blob: 8e87c0f7186437b3361c34462d867ed699b26cd6 [file] [log] [blame]
// Copyright 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "cc/scheduler/scheduler_state_machine.h"
#include "base/debug/trace_event.h"
#include "base/debug/trace_event_argument.h"
#include "base/format_macros.h"
#include "base/logging.h"
#include "base/strings/stringprintf.h"
#include "base/values.h"
#include "ui/gfx/frame_time.h"
namespace cc {
SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
: settings_(settings),
output_surface_state_(OUTPUT_SURFACE_LOST),
begin_impl_frame_state_(BEGIN_IMPL_FRAME_STATE_IDLE),
commit_state_(COMMIT_STATE_IDLE),
forced_redraw_state_(FORCED_REDRAW_STATE_IDLE),
commit_count_(0),
current_frame_number_(0),
last_frame_number_animate_performed_(-1),
last_frame_number_swap_performed_(-1),
last_frame_number_swap_requested_(-1),
last_frame_number_begin_main_frame_sent_(-1),
manage_tiles_funnel_(0),
consecutive_checkerboard_animations_(0),
max_pending_swaps_(1),
pending_swaps_(0),
needs_redraw_(false),
needs_animate_(false),
needs_manage_tiles_(false),
needs_commit_(false),
inside_poll_for_anticipated_draw_triggers_(false),
visible_(false),
can_start_(false),
can_draw_(false),
has_pending_tree_(false),
pending_tree_is_ready_for_activation_(false),
active_tree_needs_first_draw_(false),
did_commit_after_animating_(false),
did_create_and_initialize_first_output_surface_(false),
impl_latency_takes_priority_(false),
skip_next_begin_main_frame_to_reduce_latency_(false),
skip_begin_main_frame_to_reduce_latency_(false),
continuous_painting_(false),
impl_latency_takes_priority_on_battery_(false),
children_need_begin_frames_(false) {
}
const char* SchedulerStateMachine::OutputSurfaceStateToString(
OutputSurfaceState state) {
switch (state) {
case OUTPUT_SURFACE_ACTIVE:
return "OUTPUT_SURFACE_ACTIVE";
case OUTPUT_SURFACE_LOST:
return "OUTPUT_SURFACE_LOST";
case OUTPUT_SURFACE_CREATING:
return "OUTPUT_SURFACE_CREATING";
case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
return "OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT";
case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
return "OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION";
}
NOTREACHED();
return "???";
}
const char* SchedulerStateMachine::BeginImplFrameStateToString(
BeginImplFrameState state) {
switch (state) {
case BEGIN_IMPL_FRAME_STATE_IDLE:
return "BEGIN_IMPL_FRAME_STATE_IDLE";
case BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING:
return "BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING";
case BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME:
return "BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME";
case BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE:
return "BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE";
}
NOTREACHED();
return "???";
}
const char* SchedulerStateMachine::CommitStateToString(CommitState state) {
switch (state) {
case COMMIT_STATE_IDLE:
return "COMMIT_STATE_IDLE";
case COMMIT_STATE_BEGIN_MAIN_FRAME_SENT:
return "COMMIT_STATE_BEGIN_MAIN_FRAME_SENT";
case COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED:
return "COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED";
case COMMIT_STATE_READY_TO_COMMIT:
return "COMMIT_STATE_READY_TO_COMMIT";
case COMMIT_STATE_WAITING_FOR_ACTIVATION:
return "COMMIT_STATE_WAITING_FOR_ACTIVATION";
case COMMIT_STATE_WAITING_FOR_DRAW:
return "COMMIT_STATE_WAITING_FOR_DRAW";
}
NOTREACHED();
return "???";
}
const char* SchedulerStateMachine::ForcedRedrawOnTimeoutStateToString(
ForcedRedrawOnTimeoutState state) {
switch (state) {
case FORCED_REDRAW_STATE_IDLE:
return "FORCED_REDRAW_STATE_IDLE";
case FORCED_REDRAW_STATE_WAITING_FOR_COMMIT:
return "FORCED_REDRAW_STATE_WAITING_FOR_COMMIT";
case FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION:
return "FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION";
case FORCED_REDRAW_STATE_WAITING_FOR_DRAW:
return "FORCED_REDRAW_STATE_WAITING_FOR_DRAW";
}
NOTREACHED();
return "???";
}
const char* SchedulerStateMachine::ActionToString(Action action) {
switch (action) {
case ACTION_NONE:
return "ACTION_NONE";
case ACTION_ANIMATE:
return "ACTION_ANIMATE";
case ACTION_SEND_BEGIN_MAIN_FRAME:
return "ACTION_SEND_BEGIN_MAIN_FRAME";
case ACTION_COMMIT:
return "ACTION_COMMIT";
case ACTION_ACTIVATE_SYNC_TREE:
return "ACTION_ACTIVATE_SYNC_TREE";
case ACTION_DRAW_AND_SWAP_IF_POSSIBLE:
return "ACTION_DRAW_AND_SWAP_IF_POSSIBLE";
case ACTION_DRAW_AND_SWAP_FORCED:
return "ACTION_DRAW_AND_SWAP_FORCED";
case ACTION_DRAW_AND_SWAP_ABORT:
return "ACTION_DRAW_AND_SWAP_ABORT";
case ACTION_BEGIN_OUTPUT_SURFACE_CREATION:
return "ACTION_BEGIN_OUTPUT_SURFACE_CREATION";
case ACTION_MANAGE_TILES:
return "ACTION_MANAGE_TILES";
}
NOTREACHED();
return "???";
}
scoped_refptr<base::debug::ConvertableToTraceFormat>
SchedulerStateMachine::AsValue() const {
scoped_refptr<base::debug::TracedValue> state =
new base::debug::TracedValue();
AsValueInto(state.get(), gfx::FrameTime::Now());
return state;
}
void SchedulerStateMachine::AsValueInto(base::debug::TracedValue* state,
base::TimeTicks now) const {
state->BeginDictionary("major_state");
state->SetString("next_action", ActionToString(NextAction()));
state->SetString("begin_impl_frame_state",
BeginImplFrameStateToString(begin_impl_frame_state_));
state->SetString("commit_state", CommitStateToString(commit_state_));
state->SetString("output_surface_state_",
OutputSurfaceStateToString(output_surface_state_));
state->SetString("forced_redraw_state",
ForcedRedrawOnTimeoutStateToString(forced_redraw_state_));
state->EndDictionary();
state->BeginDictionary("major_timestamps_in_ms");
state->SetDouble("0_interval",
begin_impl_frame_args_.interval.InMicroseconds() / 1000.0L);
state->SetDouble(
"1_now_to_deadline",
(begin_impl_frame_args_.deadline - now).InMicroseconds() / 1000.0L);
state->SetDouble(
"2_frame_time_to_now",
(now - begin_impl_frame_args_.frame_time).InMicroseconds() / 1000.0L);
state->SetDouble("3_frame_time_to_deadline",
(begin_impl_frame_args_.deadline -
begin_impl_frame_args_.frame_time).InMicroseconds() /
1000.0L);
state->SetDouble("4_now",
(now - base::TimeTicks()).InMicroseconds() / 1000.0L);
state->SetDouble(
"5_frame_time",
(begin_impl_frame_args_.frame_time - base::TimeTicks()).InMicroseconds() /
1000.0L);
state->SetDouble(
"6_deadline",
(begin_impl_frame_args_.deadline - base::TimeTicks()).InMicroseconds() /
1000.0L);
state->EndDictionary();
state->BeginDictionary("minor_state");
state->SetInteger("commit_count", commit_count_);
state->SetInteger("current_frame_number", current_frame_number_);
state->SetInteger("last_frame_number_animate_performed",
last_frame_number_animate_performed_);
state->SetInteger("last_frame_number_swap_performed",
last_frame_number_swap_performed_);
state->SetInteger("last_frame_number_swap_requested",
last_frame_number_swap_requested_);
state->SetInteger("last_frame_number_begin_main_frame_sent",
last_frame_number_begin_main_frame_sent_);
state->SetInteger("manage_tiles_funnel", manage_tiles_funnel_);
state->SetInteger("consecutive_checkerboard_animations",
consecutive_checkerboard_animations_);
state->SetInteger("max_pending_swaps_", max_pending_swaps_);
state->SetInteger("pending_swaps_", pending_swaps_);
state->SetBoolean("needs_redraw", needs_redraw_);
state->SetBoolean("needs_animate_", needs_animate_);
state->SetBoolean("needs_manage_tiles", needs_manage_tiles_);
state->SetBoolean("needs_commit", needs_commit_);
state->SetBoolean("visible", visible_);
state->SetBoolean("can_start", can_start_);
state->SetBoolean("can_draw", can_draw_);
state->SetBoolean("has_pending_tree", has_pending_tree_);
state->SetBoolean("pending_tree_is_ready_for_activation",
pending_tree_is_ready_for_activation_);
state->SetBoolean("active_tree_needs_first_draw",
active_tree_needs_first_draw_);
state->SetBoolean("did_commit_after_animating", did_commit_after_animating_);
state->SetBoolean("did_create_and_initialize_first_output_surface",
did_create_and_initialize_first_output_surface_);
state->SetBoolean("impl_latency_takes_priority",
impl_latency_takes_priority_);
state->SetBoolean("main_thread_is_in_high_latency_mode",
MainThreadIsInHighLatencyMode());
state->SetBoolean("skip_begin_main_frame_to_reduce_latency",
skip_begin_main_frame_to_reduce_latency_);
state->SetBoolean("skip_next_begin_main_frame_to_reduce_latency",
skip_next_begin_main_frame_to_reduce_latency_);
state->SetBoolean("continuous_painting", continuous_painting_);
state->SetBoolean("impl_latency_takes_priority_on_battery",
impl_latency_takes_priority_on_battery_);
state->SetBoolean("children_need_begin_frames", children_need_begin_frames_);
state->EndDictionary();
}
void SchedulerStateMachine::AdvanceCurrentFrameNumber() {
current_frame_number_++;
// "Drain" the ManageTiles funnel.
