frameclock

.gitignore

/_build/

README.md

Reproducer for battery drain in webkit/gtk

https://bugs.webkit.org/show_bug.cgi?id=210561

frameclock.c

#include <stdio.h>
#include <string.h>
#include <gtk/gtk.h>

static gboolean tick(GtkWidget *off_window, GdkFrameClock *clock, gpointer data) {
	puts("tick");

	static int ttl = 10;
	if (--ttl <= 0)
		gtk_widget_destroy(off_window);

	return G_SOURCE_CONTINUE;
}

static void update(GdkFrameClock *clock, gpointer data) {
	puts("update");

	static int ttl = 10;
	if (--ttl <= 0) {
		gdk_frame_clock_end_updating(clock);
		gtk_widget_destroy((GtkWidget *) data);
	}
}

static gboolean timeout(gpointer data) {
	gtk_main_quit();

	return G_SOURCE_REMOVE;
}

int main(int argc, char **argv) {
	gtk_init(&argc, &argv);

	GtkWidget *off_window = gtk_offscreen_window_new();
	gtk_widget_realize(off_window);

	if (argc == 2 && strcmp(argv[1], "tick") == 0) {
		gtk_widget_add_tick_callback(off_window, tick, NULL, NULL);
	} else {
		GdkFrameClock *clock = gtk_widget_get_frame_clock(off_window);
		g_signal_connect(clock, "update", G_CALLBACK(update), off_window);
		gdk_frame_clock_begin_updating(clock);
	}

	g_timeout_add(1000, timeout, NULL);

	gtk_main();
}

Makefile

.PHONY: build
build: _build/build.ninja
	ninja -C _build

_build/build.ninja: | meson.build
	meson _build

.PHONY: clean
clean:
	git clean -fdX

meson.build

project(
  'frameclock', 'c',
  version: '0.1',
)

cc = meson.get_compiler('c')

executable(
  'frameclock',
  sources: 'frameclock.c',
  dependencies: [
    dependency('gtk+-3.0'),
  ],
)