cc/scheduler/begin_frame_source.cc

   1 // Copyright 2014 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.
   4
   5 #include "cc/scheduler/begin_frame_source.h"
   6
   7 #include "base/auto_reset.h"
   8 #include "base/debug/trace_event.h"
   9 #include "base/debug/trace_event_argument.h"
  10 #include "base/location.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "cc/scheduler/delay_based_time_source.h"
  14 #include "cc/scheduler/scheduler.h"
  15 #include "ui/gfx/frame_time.h"
  16
  17 #ifdef NDEBUG
  18 #define DEBUG_FRAMES(...)
  19 #else
  20 #define DEBUG_FRAMES(name, arg1_name, arg1_val, arg2_name, arg2_val)   \
  21   TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"), \
  22                name,                                                   \
  23                arg1_name,                                              \
  24                arg1_val,                                               \
  25                arg2_name,                                              \
  26                arg2_val);
  27 #endif
  28
  29 namespace cc {
  30
  31 // BeginFrameObserverMixIn -----------------------------------------------
  32 BeginFrameObserverMixIn::BeginFrameObserverMixIn()
  33     : last_begin_frame_args_(), dropped_begin_frame_args_(0) {
  34 }
  35
  36 const BeginFrameArgs BeginFrameObserverMixIn::LastUsedBeginFrameArgs() const {
  37   return last_begin_frame_args_;
  38 }
  39 void BeginFrameObserverMixIn::OnBeginFrame(const BeginFrameArgs& args) {
  40   DEBUG_FRAMES("BeginFrameObserverMixIn::OnBeginFrame",
  41                "last args",
  42                last_begin_frame_args_.AsValue(),
  43                "new args",
  44                args.AsValue());
  45   DCHECK(args.IsValid());
  46   DCHECK(args.frame_time >= last_begin_frame_args_.frame_time);
  47   bool used = OnBeginFrameMixInDelegate(args);
  48   if (used) {
  49     last_begin_frame_args_ = args;
  50   } else {
  51     ++dropped_begin_frame_args_;
  52   }
  53 }
  54
  55 void BeginFrameObserverMixIn::AsValueInto(
  56     base::debug::TracedValue* dict) const {
  57   dict->BeginDictionary("last_begin_frame_args_");
  58   last_begin_frame_args_.AsValueInto(dict);
  59   dict->EndDictionary();
  60   dict->SetInteger("dropped_begin_frame_args_", dropped_begin_frame_args_);
  61 }
  62
  63 // BeginFrameSourceMixIn ------------------------------------------------------
  64 BeginFrameSourceMixIn::BeginFrameSourceMixIn()
  65     : observer_(NULL),
  66       needs_begin_frames_(false),
  67       inside_as_value_into_(false) {
  68   DCHECK(!observer_);
  69   DCHECK_EQ(inside_as_value_into_, false);
  70 }
  71
  72 bool BeginFrameSourceMixIn::NeedsBeginFrames() const {
  73   return needs_begin_frames_;
  74 }
  75
  76 void BeginFrameSourceMixIn::SetNeedsBeginFrames(bool needs_begin_frames) {
  77   DEBUG_FRAMES("BeginFrameSourceMixIn::SetNeedsBeginFrames",
  78                "current state",
  79                needs_begin_frames_,
  80                "new state",
  81                needs_begin_frames);
  82   if (needs_begin_frames_ != needs_begin_frames) {
  83     needs_begin_frames_ = needs_begin_frames;
  84     OnNeedsBeginFramesChange(needs_begin_frames);
  85   }
  86 }
  87
  88 void BeginFrameSourceMixIn::AddObserver(BeginFrameObserver* obs) {
  89   DEBUG_FRAMES("BeginFrameSourceMixIn::AddObserver",
  90                "current observer",
  91                observer_,
  92                "to add observer",
  93                obs);
  94   DCHECK(!observer_);
  95   observer_ = obs;
  96 }
  97
  98 void BeginFrameSourceMixIn::RemoveObserver(BeginFrameObserver* obs) {
  99   DEBUG_FRAMES("BeginFrameSourceMixIn::RemoveObserver",
 100                "current observer",
 101                observer_,
 102                "to remove observer",
 103                obs);
 104   DCHECK_EQ(observer_, obs);
 105   observer_ = NULL;
 106 }
 107
 108 void BeginFrameSourceMixIn::CallOnBeginFrame(const BeginFrameArgs& args) {
 109   DEBUG_FRAMES("BeginFrameSourceMixIn::CallOnBeginFrame",
 110                "current observer",
 111                observer_,
 112                "args",
 113                args.AsValue());
 114   if (observer_) {
 115     return observer_->OnBeginFrame(args);
 116   }
 117 }
 118
 119 // Tracing support
 120 void BeginFrameSourceMixIn::AsValueInto(base::debug::TracedValue* dict) const {
 121   // As the observer might try to trace the source, prevent an infinte loop
 122   // from occuring.