if (manage_tiles_funnel_ > 0)
manage_tiles_funnel_--;
skip_begin_main_frame_to_reduce_latency_ =
skip_next_begin_main_frame_to_reduce_latency_;
skip_next_begin_main_frame_to_reduce_latency_ = false;
}
bool SchedulerStateMachine::HasAnimatedThisFrame() const {
return last_frame_number_animate_performed_ == current_frame_number_;
}
bool SchedulerStateMachine::HasSentBeginMainFrameThisFrame() const {
return current_frame_number_ ==
last_frame_number_begin_main_frame_sent_;
}
bool SchedulerStateMachine::HasSwappedThisFrame() const {
return current_frame_number_ == last_frame_number_swap_performed_;
}
bool SchedulerStateMachine::HasRequestedSwapThisFrame() const {
return current_frame_number_ == last_frame_number_swap_requested_;
}
bool SchedulerStateMachine::PendingDrawsShouldBeAborted() const {
// These are all the cases where we normally cannot or do not want to draw
// but, if needs_redraw_ is true and we do not draw to make forward progress,
// we might deadlock with the main thread.
// This should be a superset of PendingActivationsShouldBeForced() since
// activation of the pending tree is blocked by drawing of the active tree and
// the main thread might be blocked on activation of the most recent commit.
if (PendingActivationsShouldBeForced())
return true;
// Additional states where we should abort draws.
if (!can_draw_)
return true;
return false;
}
bool SchedulerStateMachine::PendingActivationsShouldBeForced() const {
// There is no output surface to trigger our activations.
// If we do not force activations to make forward progress, we might deadlock
// with the main thread.
if (output_surface_state_ == OUTPUT_SURFACE_LOST)
return true;
// If we're not visible, we should force activation.
// Since we set RequiresHighResToDraw when becoming visible, we ensure that we
// don't checkerboard until all visible resources are done. Furthermore, if we
// do keep the pending tree around, when becoming visible we might activate
// prematurely causing RequiresHighResToDraw flag to be reset. In all cases,
// we can simply activate on becoming invisible since we don't need to draw
// the active tree when we're in this state.
if (!visible_)
return true;
return false;
}
bool SchedulerStateMachine::ShouldBeginOutputSurfaceCreation() const {
// Don't try to initialize too early.
if (!can_start_)
return false;
// We only want to start output surface initialization after the
// previous commit is complete.
if (commit_state_ != COMMIT_STATE_IDLE)
return false;
// Make sure the BeginImplFrame from any previous OutputSurfaces
// are complete before creating the new OutputSurface.
if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_IDLE)
return false;
// We want to clear the pipline of any pending draws and activations
// before starting output surface initialization. This allows us to avoid
// weird corner cases where we abort draws or force activation while we
// are initializing the output surface.
if (active_tree_needs_first_draw_ || has_pending_tree_)
return false;
// We need to create the output surface if we don't have one and we haven't
// started creating one yet.
return output_surface_state_ == OUTPUT_SURFACE_LOST;
}
bool SchedulerStateMachine::ShouldDraw() const {
// If we need to abort draws, we should do so ASAP since the draw could
// be blocking other important actions (like output surface initialization),
// from occuring. If we are waiting for the first draw, then perfom the
// aborted draw to keep things moving. If we are not waiting for the first
// draw however, we don't want to abort for no reason.
if (PendingDrawsShouldBeAborted())
return active_tree_needs_first_draw_;
// If a commit has occurred after the animate call, we need to call animate
// again before we should draw.
if (did_commit_after_animating_)
return false;
// After this line, we only want to send a swap request once per frame.
if (HasRequestedSwapThisFrame())
return false;
// Do not queue too many swaps.
if (pending_swaps_ >= max_pending_swaps_)
return false;
// Except for the cases above, do not draw outside of the BeginImplFrame
// deadline.
if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
return false;
// Only handle forced redraws due to timeouts on the regular deadline.
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
return true;
return needs_redraw_;
}
bool SchedulerStateMachine::ShouldActivatePendingTree() const {
// There is nothing to activate.
if (!has_pending_tree_)
return false;
// We should not activate a second tree before drawing the first one.
