event: lazify screen update

Set root screen change flag in event handler, and update in
draw_callback.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/common.h

@@ -345,6 +345,8 @@ typedef struct session {
 	xcb_sync_fence_t sync_fence;
 
 	// === Operation related ===
+	/// Flags related to the root window
+	uint64_t root_flags;
 	/// Program options.
 	options_t o;
 	/// Whether we have hit unredirection timeout.

src/compton.c

@@ -48,8 +48,8 @@
 #ifdef CONFIG_DBUS
 #include "dbus.h"
 #endif
-#include "options.h"
 #include "event.h"
+#include "options.h"
 
 /// Get session_t pointer from a pointer to a member of session_t
 #define session_ptr(ptr, member)                                                         \
@@ -58,7 +58,6 @@
 		(session_t *)((char *)__mptr - offsetof(session_t, member));             \
 	})
 
-
 static bool must_use redir_start(session_t *ps);
 
 static void redir_stop(session_t *ps);
@@ -85,6 +84,10 @@ const char *const BACKEND_STRS[NUM_BKEND + 1] = {"xrender",              // BKEN
 /// XXX Limit what xerror can access by not having this pointer
 session_t *ps_g = NULL;
 
+void set_root_flags(session_t *ps, uint64_t flags) {
+	ps->root_flags |= flags;
+}
+
 /**
  * Free Xinerama screen info.
  *
@@ -96,7 +99,7 @@ static inline void free_xinerama_info(session_t *ps) {
 			pixman_region32_fini(&ps->xinerama_scr_regs[i]);
 		free(ps->xinerama_scr_regs);
 	}
-	cxfree(ps->xinerama_scrs);
+	free(ps->xinerama_scrs);
 	ps->xinerama_scrs = NULL;
 	ps->xinerama_nscrs = 0;
 }
@@ -397,6 +400,23 @@ xcb_window_t find_client_win(session_t *ps, xcb_window_t w) {
 	return ret;
 }
 
+static void handle_root_flags(session_t *ps) {
+	if ((ps->root_flags & ROOT_FLAGS_SCREEN_CHANGE) != 0) {
+		if (ps->o.xinerama_shadow_crop) {
+			cxinerama_upd_scrs(ps);
+		}
+
+		if (ps->o.sw_opti && !ps->o.refresh_rate) {
+			update_refresh_rate(ps);
+			if (!ps->refresh_rate) {
+				log_warn("Refresh rate detection failed. swopti will be "
+				         "temporarily disabled");
+			}
+		}
+		ps->root_flags &= ~ROOT_FLAGS_SCREEN_CHANGE;
+	}
+}
+
 static win *paint_preprocess(session_t *ps, bool *fade_running) {
 	// XXX need better, more general name for `fade_running`. It really
 	// means if fade is still ongoing after the current frame is rendered
@@ -970,7 +990,6 @@ void update_ewmh_active_win(session_t *ps) {
 		win_set_focused(ps, w, true);
 }
 
-
 // === Main ===
 
 /**
@@ -1406,6 +1425,11 @@ static void _draw_callback(EV_P_ session_t *ps, int revents) {
 		}
 	}
 
+	// TODO xcb_grab_server
+	// TODO clean up event queue
+
+	handle_root_flags(ps);
+
 	bool fade_running = false;
 	win *t = paint_preprocess(ps, &fade_running);
 	ps->tmout_unredir_hit = false;
@@ -1435,6 +1459,8 @@ static void _draw_callback(EV_P_ session_t *ps, int revents) {
 	if (!fade_running)
 		ps->fade_time = 0L;
 
+	// TODO xcb_ungrab_server
+
 	ps->redraw_needed = false;
 }
 

src/compton.h

@@ -25,6 +25,10 @@
 #include "win.h"
 #include "x.h"
 
+enum root_flags {
+	ROOT_FLAGS_SCREEN_CHANGE = 1
+};
+
 // == Functions ==
 // TODO move static inline functions that are only used in compton.c, into
 //      compton.c
@@ -62,6 +66,8 @@ void queue_redraw(session_t *ps);
 
 void discard_ignore(session_t *ps, unsigned long sequence);
 
+void set_root_flags(session_t *ps, uint64_t flags);
+
 /**
  * Set a <code>switch_t</code> array of all unset wintypes to true.
  */
@@ -151,5 +157,3 @@ static inline void dump_drawable(session_t *ps, xcb_drawable_t drawable) {
 	          drawable, r->x, r->y, r->width, r->height, r->border_width, r->depth);
 	free(r);
 }
-
-// vim: set et sw=2 :

src/event.c

@@ -506,23 +506,6 @@ static inline void ev_shape_notify(session_t *ps, xcb_shape_notify_event_t *ev)
 	w->reg_ignore_valid = false;
 }
 
-/**
- * Handle ScreenChangeNotify events from X RandR extension.
- */
-static void ev_screen_change_notify(session_t *ps,
-                                    xcb_randr_screen_change_notify_event_t attr_unused *ev) {
-	if (ps->o.xinerama_shadow_crop)
-		cxinerama_upd_scrs(ps);
-
-	if (ps->o.sw_opti && !ps->o.refresh_rate) {
-		update_refresh_rate(ps);
-		if (!ps->refresh_rate) {
-			log_warn("Refresh rate detection failed. swopti will be "
-			         "temporarily disabled");
-		}
-	}
-}
-
 static inline void
 ev_selection_clear(session_t *ps, xcb_selection_clear_event_t attr_unused *ev) {
 	// The only selection we own is the _NET_WM_CM_Sn selection.
@@ -603,8 +586,7 @@ void ev_handle(session_t *ps, xcb_generic_event_t *ev) {
 		}
 		if (ps->randr_exists &&
 		    ev->response_type == (ps->randr_event + XCB_RANDR_SCREEN_CHANGE_NOTIFY)) {
-			ev_screen_change_notify(
+			set_root_flags(ps, ROOT_FLAGS_SCREEN_CHANGE);
-			    ps, (xcb_randr_screen_change_notify_event_t *)ev);
 			break;
 		}
 		if (ps->damage_event + XCB_DAMAGE_NOTIFY == ev->response_type) {