 123   if (inside_as_value_into_) {
 124     dict->SetString("observer", "<loop detected>");
 125     return;
 126   }
 127
 128   if (observer_) {
 129     base::AutoReset<bool> prevent_loops(
 130         const_cast<bool*>(&inside_as_value_into_), true);
 131     dict->BeginDictionary("observer");
 132     observer_->AsValueInto(dict);
 133     dict->EndDictionary();
 134   } else {
 135     dict->SetString("observer", "NULL");
 136   }
 137   dict->SetBoolean("needs_begin_frames", NeedsBeginFrames());
 138 }
 139
 140 // BackToBackBeginFrameSourceMixIn --------------------------------------------
 141 scoped_ptr<BackToBackBeginFrameSource> BackToBackBeginFrameSource::Create(
 142     base::SingleThreadTaskRunner* task_runner) {
 143   return make_scoped_ptr(new BackToBackBeginFrameSource(task_runner));
 144 }
 145
 146 BackToBackBeginFrameSource::BackToBackBeginFrameSource(
 147     base::SingleThreadTaskRunner* task_runner)
 148     : BeginFrameSourceMixIn(),
 149       task_runner_(task_runner),
 150       send_begin_frame_posted_(false),
 151       weak_factory_(this) {
 152   DCHECK(task_runner);
 153   DCHECK_EQ(needs_begin_frames_, false);
 154   DCHECK_EQ(send_begin_frame_posted_, false);
 155 }
 156
 157 BackToBackBeginFrameSource::~BackToBackBeginFrameSource() {
 158 }
 159
 160 base::TimeTicks BackToBackBeginFrameSource::Now() {
 161   return gfx::FrameTime::Now();
 162 }
 163
 164 void BackToBackBeginFrameSource::OnNeedsBeginFramesChange(
 165     bool needs_begin_frames) {
 166   if (!needs_begin_frames)
 167     return;
 168
 169   if (send_begin_frame_posted_)
 170     return;
 171
 172   send_begin_frame_posted_ = true;
 173   task_runner_->PostTask(FROM_HERE,
 174                          base::Bind(&BackToBackBeginFrameSource::BeginFrame,
 175                                     weak_factory_.GetWeakPtr()));
 176 }
 177
 178 void BackToBackBeginFrameSource::BeginFrame() {
 179   send_begin_frame_posted_ = false;
 180
 181   if (!needs_begin_frames_)
 182     return;
 183
 184   base::TimeTicks now = Now();
 185   BeginFrameArgs args = BeginFrameArgs::Create(
 186       BEGINFRAME_FROM_HERE, now, now + BeginFrameArgs::DefaultInterval(),
 187       BeginFrameArgs::DefaultInterval(), BeginFrameArgs::NORMAL);
 188   CallOnBeginFrame(args);
 189 }
 190
 191 // BeginFrameSource support
 192
 193 void BackToBackBeginFrameSource::DidFinishFrame(size_t remaining_frames) {
 194   if (remaining_frames == 0) {
 195     OnNeedsBeginFramesChange(NeedsBeginFrames());
 196   }
 197 }
 198
 199 // Tracing support
 200 void BackToBackBeginFrameSource::AsValueInto(
 201     base::debug::TracedValue* dict) const {
 202   dict->SetString("type", "BackToBackBeginFrameSource");
 203   BeginFrameSourceMixIn::AsValueInto(dict);
 204   dict->SetBoolean("send_begin_frame_posted_", send_begin_frame_posted_);
 205 }
 206
 207 // SyntheticBeginFrameSource ---------------------------------------------
 208 scoped_ptr<SyntheticBeginFrameSource> SyntheticBeginFrameSource::Create(
