clients/simple-dmabuf-feedback: use time instead of redraws

Weston uses a timeout of 2 seconds before it sends scanout
tranches to clients in order to not trigger excessive buffer
reallocations in clients.
`simple-dmabuf-feedback` in turn counts redraws (200) before
exiting. That doesn't work on e.g. 144Hz screens, thus use a
timer here as well.

Signed-off-by: Robert Mader <robert.mader@collabora.com>
(cherry picked from commit 34f7e01c2b)

clients/simple-dmabuf-feedback.c

@@ -32,6 +32,7 @@
 #include <stdio.h>
 #include <libudev.h>
 #include <sys/mman.h>
+#include <time.h>
 
 #include "shared/helpers.h"
 #include "shared/platform.h"
@@ -667,8 +668,6 @@ redraw(void *data, struct wl_callback *callback, uint32_t time)
 		      window->display->output.height);
 	wl_surface_set_opaque_region(window->surface, region);
 	wl_region_destroy(region);
-
-	window->n_redraws++;
 }
 
 static const struct wl_callback_listener frame_listener = {
@@ -1451,6 +1450,9 @@ main(int argc, char **argv)
 	struct display *display;
 	struct window *window;
 	int ret = 0;
+	struct timespec start_time, current_time;
+	const time_t MAX_TIME_SECONDS = 3;
+	time_t delta_time = 0;
 
 	fprintf(stderr, "This client was written with the purpose of manually test " \
 			"Weston's dma-buf feedback implementation. See main() " \
@@ -1459,9 +1461,14 @@ main(int argc, char **argv)
 	display = create_display();
 	window = create_window(display);
 
+	clock_gettime(CLOCK_MONOTONIC, &start_time);
+
 	redraw(window, NULL, 0);
-	while (ret != -1 && window->n_redraws < 200)
+	while (ret != -1 && delta_time < MAX_TIME_SECONDS) {
 		ret = wl_display_dispatch(display->display);
+		clock_gettime(CLOCK_MONOTONIC, &current_time);
+		delta_time = current_time.tv_sec - start_time.tv_sec;
+	}
 
 	destroy_window(window);
 	destroy_display(display);