18:24:13 -0400 |
| commit | c22b5b2ae67b77f58821d4fe2fdf24f0825d2401 (patch) | |
| tree | 60966a6856487978d4b7431765eb2817c8d47e14 | |
| parent | 5f8f2ba1c4f9ac74c8f301dcca8566e296e37995 (diff) | |
This allows an application to do a scatter/gather operation on a large
image buffer to avoid the extra memcpy.
MacOSX 10.6 mentions UIO_MAXIOV in the man page for writev, but does not
define it in any system header. Use autoconf to test for MAX_IOV from
<limits.h> in that case.
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 e94e32c..4e9eab2 100644 --- a/configure.ac +++ b/configure.ac @@ -110,6 +110,13 @@ dnl check for support for Solaris Trusted Extensions AC_CHECK_HEADERS([tsol/label.h]) AC_CHECK_FUNCS([is_system_labeled]) +dnl check for UIO_MAXIOV, or at least IOV_MAX +AC_CHECK_DECL([UIO_MAXIOV], [], + [AC_CHECK_DECL([IOV_MAX], [AC_DEFINE([UIO_MAXIOV], [IOV_MAX])], + [AC_DEFINE([UIO_MAXIOV], [16], [Define if not provided by <sys/uio.h>])], + [[#include <limits.h>]])], + [[#include <sys/uio.h>]]) + xcbincludedir='${includedir}/xcb' AC_SUBST(xcbincludedir) diff --git a/src/xcb_conn.c b/src/xcb_conn.c index 725502a..9abd640 100644 --- a/src/xcb_conn.c +++ b/src/xcb_conn.c @@ -32,6 +32,7 @@ #include <stdlib.h> #include <fcntl.h> #include <errno.h> +#include <limits.h> #include "xcb.h" #include "xcbint.h" @@ -204,7 +205,11 @@ 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 > UIO_MAXIOV) + n = UIO_MAXIOV; + + n = writev(c->fd, *vector, n); if(n < 0 && errno == EAGAIN) return 1; #endif /* _WIN32 */ |