Wayland: Remove the 120ms penalty from waiting for window creation

When showing the window we loop in the wayland backend using a
temporary buffer of blank pixels to force the compositor to finish
setting up the top level surface pronto.

TODO: Set the color of the temmporary buffer to the background color

glfw/glfw.py

@@ -316,7 +316,6 @@ def generate_wrappers(glfw_header: str) -> None:
     void glfwWaylandRedrawCSDWindowTitle(GLFWwindow *handle)
     void glfwWaylandSetupLayerShellForNextWindow(GLFWLayerShellConfig c)
     pid_t glfwWaylandCompositorPID(void)
-    bool glfwWaylandWindowFullyCreated(GLFWwindow *handle)
     unsigned long long glfwDBusUserNotify(const char *app_name, const char* icon, const char *summary, const char *body, \
 const char *action_text, int32_t timeout, GLFWDBusnotificationcreatedfun callback, void *data)
     void glfwDBusSetUserNotificationHandler(GLFWDBusnotificationactivatedfun handler)

glfw/wl_platform.h

@@ -172,6 +172,7 @@ typedef struct _GLFWwindowWayland
     struct {
         bool surface_configured, fractional_scale_received, preferred_scale_received;
     } once;
+    struct wl_buffer *temp_buffer_used_during_window_creation;
     struct {
         GLFWLayerShellConfig config;
         struct zwlr_layer_surface_v1* zwlr_layer_surface_v1;

glfw/wl_window.c

@@ -373,6 +373,10 @@ _glfwWaylandAfterBufferSwap(_GLFWwindow* window) {
         // this is not really needed, since I think eglSwapBuffers() calls wl_surface_commit()
         // but lets be safe. See https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/src/egl/drivers/dri2/platform_wayland.c#L1510
         wl_surface_commit(window->wl.surface);
+        if (window->wl.temp_buffer_used_during_window_creation) {
+            wl_buffer_destroy(window->wl.temp_buffer_used_during_window_creation);
+            window->wl.temp_buffer_used_during_window_creation = NULL;
+        }
     }
 }
 
@@ -748,6 +752,51 @@ apply_xdg_configure_changes(_GLFWwindow *window) {
     window->wl.pending_state = 0;
 }
 
+static bool
+attach_temp_buffer_during_window_creation(_GLFWwindow *window) {
+    int width, height;
+    _glfwPlatformGetFramebufferSize(window, &width, &height);
+    const size_t size = 4 * width * height;
+    int fd = createAnonymousFile(size);
+    if (fd < 0) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Wayland: failed to create anonymouse file");
+        return false;
+    }
+    struct wl_shm_pool *pool = wl_shm_create_pool(_glfw.wl.shm, fd, size);
+    if (!pool) {
+        close(fd);
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Wayland: failed to create wl_shm_pool of size: %zu", size);
+        return false;
+    }
+    struct wl_buffer *buffer = wl_shm_pool_create_buffer(pool, 0, width, height, width * 4, WL_SHM_FORMAT_ARGB8888);
+    wl_shm_pool_destroy(pool); close(fd);
+    if (!buffer) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Wayland: failed to create wl_buffer of size: %zu", size);
+        return false;
+    }
+    if (window->wl.temp_buffer_used_during_window_creation) wl_buffer_destroy(window->wl.temp_buffer_used_during_window_creation);
+    window->wl.temp_buffer_used_during_window_creation = buffer;
+    wl_surface_set_buffer_scale(window->wl.surface, window->wl.fractional_scale ? 1: _glfwWaylandIntegerWindowScale(window));
+    wl_surface_attach(window->wl.surface, buffer, 0, 0);
+    if (window->wl.wp_viewport) wp_viewport_set_destination(window->wl.wp_viewport, window->wl.width, window->wl.height);
+    wl_surface_commit(window->wl.surface);
+    debug("Attached temp buffer during window creation of size: %dx%d\n", width, height);
+    return true;
+}
+
+static void
+loop_till_window_fully_created(_GLFWwindow *window) {
+    if (!window->wl.window_fully_created) {
+        monotonic_t start = monotonic();
+        while (!window->wl.window_fully_created && monotonic() - start < ms_to_monotonic_t(300)) {
+            if (wl_display_roundtrip(_glfw.wl.display) == -1) {
+                window->wl.window_fully_created = true;
+            }
+        }
+        window->wl.window_fully_created = true;
+    }
+}
+
 static void
 xdgSurfaceHandleConfigure(void* data, struct xdg_surface* surface, uint32_t serial) {
     // The poorly documented pattern Wayland requires is:
@@ -763,6 +812,9 @@ xdgSurfaceHandleConfigure(void* data, struct xdg_surface* surface, uint32_t seri
     xdg_surface_ack_configure(surface, serial);
     debug("XDG surface configure event received and acknowledged\n");
     apply_xdg_configure_changes(window);
+    if (!window->wl.window_fully_created) {
+        if (!attach_temp_buffer_during_window_creation(window)) window->wl.window_fully_created = true;
+    }
 }
 
