forked from mirrors/gecko-dev
		
	 1c6df38b7c
			
		
	
	
		1c6df38b7c
		
	
	
	
	
		
			
			This patch introduces a new way to way to schedule input tasks, such
that input tasks remain at `InputHigh` priority normally, however, when
there's a pending `Vsync` priority task in the task queue, we
increase the priority of input tasks from `InputHigh` to `InputHighest` to
rush processing the pending input tasks.
There are two restrictions to ensure we don't delay vsync too much:
  - There's a hard limit duration
  - We won't process the input tasks that are newly added after we've
    started to process the current number of input tasks
Differential Revision: https://phabricator.services.mozilla.com/D109499
		
	
			
		
			
				
	
	
		
			103 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			103 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 | |
| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 | |
| /* This Source Code Form is subject to the terms of the Mozilla Public
 | |
|  * License, v. 2.0. If a copy of the MPL was not distributed with this
 | |
|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 | |
| 
 | |
| #if !defined(InputEventStatistics_h_)
 | |
| #  define InputEventStatistics_h_
 | |
| 
 | |
| #  include "mozilla/TimeStamp.h"
 | |
| #  include "mozilla/UniquePtr.h"
 | |
| #  include "nsTArray.h"
 | |
| 
 | |
| namespace mozilla {
 | |
| 
 | |
| class InputEventStatistics {
 | |
|   // The default amount of time (milliseconds) required for handling a input
 | |
|   // event.
 | |
|   static const uint16_t sDefaultInputDuration = 1;
 | |
| 
 | |
|   // The number of processed input events we use to predict the amount of time
 | |
|   // required to process the following input events.
 | |
|   static const uint16_t sInputCountForPrediction = 9;
 | |
| 
 | |
|   // The default maximum and minimum time (milliseconds) we reserve for handling
 | |
|   // input events in each frame.
 | |
|   static const uint16_t sMaxReservedTimeForHandlingInput = 8;
 | |
|   static const uint16_t sMinReservedTimeForHandlingInput = 1;
 | |
| 
 | |
|   class TimeDurationCircularBuffer {
 | |
|     int16_t mSize;
 | |
|     int16_t mCurrentIndex;
 | |
|     nsTArray<TimeDuration> mBuffer;
 | |
|     TimeDuration mTotal;
 | |
| 
 | |
|    public:
 | |
|     TimeDurationCircularBuffer(uint32_t aSize, TimeDuration& aDefaultValue)
 | |
|         : mSize(aSize), mCurrentIndex(0) {
 | |
|       mSize = mSize == 0 ? sInputCountForPrediction : mSize;
 | |
|       for (int16_t index = 0; index < mSize; ++index) {
 | |
|         mBuffer.AppendElement(aDefaultValue);
 | |
|         mTotal += aDefaultValue;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     void Insert(TimeDuration& aDuration) {
 | |
|       mTotal += (aDuration - mBuffer[mCurrentIndex]);
 | |
|       mBuffer[mCurrentIndex++] = aDuration;
 | |
|       if (mCurrentIndex == mSize) {
 | |
|         mCurrentIndex = 0;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     TimeDuration GetMean();
 | |
|   };
 | |
| 
 | |
|   UniquePtr<TimeDurationCircularBuffer> mLastInputDurations;
 | |
|   TimeDuration mMaxInputDuration;
 | |
|   TimeDuration mMinInputDuration;
 | |
|   bool mEnable;
 | |
| 
 | |
|   // We'd like to have our constructor and destructor be private to enforce our
 | |
|   // singleton, but because UniquePtr needs to be able to destruct our class we
 | |
|   // can't. This is a trick that ensures that we're the only code that can
 | |
|   // construct ourselves: nobody else can access ConstructorCookie and therefore
 | |
|   // nobody else can construct an InputEventStatistics.
 | |
|   struct ConstructorCookie {};
 | |
| 
 | |
|  public:
 | |
|   explicit InputEventStatistics(ConstructorCookie&&);
 | |
|   ~InputEventStatistics() = default;
 | |
| 
 | |
|   static InputEventStatistics& Get();
 | |
| 
 | |
|   void UpdateInputDuration(TimeDuration aDuration) {
 | |
|     if (!mEnable) {
 | |
|       return;
 | |
|     }
 | |
|     mLastInputDurations->Insert(aDuration);
 | |
|   }
 | |
| 
 | |
|   TimeStamp GetInputHandlingStartTime(uint32_t aInputCount);
 | |
|   TimeDuration GetMaxInputHandlingDuration() const;
 | |
| 
 | |
|   void SetEnable(bool aEnable) { mEnable = aEnable; }
 | |
| };
 | |
| 
 | |
| class MOZ_RAII AutoTimeDurationHelper final {
 | |
|  public:
 | |
|   AutoTimeDurationHelper() { mStartTime = TimeStamp::Now(); }
 | |
| 
 | |
|   ~AutoTimeDurationHelper() {
 | |
|     InputEventStatistics::Get().UpdateInputDuration(TimeStamp::Now() -
 | |
|                                                     mStartTime);
 | |
|   }
 | |
| 
 | |
|  private:
 | |
|   TimeStamp mStartTime;
 | |
| };
 | |
| 
 | |
| }  // namespace mozilla
 | |
| 
 | |
| #endif  // InputEventStatistics_h_
 |