// Even if we need to force activation of the pending tree, we should abort
// drawing the active tree first.
if (active_tree_needs_first_draw_)
return false;
// If we want to force activation, do so ASAP.
if (PendingActivationsShouldBeForced())
return true;
// At this point, only activate if we are ready to activate.
return pending_tree_is_ready_for_activation_;
}
bool SchedulerStateMachine::ShouldAnimate() const {
// If a commit occurred after our last call, we need to do animation again.
if (HasAnimatedThisFrame() && !did_commit_after_animating_)
return false;
if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING &&
begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
return false;
return needs_redraw_ || needs_animate_;
}
bool SchedulerStateMachine::CouldSendBeginMainFrame() const {
if (!needs_commit_)
return false;
// We can not perform commits if we are not visible.
if (!visible_)
return false;
return true;
}
bool SchedulerStateMachine::ShouldSendBeginMainFrame() const {
if (!CouldSendBeginMainFrame())
return false;
// Only send BeginMainFrame when there isn't another commit pending already.
if (commit_state_ != COMMIT_STATE_IDLE)
return false;
// Don't send BeginMainFrame early if we are prioritizing the active tree
// because of impl_latency_takes_priority_.
if (impl_latency_takes_priority_ &&
(has_pending_tree_ || active_tree_needs_first_draw_)) {
return false;
}
// We want to start the first commit after we get a new output surface ASAP.
if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT)
return true;
// We should not send BeginMainFrame while we are in
// BEGIN_IMPL_FRAME_STATE_IDLE since we might have new
// user input arriving soon.
// TODO(brianderson): Allow sending BeginMainFrame while idle when the main
// thread isn't consuming user input.
if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_IDLE &&
BeginFrameNeeded())
return false;
// We need a new commit for the forced redraw. This honors the
// single commit per interval because the result will be swapped to screen.
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_COMMIT)
return true;
// After this point, we only start a commit once per frame.
if (HasSentBeginMainFrameThisFrame())
return false;
// We shouldn't normally accept commits if there isn't an OutputSurface.
if (!HasInitializedOutputSurface())
return false;
// SwapAck throttle the BeginMainFrames unless we just swapped.
// TODO(brianderson): Remove this restriction to improve throughput.
bool just_swapped_in_deadline =
begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE &&
HasSwappedThisFrame();
if (pending_swaps_ >= max_pending_swaps_ && !just_swapped_in_deadline)
return false;
if (skip_begin_main_frame_to_reduce_latency_)
return false;
return true;
}
bool SchedulerStateMachine::ShouldCommit() const {
if (commit_state_ != COMMIT_STATE_READY_TO_COMMIT)
return false;
// We must not finish the commit until the pending tree is free.
if (has_pending_tree_) {
DCHECK(settings_.main_frame_before_activation_enabled);
return false;
}
// Prioritize drawing the previous commit before finishing the next commit.
if (active_tree_needs_first_draw_)
return false;
return true;
}
bool SchedulerStateMachine::ShouldManageTiles() const {
// ManageTiles only really needs to be called immediately after commit
// and then periodically after that. Use a funnel to make sure we average
// one ManageTiles per BeginImplFrame in the long run.
if (manage_tiles_funnel_ > 0)
return false;
// Limiting to once per-frame is not enough, since we only want to
// manage tiles _after_ draws. Polling for draw triggers and
// begin-frame are mutually exclusive, so we limit to these two cases.
if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE &&
!inside_poll_for_anticipated_draw_triggers_)
return false;
return needs_manage_tiles_;
}
SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
if (ShouldActivatePendingTree())
return ACTION_ACTIVATE_SYNC_TREE;
if (ShouldCommit())
return ACTION_COMMIT;
if (ShouldAnimate())
return ACTION_ANIMATE;
if (ShouldDraw()) {
if (PendingDrawsShouldBeAborted())
return ACTION_DRAW_AND_SWAP_ABORT;
else if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
return ACTION_DRAW_AND_SWAP_FORCED;
else
return ACTION_DRAW_AND_SWAP_IF_POSSIBLE;
}
if (ShouldManageTiles())
return ACTION_MANAGE_TILES;
if (ShouldSendBeginMainFrame())
return ACTION_SEND_BEGIN_MAIN_FRAME;
if (ShouldBeginOutputSurfaceCreation())
return ACTION_BEGIN_OUTPUT_SURFACE_CREATION;
return ACTION_NONE;
}
void SchedulerStateMachine::UpdateState(Action action) {
switch (action) {
case ACTION_NONE:
return;
case ACTION_ACTIVATE_SYNC_TREE:
UpdateStateOnActivation();
return;
case ACTION_ANIMATE:
last_frame_number_animate_performed_ = current_frame_number_;
needs_animate_ = false;
did_commit_after_animating_ = false;
// TODO(skyostil): Instead of assuming this, require the client to tell
// us.
