1 // Copyright 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "cc/scheduler/scheduler_state_machine.h"
7 #include "base/debug/trace_event.h"
8 #include "base/debug/trace_event_argument.h"
9 #include "base/format_macros.h"
10 #include "base/logging.h"
11 #include "base/strings/stringprintf.h"
12 #include "base/values.h"
13 #include "ui/gfx/frame_time.h"
17 SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
18 : settings_(settings),
19 output_surface_state_(OUTPUT_SURFACE_LOST),
20 begin_impl_frame_state_(BEGIN_IMPL_FRAME_STATE_IDLE),
21 commit_state_(COMMIT_STATE_IDLE),
22 forced_redraw_state_(FORCED_REDRAW_STATE_IDLE),
24 current_frame_number_(0),
25 last_frame_number_animate_performed_(-1),
26 last_frame_number_swap_performed_(-1),
27 last_frame_number_swap_requested_(-1),
28 last_frame_number_begin_main_frame_sent_(-1),
29 last_frame_number_update_visible_tiles_was_called_(-1),
30 manage_tiles_funnel_(0),
31 consecutive_checkerboard_animations_(0),
32 max_pending_swaps_(1),
35 needs_animate_(false),
36 needs_manage_tiles_(false),
37 swap_used_incomplete_tile_(false),
39 inside_poll_for_anticipated_draw_triggers_(false),
43 has_pending_tree_(false),
44 pending_tree_is_ready_for_activation_(false),
45 active_tree_needs_first_draw_(false),
46 did_create_and_initialize_first_output_surface_(false),
47 impl_latency_takes_priority_(false),
48 skip_next_begin_main_frame_to_reduce_latency_(false),
49 skip_begin_main_frame_to_reduce_latency_(false),
50 continuous_painting_(false) {
53 const char* SchedulerStateMachine::OutputSurfaceStateToString(
54 OutputSurfaceState state) {
56 case OUTPUT_SURFACE_ACTIVE:
57 return "OUTPUT_SURFACE_ACTIVE";
58 case OUTPUT_SURFACE_LOST:
59 return "OUTPUT_SURFACE_LOST";
60 case OUTPUT_SURFACE_CREATING:
61 return "OUTPUT_SURFACE_CREATING";
62 case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
63 return "OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT";
64 case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
65 return "OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION";
71 const char* SchedulerStateMachine::BeginImplFrameStateToString(
72 BeginImplFrameState state) {
74 case BEGIN_IMPL_FRAME_STATE_IDLE:
75 return "BEGIN_IMPL_FRAME_STATE_IDLE";
76 case BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING:
77 return "BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING";
78 case BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME:
79 return "BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME";
80 case BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE:
81 return "BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE";
87 const char* SchedulerStateMachine::CommitStateToString(CommitState state) {
89 case COMMIT_STATE_IDLE:
90 return "COMMIT_STATE_IDLE";
91 case COMMIT_STATE_BEGIN_MAIN_FRAME_SENT:
92 return "COMMIT_STATE_BEGIN_MAIN_FRAME_SENT";
93 case COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED:
94 return "COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED";
95 case COMMIT_STATE_READY_TO_COMMIT:
96 return "COMMIT_STATE_READY_TO_COMMIT";
97 case COMMIT_STATE_WAITING_FOR_ACTIVATION:
98 return "COMMIT_STATE_WAITING_FOR_ACTIVATION";
99 case COMMIT_STATE_WAITING_FOR_FIRST_DRAW:
100 return "COMMIT_STATE_WAITING_FOR_FIRST_DRAW";
106 const char* SchedulerStateMachine::ForcedRedrawOnTimeoutStateToString(
107 ForcedRedrawOnTimeoutState state) {
109 case FORCED_REDRAW_STATE_IDLE:
110 return "FORCED_REDRAW_STATE_IDLE";
111 case FORCED_REDRAW_STATE_WAITING_FOR_COMMIT:
112 return "FORCED_REDRAW_STATE_WAITING_FOR_COMMIT";
113 case FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION:
114 return "FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION";
115 case FORCED_REDRAW_STATE_WAITING_FOR_DRAW:
116 return "FORCED_REDRAW_STATE_WAITING_FOR_DRAW";
122 const char* SchedulerStateMachine::ActionToString(Action action) {
125 return "ACTION_NONE";
127 return "ACTION_ANIMATE";
128 case ACTION_SEND_BEGIN_MAIN_FRAME:
129 return "ACTION_SEND_BEGIN_MAIN_FRAME";
131 return "ACTION_COMMIT";
132 case ACTION_UPDATE_VISIBLE_TILES:
133 return "ACTION_UPDATE_VISIBLE_TILES";
134 case ACTION_ACTIVATE_SYNC_TREE:
135 return "ACTION_ACTIVATE_SYNC_TREE";
136 case ACTION_DRAW_AND_SWAP_IF_POSSIBLE:
137 return "ACTION_DRAW_AND_SWAP_IF_POSSIBLE";
138 case ACTION_DRAW_AND_SWAP_FORCED:
139 return "ACTION_DRAW_AND_SWAP_FORCED";
