cache GLX fbconfigs

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 * Allow `corner-radius-rules` to override `corner-radius = 0`. Previously setting corner radius to 0 globally disables rounded corners. (#1170)
 
+## Notable changes
+
+* Marginally improve performance when resizing/opening/closing windows. (#1190)
+
 # v11.2 (2024-Feb-13)
 
 ## Build changes

src/backend/gl/glx.c

@@ -17,6 +17,7 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
+#include <uthash.h>
 #include <xcb/composite.h>
 #include <xcb/xcb.h>
 
@@ -44,6 +45,13 @@
 	struct gl_data gl;
 	xcb_window_t target_win;
 	GLXContext ctx;
+	struct glx_fbconfig_cache *cached_fbconfigs;
+};
+
+struct glx_fbconfig_cache {
+	UT_hash_handle hh;
+	struct xvisual_info visual_info;
+	struct glx_fbconfig_info info;
 };
 
 #define glXGetFBConfigAttribChecked(a, b, attr, c)                                       \
@@ -54,9 +62,12 @@
 		}                                                                        \
 	} while (0)
 
-struct glx_fbconfig_info *glx_find_fbconfig(struct x_connection *c, struct xvisual_info m) {
-	log_debug("Looking for FBConfig for RGBA%d%d%d%d, depth %d", m.red_size,
-	          m.blue_size, m.green_size, m.alpha_size, m.visual_depth);
+bool glx_find_fbconfig(struct x_connection *c, struct xvisual_info m,
+                       struct glx_fbconfig_info *info) {
+	log_debug("Looking for FBConfig for RGBA%d%d%d%d, depth: %d, visual id: %#x", m.red_size,
+	          m.blue_size, m.green_size, m.alpha_size, m.visual_depth, m.visual);
+
+	info->cfg = NULL;
 
 	int ncfg;
 	// clang-format off
@@ -143,16 +154,13 @@
 		min_cost = depthbuf + stencil + bufsize * (doublebuf + 1);
 	}
 	free(cfg);
-	if (!found) {
-		return NULL;
+	if (found) {
+		info->cfg = ret;
+		info->texture_tgts = texture_tgts;
+		info->texture_fmt = texture_fmt;
+		info->y_inverted = y_inverted;
 	}
-
-	auto info = cmalloc(struct glx_fbconfig_info);
-	info->cfg = ret;
-	info->texture_tgts = texture_tgts;
-	info->texture_fmt = texture_fmt;
-	info->y_inverted = y_inverted;
-	return info;
+	return found;
 }
 
 /**
@@ -197,6 +205,12 @@
 		gd->ctx = 0;
 	}
 
+	struct glx_fbconfig_cache *cached_fbconfig = NULL, *tmp = NULL;
+	HASH_ITER(hh, gd->cached_fbconfigs, cached_fbconfig, tmp) {
+		HASH_DEL(gd->cached_fbconfigs, cached_fbconfig);
+		free(cached_fbconfig);
+	}
+
 	free(gd);
 }
 
@@ -367,6 +381,7 @@
 static void *
 glx_bind_pixmap(backend_t *base, xcb_pixmap_t pixmap, struct xvisual_info fmt, bool owned) {
 	struct _glx_pixmap *glxpixmap = NULL;
+	auto gd = (struct _glx_data *)base;
 	// Retrieve pixmap parameters, if they aren't provided
 	if (fmt.visual_depth > OPENGL_MAX_DEPTH) {
 		log_error("Requested depth %d higher than max possible depth %d.",
@@ -394,38 +409,52 @@
 	wd->inner = (struct backend_image_inner_base *)inner;
 	free(r);
 
