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authorAlan Coopersmith <alan.coopersmith@oracle.com>2010-10-03 18:47:07 (GMT)
committer Alan Coopersmith <alan.coopersmith@oracle.com>2010-10-04 15:14:48 (GMT)
commit072fc46b2af370e78fa53426626ca3c33b74bdf2 (patch) (side-by-side diff)
tree575a85d3e1451e604f81c3292102356b37019c3e
parent30bc4b0ada659809c64f6a8292cbde3166267e8d (diff)
downloadxdpyinfo-072fc46b2af370e78fa53426626ca3c33b74bdf2.zip
xdpyinfo-072fc46b2af370e78fa53426626ca3c33b74bdf2.tar.gz
Use xcb for -queryExt instead of a round-trip per extension
On a system with 30 extensions listed by xdpyinfo, truss -c reports this saves quite a few system calls by batching the QueryExtension requests instead of a round-trip for each one: Xlib xcb writev 40 11 poll 80 22 recv 117 29 total (*) 464 296 (*) total includes all system calls, including many not shown since their count did not change significantly. There was one additional set of open/mmap/close etc. for loading the added libX11-xcb library. Over a tcp connection, this reduced both the number of packets, and due to tcp packet header overhead, the overall amount of data: Xlib xcb TCP packets 93 35 TCP bytes 11554 7726 Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> Reviewed-by: Jamey Sharp <jamey@minilop.net>
Diffstat (more/less context) (ignore whitespace changes)
-rw-r--r--configure.ac2
-rw-r--r--xdpyinfo.c56
2 files changed, 45 insertions, 13 deletions
diff --git a/configure.ac b/configure.ac
index 48ae434..47a1246 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,7 +36,7 @@ XORG_DEFAULT_OPTIONS
AM_CONFIG_HEADER(config.h)
# Checks for pkg-config packages
-PKG_CHECK_MODULES(XDPYINFO, xext x11 xtst)
+PKG_CHECK_MODULES(XDPYINFO, xext x11 xtst x11-xcb xcb)
# This is used below to allow <X11/Xlib.h> to be found
PKG_CHECK_MODULES(DPY_X11, x11)
diff --git a/xdpyinfo.c b/xdpyinfo.c
index db4a438..017738f 100644
--- a/xdpyinfo.c
+++ b/xdpyinfo.c
@@ -82,6 +82,7 @@ in this Software without prior written authorization from The Open Group.
#endif
+#include <X11/Xlib-xcb.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#ifdef MULTIBUFFER
@@ -170,22 +171,53 @@ print_extension_info(Display *dpy)
printf ("number of extensions: %d\n", n);
if (extlist) {
- register int i;
- int opcode, event, error;
+ int i;
qsort(extlist, n, sizeof(char *), StrCmp);
- for (i = 0; i < n; i++) {
- if (!queryExtensions) {
+
+ if (!queryExtensions) {
+ for (i = 0; i < n; i++) {
printf (" %s\n", extlist[i]);
- continue;
}
- XQueryExtension(dpy, extlist[i], &opcode, &event, &error);
- printf (" %s (opcode: %d", extlist[i], opcode);
- if (event)
- printf (", base event: %d", event);
- if (error)
- printf (", base error: %d", error);
- printf(")\n");
+ } else {
+ xcb_connection_t *xcb_conn = XGetXCBConnection (dpy);
+ xcb_query_extension_cookie_t *qe_cookies;
+
+ qe_cookies = calloc(n, sizeof(xcb_query_extension_cookie_t));
+ if (!qe_cookies) {
+ perror ("calloc failed to allocate memory for extensions");
+ return;
+ }
+
+ /*
+ * Generate all extension queries at once, so they can be
+ * sent to the xserver in a single batch
+ */
+ for (i = 0; i < n; i++) {
+ qe_cookies[i] = xcb_query_extension (xcb_conn,
+ strlen(extlist[i]),
+ extlist[i]);
+ }
+
+ /*
+ * Start processing replies as they come in.
+ * The first call will flush the queue to the server, then
+ * each one will wait, if needed, for its reply.
+ */
+ for (i = 0; i < n; i++) {
+ xcb_query_extension_reply_t *rep
+ = xcb_query_extension_reply(xcb_conn, qe_cookies[i], NULL);
+
+ printf (" %s (opcode: %d", extlist[i], rep->major_opcode);
+ if (rep->first_event)
+ printf (", base event: %d", rep->first_event);
+ if (rep->first_error)
+ printf (", base error: %d", rep->first_error);
+ printf (")\n");
+
+ free (rep);
+ }
+ free (qe_cookies);
}
/* do not free, Xlib can depend on contents being unaltered */
/* XFreeExtensionList (extlist); */