140 case ACTION_DRAW_AND_SWAP_ABORT:
141 return "ACTION_DRAW_AND_SWAP_ABORT";
142 case ACTION_BEGIN_OUTPUT_SURFACE_CREATION:
143 return "ACTION_BEGIN_OUTPUT_SURFACE_CREATION";
144 case ACTION_MANAGE_TILES:
145 return "ACTION_MANAGE_TILES";
151 scoped_refptr<base::debug::ConvertableToTraceFormat>
152 SchedulerStateMachine::AsValue() const {
153 scoped_refptr<base::debug::TracedValue> state =
154 new base::debug::TracedValue();
155 AsValueInto(state.get(), gfx::FrameTime::Now());
159 void SchedulerStateMachine::AsValueInto(base::debug::TracedValue* state,
160 base::TimeTicks now) const {
161 state->BeginDictionary("major_state");
162 state->SetString("next_action", ActionToString(NextAction()));
163 state->SetString("begin_impl_frame_state",
164 BeginImplFrameStateToString(begin_impl_frame_state_));
165 state->SetString("commit_state", CommitStateToString(commit_state_));
166 state->SetString("output_surface_state_",
167 OutputSurfaceStateToString(output_surface_state_));
168 state->SetString("forced_redraw_state",
169 ForcedRedrawOnTimeoutStateToString(forced_redraw_state_));
170 state->EndDictionary();
172 state->BeginDictionary("major_timestamps_in_ms");
173 state->SetDouble("0_interval",
174 begin_impl_frame_args_.interval.InMicroseconds() / 1000.0L);
177 (begin_impl_frame_args_.deadline - now).InMicroseconds() / 1000.0L);
179 "2_frame_time_to_now",
180 (now - begin_impl_frame_args_.frame_time).InMicroseconds() / 1000.0L);
181 state->SetDouble("3_frame_time_to_deadline",
182 (begin_impl_frame_args_.deadline -
183 begin_impl_frame_args_.frame_time).InMicroseconds() /
185 state->SetDouble("4_now",
186 (now - base::TimeTicks()).InMicroseconds() / 1000.0L);
189 (begin_impl_frame_args_.frame_time - base::TimeTicks()).InMicroseconds() /
193 (begin_impl_frame_args_.deadline - base::TimeTicks()).InMicroseconds() /
195 state->EndDictionary();
197 state->BeginDictionary("minor_state");
198 state->SetInteger("commit_count", commit_count_);
199 state->SetInteger("current_frame_number", current_frame_number_);
201 state->SetInteger("last_frame_number_animate_performed",
202 last_frame_number_animate_performed_);
203 state->SetInteger("last_frame_number_swap_performed",
204 last_frame_number_swap_performed_);
205 state->SetInteger("last_frame_number_swap_requested",
206 last_frame_number_swap_requested_);
207 state->SetInteger("last_frame_number_begin_main_frame_sent",
208 last_frame_number_begin_main_frame_sent_);
209 state->SetInteger("last_frame_number_update_visible_tiles_was_called",
210 last_frame_number_update_visible_tiles_was_called_);
212 state->SetInteger("manage_tiles_funnel", manage_tiles_funnel_);
213 state->SetInteger("consecutive_checkerboard_animations",
214 consecutive_checkerboard_animations_);
215 state->SetInteger("max_pending_swaps_", max_pending_swaps_);
216 state->SetInteger("pending_swaps_", pending_swaps_);
217 state->SetBoolean("needs_redraw", needs_redraw_);
218 state->SetBoolean("needs_animate_", needs_animate_);
219 state->SetBoolean("needs_manage_tiles", needs_manage_tiles_);
220 state->SetBoolean("swap_used_incomplete_tile", swap_used_incomplete_tile_);
221 state->SetBoolean("needs_commit", needs_commit_);
222 state->SetBoolean("visible", visible_);
223 state->SetBoolean("can_start", can_start_);
224 state->SetBoolean("can_draw", can_draw_);
225 state->SetBoolean("has_pending_tree", has_pending_tree_);
226 state->SetBoolean("pending_tree_is_ready_for_activation",
227 pending_tree_is_ready_for_activation_);
228 state->SetBoolean("active_tree_needs_first_draw",
229 active_tree_needs_first_draw_);
230 state->SetBoolean("did_create_and_initialize_first_output_surface",
231 did_create_and_initialize_first_output_surface_);
232 state->SetBoolean("impl_latency_takes_priority",
233 impl_latency_takes_priority_);
234 state->SetBoolean("main_thread_is_in_high_latency_mode",
235 MainThreadIsInHighLatencyMode());
236 state->SetBoolean("skip_begin_main_frame_to_reduce_latency",
237 skip_begin_main_frame_to_reduce_latency_);
238 state->SetBoolean("skip_next_begin_main_frame_to_reduce_latency",
239 skip_next_begin_main_frame_to_reduce_latency_);
240 state->SetBoolean("continuous_painting", continuous_painting_);
241 state->EndDictionary();
244 void SchedulerStateMachine::AdvanceCurrentFrameNumber() {
245 current_frame_number_++;
247 // "Drain" the ManageTiles funnel.