-	auto fbcfg = glx_find_fbconfig(base->c, fmt);
-	if (!fbcfg) {
-		log_error("Couldn't find FBConfig with requested visual %x", fmt.visual);
-		goto err;
+	struct glx_fbconfig_cache *cached_fbconfig = NULL;
+	HASH_FIND(hh, gd->cached_fbconfigs, &fmt, sizeof(fmt), cached_fbconfig);
+	if (!cached_fbconfig) {
+		struct glx_fbconfig_info fbconfig;
+		if (!glx_find_fbconfig(base->c, fmt, &fbconfig)) {
+			log_error("Couldn't find FBConfig with requested visual %#x",
+			          fmt.visual);
+			goto err;
+		}
+		cached_fbconfig = cmalloc(struct glx_fbconfig_cache);
+		cached_fbconfig->visual_info = fmt;
+		cached_fbconfig->info = fbconfig;
+		HASH_ADD(hh, gd->cached_fbconfigs, visual_info, sizeof(fmt), cached_fbconfig);
+	} else {
+		log_debug("Found cached FBConfig for RGBA%d%d%d%d, depth: %d, visual id: "
+		          "%#x",
+		          fmt.red_size, fmt.blue_size, fmt.green_size, fmt.alpha_size,
+		          fmt.visual_depth, fmt.visual);
 	}
+	struct glx_fbconfig_info *fbconfig = &cached_fbconfig->info;
 
 	// Choose a suitable texture target for our pixmap.
 	// Refer to GLX_EXT_texture_om_pixmap spec to see what are the mean
 	// of the bits in texture_tgts
-	if (!(fbcfg->texture_tgts & GLX_TEXTURE_2D_BIT_EXT)) {
+	if (!(fbconfig->texture_tgts & GLX_TEXTURE_2D_BIT_EXT)) {
 		log_error("Cannot bind pixmap to GL_TEXTURE_2D, giving up");
 		goto err;
 	}
 
 	log_debug("depth %d, rgba %d", fmt.visual_depth,
-	          (fbcfg->texture_fmt == GLX_TEXTURE_FORMAT_RGBA_EXT));
+	          (fbconfig->texture_fmt == GLX_TEXTURE_FORMAT_RGBA_EXT));
 
 	GLint attrs[] = {
 	    GLX_TEXTURE_FORMAT_EXT,
-	    fbcfg->texture_fmt,
+	    fbconfig->texture_fmt,
 	    GLX_TEXTURE_TARGET_EXT,
 	    GLX_TEXTURE_2D_EXT,
 	    0,
 	};
 
-	inner->y_inverted = fbcfg->y_inverted;
+	inner->y_inverted = fbconfig->y_inverted;
 
 	glxpixmap = cmalloc(struct _glx_pixmap);
 	glxpixmap->pixmap = pixmap;
-	glxpixmap->glpixmap = glXCreatePixmap(base->c->dpy, fbcfg->cfg, pixmap, attrs);
+	glxpixmap->glpixmap = glXCreatePixmap(base->c->dpy, fbconfig->cfg, pixmap, attrs);
 	glxpixmap->owned = owned;
-	free(fbcfg);
 
 	if (!glxpixmap->glpixmap) {
 		log_error("Failed to create glpixmap for pixmap %#010x", pixmap);

src/backend/gl/glx.h

@@ -19,21 +19,8 @@ struct glx_fbconfig_info {
 	int y_inverted;
 };
 
-/// The search criteria for glx_find_fbconfig
-struct glx_fbconfig_criteria {
-	/// Bit width of the red component
-	int red_size;
-	/// Bit width of the green component
-	int green_size;
-	/// Bit width of the blue component
-	int blue_size;
-	/// Bit width of the alpha component
-	int alpha_size;
-	/// The depth of X visual
-	int visual_depth;
-};
-
-struct glx_fbconfig_info *glx_find_fbconfig(struct x_connection *, struct xvisual_info);
+bool glx_find_fbconfig(struct x_connection *c, struct xvisual_info m,
+                       struct glx_fbconfig_info *info);
 
 struct glxext_info {
 	bool initialized;

src/common.h

@@ -204,7 +204,7 @@ typedef struct session {
 	/// Custom GLX program used for painting window.
 	// XXX should be in struct glx_session
 	glx_prog_main_t glx_prog_win;
-	struct glx_fbconfig_info *argb_fbconfig;
+	struct glx_fbconfig_info argb_fbconfig;
 #endif
 	/// Sync fence to sync draw operations
 	xcb_sync_fence_t sync_fence;

src/opengl.c

@@ -279,7 +279,7 @@
 
 	free(ps->psglx);
 	ps->psglx = NULL;
-	ps->argb_fbconfig = NULL;
+	ps->argb_fbconfig = (struct glx_fbconfig_info){0};
 }
 
