From 82cdf90a716db2e0bfa95b9e6b7d30f48b37d203 Mon Sep 17 00:00:00 2001 From: Dor Askayo Date: Sun, 4 Feb 2024 00:54:45 +0200 Subject: [PATCH] clutter/frame-clock: Add a state for when scheduled "now" The new CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW state is almost identical to CLUTTER_FRAME_CLOCK_STATE_SCHEDULED, with one important difference being that it avoids updates from being repeatedly rescheduled "now" when multiple calls to clutter_frame_clock_schedule_update_now() are done before the source is actually dispatched. Such repeated calls to schedule an update "now" may actually postpone the dispatch if the CPU is very busy and the source dispatch is delayed, defeating the purpose of scheduling a frame "now". It also allows rescheduling "now" when the frame clock is uninhibited after being inhibited while an update was scheduled "now". This may be important in cases where the frame clock is inhibited for very short periods in which it would otherwise lose the state of being scheduled "now". Scenarios such as this would become more common with the introduction of variable refresh rate since it makes scheduling "now" a commonplace occurrence. Part-of: --- clutter/clutter/clutter-frame-clock.c | 14 +++++++++++++- doc/clutter-frame-scheduling.md | 8 ++++---- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/clutter/clutter/clutter-frame-clock.c b/clutter/clutter/clutter-frame-clock.c index 85f74d81f..d0864ed8f 100644 --- a/clutter/clutter/clutter-frame-clock.c +++ b/clutter/clutter/clutter-frame-clock.c @@ -55,6 +55,7 @@ typedef enum _ClutterFrameClockState CLUTTER_FRAME_CLOCK_STATE_INIT, CLUTTER_FRAME_CLOCK_STATE_IDLE, CLUTTER_FRAME_CLOCK_STATE_SCHEDULED, + CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW, CLUTTER_FRAME_CLOCK_STATE_DISPATCHING, CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED, } ClutterFrameClockState; @@ -390,6 +391,7 @@ clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock, case CLUTTER_FRAME_CLOCK_STATE_INIT: case CLUTTER_FRAME_CLOCK_STATE_IDLE: case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED: + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: g_warn_if_reached (); break; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: @@ -411,6 +413,7 @@ clutter_frame_clock_notify_ready (ClutterFrameClock *frame_clock) case CLUTTER_FRAME_CLOCK_STATE_INIT: case CLUTTER_FRAME_CLOCK_STATE_IDLE: case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED: + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: g_warn_if_reached (); break; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: @@ -620,6 +623,11 @@ clutter_frame_clock_inhibit (ClutterFrameClock *frame_clock) frame_clock->pending_reschedule = TRUE; frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE; break; + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: + frame_clock->pending_reschedule = TRUE; + frame_clock->pending_reschedule_now = TRUE; + frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE; + break; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED: break; @@ -659,6 +667,8 @@ clutter_frame_clock_schedule_update_now (ClutterFrameClock *frame_clock) case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED: next_update_time_us = g_get_monotonic_time (); break; + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: + return; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED: frame_clock->pending_reschedule = TRUE; @@ -670,7 +680,7 @@ clutter_frame_clock_schedule_update_now (ClutterFrameClock *frame_clock) frame_clock->next_update_time_us = next_update_time_us; g_source_set_ready_time (frame_clock->source, next_update_time_us); - frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED; + frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW; frame_clock->is_next_presentation_time_valid = FALSE; frame_clock->has_next_frame_deadline = FALSE; } @@ -702,6 +712,7 @@ clutter_frame_clock_schedule_update (ClutterFrameClock *frame_clock) (frame_clock->next_frame_deadline_us != 0); break; case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED: + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: return; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED: @@ -808,6 +819,7 @@ clutter_frame_clock_dispatch (ClutterFrameClock *frame_clock, break; case CLUTTER_FRAME_CLOCK_STATE_IDLE: case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED: + case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED_NOW: break; case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING: switch (result) diff --git a/doc/clutter-frame-scheduling.md b/doc/clutter-frame-scheduling.md index 50d0985da..f6ac3cbc2 100644 --- a/doc/clutter-frame-scheduling.md +++ b/doc/clutter-frame-scheduling.md @@ -4,11 +4,11 @@ ```mermaid stateDiagram - Init --> Scheduled : schedule update() -> now - Idle --> Scheduled : schedule update() -> given presentation time - Scheduled --> Dispatching : target time hit + Init --> Scheduled/ScheduledNow : schedule update() -> now + Idle --> Scheduled/ScheduledNow : schedule update() -> given presentation time + Scheduled/ScheduledNow --> Dispatching : target time hit Dispatching --> PendingPresented : queued page flip Dispatching --> Idle : no queued page flip - PendingPresented --> Scheduled : page flipped, if recent schedule update + PendingPresented --> Scheduled/ScheduledNow : page flipped, if recent schedule update PendingPresented --> Idle : page flipped ```