248 if (manage_tiles_funnel_ > 0)
249 manage_tiles_funnel_--;
251 skip_begin_main_frame_to_reduce_latency_ =
252 skip_next_begin_main_frame_to_reduce_latency_;
253 skip_next_begin_main_frame_to_reduce_latency_ = false;
256 bool SchedulerStateMachine::HasSentBeginMainFrameThisFrame() const {
257 return current_frame_number_ ==
258 last_frame_number_begin_main_frame_sent_;
261 bool SchedulerStateMachine::HasUpdatedVisibleTilesThisFrame() const {
262 return current_frame_number_ ==
263 last_frame_number_update_visible_tiles_was_called_;
266 bool SchedulerStateMachine::HasSwappedThisFrame() const {
267 return current_frame_number_ == last_frame_number_swap_performed_;
270 bool SchedulerStateMachine::HasRequestedSwapThisFrame() const {
271 return current_frame_number_ == last_frame_number_swap_requested_;
274 bool SchedulerStateMachine::PendingDrawsShouldBeAborted() const {
275 // These are all the cases where we normally cannot or do not want to draw
276 // but, if needs_redraw_ is true and we do not draw to make forward progress,
277 // we might deadlock with the main thread.
278 // This should be a superset of PendingActivationsShouldBeForced() since
279 // activation of the pending tree is blocked by drawing of the active tree and
280 // the main thread might be blocked on activation of the most recent commit.
281 if (PendingActivationsShouldBeForced())
284 // Additional states where we should abort draws.
285 // Note: We don't force activation in these cases because doing so would
286 // result in checkerboarding on resize, becoming visible, etc.
294 bool SchedulerStateMachine::PendingActivationsShouldBeForced() const {
295 // These are all the cases where, if we do not force activations to make
296 // forward progress, we might deadlock with the main thread.
298 // There is no output surface to trigger our activations.
299 if (output_surface_state_ == OUTPUT_SURFACE_LOST)
305 bool SchedulerStateMachine::ShouldBeginOutputSurfaceCreation() const {
306 // Don't try to initialize too early.
310 // We only want to start output surface initialization after the
311 // previous commit is complete.
312 if (commit_state_ != COMMIT_STATE_IDLE)
315 // Make sure the BeginImplFrame from any previous OutputSurfaces
316 // are complete before creating the new OutputSurface.
317 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_IDLE)
320 // We want to clear the pipline of any pending draws and activations
321 // before starting output surface initialization. This allows us to avoid
322 // weird corner cases where we abort draws or force activation while we
323 // are initializing the output surface.
324 if (active_tree_needs_first_draw_ || has_pending_tree_)
327 // We need to create the output surface if we don't have one and we haven't
328 // started creating one yet.
329 return output_surface_state_ == OUTPUT_SURFACE_LOST;
332 bool SchedulerStateMachine::ShouldDraw() const {
333 // If we need to abort draws, we should do so ASAP since the draw could
334 // be blocking other important actions (like output surface initialization),
335 // from occuring. If we are waiting for the first draw, then perfom the
336 // aborted draw to keep things moving. If we are not waiting for the first
337 // draw however, we don't want to abort for no reason.
338 if (PendingDrawsShouldBeAborted())
339 return active_tree_needs_first_draw_;
341 // After this line, we only want to send a swap request once per frame.
342 if (HasRequestedSwapThisFrame())
345 // Do not queue too many swaps.
346 if (pending_swaps_ >= max_pending_swaps_)
349 // Except for the cases above, do not draw outside of the BeginImplFrame
351 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
354 // Only handle forced redraws due to timeouts on the regular deadline.
355 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
358 return needs_redraw_;
361 bool SchedulerStateMachine::ShouldActivatePendingTree() const {
362 // There is nothing to activate.
363 if (!has_pending_tree_)
366 // We should not activate a second tree before drawing the first one.
