Avoid calling XGetAtomName in a loop when fetching monitor attributes

* src/xfns.c (x_get_monitor_attributes_xrandr): Avoid syncing on
each monitor when waiting for XGetAtomName when built with XCB.

1 files changed, 38 insertions, 0 deletions

diff --git a/src/xfns.c b/src/xfns.c
index 37e0628464f..4fa919f36a5 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -5768,6 +5768,12 @@ x_get_monitor_attributes_xrandr (struct x_display_info *dpyinfo)
 
 #if RANDR_MAJOR > 1 || (RANDR_MAJOR == 1 && RANDR_MINOR >= 5)
   XRRMonitorInfo *rr_monitors;
+#ifdef USE_XCB
+  xcb_get_atom_name_cookie_t *atom_name_cookies;
+  xcb_get_atom_name_reply_t *reply;
+  xcb_generic_error_t *error;
+  int length;
+#endif
 
   /* If RandR 1.5 or later is available, use that instead, as some
      video drivers don't report correct dimensions via other versions
@@ -5786,6 +5792,9 @@ x_get_monitor_attributes_xrandr (struct x_display_info *dpyinfo)
         goto fallback;
 
       monitors = xzalloc (n_monitors * sizeof *monitors);
+#ifdef USE_XCB
+      atom_name_cookies = alloca (n_monitors * sizeof *atom_name_cookies);
+#endif
 
       for (int i = 0; i < n_monitors; ++i)
         {
@@ -5796,6 +5805,7 @@ x_get_monitor_attributes_xrandr (struct x_display_info *dpyinfo)
           monitors[i].mm_width = rr_monitors[i].mwidth;
           monitors[i].mm_height = rr_monitors[i].mheight;
 
+#ifndef USE_XCB
           name = XGetAtomName (dpyinfo->display, rr_monitors[i].name);
           if (name)
             {
@@ -5804,6 +5814,11 @@ x_get_monitor_attributes_xrandr (struct x_display_info *dpyinfo)
             }
           else
             monitors[i].name = xstrdup ("Unknown Monitor");
+#else
+          atom_name_cookies[i]
+            = xcb_get_atom_name (dpyinfo->xcb_connection,
+                                 (xcb_atom_t) rr_monitors[i].name);
+#endif
 
           if (rr_monitors[i].primary)
             primary = i;
@@ -5821,6 +5836,29 @@ x_get_monitor_attributes_xrandr (struct x_display_info *dpyinfo)
             monitors[i].work = monitors[i].geom;
         }
 
+#ifdef USE_XCB
+      for (int i = 0; i < n_monitors; ++i)
+        {
+          reply = xcb_get_atom_name_reply (dpyinfo->xcb_connection,
+                                           atom_name_cookies[i], &error);
+
+          if (!reply)
+            {
+              monitors[i].name = xstrdup ("Unknown monitor");
+              free (error);
+            }
+          else
+            {
+              length = xcb_get_atom_name_name_length (reply);
+              name = xmalloc (length + 1);
+              memcpy (name, xcb_get_atom_name_name (reply), length);
+              name[length] = '\0';
+              monitors[i].name = name;
+              free (reply);
+            }
+        }
+#endif
+
       XRRFreeMonitors (rr_monitors);
       randr15_p = true;
       goto out;