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/location.h"
   9 #include "base/logging.h"
  10 #include "base/strings/string_number_conversions.h"
  11 #include "base/trace_event/trace_event.h"
  12 #include "base/trace_event/trace_event_argument.h"
  13 #include "cc/scheduler/delay_based_time_source.h"
  14 #include "cc/scheduler/scheduler.h"
  15
  16 #ifdef NDEBUG
  17 #define DEBUG_FRAMES(...)
  18 #else
  19 #define DEBUG_FRAMES(name, arg1_name, arg1_val, arg2_name, arg2_val)   \
  20   TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"), \
  21                name,                                                   \
  22                arg1_name,                                              \
  23                arg1_val,                                               \
  24                arg2_name,                                              \
  25                arg2_val);
  26 #endif
  27
  28 namespace cc {
  29
  30 // BeginFrameObserverMixIn -----------------------------------------------
  31 BeginFrameObserverMixIn::BeginFrameObserverMixIn()
  32     : last_begin_frame_args_(), dropped_begin_frame_args_(0) {
  33 }
  34
  35 const BeginFrameArgs BeginFrameObserverMixIn::LastUsedBeginFrameArgs() const {
  36   return last_begin_frame_args_;
  37 }
  38 void BeginFrameObserverMixIn::OnBeginFrame(const BeginFrameArgs& args) {
  39   DEBUG_FRAMES("BeginFrameObserverMixIn::OnBeginFrame",
  40                "last args",
  41                last_begin_frame_args_.AsValue(),
  42                "new args",
  43                args.AsValue());
  44   DCHECK(args.IsValid());
  45   DCHECK(args.frame_time >= last_begin_frame_args_.frame_time);
  46   bool used = OnBeginFrameMixInDelegate(args);
  47   if (used) {
  48     last_begin_frame_args_ = args;
  49   } else {
  50     ++dropped_begin_frame_args_;
  51   }
  52 }
  53
  54 void BeginFrameObserverMixIn::AsValueInto(
  55     base::trace_event::TracedValue* dict) const {
  56   dict->BeginDictionary("last_begin_frame_args_");
  57   last_begin_frame_args_.AsValueInto(dict);
  58   dict->EndDictionary();
  59   dict->SetInteger("dropped_begin_frame_args_", dropped_begin_frame_args_);
  60 }
  61
  62 // BeginFrameSourceMixIn ------------------------------------------------------
  63 BeginFrameSourceMixIn::BeginFrameSourceMixIn()
  64     : observer_(NULL),
  65       needs_begin_frames_(false),
  66       inside_as_value_into_(false) {
  67   DCHECK(!observer_);
  68   DCHECK_EQ(inside_as_value_into_, false);
  69 }
  70
  71 bool BeginFrameSourceMixIn::NeedsBeginFrames() const {
  72   return needs_begin_frames_;
  73 }
  74
  75 void BeginFrameSourceMixIn::SetNeedsBeginFrames(bool needs_begin_frames) {
  76   DEBUG_FRAMES("BeginFrameSourceMixIn::SetNeedsBeginFrames",
  77                "current state",
  78                needs_begin_frames_,
  79                "new state",
  80                needs_begin_frames);
  81   if (needs_begin_frames_ != needs_begin_frames) {
  82     needs_begin_frames_ = needs_begin_frames;
  83     OnNeedsBeginFramesChange(needs_begin_frames);
  84   }
  85 }
  86
  87 void BeginFrameSourceMixIn::AddObserver(BeginFrameObserver* obs) {
  88   DEBUG_FRAMES("BeginFrameSourceMixIn::AddObserver",
  89                "current observer",