367 // Even if we need to force activation of the pending tree, we should abort
368 // drawing the active tree first.
369 if (active_tree_needs_first_draw_)
372 // If we want to force activation, do so ASAP.
373 if (PendingActivationsShouldBeForced())
376 // At this point, only activate if we are ready to activate.
377 return pending_tree_is_ready_for_activation_;
380 bool SchedulerStateMachine::ShouldUpdateVisibleTiles() const {
381 if (!settings_.impl_side_painting)
383 if (HasUpdatedVisibleTilesThisFrame())
386 // We don't want to update visible tiles right after drawing.
387 if (HasRequestedSwapThisFrame())
390 // There's no reason to check for tiles if we don't have an output surface.
391 if (!HasInitializedOutputSurface())
394 // We should not check for visible tiles until we've entered the deadline so
395 // we check as late as possible and give the tiles more time to initialize.
396 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
399 // If the last swap drew with checkerboard or missing tiles, we should
400 // poll for any new visible tiles so we can be notified to draw again
402 if (swap_used_incomplete_tile_)
408 bool SchedulerStateMachine::ShouldAnimate() const {
412 if (last_frame_number_animate_performed_ == current_frame_number_)
415 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING &&
416 begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
419 return needs_redraw_ || needs_animate_;
422 bool SchedulerStateMachine::CouldSendBeginMainFrame() const {
426 // We can not perform commits if we are not visible.
433 bool SchedulerStateMachine::ShouldSendBeginMainFrame() const {
434 if (!CouldSendBeginMainFrame())
437 // Only send BeginMainFrame when there isn't another commit pending already.
438 if (commit_state_ != COMMIT_STATE_IDLE)
441 // Don't send BeginMainFrame early if we are prioritizing the active tree
442 // because of impl_latency_takes_priority_.
443 if (impl_latency_takes_priority_ &&
444 (has_pending_tree_ || active_tree_needs_first_draw_)) {
448 // We want to start the first commit after we get a new output surface ASAP.
449 if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT)
452 // We should not send BeginMainFrame while we are in
453 // BEGIN_IMPL_FRAME_STATE_IDLE since we might have new
454 // user input arriving soon.
455 // TODO(brianderson): Allow sending BeginMainFrame while idle when the main
456 // thread isn't consuming user input.
457 if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_IDLE &&
461 // We need a new commit for the forced redraw. This honors the
462 // single commit per interval because the result will be swapped to screen.
463 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_COMMIT)
466 // After this point, we only start a commit once per frame.
467 if (HasSentBeginMainFrameThisFrame())
470 // We shouldn't normally accept commits if there isn't an OutputSurface.
471 if (!HasInitializedOutputSurface())
474 // SwapAck throttle the BeginMainFrames unless we just swapped.
475 // TODO(brianderson): Remove this restriction to improve throughput.
476 bool just_swapped_in_deadline =
477 begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE &&
478 HasSwappedThisFrame();
479 if (pending_swaps_ >= max_pending_swaps_ && !just_swapped_in_deadline)
482 if (skip_begin_main_frame_to_reduce_latency_)
488 bool SchedulerStateMachine::ShouldCommit() const {
489 if (commit_state_ != COMMIT_STATE_READY_TO_COMMIT)
492 // We must not finish the commit until the pending tree is free.
493 if (has_pending_tree_) {
494 DCHECK(settings_.main_frame_before_activation_enabled);
498 // Prioritize drawing the previous commit before finishing the next commit.
499 if (active_tree_needs_first_draw_)
505 bool SchedulerStateMachine::ShouldManageTiles() const {
506 // ManageTiles only really needs to be called immediately after commit
507 // and then periodically after that. Use a funnel to make sure we average
508 // one ManageTiles per BeginImplFrame in the long run.
509 if (manage_tiles_funnel_ > 0)
512 // Limiting to once per-frame is not enough, since we only want to
513 // manage tiles _after_ draws. Polling for draw triggers and
514 // begin-frame are mutually exclusive, so we limit to these two cases.
