From 88f8d6ef351c01b646725b389e7f521494637e14 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Tue, 3 Feb 2026 19:22:58 +0000
Subject: [PATCH] Performance: Replace XSync with XFlush in drw_map

Replaces the blocking `XSync(drw->dpy, False)` call with `XFlush(drw->dpy)` in `drw_map`.
`XSync` forces a round-trip to the X server, causing the window manager to block until the server processes the drawing request. This is unnecessary for basic drawing operations and degrades responsiveness. `XFlush` ensures the request is sent without waiting for a reply.

Impact:
- Reduces latency during UI updates (bar drawing, etc.).
- Eliminates unnecessary context switches and blocking I/O.

Co-authored-by: paperbenni <15818888+paperbenni@users.noreply.github.com>
---
 .jules/bolt.md | 4 ++++
 drw.c          | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 00000000..130a3e90
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,4 @@
+
+## 2026-02-03 - XSync in Drawing Loops
+**Learning:** `XSync` forces a blocking round-trip to the X server, which is catastrophic for performance in frequently called drawing functions like `drw_map`.
+**Action:** Replace `XSync` with `XFlush` in drawing routines where strict synchronization is not required.
diff --git a/drw.c b/drw.c
index 7e99a386..35362fcf 100644
--- a/drw.c
+++ b/drw.c
@@ -494,7 +494,9 @@ void drw_map(Drw *drw, Window win, int x, int y, unsigned int w,
     }
 
     XCopyArea(drw->dpy, drw->drawable, win, drw->gc, x, y, w, h, x, y);
-    XSync(drw->dpy, False);
+    /* Performance: XFlush is sufficient here; XSync causes unnecessary blocking
+     * round-trips. */
+    XFlush(drw->dpy);
 }
 
 unsigned int drw_fontset_getwidth(Drw *drw, const char *text) {