  90                observer_,
  91                "to add observer",
  92                obs);
  93   DCHECK(!observer_);
  94   observer_ = obs;
  95 }
  96
  97 void BeginFrameSourceMixIn::RemoveObserver(BeginFrameObserver* obs) {
  98   DEBUG_FRAMES("BeginFrameSourceMixIn::RemoveObserver",
  99                "current observer",
 100                observer_,
 101                "to remove observer",
 102                obs);
 103   DCHECK_EQ(observer_, obs);
 104   observer_ = NULL;
 105 }
 106
 107 void BeginFrameSourceMixIn::CallOnBeginFrame(const BeginFrameArgs& args) {
 108   DEBUG_FRAMES("BeginFrameSourceMixIn::CallOnBeginFrame",
 109                "current observer",
 110                observer_,
 111                "args",
 112                args.AsValue());
 113   if (observer_) {
 114     return observer_->OnBeginFrame(args);
 115   }
 116 }
 117
 118 // Tracing support
 119 void BeginFrameSourceMixIn::AsValueInto(
 120     base::trace_event::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 base::TimeTicks::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::trace_event::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   time_source =
 214       DelayBasedTimeSource::Create(initial_vsync_interval, task_runner);
 215   return make_scoped_ptr(new SyntheticBeginFrameSource(time_source));
 216 }
 217
 218 SyntheticBeginFrameSource::SyntheticBeginFrameSource(
 219     scoped_refptr<DelayBasedTimeSource> time_source)
 220     : BeginFrameSourceMixIn(), time_source_(time_source) {
 221   time_source_->SetActive(false);
 222   time_source_->SetClient(this);
 223 }
 224
 225 SyntheticBeginFrameSource::~SyntheticBeginFrameSource() {
 226   if (NeedsBeginFrames())
 227     time_source_->SetActive(false);
 228 }
 229
 230 void SyntheticBeginFrameSource::OnUpdateVSyncParameters(
 231     base::TimeTicks new_vsync_timebase,
 232     base::TimeDelta new_vsync_interval) {
 233   time_source_->SetTimebaseAndInterval(new_vsync_timebase, new_vsync_interval);
 234 }
 235
 236 BeginFrameArgs SyntheticBeginFrameSource::CreateBeginFrameArgs(
 237     base::TimeTicks frame_time,
 238     BeginFrameArgs::BeginFrameArgsType type) {
 239   base::TimeTicks deadline = time_source_->NextTickTime();
 240   return BeginFrameArgs::Create(BEGINFRAME_FROM_HERE, frame_time, deadline,
 241                                 time_source_->Interval(), type);
 242 }
 243
 244 // TimeSourceClient support
 245 void SyntheticBeginFrameSource::OnTimerTick() {
 246   CallOnBeginFrame(CreateBeginFrameArgs(time_source_->LastTickTime(),
 247                                         BeginFrameArgs::NORMAL));
 248 }
 249
 250 // BeginFrameSourceMixIn support
 251 void SyntheticBeginFrameSource::OnNeedsBeginFramesChange(
 252     bool needs_begin_frames) {
 253   base::TimeTicks missed_tick_time =
 254       time_source_->SetActive(needs_begin_frames);
 255   if (!missed_tick_time.is_null()) {
 256     CallOnBeginFrame(
 257         CreateBeginFrameArgs(missed_tick_time, BeginFrameArgs::MISSED));
 258   }
 259 }
 260
 261 // Tracing support
 262 void SyntheticBeginFrameSource::AsValueInto(
 263     base::trace_event::TracedValue* dict) const {
 264   dict->SetString("type", "SyntheticBeginFrameSource");
 265   BeginFrameSourceMixIn::AsValueInto(dict);