 /**

src/opengl.h

@@ -228,10 +228,7 @@ static inline void free_texture(session_t *ps, glx_texture_t **pptex) {
  */
 static inline void free_paint_glx(session_t *ps, paint_t *ppaint) {
 	free_texture(ps, &ppaint->ptex);
-#ifdef CONFIG_OPENGL
-	free(ppaint->fbcfg);
-#endif
-	ppaint->fbcfg = NULL;
+	ppaint->fbcfg = (struct glx_fbconfig_info){0};
 }
 
 /**

src/picom.c

@@ -2640,11 +2640,6 @@ static void session_destroy(session_t *ps) {
 		unredirect(ps);
 	}
 
-#ifdef CONFIG_OPENGL
-	free(ps->argb_fbconfig);
-	ps->argb_fbconfig = NULL;
-#endif
-
 	file_watch_destroy(ps->loop, ps->file_watch_handle);
 	ps->file_watch_handle = NULL;
 

src/render.c

@@ -55,19 +55,20 @@
 	struct glx_fbconfig_info *fbcfg;
 	if (!visual) {
 		assert(depth == 32);
-		if (!ps->argb_fbconfig) {
-			ps->argb_fbconfig = glx_find_fbconfig(
-			    &ps->c, (struct xvisual_info){.red_size = 8,
-			                                  .green_size = 8,
-			                                  .blue_size = 8,
-			                                  .alpha_size = 8,
-			                                  .visual_depth = 32});
+		if (!ps->argb_fbconfig.cfg) {
+			glx_find_fbconfig(&ps->c,
+			                  (struct xvisual_info){.red_size = 8,
+			                                        .green_size = 8,
+			                                        .blue_size = 8,
+			                                        .alpha_size = 8,
+			                                        .visual_depth = 32},
+			                  &ps->argb_fbconfig);
 		}
-		if (!ps->argb_fbconfig) {
+		if (!ps->argb_fbconfig.cfg) {
 			log_error("Failed to find appropriate FBConfig for 32 bit depth");
 			return false;
 		}
-		fbcfg = ps->argb_fbconfig;
+		fbcfg = &ps->argb_fbconfig;
 	} else {
 		auto m = x_get_visual_info(&ps->c, visual);
 		if (m.visual_depth < 0) {
@@ -79,14 +80,14 @@
 			return false;
 		}
 
-		if (!ppaint->fbcfg) {
-			ppaint->fbcfg = glx_find_fbconfig(&ps->c, m);
+		if (!ppaint->fbcfg.cfg) {
+			glx_find_fbconfig(&ps->c, m, &ppaint->fbcfg);
 		}
-		if (!ppaint->fbcfg) {
+		if (!ppaint->fbcfg.cfg) {
 			log_error("Failed to find appropriate FBConfig for X pixmap");
 			return false;
 		}
-		fbcfg = ppaint->fbcfg;
+		fbcfg = &ppaint->fbcfg;
 	}
 
 	if (force || !glx_tex_bound(ppaint->ptex, ppaint->pixmap)) {
@@ -1528,7 +1529,7 @@
 	free_root_tile(ps);
 
 #ifdef CONFIG_OPENGL
-	free(ps->root_tile_paint.fbcfg);
+	ps->root_tile_paint.fbcfg = (struct glx_fbconfig_info){0};
 	if (bkend_use_glx(ps)) {
 		glx_destroy(ps);
 	}

src/render.h

@@ -21,7 +21,7 @@ typedef struct paint {
 	xcb_render_picture_t pict;
 	glx_texture_t *ptex;
 #ifdef CONFIG_OPENGL
-	struct glx_fbconfig_info *fbcfg;
+	struct glx_fbconfig_info fbcfg;
 #endif
 } paint_t;