 209     base::SingleThreadTaskRunner* task_runner,
 210     base::TimeTicks initial_vsync_timebase,
 211     base::TimeDelta initial_vsync_interval) {
 212   scoped_refptr<DelayBasedTimeSource> time_source;
 213   if (gfx::FrameTime::TimestampsAreHighRes()) {
 214     time_source = DelayBasedTimeSourceHighRes::Create(initial_vsync_interval,
 215                                                       task_runner);
 216   } else {
 217     time_source =
 218         DelayBasedTimeSource::Create(initial_vsync_interval, task_runner);
 219   }
 220
 221   return make_scoped_ptr(new SyntheticBeginFrameSource(time_source));
 222 }
 223
 224 SyntheticBeginFrameSource::SyntheticBeginFrameSource(
 225     scoped_refptr<DelayBasedTimeSource> time_source)
 226     : BeginFrameSourceMixIn(), time_source_(time_source) {
 227   time_source_->SetActive(false);
 228   time_source_->SetClient(this);
 229 }
 230
 231 SyntheticBeginFrameSource::~SyntheticBeginFrameSource() {
 232   if (NeedsBeginFrames())
 233     time_source_->SetActive(false);
 234 }
 235
 236 void SyntheticBeginFrameSource::OnUpdateVSyncParameters(
 237     base::TimeTicks new_vsync_timebase,
 238     base::TimeDelta new_vsync_interval) {
 239   time_source_->SetTimebaseAndInterval(new_vsync_timebase, new_vsync_interval);
 240 }
 241
 242 BeginFrameArgs SyntheticBeginFrameSource::CreateBeginFrameArgs(
 243     base::TimeTicks frame_time,
 244     BeginFrameArgs::BeginFrameArgsType type) {
 245   base::TimeTicks deadline = time_source_->NextTickTime();
 246   return BeginFrameArgs::Create(BEGINFRAME_FROM_HERE, frame_time, deadline,
 247                                 time_source_->Interval(), type);
 248 }
 249
 250 // TimeSourceClient support
 251 void SyntheticBeginFrameSource::OnTimerTick() {
 252   CallOnBeginFrame(CreateBeginFrameArgs(time_source_->LastTickTime(),
 253                                         BeginFrameArgs::NORMAL));
 254 }
 255
 256 // BeginFrameSourceMixIn support
 257 void SyntheticBeginFrameSource::OnNeedsBeginFramesChange(
 258     bool needs_begin_frames) {
 259   base::TimeTicks missed_tick_time =
 260       time_source_->SetActive(needs_begin_frames);
 261   if (!missed_tick_time.is_null()) {
 262     CallOnBeginFrame(
 263         CreateBeginFrameArgs(missed_tick_time, BeginFrameArgs::MISSED));
 264   }
 265 }
 266
 267 bool SyntheticBeginFrameSource::NeedsBeginFrames() const {
 268   return time_source_->Active();
 269 }
 270
 271 // Tracing support
 272 void SyntheticBeginFrameSource::AsValueInto(
 273     base::debug::TracedValue* dict) const {
 274   dict->SetString("type", "SyntheticBeginFrameSource");
 275   BeginFrameSourceMixIn::AsValueInto(dict);
 276
 277   dict->BeginDictionary("time_source");
 278   time_source_->AsValueInto(dict);
 279   dict->EndDictionary();
 280 }
 281
 282 // BeginFrameSourceMultiplexer -------------------------------------------
 283 scoped_ptr<BeginFrameSourceMultiplexer> BeginFrameSourceMultiplexer::Create() {
 284   return make_scoped_ptr(new BeginFrameSourceMultiplexer());
 285 }
 286
 287 BeginFrameSourceMultiplexer::BeginFrameSourceMultiplexer()
 288     : BeginFrameSourceMixIn(),
 289       minimum_interval_(base::TimeDelta()),
 290       active_source_(NULL),
 291       source_list_() {
 292 }
 293
 294 BeginFrameSourceMultiplexer::BeginFrameSourceMultiplexer(
 295     base::TimeDelta minimum_interval)
 296     : BeginFrameSourceMixIn(),
 297       minimum_interval_(minimum_interval),
 298       active_source_(NULL),
 299       source_list_() {
 300 }
 301
 302 BeginFrameSourceMultiplexer::~BeginFrameSourceMultiplexer() {
 303 }
 304
 305 void BeginFrameSourceMultiplexer::SetMinimumInterval(
 306     base::TimeDelta new_minimum_interval) {
 307   DEBUG_FRAMES("BeginFrameSourceMultiplexer::SetMinimumInterval",
 308                "current minimum (us)",
 309                minimum_interval_.InMicroseconds(),
 310                "new minimum (us)",
 311                new_minimum_interval.InMicroseconds());
 312   DCHECK_GE(new_minimum_interval.ToInternalValue(), 0);
 313   minimum_interval_ = new_minimum_interval;
 314 }
 315
 316 void BeginFrameSourceMultiplexer::AddSource(BeginFrameSource* new_source) {
 317   DEBUG_FRAMES("BeginFrameSourceMultiplexer::AddSource",
 318                "current active",
 319                active_source_,
 320                "source to remove",
 321                new_source);
 322   DCHECK(new_source);
 323   DCHECK(!HasSource(new_source));
 324
 325   source_list_.insert(new_source);
 326
 327   // If there is no active source, set the new one as the active one.
 328   if (!active_source_)
 329     SetActiveSource(new_source);
 330 }
 331
 332 void BeginFrameSourceMultiplexer::RemoveSource(
 333     BeginFrameSource* existing_source) {
 334   DEBUG_FRAMES("BeginFrameSourceMultiplexer::RemoveSource",
 335                "current active",
 336                active_source_,
 337                "source to remove",
 338                existing_source);
 339   DCHECK(existing_source);
 340   DCHECK(HasSource(existing_source));
 341   DCHECK_NE(existing_source, active_source_);
 342   source_list_.erase(existing_source);
 343 }
 344
 345 void BeginFrameSourceMultiplexer::SetActiveSource(
 346     BeginFrameSource* new_source) {
 347   DEBUG_FRAMES("BeginFrameSourceMultiplexer::SetActiveSource",
 348                "current active",
 349                active_source_,
 350                "to become active",
 351                new_source);
 352
 353   DCHECK(HasSource(new_source) || new_source == NULL);
 354
 355   bool needs_begin_frames = NeedsBeginFrames();
 356   if (active_source_) {
 357     if (needs_begin_frames)
 358       SetNeedsBeginFrames(false);
 359
 360     // Technically we shouldn't need to remove observation, but this prevents
 361     // the case where SetNeedsBeginFrames message gets to the source after a
 362     // message has already been sent.