 static const struct xdg_surface_listener xdgSurfaceListener = {
@@ -877,6 +929,9 @@ layer_surface_handle_configure(void* data, struct zwlr_layer_surface_v1* surface
         layer_set_properties(window);
     }
     commit_window_surface_if_safe(window);
+    if (!window->wl.window_fully_created) {
+        if (!attach_temp_buffer_during_window_creation(window)) window->wl.window_fully_created = true;
+    }
 }
 
 static void
@@ -1200,7 +1255,7 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
     window->wl.monitors = calloc(1, sizeof(_GLFWmonitor*));
     window->wl.monitorsCount = 0;
     window->wl.monitorsSize = 1;
-
+    if (window->wl.visible) loop_till_window_fully_created(window);
     return true;
 }
 
@@ -1220,6 +1275,9 @@ void _glfwPlatformDestroyWindow(_GLFWwindow* window)
         _glfw.wl.keyRepeatInfo.keyboardFocusId = 0;
     }
 
+    if (window->wl.temp_buffer_used_during_window_creation)
+        wl_buffer_destroy(window->wl.temp_buffer_used_during_window_creation);
+
     if (window->wl.wp_fractional_scale_v1)
         wp_fractional_scale_v1_destroy(window->wl.wp_fractional_scale_v1);
     if (window->wl.wp_viewport)
@@ -1422,10 +1480,10 @@ void _glfwPlatformMaximizeWindow(_GLFWwindow* window)
 
 void _glfwPlatformShowWindow(_GLFWwindow* window)
 {
-    if (!window->wl.visible)
-    {
+    if (!window->wl.visible) {
         create_window_desktop_surface(window);
         window->wl.visible = true;
+        loop_till_window_fully_created(window);
     }
 }
 
@@ -2585,8 +2643,3 @@ GLFWAPI void glfwWaylandSetupLayerShellForNextWindow(GLFWLayerShellConfig c) {
     if (layer_shell_config_for_next_window.output_name && !layer_shell_config_for_next_window.output_name[0]) layer_shell_config_for_next_window.output_name = NULL;
     if (layer_shell_config_for_next_window.output_name) layer_shell_config_for_next_window.output_name = strdup(layer_shell_config_for_next_window.output_name);
 }
-
-GLFWAPI bool glfwWaylandWindowFullyCreated(GLFWwindow *handle) {
-    _GLFWwindow* window = (_GLFWwindow*) handle;
-    return window->wl.window_fully_created;
-}

kitty/fast_data_types.pyi

@@ -1574,5 +1574,4 @@ def replace_c0_codes_except_nl_space_tab(text: str) -> str:...
 def replace_c0_codes_except_nl_space_tab(text: Union[bytes, memoryview, bytearray]) -> bytes:...
 def terminfo_data() -> bytes:...
 def wayland_compositor_pid() -> int:...
-def window_fully_created(kitty_window_id: int) -> bool: ...
 def monotonic() -> float: ...

kitty/glfw-wrapper.c

@@ -485,9 +485,6 @@ load_glfw(const char* path) {
     *(void **) (&glfwWaylandCompositorPID_impl) = dlsym(handle, "glfwWaylandCompositorPID");
     if (glfwWaylandCompositorPID_impl == NULL) dlerror(); // clear error indicator
 