 266
 267   dict->BeginDictionary("time_source");
 268   time_source_->AsValueInto(dict);
 269   dict->EndDictionary();
 270 }
 271
 272 // BeginFrameSourceMultiplexer -------------------------------------------
 273 scoped_ptr<BeginFrameSourceMultiplexer> BeginFrameSourceMultiplexer::Create() {
 274   return make_scoped_ptr(new BeginFrameSourceMultiplexer());
 275 }
 276
 277 BeginFrameSourceMultiplexer::BeginFrameSourceMultiplexer()
 278     : BeginFrameSourceMixIn(),
 279       minimum_interval_(base::TimeDelta()),
 280       active_source_(NULL),
 281       source_list_() {
 282 }
 283
 284 BeginFrameSourceMultiplexer::BeginFrameSourceMultiplexer(
 285     base::TimeDelta minimum_interval)
 286     : BeginFrameSourceMixIn(),
 287       minimum_interval_(minimum_interval),
 288       active_source_(NULL),
 289       source_list_() {
 290 }
 291
 292 BeginFrameSourceMultiplexer::~BeginFrameSourceMultiplexer() {
 293   if (active_source_) {
 294     active_source_->SetNeedsBeginFrames(false);
 295     active_source_->RemoveObserver(this);
 296   }
 297 }
 298
 299 void BeginFrameSourceMultiplexer::SetMinimumInterval(
 300     base::TimeDelta new_minimum_interval) {
 301   DEBUG_FRAMES("BeginFrameSourceMultiplexer::SetMinimumInterval",
 302                "current minimum (us)",
 303                minimum_interval_.InMicroseconds(),
 304                "new minimum (us)",
 305                new_minimum_interval.InMicroseconds());
 306   DCHECK_GE(new_minimum_interval.ToInternalValue(), 0);
 307   minimum_interval_ = new_minimum_interval;
 308 }
 309
 310 void BeginFrameSourceMultiplexer::AddSource(BeginFrameSource* new_source) {
 311   DEBUG_FRAMES("BeginFrameSourceMultiplexer::AddSource", "current active",
 312                active_source_, "source to be added", new_source);
 313   DCHECK(new_source);
 314   DCHECK(!HasSource(new_source));
 315
 316   source_list_.insert(new_source);
 317
 318   // If there is no active source, set the new one as the active one.
 319   if (!active_source_)
 320     SetActiveSource(new_source);
 321 }
 322
 323 void BeginFrameSourceMultiplexer::RemoveSource(
 324     BeginFrameSource* existing_source) {
 325   DEBUG_FRAMES("BeginFrameSourceMultiplexer::RemoveSource", "current active",
 326                active_source_, "source to be removed", existing_source);
 327   DCHECK(existing_source);
 328   DCHECK(HasSource(existing_source));
 329   DCHECK_NE(existing_source, active_source_);
 330   source_list_.erase(existing_source);
 331 }
 332
 333 void BeginFrameSourceMultiplexer::SetActiveSource(
 334     BeginFrameSource* new_source) {
 335   DEBUG_FRAMES("BeginFrameSourceMultiplexer::SetActiveSource",
 336                "current active",
 337                active_source_,
 338                "to become active",
 339                new_source);
 340
 341   DCHECK(HasSource(new_source) || new_source == NULL);
 342
 343   bool needs_begin_frames = NeedsBeginFrames();
 344   if (active_source_) {
 345     if (needs_begin_frames)
 346       SetNeedsBeginFrames(false);
 347
 348     // Technically we shouldn't need to remove observation, but this prevents
 349     // the case where SetNeedsBeginFrames message gets to the source after a
 350     // message has already been sent.