 363     active_source_->RemoveObserver(this);
 364     active_source_ = NULL;
 365   }
 366   DCHECK(!active_source_);
 367   active_source_ = new_source;
 368
 369   if (active_source_) {
 370     active_source_->AddObserver(this);
 371
 372     if (needs_begin_frames) {
 373       SetNeedsBeginFrames(true);
 374     }
 375   }
 376 }
 377
 378 const BeginFrameSource* BeginFrameSourceMultiplexer::ActiveSource() {
 379   return active_source_;
 380 }
 381
 382 // BeginFrameObserver support
 383 void BeginFrameSourceMultiplexer::OnBeginFrame(const BeginFrameArgs& args) {
 384   if (!IsIncreasing(args)) {
 385     DEBUG_FRAMES("BeginFrameSourceMultiplexer::OnBeginFrame",
 386                  "action",
 387                  "discarding",
 388                  "new args",
 389                  args.AsValue());
 390     return;
 391   }
 392   DEBUG_FRAMES("BeginFrameSourceMultiplexer::OnBeginFrame",
 393                "action",
 394                "using",
 395                "new args",
 396                args.AsValue());
 397   CallOnBeginFrame(args);
 398 }
 399
 400 const BeginFrameArgs BeginFrameSourceMultiplexer::LastUsedBeginFrameArgs()
 401     const {
 402   if (observer_)
 403     return observer_->LastUsedBeginFrameArgs();
 404   else
 405     return BeginFrameArgs();
 406 }
 407
 408 // BeginFrameSource support
 409 bool BeginFrameSourceMultiplexer::NeedsBeginFrames() const {
 410   if (active_source_) {
 411     return active_source_->NeedsBeginFrames();
 412   } else {
 413     return false;
 414   }
 415 }
 416
 417 void BeginFrameSourceMultiplexer::SetNeedsBeginFrames(bool needs_begin_frames) {
 418   DEBUG_FRAMES("BeginFrameSourceMultiplexer::SetNeedsBeginFrames",
 419                "active_source",
 420                active_source_,
 421                "needs_begin_frames",
 422                needs_begin_frames);
 423   if (active_source_) {
 424     active_source_->SetNeedsBeginFrames(needs_begin_frames);
 425   } else {
 426     DCHECK(!needs_begin_frames);
 427   }
 428 }
 429
 430 void BeginFrameSourceMultiplexer::DidFinishFrame(size_t remaining_frames) {
 431   DEBUG_FRAMES("BeginFrameSourceMultiplexer::DidFinishFrame",
 432                "active_source",
 433                active_source_,
 434                "remaining_frames",
 435                remaining_frames);
 436   if (active_source_) {
 437     active_source_->DidFinishFrame(remaining_frames);
 438   }
 439 }
 440
 441 // Tracing support
 442 void BeginFrameSourceMultiplexer::AsValueInto(
 443     base::debug::TracedValue* dict) const {
 444   dict->SetString("type", "BeginFrameSourceMultiplexer");
 445
 446   dict->SetInteger("minimum_interval_us", minimum_interval_.InMicroseconds());
 447   if (observer_) {
 448     dict->BeginDictionary("last_begin_frame_args");
 449     observer_->LastUsedBeginFrameArgs().AsValueInto(dict);
 450     dict->EndDictionary();
 451   }
 452
 453   if (active_source_) {
 454     dict->BeginDictionary("active_source");
 455     active_source_->AsValueInto(dict);
 456     dict->EndDictionary();
 457   } else {
 458     dict->SetString("active_source", "NULL");
 459   }
 460
 461   dict->BeginArray("sources");
 462   for (std::set<BeginFrameSource*>::const_iterator it = source_list_.begin();
 463        it != source_list_.end();
 464        ++it) {
 465     dict->BeginDictionary();
 466     (*it)->AsValueInto(dict);
 467     dict->EndDictionary();
 468   }
 469   dict->EndArray();
 470 }
 471
 472 // protected methods
 473 bool BeginFrameSourceMultiplexer::HasSource(BeginFrameSource* source) {
 474   return (source_list_.find(source) != source_list_.end());
 475 }
 476
 477 bool BeginFrameSourceMultiplexer::IsIncreasing(const BeginFrameArgs& args) {
 478   DCHECK(args.IsValid());
 479   if (!observer_)
 480     return false;
 481
 482   // If the last begin frame is invalid, then any new begin frame is valid.
 483   if (!observer_->LastUsedBeginFrameArgs().IsValid())
 484     return true;
 485
 486   // Only allow new args have a *strictly bigger* frame_time value and statisfy
 487   // minimum interval requirement.
 488   return (args.frame_time >=
 489           observer_->LastUsedBeginFrameArgs().frame_time + minimum_interval_);
 490 }
 491
 492 }  // namespace cc