SetNeedsRedraw();
return;
case ACTION_SEND_BEGIN_MAIN_FRAME:
DCHECK(!has_pending_tree_ ||
settings_.main_frame_before_activation_enabled);
DCHECK(visible_);
commit_state_ = COMMIT_STATE_BEGIN_MAIN_FRAME_SENT;
needs_commit_ = false;
last_frame_number_begin_main_frame_sent_ =
current_frame_number_;
return;
case ACTION_COMMIT: {
bool commit_was_aborted = false;
UpdateStateOnCommit(commit_was_aborted);
return;
}
case ACTION_DRAW_AND_SWAP_FORCED:
case ACTION_DRAW_AND_SWAP_IF_POSSIBLE: {
bool did_request_swap = true;
UpdateStateOnDraw(did_request_swap);
return;
}
case ACTION_DRAW_AND_SWAP_ABORT: {
bool did_request_swap = false;
UpdateStateOnDraw(did_request_swap);
return;
}
case ACTION_BEGIN_OUTPUT_SURFACE_CREATION:
DCHECK_EQ(output_surface_state_, OUTPUT_SURFACE_LOST);
output_surface_state_ = OUTPUT_SURFACE_CREATING;
// The following DCHECKs make sure we are in the proper quiescent state.
// The pipeline should be flushed entirely before we start output
// surface creation to avoid complicated corner cases.
DCHECK_EQ(commit_state_, COMMIT_STATE_IDLE);
DCHECK(!has_pending_tree_);
DCHECK(!active_tree_needs_first_draw_);
return;
case ACTION_MANAGE_TILES:
UpdateStateOnManageTiles();
return;
}
}
void SchedulerStateMachine::UpdateStateOnCommit(bool commit_was_aborted) {
commit_count_++;
if (!commit_was_aborted && HasAnimatedThisFrame())
did_commit_after_animating_ = true;
if (commit_was_aborted || settings_.main_frame_before_activation_enabled) {
commit_state_ = COMMIT_STATE_IDLE;
} else if (settings_.impl_side_painting) {
commit_state_ = COMMIT_STATE_WAITING_FOR_ACTIVATION;
} else {
commit_state_ = settings_.main_thread_should_always_be_low_latency
? COMMIT_STATE_WAITING_FOR_DRAW
: COMMIT_STATE_IDLE;
}
// If we are impl-side-painting but the commit was aborted, then we behave
// mostly as if we are not impl-side-painting since there is no pending tree.
has_pending_tree_ = settings_.impl_side_painting && !commit_was_aborted;
// Update state related to forced draws.
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_COMMIT) {
forced_redraw_state_ = has_pending_tree_
? FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION
: FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
}
// Update the output surface state.
DCHECK_NE(output_surface_state_, OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION);
if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT) {
if (has_pending_tree_) {
output_surface_state_ = OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION;
} else {
output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
needs_redraw_ = true;
}
}
// Update state if we have a new active tree to draw, or if the active tree
// was unchanged but we need to do a forced draw.
if (!has_pending_tree_ &&
(!commit_was_aborted ||
forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)) {
needs_redraw_ = true;
active_tree_needs_first_draw_ = true;
}
// This post-commit work is common to both completed and aborted commits.
pending_tree_is_ready_for_activation_ = false;
if (continuous_painting_)
needs_commit_ = true;
}
void SchedulerStateMachine::UpdateStateOnActivation() {
if (commit_state_ == COMMIT_STATE_WAITING_FOR_ACTIVATION) {
commit_state_ = settings_.main_thread_should_always_be_low_latency
? COMMIT_STATE_WAITING_FOR_DRAW
: COMMIT_STATE_IDLE;
}
if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION)
output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION)
forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_DRAW;
has_pending_tree_ = false;
pending_tree_is_ready_for_activation_ = false;
active_tree_needs_first_draw_ = true;
needs_redraw_ = true;
}
void SchedulerStateMachine::UpdateStateOnDraw(bool did_request_swap) {
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
if (commit_state_ == COMMIT_STATE_WAITING_FOR_DRAW)
commit_state_ = COMMIT_STATE_IDLE;
needs_redraw_ = false;
active_tree_needs_first_draw_ = false;
if (did_request_swap)
last_frame_number_swap_requested_ = current_frame_number_;
}
void SchedulerStateMachine::UpdateStateOnManageTiles() {
needs_manage_tiles_ = false;
}
void SchedulerStateMachine::SetSkipNextBeginMainFrameToReduceLatency() {
TRACE_EVENT_INSTANT0("cc",
"Scheduler: SkipNextBeginMainFrameToReduceLatency",
TRACE_EVENT_SCOPE_THREAD);
skip_next_begin_main_frame_to_reduce_latency_ = true;
}
bool SchedulerStateMachine::BeginFrameNeededForChildren() const {
if (HasInitializedOutputSurface())
return children_need_begin_frames_;
return false;
}
bool SchedulerStateMachine::BeginFrameNeeded() const {
if (SupportsProactiveBeginFrame()) {
return (BeginFrameNeededToAnimateOrDraw() ||
BeginFrameNeededForChildren() ||
ProactiveBeginFrameWanted());
}
// Proactive BeginFrames are bad for the synchronous compositor because we
// have to draw when we get the BeginFrame and could end up drawing many
// duplicate frames if our new frame isn't ready in time.
// To poll for state with the synchronous compositor without having to draw,
// we rely on ShouldPollForAnticipatedDrawTriggers instead.
// Synchronous compositor doesn't have a browser.
DCHECK(!children_need_begin_frames_);
return BeginFrameNeededToAnimateOrDraw();
}
bool SchedulerStateMachine::ShouldPollForAnticipatedDrawTriggers() const {
// ShouldPollForAnticipatedDrawTriggers is what we use in place of
// ProactiveBeginFrameWanted when we are using the synchronous
// compositor.
if (!SupportsProactiveBeginFrame()) {
return !BeginFrameNeededToAnimateOrDraw() && ProactiveBeginFrameWanted();
}
// Non synchronous compositors should rely on
// ProactiveBeginFrameWanted to poll for state instead.
return false;
}
// Note: If SupportsProactiveBeginFrame is false, the scheduler should poll
// for changes in it's draw state so it can request a BeginFrame when it's
// actually ready.
bool SchedulerStateMachine::SupportsProactiveBeginFrame() const {
// It is undesirable to proactively request BeginFrames if we are
// using a synchronous compositor because we *must* draw for every
// BeginFrame, which could cause duplicate draws.
return !settings_.using_synchronous_renderer_compositor;
}
void SchedulerStateMachine::SetChildrenNeedBeginFrames(
bool children_need_begin_frames) {
DCHECK(settings_.forward_begin_frames_to_children);
children_need_begin_frames_ = children_need_begin_frames;
}
// These are the cases where we definitely (or almost definitely) have a
// new frame to animate and/or draw and can draw.
bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
// The output surface is the provider of BeginImplFrames, so we are not going
// to get them even if we ask for them.
if (!HasInitializedOutputSurface())
return false;
// The forced draw respects our normal draw scheduling, so we need to
// request a BeginImplFrame for it.
if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
return true;
return needs_animate_ || needs_redraw_;
}
// These are cases where we are very likely to draw soon, but might not
// actually have a new frame to draw when we receive the next BeginImplFrame.
// Proactively requesting the BeginImplFrame helps hide the round trip latency
// of the SetNeedsBeginFrame request that has to go to the Browser.
bool SchedulerStateMachine::ProactiveBeginFrameWanted() const {
// The output surface is the provider of BeginImplFrames,
// so we are not going to get them even if we ask for them.
if (!HasInitializedOutputSurface())
return false;
// Do not be proactive when invisible.
if (!visible_)
return false;
// We should proactively request a BeginImplFrame if a commit is pending
// because we will want to draw if the commit completes quickly.
if (needs_commit_ || commit_state_ != COMMIT_STATE_IDLE)
return true;
// If the pending tree activates quickly, we'll want a BeginImplFrame soon
// to draw the new active tree.
if (has_pending_tree_)
return true;
// Changing priorities may allow us to activate (given the new priorities),
// which may result in a new frame.
if (needs_manage_tiles_)
return true;
// If we just sent a swap request, it's likely that we are going to produce
// another frame soon. This helps avoid negative glitches in our
// SetNeedsBeginFrame requests, which may propagate to the BeginImplFrame
// provider and get sampled at an inopportune time, delaying the next
// BeginImplFrame.
if (HasRequestedSwapThisFrame())
return true;
return false;
}
void SchedulerStateMachine::OnBeginImplFrame(const BeginFrameArgs& args) {
AdvanceCurrentFrameNumber();
begin_impl_frame_args_ = args;
DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_IDLE)
<< AsValue()->ToString();
begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING;
}
void SchedulerStateMachine::OnBeginImplFrameDeadlinePending() {
DCHECK_EQ(begin_impl_frame_state_,
BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING)
<< AsValue()->ToString();
begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME;
}
void SchedulerStateMachine::OnBeginImplFrameDeadline() {
DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
<< AsValue()->ToString();
begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE;
}
void SchedulerStateMachine::OnBeginImplFrameIdle() {
DCHECK_EQ(begin_impl_frame_state_, BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)
<< AsValue()->ToString();
begin_impl_frame_state_ = BEGIN_IMPL_FRAME_STATE_IDLE;
}
SchedulerStateMachine::BeginImplFrameDeadlineMode
SchedulerStateMachine::CurrentBeginImplFrameDeadlineMode() const {
if (ShouldTriggerBeginImplFrameDeadlineImmediately()) {
return BEGIN_IMPL_FRAME_DEADLINE_MODE_IMMEDIATE;
} else if (needs_redraw_ && pending_swaps_ < max_pending_swaps_) {
// We have an animation or fast input path on the impl thread that wants
// to draw, so don't wait too long for a new active tree.
// If we are swap throttled we should wait until we are unblocked.
return BEGIN_IMPL_FRAME_DEADLINE_MODE_REGULAR;
} else {
// The impl thread doesn't have anything it wants to draw and we are just
// waiting for a new active tree or we are swap throttled. In short we are
// blocked.
return BEGIN_IMPL_FRAME_DEADLINE_MODE_LATE;
}
}
bool SchedulerStateMachine::ShouldTriggerBeginImplFrameDeadlineImmediately()
const {
// TODO(brianderson): This should take into account multiple commit sources.
if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
return false;
// If we've lost the output surface, end the current BeginImplFrame ASAP
// so we can start creating the next output surface.
if (output_surface_state_ == OUTPUT_SURFACE_LOST)
return true;
// SwapAck throttle the deadline since we wont draw and swap anyway.
if (pending_swaps_ >= max_pending_swaps_)
return false;
if (active_tree_needs_first_draw_)
return true;
if (!needs_redraw_)
return false;
// This is used to prioritize impl-thread draws when the main thread isn't
// producing anything, e.g., after an aborted commit. We also check that we
// don't have a pending tree -- otherwise we should give it a chance to
// activate.
// TODO(skyostil): Revisit this when we have more accurate deadline estimates.
if (commit_state_ == COMMIT_STATE_IDLE && !has_pending_tree_)
return true;
// Prioritize impl-thread draws in impl_latency_takes_priority_ mode.
if (impl_latency_takes_priority_)
return true;
// If we are on battery power and want to prioritize impl latency because
// we don't trust deadline tasks to execute at the right time.
if (impl_latency_takes_priority_on_battery_)
return true;
return false;
}
bool SchedulerStateMachine::MainThreadIsInHighLatencyMode() const {
// If a commit is pending before the previous commit has been drawn, we
// are definitely in a high latency mode.
if (CommitPending() && (active_tree_needs_first_draw_ || has_pending_tree_))
return true;
// If we just sent a BeginMainFrame and haven't hit the deadline yet, the main
// thread is in a low latency mode.
if (HasSentBeginMainFrameThisFrame() &&
(begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING ||
begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME))
return false;
// If there's a commit in progress it must either be from the previous frame
// or it started after the impl thread's deadline. In either case the main
// thread is in high latency mode.
if (CommitPending())
return true;
// Similarly, if there's a pending tree the main thread is in high latency
// mode, because either
// it's from the previous frame
// or
// we're currently drawing the active tree and the pending tree will thus
// only be drawn in the next frame.
if (has_pending_tree_)
return true;
if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE) {
// Even if there's a new active tree to draw at the deadline or we've just
// swapped it, it may have been triggered by a previous BeginImplFrame, in
// which case the main thread is in a high latency mode.
return (active_tree_needs_first_draw_ || HasSwappedThisFrame()) &&
!HasSentBeginMainFrameThisFrame();
}
// If the active tree needs its first draw in any other state, we know the
// main thread is in a high latency mode.
return active_tree_needs_first_draw_;
}
void SchedulerStateMachine::DidEnterPollForAnticipatedDrawTriggers() {
AdvanceCurrentFrameNumber();
inside_poll_for_anticipated_draw_triggers_ = true;
}
void SchedulerStateMachine::DidLeavePollForAnticipatedDrawTriggers() {
inside_poll_for_anticipated_draw_triggers_ = false;
}
void SchedulerStateMachine::SetVisible(bool visible) { visible_ = visible; }
void SchedulerStateMachine::SetCanDraw(bool can_draw) { can_draw_ = can_draw; }
void SchedulerStateMachine::SetNeedsRedraw() { needs_redraw_ = true; }
void SchedulerStateMachine::SetNeedsAnimate() {
needs_animate_ = true;
}
void SchedulerStateMachine::SetNeedsManageTiles() {
if (!needs_manage_tiles_) {
TRACE_EVENT0("cc",
"SchedulerStateMachine::SetNeedsManageTiles");
needs_manage_tiles_ = true;
}
}
void SchedulerStateMachine::SetMaxSwapsPending(int max) {
max_pending_swaps_ = max;
}
void SchedulerStateMachine::DidSwapBuffers() {
pending_swaps_++;
DCHECK_LE(pending_swaps_, max_pending_swaps_);
last_frame_number_swap_performed_ = current_frame_number_;
}
void SchedulerStateMachine::DidSwapBuffersComplete() {
DCHECK_GT(pending_swaps_, 0);
pending_swaps_--;
}
void SchedulerStateMachine::SetImplLatencyTakesPriority(
bool impl_latency_takes_priority) {
impl_latency_takes_priority_ = impl_latency_takes_priority;
}
void SchedulerStateMachine::DidDrawIfPossibleCompleted(DrawResult result) {
switch (result) {
case INVALID_RESULT:
NOTREACHED() << "Uninitialized DrawResult.";
break;
case DRAW_ABORTED_CANT_DRAW:
case DRAW_ABORTED_CONTEXT_LOST:
NOTREACHED() << "Invalid return value from DrawAndSwapIfPossible:"
<< result;
break;
case DRAW_SUCCESS:
consecutive_checkerboard_animations_ = 0;
forced_redraw_state_ = FORCED_REDRAW_STATE_IDLE;
break;
case DRAW_ABORTED_CHECKERBOARD_ANIMATIONS:
needs_redraw_ = true;
// If we're already in the middle of a redraw, we don't need to
// restart it.