515 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE &&
516 !inside_poll_for_anticipated_draw_triggers_)
518 return needs_manage_tiles_;
521 SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
522 if (ShouldUpdateVisibleTiles())
523 return ACTION_UPDATE_VISIBLE_TILES;
524 if (ShouldActivatePendingTree())
525 return ACTION_ACTIVATE_SYNC_TREE;
527 return ACTION_COMMIT;
529 return ACTION_ANIMATE;
531 if (PendingDrawsShouldBeAborted())
532 return ACTION_DRAW_AND_SWAP_ABORT;
533 else if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
534 return ACTION_DRAW_AND_SWAP_FORCED;
536 return ACTION_DRAW_AND_SWAP_IF_POSSIBLE;
538 if (ShouldManageTiles())
539 return ACTION_MANAGE_TILES;
540 if (ShouldSendBeginMainFrame())
541 return ACTION_SEND_BEGIN_MAIN_FRAME;
542 if (ShouldBeginOutputSurfaceCreation())
543 return ACTION_BEGIN_OUTPUT_SURFACE_CREATION;
547 void SchedulerStateMachine::UpdateState(Action action) {
552 case ACTION_UPDATE_VISIBLE_TILES:
553 last_frame_number_update_visible_tiles_was_called_ =
554 current_frame_number_;
557 case ACTION_ACTIVATE_SYNC_TREE:
558 UpdateStateOnActivation();
562 last_frame_number_animate_performed_ = current_frame_number_;
563 needs_animate_ = false;
564 // TODO(skyostil): Instead of assuming this, require the client to tell
569 case ACTION_SEND_BEGIN_MAIN_FRAME:
570 DCHECK(!has_pending_tree_ ||
571 settings_.main_frame_before_activation_enabled);
572 DCHECK(!active_tree_needs_first_draw_ ||
573 settings_.main_frame_before_draw_enabled);
575 commit_state_ = COMMIT_STATE_BEGIN_MAIN_FRAME_SENT;
576 needs_commit_ = false;
577 last_frame_number_begin_main_frame_sent_ =
578 current_frame_number_;
581 case ACTION_COMMIT: {
582 bool commit_was_aborted = false;
583 UpdateStateOnCommit(commit_was_aborted);
587 case ACTION_DRAW_AND_SWAP_FORCED:
588 case ACTION_DRAW_AND_SWAP_IF_POSSIBLE: {
589 bool did_request_swap = true;
590 UpdateStateOnDraw(did_request_swap);
594 case ACTION_DRAW_AND_SWAP_ABORT: {
595 bool did_request_swap = false;
596 UpdateStateOnDraw(did_request_swap);
600 case ACTION_BEGIN_OUTPUT_SURFACE_CREATION:
601 DCHECK_EQ(output_surface_state_, OUTPUT_SURFACE_LOST);
602 output_surface_state_ = OUTPUT_SURFACE_CREATING;
604 // The following DCHECKs make sure we are in the proper quiescent state.
605 // The pipeline should be flushed entirely before we start output
606 // surface creation to avoid complicated corner cases.
607 DCHECK_EQ(commit_state_, COMMIT_STATE_IDLE);
608 DCHECK(!has_pending_tree_);
609 DCHECK(!active_tree_needs_first_draw_);
612 case ACTION_MANAGE_TILES:
613 UpdateStateOnManageTiles();
618 void SchedulerStateMachine::UpdateStateOnCommit(bool commit_was_aborted) {
621 if (commit_was_aborted || settings_.main_frame_before_activation_enabled) {
622 commit_state_ = COMMIT_STATE_IDLE;
623 } else if (settings_.main_frame_before_draw_enabled) {
624 commit_state_ = settings_.impl_side_painting
625 ? COMMIT_STATE_WAITING_FOR_ACTIVATION
628 commit_state_ = COMMIT_STATE_WAITING_FOR_FIRST_DRAW;
631 // If we are impl-side-painting but the commit was aborted, then we behave
632 // mostly as if we are not impl-side-painting since there is no pending tree.
633 has_pending_tree_ = settings_.impl_side_painting && !commit_was_aborted;
635 // Update state related to forced draws.
636 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_COMMIT) {
637 forced_redraw_state_ = has_pending_tree_
638 ? FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION
639 : FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
642 // Update the output surface state.
643 DCHECK_NE(output_surface_state_, OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION);
644 if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT) {
645 if (has_pending_tree_) {
646 output_surface_state_ = OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION;
648 output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
649 needs_redraw_ = true;
653 // Update state if we have a new active tree to draw, or if the active tree
654 // was unchanged but we need to do a forced draw.
655 if (!has_pending_tree_ &&
656 (!commit_was_aborted ||
657 forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)) {
658 needs_redraw_ = true;
659 active_tree_needs_first_draw_ = true;
662 // This post-commit work is common to both completed and aborted commits.
663 pending_tree_is_ready_for_activation_ = false;
665 if (continuous_painting_)
666 needs_commit_ = true;
669 void SchedulerStateMachine::UpdateStateOnActivation() {
670 if (commit_state_ == COMMIT_STATE_WAITING_FOR_ACTIVATION)
671 commit_state_ = COMMIT_STATE_IDLE;
673 if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION)
674 output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
676 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION)
677 forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
679 has_pending_tree_ = false;
680 pending_tree_is_ready_for_activation_ = false;
681 active_tree_needs_first_draw_ = true;
682 needs_redraw_ = true;
685 void SchedulerStateMachine::UpdateStateOnDraw(bool did_request_swap) {
686 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
687 forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
689 if (!has_pending_tree_ &&
690 commit_state_ == COMMIT_STATE_WAITING_FOR_FIRST_DRAW) {
691 commit_state_ = COMMIT_STATE_IDLE;
694 needs_redraw_ = false;
695 active_tree_needs_first_draw_ = false;
697 if (did_request_swap)
698 last_frame_number_swap_requested_ = current_frame_number_;
701 void SchedulerStateMachine::UpdateStateOnManageTiles() {
702 needs_manage_tiles_ = false;
705 void SchedulerStateMachine::SetSkipNextBeginMainFrameToReduceLatency() {
706 skip_next_begin_main_frame_to_reduce_latency_ = true;
709 bool SchedulerStateMachine::BeginFrameNeeded() const {
710 // Proactive BeginFrames are bad for the synchronous compositor because we
711 // have to draw when we get the BeginFrame and could end up drawing many
712 // duplicate frames if our new frame isn't ready in time.
713 // To poll for state with the synchronous compositor without having to draw,
714 // we rely on ShouldPollForAnticipatedDrawTriggers instead.
715 if (!SupportsProactiveBeginFrame())
716 return BeginFrameNeededToAnimateOrDraw();
718 return BeginFrameNeededToAnimateOrDraw() || ProactiveBeginFrameWanted();
721 bool SchedulerStateMachine::ShouldPollForAnticipatedDrawTriggers() const {
722 // ShouldPollForAnticipatedDrawTriggers is what we use in place of
723 // ProactiveBeginFrameWanted when we are using the synchronous
725 if (!SupportsProactiveBeginFrame()) {
726 return !BeginFrameNeededToAnimateOrDraw() && ProactiveBeginFrameWanted();
729 // Non synchronous compositors should rely on
730 // ProactiveBeginFrameWanted to poll for state instead.
734 // Note: If SupportsProactiveBeginFrame is false, the scheduler should poll
735 // for changes in it's draw state so it can request a BeginFrame when it's
737 bool SchedulerStateMachine::SupportsProactiveBeginFrame() const {
738 // It is undesirable to proactively request BeginFrames if we are
739 // using a synchronous compositor because we *must* draw for every
740 // BeginFrame, which could cause duplicate draws.
741 return !settings_.using_synchronous_renderer_compositor;
744 // These are the cases where we definitely (or almost definitely) have a
745 // new frame to animate and/or draw and can draw.
746 bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
747 // The output surface is the provider of BeginImplFrames, so we are not going
748 // to get them even if we ask for them.
749 if (!HasInitializedOutputSurface())
752 // If we can't draw, don't tick until we are notified that we can draw again.
756 // The forced draw respects our normal draw scheduling, so we need to
757 // request a BeginImplFrame for it.
758 if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
761 // There's no need to produce frames if we are not visible.
765 // We need to draw a more complete frame than we did the last BeginImplFrame,
766 // so request another BeginImplFrame in anticipation that we will have
767 // additional visible tiles.
768 if (swap_used_incomplete_tile_)
774 return needs_redraw_;
777 // These are cases where we are very likely to draw soon, but might not
778 // actually have a new frame to draw when we receive the next BeginImplFrame.
779 // Proactively requesting the BeginImplFrame helps hide the round trip latency
780 // of the SetNeedsBeginFrame request that has to go to the Browser.
781 bool SchedulerStateMachine::ProactiveBeginFrameWanted() const {
782 // The output surface is the provider of BeginImplFrames,
783 // so we are not going to get them even if we ask for them.
784 if (!HasInitializedOutputSurface())
787 // Do not be proactive when invisible.
791 // We should proactively request a BeginImplFrame if a commit is pending
792 // because we will want to draw if the commit completes quickly.
793 if (needs_commit_ || commit_state_ != COMMIT_STATE_IDLE)
796 // If the pending tree activates quickly, we'll want a BeginImplFrame soon
797 // to draw the new active tree.
798 if (has_pending_tree_)
801 // Changing priorities may allow us to activate (given the new priorities),
802 // which may result in a new frame.
803 if (needs_manage_tiles_)
806 // If we just sent a swap request, it's likely that we are going to produce
807 // another frame soon. This helps avoid negative glitches in our
808 // SetNeedsBeginFrame requests, which may propagate to the BeginImplFrame
809 // provider and get sampled at an inopportune time, delaying the next
811 if (HasRequestedSwapThisFrame())
817 void SchedulerStateMachine::OnBeginImplFrame(const BeginFrameArgs& args) {
818 AdvanceCurrentFrameNumber();
819 begin_impl_frame_args_ = args;
820 DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_IDLE)
821 << AsValue()->ToString();
822 begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING;
825 void SchedulerStateMachine::OnBeginImplFrameDeadlinePending() {
826 DCHECK_EQ(begin_impl_frame_state_,
827 BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING)
828 << AsValue()->ToString();
829 begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME;
832 void SchedulerStateMachine::OnBeginImplFrameDeadline() {
833 DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
834 << AsValue()->ToString();
835 begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE;
838 void SchedulerStateMachine::OnBeginImplFrameIdle() {
839 DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
840 << AsValue()->ToString();
841 begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_IDLE;
844 bool SchedulerStateMachine::ShouldTriggerBeginImplFrameDeadlineEarly() const {
845 // TODO(brianderson): This should take into account multiple commit sources.
847 if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
850 // If we've lost the output surface, end the current BeginImplFrame ASAP
851 // so we can start creating the next output surface.
852 if (output_surface_state_ == OUTPUT_SURFACE_LOST)
855 // SwapAck throttle the deadline since we wont draw and swap anyway.
856 if (pending_swaps_ >= max_pending_swaps_)
859 if (active_tree_needs_first_draw_)
865 // This is used to prioritize impl-thread draws when the main thread isn't
866 // producing anything, e.g., after an aborted commit. We also check that we
867 // don't have a pending tree -- otherwise we should give it a chance to
869 // TODO(skyostil): Revisit this when we have more accurate deadline estimates.
870 if (commit_state_ == COMMIT_STATE_IDLE && !has_pending_tree_)
873 // Prioritize impl-thread draws in impl_latency_takes_priority_ mode.
874 if (impl_latency_takes_priority_)
880 bool SchedulerStateMachine::MainThreadIsInHighLatencyMode() const {
881 // If a commit is pending before the previous commit has been drawn, we
882 // are definitely in a high latency mode.
883 if (CommitPending() && (active_tree_needs_first_draw_ || has_pending_tree_))
886 // If we just sent a BeginMainFrame and haven't hit the deadline yet, the main
887 // thread is in a low latency mode.
888 if (HasSentBeginMainFrameThisFrame() &&
889 (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING ||
890 begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME))
893 // If there's a commit in progress it must either be from the previous frame
894 // or it started after the impl thread's deadline. In either case the main
895 // thread is in high latency mode.
899 // Similarly, if there's a pending tree the main thread is in high latency
900 // mode, because either
901 // it's from the previous frame
903 // we're currently drawing the active tree and the pending tree will thus
904 // only be drawn in the next frame.
905 if (has_pending_tree_)
908 if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE) {
909 // Even if there's a new active tree to draw at the deadline or we've just
910 // swapped it, it may have been triggered by a previous BeginImplFrame, in
911 // which case the main thread is in a high latency mode.
912 return (active_tree_needs_first_draw_ || HasSwappedThisFrame()) &&
913 !HasSentBeginMainFrameThisFrame();
916 // If the active tree needs its first draw in any other state, we know the
917 // main thread is in a high latency mode.
918 return active_tree_needs_first_draw_;
921 void SchedulerStateMachine::DidEnterPollForAnticipatedDrawTriggers() {
922 AdvanceCurrentFrameNumber();
923 inside_poll_for_anticipated_draw_triggers_ = true;
926 void SchedulerStateMachine::DidLeavePollForAnticipatedDrawTriggers() {
927 inside_poll_for_anticipated_draw_triggers_ = false;
930 void SchedulerStateMachine::SetVisible(bool visible) { visible_ = visible; }
932 void SchedulerStateMachine::SetCanDraw(bool can_draw) { can_draw_ = can_draw; }
934 void SchedulerStateMachine::SetNeedsRedraw() { needs_redraw_ = true; }
936 void SchedulerStateMachine::SetNeedsAnimate() {
937 needs_animate_ = true;
940 void SchedulerStateMachine::SetNeedsManageTiles() {
941 if (!needs_manage_tiles_) {
943 "SchedulerStateMachine::SetNeedsManageTiles");
944 needs_manage_tiles_ = true;
948 void SchedulerStateMachine::SetMaxSwapsPending(int max) {
949 max_pending_swaps_ = max;
952 void SchedulerStateMachine::DidSwapBuffers() {
954 DCHECK_LE(pending_swaps_, max_pending_swaps_);
956 last_frame_number_swap_performed_ = current_frame_number_;
959 void SchedulerStateMachine::SetSwapUsedIncompleteTile(
960 bool used_incomplete_tile) {
961 swap_used_incomplete_tile_ = used_incomplete_tile;
964 void SchedulerStateMachine::DidSwapBuffersComplete() {
965 DCHECK_GT(pending_swaps_, 0);
969 void SchedulerStateMachine::SetImplLatencyTakesPriority(
970 bool impl_latency_takes_priority) {
971 impl_latency_takes_priority_ = impl_latency_takes_priority;
974 void SchedulerStateMachine::DidDrawIfPossibleCompleted(DrawResult result) {
977 NOTREACHED() << "Uninitialized DrawResult.";
979 case DRAW_ABORTED_CANT_DRAW:
980 case DRAW_ABORTED_CONTEXT_LOST:
981 NOTREACHED() << "Invalid return value from DrawAndSwapIfPossible:"
985 consecutive_checkerboard_animations_ = 0;
986 forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
988 case DRAW_ABORTED_CHECKERBOARD_ANIMATIONS:
989 needs_redraw_ = true;
991 // If we're already in the middle of a redraw, we don't need to
993 if (forced_redraw_state_ != FORCED_REDRAW_STATE_IDLE)
996 needs_commit_ = true;
997 consecutive_checkerboard_animations_++;
998 if (settings_.timeout_and_draw_when_animation_checkerboards &&
999 consecutive_checkerboard_animations_ >=
1000 settings_.maximum_number_of_failed_draws_before_draw_is_forced_) {
1001 consecutive_checkerboard_animations_ = 0;
1002 // We need to force a draw, but it doesn't make sense to do this until
1003 // we've committed and have new textures.