-    *(void **) (&glfwWaylandWindowFullyCreated_impl) = dlsym(handle, "glfwWaylandWindowFullyCreated");
-    if (glfwWaylandWindowFullyCreated_impl == NULL) dlerror(); // clear error indicator
-
     *(void **) (&glfwDBusUserNotify_impl) = dlsym(handle, "glfwDBusUserNotify");
     if (glfwDBusUserNotify_impl == NULL) dlerror(); // clear error indicator
 

kitty/glfw-wrapper.h

@@ -2316,10 +2316,6 @@ typedef pid_t (*glfwWaylandCompositorPID_func)(void);
 GFW_EXTERN glfwWaylandCompositorPID_func glfwWaylandCompositorPID_impl;
 #define glfwWaylandCompositorPID glfwWaylandCompositorPID_impl
 
-typedef bool (*glfwWaylandWindowFullyCreated_func)(GLFWwindow*);
-GFW_EXTERN glfwWaylandWindowFullyCreated_func glfwWaylandWindowFullyCreated_impl;
-#define glfwWaylandWindowFullyCreated glfwWaylandWindowFullyCreated_impl
-
 typedef unsigned long long (*glfwDBusUserNotify_func)(const char*, const char*, const char*, const char*, const char*, int32_t, GLFWDBusnotificationcreatedfun, void*);
 GFW_EXTERN glfwDBusUserNotify_func glfwDBusUserNotify_impl;
 #define glfwDBusUserNotify glfwDBusUserNotify_impl

kitty/glfw.c

@@ -2210,16 +2210,6 @@ make_x11_window_a_dock_window(PyObject *self UNUSED, PyObject *args UNUSED) {
     Py_RETURN_NONE;
 }
 
-static PyObject*
-window_fully_created(PyObject *self UNUSED, PyObject *wid) {
-    // On Wayland a window does not receive its final size by the time glfwCreateWindow returns
-    if (!global_state.is_wayland) Py_RETURN_TRUE;
-    OSWindow *w = os_window_for_kitty_window(PyLong_AsUnsignedLongLong(wid));
-    if (!w || !w->handle) Py_RETURN_FALSE;
-    if (glfwWaylandWindowFullyCreated(w->handle)) Py_RETURN_TRUE;
-    Py_RETURN_FALSE;
-}
-
 // Boilerplate {{{
 
 static PyMethodDef module_methods[] = {
@@ -2239,7 +2229,6 @@ static PyMethodDef module_methods[] = {
     METHODB(glfw_window_hint, METH_VARARGS),
     METHODB(x11_display, METH_NOARGS),
     METHODB(wayland_compositor_pid, METH_NOARGS),
-    METHODB(window_fully_created, METH_O),
     METHODB(get_click_interval, METH_NOARGS),
     METHODB(x11_window_id, METH_O),
     METHODB(make_x11_window_a_dock_window, METH_VARARGS),

kitty/window.py

@@ -86,7 +86,6 @@ from .fast_data_types import (
     update_window_title,
     update_window_visibility,
     wakeup_main_loop,
-    window_fully_created,
 )
 from .keys import keyboard_mode_name, mod_mask
 from .notify import (
@@ -839,14 +838,14 @@ class Window:
             boss = get_boss()
             boss.child_monitor.resize_pty(self.id, *current_pty_size)
             self.last_resized_at = monotonic()
-            if not self.child_is_launched and window_fully_created(self.id):
+            if not self.child_is_launched:
                 self.child.mark_terminal_ready()
                 self.child_is_launched = True
                 update_ime_position = True
                 if boss.args.debug_rendering:
                     now = monotonic()
-                    print(f'[{now:.3f}] Child launched {now - self.started_at:.2f} seconds after window creation', file=sys.stderr)
-            if boss.args.debug_rendering and self.child_is_launched:
+                    print(f'[{now:.3f}] Child launched', file=sys.stderr)
+            elif boss.args.debug_rendering:
                 print(f'[{monotonic():.3f}] SIGWINCH sent to child in window: {self.id} with size: {current_pty_size}', file=sys.stderr)
             self.last_reported_pty_size = current_pty_size
         else: