libweston/backend-pipewire/pipewire.c

@@ -249,10 +249,6 @@ static int
 finish_frame_handler(void *data)
 {
 	struct pipewire_output *output = data;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	struct timespec ts;
-	struct timespec now;
-	int64_t delta;
 
 	/*
 	 * Skip weston_output_finish_frame() if the repaint state machine was
@@ -261,20 +257,7 @@ finish_frame_handler(void *data)
 	if (output->base.repaint_status != REPAINT_AWAITING_COMPLETION)
 		return 1;
 
-	/*
-	 * The timer only has msec precision, but if the approximately hit our
-	 * target, report an exact time stamp by adding to the previous frame
-	 * time.
-	 */
-	timespec_add_nsec(&ts,&output->base.frame_time, refresh_nsec);
-
-	/* If we are more than 1.5 ms late, report the current time instead. */
-	weston_compositor_read_presentation_clock(output->base.compositor, &now);
-	delta = timespec_sub_to_nsec(&now, &ts);
-	if (delta > 1500000)
-		ts = now;
-
-	weston_output_finish_frame(&output->base, &ts, 0);
+	weston_output_finish_frame_from_timer(&output->base);
 
 	return 1;
 }
@@ -739,24 +722,6 @@ pipewire_submit_buffer(struct pipewire_output *output,
 	output->seq++;
 }
 
-static void
-pipewire_output_arm_timer(struct pipewire_output *output)
-{
-	struct weston_compositor *ec = output->base.compositor;
-	struct timespec now;
-	struct timespec target;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	int64_t delay_nsec;
-
-	weston_compositor_read_presentation_clock(ec, &now);
-	timespec_add_nsec(&target, &output->base.frame_time, refresh_nsec);
-
-	delay_nsec = CLIP(timespec_sub_to_nsec(&target, &now), 1, refresh_nsec);
-
-	wl_event_source_timer_update(output->finish_frame_timer,
-				     DIV_ROUND_UP(delay_nsec, 1000000));
-}
-
 static int
 pipewire_output_repaint(struct weston_output *base, pixman_region32_t *damage)
 {
@@ -787,7 +752,7 @@ pipewire_output_repaint(struct weston_output *base, pixman_region32_t *damage)
 
 out:
 
-	pipewire_output_arm_timer(output);
+	weston_output_arm_frame_timer(base, output->finish_frame_timer);
 
 	return 0;
 }

libweston/backend-rdp/rdp.c

@@ -278,20 +278,6 @@ rdp_output_repaint(struct weston_output *output_base, pixman_region32_t *damage)
 	struct weston_compositor *ec = output->base.compositor;
 	struct rdp_backend *b = output->backend;
 	struct rdp_peers_item *peer;
-	struct timespec now, target;
-	int refresh_nsec = millihz_to_nsec(output_base->current_mode->refresh);
-	int64_t delay_nsec;
-
-	/* Calculate the time we should complete this frame such that frames
-	   are spaced out by the specified monitor refresh. Note that our timer
-	   mechanism only has msec precision, so we won't exactly hit our
-	   target refresh rate.
-	 */
-	weston_compositor_read_presentation_clock(ec, &now);
-
-	timespec_add_nsec(&target, &output_base->frame_time, refresh_nsec);
-
-	delay_nsec = CLIP(timespec_sub_to_nsec(&target, &now), 1, refresh_nsec);
 
 	assert(output);
 
@@ -313,8 +299,8 @@ rdp_output_repaint(struct weston_output *output_base, pixman_region32_t *damage)
 		pixman_region32_fini(&transformed_damage);
 	}
 
-	wl_event_source_timer_update(output->finish_frame_timer,
-				     DIV_ROUND_UP(delay_nsec, 1000000));
+	weston_output_arm_frame_timer(output_base, output->finish_frame_timer);
+
 	return 0;
 }
 
@@ -322,10 +308,8 @@ static int
 finish_frame_handler(void *data)
 {
 	struct rdp_output *output = data;
-	struct timespec ts;
 
-	weston_compositor_read_presentation_clock(output->base.compositor, &ts);
-	weston_output_finish_frame(&output->base, &ts, 0);
+	weston_output_finish_frame_from_timer(&output->base);
 
 	return 1;
 }

libweston/backend-vnc/vnc.c

@@ -709,28 +709,12 @@ vnc_new_client(struct nvnc_client *client)
 	weston_output_schedule_repaint(&output->base);
 }
 
-
 static int
 finish_frame_handler(void *data)
 {
 	struct vnc_output *output = data;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	struct timespec now, ts;
-	int delta;
-
-	/* The timer only has msec precision, but if we approximately hit our
-	 * target, report an exact time stamp by adding to the previous frame
-	 * time.
-	 */
-	timespec_add_nsec(&ts, &output->base.frame_time, refresh_nsec);
-
-	/* If we are more than 1.5 ms late, report the current time instead. */
-	weston_compositor_read_presentation_clock(output->base.compositor, &now);
-	delta = (int)timespec_sub_to_nsec(&now, &ts);
-	if (delta > 1500000)
-		ts = now;
 
-	weston_output_finish_frame(&output->base, &ts, 0);
+	weston_output_finish_frame_from_timer(&output->base);
 
 	return 1;
 }
@@ -949,11 +933,7 @@ static int
 vnc_output_repaint(struct weston_output *base, pixman_region32_t *damage)
 {
 	struct vnc_output *output = to_vnc_output(base);
-	struct weston_compositor *ec = output->base.compositor;
 	struct vnc_backend *backend = output->backend;
-	struct timespec now, target;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	int64_t delay_nsec;
 
 	assert(output);
 
@@ -972,13 +952,7 @@ vnc_output_repaint(struct weston_output *base, pixman_region32_t *damage)
 	 */
 	aml_dispatch(backend->aml);
 
-	weston_compositor_read_presentation_clock(ec, &now);
-	timespec_add_nsec(&target, &output->base.frame_time, refresh_nsec);
-
-	delay_nsec = CLIP(timespec_sub_to_nsec(&target, &now), 1, refresh_nsec);
-
-	wl_event_source_timer_update(output->finish_frame_timer,
-				     DIV_ROUND_UP(delay_nsec, 1000000));
+	weston_output_arm_frame_timer(base, output->finish_frame_timer);
 
 	return 0;
 }

libweston/backend-x11/x11.c

@@ -428,24 +428,6 @@ x11_output_start_repaint_loop(struct weston_output *output)
 	return 0;
 }
 
-static void
-x11_output_arm_timer(struct x11_output *output)
-{
-	struct weston_compositor *ec = output->base.compositor;
-	struct timespec now;
-	struct timespec target;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	int64_t delay_nsec;
-
-	weston_compositor_read_presentation_clock(ec, &now);
-	timespec_add_nsec(&target, &output->base.frame_time, refresh_nsec);
-
-	delay_nsec = CLIP(timespec_sub_to_nsec(&target, &now), 1, refresh_nsec);
-
-	wl_event_source_timer_update(output->finish_frame_timer,
-				     DIV_ROUND_UP(delay_nsec, 1000000));
-}
-
 static int
 x11_output_repaint_gl(struct weston_output *output_base,
 		      pixman_region32_t *damage)
@@ -459,7 +441,7 @@ x11_output_repaint_gl(struct weston_output *output_base,
 
 	ec->renderer->repaint_output(output_base, damage, NULL);
 
-	x11_output_arm_timer(output);
+	weston_output_arm_frame_timer(output_base, output->finish_frame_timer);
 	return 0;
 }
 
@@ -552,7 +534,7 @@ x11_output_repaint_shm(struct weston_output *output_base,
 		free(err);
 	}
 
-	x11_output_arm_timer(output);
+	weston_output_arm_frame_timer(output_base, output->finish_frame_timer);
 	return 0;
 }
 
@@ -560,23 +542,8 @@ static int
 finish_frame_handler(void *data)
 {
 	struct x11_output *output = data;
-	int refresh_nsec = millihz_to_nsec(output->base.current_mode->refresh);
-	struct timespec now, ts;
-	int delta;
-
-	/* The timer only has msec precision, but if we approximately hit our
-	 * target, report an exact time stamp by adding to the previous frame
-	 * time.
-	 */
-	timespec_add_nsec(&ts, &output->base.frame_time, refresh_nsec);
-
-	/* If we are more than 1.5 ms late, report the current time instead. */
-	weston_compositor_read_presentation_clock(output->base.compositor, &now);
-	delta = (int)timespec_sub_to_nsec(&now, &ts);
-	if (delta > 1500000)
-		ts = now;
-
-	weston_output_finish_frame(&output->base, &ts, 0);
+
+	weston_output_finish_frame_from_timer(&output->base);
 
 	return 1;
 }

libweston/backend.h

@@ -194,6 +194,12 @@ weston_region_global_to_output(pixman_region32_t *dst,
 const struct weston_hdr_metadata_type1 *
 weston_output_get_hdr_metadata_type1(const struct weston_output *output);
 
+void
+weston_output_arm_frame_timer(struct weston_output *output,
+			      struct wl_event_source *frame_timer);
+void
+weston_output_finish_frame_from_timer(struct weston_output *output);
+
 /* weston_seat */
 
 void

libweston/compositor.c

@@ -9736,3 +9736,58 @@ weston_renderer_resize_output(struct weston_output *output,
 			   output->name);
 	}
 }
+
+/** Queue a frame timer callback
+ *
+ * \param output The output to queue a frame timer callback for.
+ * \param frame_timer The timer that calls weston_output_finish_frame().
+ *
+ * This function calculates the time when the current frame should be completed
+ * such that frames are spaced out evenly by the specified refresh rate.
+ */
+WL_EXPORT void
+weston_output_arm_frame_timer(struct weston_output *output,
+			      struct wl_event_source *frame_timer)
+{
+	struct weston_compositor *ec = output->compositor;
+	struct timespec now;
+	struct timespec target;
+	int refresh_nsec = millihz_to_nsec(output->current_mode->refresh);
+	int64_t delay_nsec;
+
+	weston_compositor_read_presentation_clock(ec, &now);
+	timespec_add_nsec(&target, &output->frame_time, refresh_nsec);
+
+	delay_nsec = CLIP(timespec_sub_to_nsec(&target, &now), 1, refresh_nsec);
+
+	/* The libwayland event source timer API only has msec precision. */
+	wl_event_source_timer_update(frame_timer,
+				     DIV_ROUND_UP(delay_nsec, 1000000));
+}
+
+/** Helper to call weston_output_finish_frame() from frame timer callbacks
+ *
+ * \param output The output to call weston_output_finish_frame() for.
+ */
+WL_EXPORT void
+weston_output_finish_frame_from_timer(struct weston_output *output)
+{
+	int refresh_nsec = millihz_to_nsec(output->current_mode->refresh);
+	struct timespec ts;
+	struct timespec now;
+	int delta;
+
+	/* The timer only has msec precision, but if we approximately hit our
+	 * target, report an exact time stamp by adding to the previous frame
+	 * time.
+	 */
+	timespec_add_nsec(&ts, &output->frame_time, refresh_nsec);
+
+	/* If we are more than 1.5 ms late, report the current time instead. */
+	weston_compositor_read_presentation_clock(output->compositor, &now);
+	delta = (int)timespec_sub_to_nsec(&now, &ts);
+	if (delta > 1500000)
+		ts = now;
+
+	weston_output_finish_frame(output, &ts, 0);
+}