cc/output/begin_frame_args.cc

   1 // Copyright 2013 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/output/begin_frame_args.h"
   6
   7 #include "base/debug/trace_event_argument.h"
   8 #include "ui/gfx/frame_time.h"
   9
  10 namespace cc {
  11
  12 BeginFrameArgs::BeginFrameArgs()
  13     : frame_time(base::TimeTicks()),
  14       deadline(base::TimeTicks()),
  15       interval(base::TimeDelta::FromMicroseconds(-1)),
  16       type(BeginFrameArgs::INVALID) {
  17 }
  18
  19 BeginFrameArgs::BeginFrameArgs(base::TimeTicks frame_time,
  20                                base::TimeTicks deadline,
  21                                base::TimeDelta interval,
  22                                BeginFrameArgs::BeginFrameArgsType type)
  23     : frame_time(frame_time),
  24       deadline(deadline),
  25       interval(interval),
  26       type(type) {
  27 }
  28
  29 BeginFrameArgs BeginFrameArgs::CreateTyped(
  30     base::TimeTicks frame_time,
  31     base::TimeTicks deadline,
  32     base::TimeDelta interval,
  33     BeginFrameArgs::BeginFrameArgsType type) {
  34   DCHECK_NE(type, BeginFrameArgs::INVALID);
  35   return BeginFrameArgs(frame_time, deadline, interval, type);
  36 }
  37
  38 BeginFrameArgs BeginFrameArgs::Create(base::TimeTicks frame_time,
  39                                       base::TimeTicks deadline,
  40                                       base::TimeDelta interval) {
  41   return CreateTyped(frame_time, deadline, interval, BeginFrameArgs::NORMAL);
  42 }
  43
  44 scoped_refptr<base::debug::ConvertableToTraceFormat> BeginFrameArgs::AsValue()
  45     const {
  46   scoped_refptr<base::debug::TracedValue> state =
  47       new base::debug::TracedValue();
  48   AsValueInto(state.get());
  49   return state;
  50 }
  51
  52 void BeginFrameArgs::AsValueInto(base::debug::TracedValue* state) const {
  53   state->SetString("type", "BeginFrameArgs");
  54   switch (type) {
  55     case BeginFrameArgs::INVALID:
  56       state->SetString("subtype", "INVALID");
  57       break;
  58     case BeginFrameArgs::NORMAL:
  59       state->SetString("subtype", "NORMAL");
  60       break;
  61     case BeginFrameArgs::SYNCHRONOUS:
  62       state->SetString("subtype", "SYNCHRONOUS");
  63       break;
  64     case BeginFrameArgs::MISSED:
  65       state->SetString("subtype", "MISSED");
  66       break;
  67   }
  68   state->SetDouble("frame_time_us", frame_time.ToInternalValue());
  69   state->SetDouble("deadline_us", deadline.ToInternalValue());
  70   state->SetDouble("interval_us", interval.InMicroseconds());
  71 }
  72
  73 BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor(
  74     base::TimeTicks now) {
  75   // For WebView/SynchronousCompositor, we always want to draw immediately,
  76   // so we set the deadline to 0 and guess that the interval is 16 milliseconds.
  77   if (now.is_null())
  78     now = gfx::FrameTime::Now();
  79   return CreateTyped(
  80       now, base::TimeTicks(), DefaultInterval(), BeginFrameArgs::SYNCHRONOUS);
  81 }
  82
  83 // This is a hard-coded deadline adjustment that assumes 60Hz, to be used in
  84 // cases where a good estimated draw time is not known. Using 1/3 of the vsync
  85 // as the default adjustment gives the Browser the last 1/3 of a frame to
  86 // produce output, the Renderer Impl thread the middle 1/3 of a frame to produce
  87 // ouput, and the Renderer Main thread the first 1/3 of a frame to produce
  88 // output.
  89 base::TimeDelta BeginFrameArgs::DefaultEstimatedParentDrawTime() {
  90   return base::TimeDelta::FromMicroseconds(16666 / 3);
  91 }
  92
  93 base::TimeDelta BeginFrameArgs::DefaultInterval() {
  94   return base::TimeDelta::FromMicroseconds(16666);
  95 }
  96
  97 base::TimeDelta BeginFrameArgs::DefaultRetroactiveBeginFramePeriod() {
  98   return base::TimeDelta::FromMicroseconds(4444);
  99 }
 100
 101 }  // namespace cc