1004 forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
1007 case DRAW_ABORTED_MISSING_HIGH_RES_CONTENT:
1008 // It's not clear whether this missing content is because of missing
1009 // pictures (which requires a commit) or because of memory pressure
1010 // removing textures (which might not). To be safe, request a commit
1012 needs_commit_ = true;
1017 void SchedulerStateMachine::SetNeedsCommit() {
1018 needs_commit_ = true;
1021 void SchedulerStateMachine::NotifyReadyToCommit() {
1022 DCHECK(commit_state_ == COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED)
1023 << AsValue()->ToString();
1024 commit_state_ = COMMIT_STATE_READY_TO_COMMIT;
1027 void SchedulerStateMachine::BeginMainFrameAborted(bool did_handle) {
1028 DCHECK_EQ(commit_state_, COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
1030 bool commit_was_aborted = true;
1031 UpdateStateOnCommit(commit_was_aborted);
1033 commit_state_ = COMMIT_STATE_IDLE;
1038 void SchedulerStateMachine::DidManageTiles() {
1039 needs_manage_tiles_ = false;
1040 // "Fill" the ManageTiles funnel.
1041 manage_tiles_funnel_++;
1044 void SchedulerStateMachine::DidLoseOutputSurface() {
1045 if (output_surface_state_ == OUTPUT_SURFACE_LOST ||
1046 output_surface_state_ == OUTPUT_SURFACE_CREATING)
1048 output_surface_state_ = OUTPUT_SURFACE_LOST;
1049 needs_redraw_ = false;
1052 void SchedulerStateMachine::NotifyReadyToActivate() {
1053 if (has_pending_tree_)
1054 pending_tree_is_ready_for_activation_ = true;
1057 void SchedulerStateMachine::DidCreateAndInitializeOutputSurface() {
1058 DCHECK_EQ(output_surface_state_, OUTPUT_SURFACE_CREATING);
1059 output_surface_state_ = OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT;
1061 if (did_create_and_initialize_first_output_surface_) {
1062 // TODO(boliu): See if we can remove this when impl-side painting is always
1063 // on. Does anything on the main thread need to update after recreate?
1064 needs_commit_ = true;
1066 did_create_and_initialize_first_output_surface_ = true;
1070 void SchedulerStateMachine::NotifyBeginMainFrameStarted() {
1071 DCHECK_EQ(commit_state_, COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
1072 commit_state_ = COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED;
1075 bool SchedulerStateMachine::HasInitializedOutputSurface() const {
1076 switch (output_surface_state_) {
1077 case OUTPUT_SURFACE_LOST:
1078 case OUTPUT_SURFACE_CREATING:
1081 case OUTPUT_SURFACE_ACTIVE:
1082 case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
1083 case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
1090 std::string SchedulerStateMachine::GetStatesForDebugging() const {
1091 return base::StringPrintf("%c %d %d %d %c %c %c %d %d",
1092 needs_commit_ ? 'T' : 'F',
1093 static_cast<int>(output_surface_state_),
1094 static_cast<int>(begin_impl_frame_state_),
1095 static_cast<int>(commit_state_),
1096 has_pending_tree_ ? 'T' : 'F',
1097 pending_tree_is_ready_for_activation_ ? 'T' : 'F',
1098 active_tree_needs_first_draw_ ? 'T' : 'F',