if (forced_redraw_state_ != FORCED_REDRAW_STATE_IDLE)
return;
needs_commit_ = true;
consecutive_checkerboard_animations_++;
if (settings_.timeout_and_draw_when_animation_checkerboards &&
consecutive_checkerboard_animations_ >=
settings_.maximum_number_of_failed_draws_before_draw_is_forced_) {
consecutive_checkerboard_animations_ = 0;
// We need to force a draw, but it doesn't make sense to do this until
// we've committed and have new textures.
forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
}
break;
case DRAW_ABORTED_MISSING_HIGH_RES_CONTENT:
// It's not clear whether this missing content is because of missing
// pictures (which requires a commit) or because of memory pressure
// removing textures (which might not). To be safe, request a commit
// anyway.
needs_commit_ = true;
break;
}
}
void SchedulerStateMachine::SetNeedsCommit() {
needs_commit_ = true;
}
void SchedulerStateMachine::NotifyReadyToCommit() {
DCHECK(commit_state_ == COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED)
<< AsValue()->ToString();
commit_state_ = COMMIT_STATE_READY_TO_COMMIT;
// In main thread low latency mode, commit should happen right after
// BeginFrame, meaning when this function is called, next action should be
// commit.
if (settings_.main_thread_should_always_be_low_latency)
DCHECK(ShouldCommit());
}
void SchedulerStateMachine::BeginMainFrameAborted(bool did_handle) {
DCHECK_EQ(commit_state_, COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
if (did_handle) {
bool commit_was_aborted = true;
UpdateStateOnCommit(commit_was_aborted);
} else {
commit_state_ = COMMIT_STATE_IDLE;
SetNeedsCommit();
}
}
void SchedulerStateMachine::DidManageTiles() {
needs_manage_tiles_ = false;
// "Fill" the ManageTiles funnel.
manage_tiles_funnel_++;
}
void SchedulerStateMachine::DidLoseOutputSurface() {
if (output_surface_state_ == OUTPUT_SURFACE_LOST ||
output_surface_state_ == OUTPUT_SURFACE_CREATING)
return;
output_surface_state_ = OUTPUT_SURFACE_LOST;
needs_redraw_ = false;
}
void SchedulerStateMachine::NotifyReadyToActivate() {
if (has_pending_tree_)
pending_tree_is_ready_for_activation_ = true;
}
void SchedulerStateMachine::DidCreateAndInitializeOutputSurface() {
DCHECK_EQ(output_surface_state_, OUTPUT_SURFACE_CREATING);
output_surface_state_ = OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT;
if (did_create_and_initialize_first_output_surface_) {
// TODO(boliu): See if we can remove this when impl-side painting is always
// on. Does anything on the main thread need to update after recreate?
needs_commit_ = true;
}
did_create_and_initialize_first_output_surface_ = true;
pending_swaps_ = 0;
}
void SchedulerStateMachine::NotifyBeginMainFrameStarted() {
DCHECK_EQ(commit_state_, COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
commit_state_ = COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED;
}
bool SchedulerStateMachine::HasInitializedOutputSurface() const {
switch (output_surface_state_) {
case OUTPUT_SURFACE_LOST:
case OUTPUT_SURFACE_CREATING:
return false;
case OUTPUT_SURFACE_ACTIVE:
case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
return true;
}
NOTREACHED();
return false;
}
std::string SchedulerStateMachine::GetStatesForDebugging() const {
return base::StringPrintf("%c %d %d %d %c %c %c %d %d",
needs_commit_ ? 'T' : 'F',
static_cast<int>(output_surface_state_),
static_cast<int>(begin_impl_frame_state_),
static_cast<int>(commit_state_),
has_pending_tree_ ? 'T' : 'F',
pending_tree_is_ready_for_activation_ ? 'T' : 'F',
active_tree_needs_first_draw_ ? 'T' : 'F',
max_pending_swaps_,
pending_swaps_);
}
} // namespace cc