 351     active_source_->RemoveObserver(this);
 352     active_source_ = NULL;
 353   }
 354   DCHECK(!active_source_);
 355   active_source_ = new_source;
 356
 357   if (active_source_) {
 358     active_source_->AddObserver(this);
 359
 360     if (needs_begin_frames) {
 361       SetNeedsBeginFrames(true);
 362     }
 363   }
 364 }
 365
 366 const BeginFrameSource* BeginFrameSourceMultiplexer::ActiveSource() {
 367   return active_source_;
 368 }
 369
 370 // BeginFrameObserver support
 371 void BeginFrameSourceMultiplexer::OnBeginFrame(const BeginFrameArgs& args) {
 372   if (!IsIncreasing(args)) {
 373     DEBUG_FRAMES("BeginFrameSourceMultiplexer::OnBeginFrame",
 374                  "action",
 375                  "discarding",
 376                  "new args",
 377                  args.AsValue());
 378     return;
 379   }
 380   DEBUG_FRAMES("BeginFrameSourceMultiplexer::OnBeginFrame",
 381                "action",
 382                "using",
 383                "new args",
 384                args.AsValue());
 385   CallOnBeginFrame(args);
 386 }
 387
 388 const BeginFrameArgs BeginFrameSourceMultiplexer::LastUsedBeginFrameArgs()
 389     const {
 390   if (observer_)
 391     return observer_->LastUsedBeginFrameArgs();
 392   else
 393     return BeginFrameArgs();
 394 }
 395
 396 // BeginFrameSource support
 397 void BeginFrameSourceMultiplexer::OnNeedsBeginFramesChange(
 398     bool needs_begin_frames) {
 399   DEBUG_FRAMES("BeginFrameSourceMultiplexer::OnNeedsBeginFramesChange",
 400                "active_source", active_source_, "needs_begin_frames",
 401                needs_begin_frames);
 402   if (active_source_) {
 403     active_source_->SetNeedsBeginFrames(needs_begin_frames);
 404   } else {
 405     DCHECK(!needs_begin_frames);
 406   }
 407 }
 408
 409 void BeginFrameSourceMultiplexer::DidFinishFrame(size_t remaining_frames) {
 410   DEBUG_FRAMES("BeginFrameSourceMultiplexer::DidFinishFrame",
 411                "active_source",
 412                active_source_,
 413                "remaining_frames",
 414                remaining_frames);
 415   if (active_source_) {
 416     active_source_->DidFinishFrame(remaining_frames);
 417   }
 418 }
 419
 420 // Tracing support
 421 void BeginFrameSourceMultiplexer::AsValueInto(
 422     base::trace_event::TracedValue* dict) const {
 423   dict->SetString("type", "BeginFrameSourceMultiplexer");
 424
 425   dict->SetInteger("minimum_interval_us", minimum_interval_.InMicroseconds());
 426   if (observer_) {
 427     dict->BeginDictionary("last_begin_frame_args");
 428     observer_->LastUsedBeginFrameArgs().AsValueInto(dict);
 429     dict->EndDictionary();
 430   }
 431
 432   if (active_source_) {
 433     dict->BeginDictionary("active_source");
 434     active_source_->AsValueInto(dict);
 435     dict->EndDictionary();
 436   } else {
 437     dict->SetString("active_source", "NULL");
 438   }
 439
 440   dict->BeginArray("sources");
 441   for (std::set<BeginFrameSource*>::const_iterator it = source_list_.begin();
 442        it != source_list_.end();
 443        ++it) {
 444     dict->BeginDictionary();
 445     (*it)->AsValueInto(dict);
 446     dict->EndDictionary();
 447   }
 448   dict->EndArray();
 449 }
 450
 451 // protected methods
 452 bool BeginFrameSourceMultiplexer::HasSource(BeginFrameSource* source) {
 453   return (source_list_.find(source) != source_list_.end());
 454 }
 455
 456 bool BeginFrameSourceMultiplexer::IsIncreasing(const BeginFrameArgs& args) {
 457   DCHECK(args.IsValid());
 458   if (!observer_)
 459     return false;
 460
 461   // If the last begin frame is invalid, then any new begin frame is valid.
 462   if (!observer_->LastUsedBeginFrameArgs().IsValid())
 463     return true;
 464
 465   // Only allow new args have a *strictly bigger* frame_time value and statisfy
 466   // minimum interval requirement.
 467   return (args.frame_time >=
 468           observer_->LastUsedBeginFrameArgs().frame_time + minimum_interval_);
 469 }
 470
 471 }  // namespace cc