Blink Scheduler

This directory contains the Blink Scheduler, which coordinates task execution in renderer processes. The main subdirectories are:

• base/ -- basic scheduling primitives such as TaskQueue and SequenceManager.
• child/ -- contains the ChildScheduler which is the base class for all thread schedulers, as well as a WorkerScheduler for worker threads.
• utility/ -- a small scheduler for utility processes.
• renderer/ -- RendererScheduler for the renderer process.

The scheduler exposes an API at public/platform/scheduler.

Documentation

The following is a collection of scheduling-related documentation about the Blink Scheduler as well as other schedulers in Chrome.

2018

• Browser-side scheduling roadmap
• Browser UI thread scheduler
• Browser IO thread scheduling for input latency
• Off Main Thread: Scheduling API
• Task traits for sequence scheduling in //content
• Stop more task queues in background on Android
• Discussion of more graceful worker shutdown
• Stop loading in background on Android
• Android startup performance tweaks
• C++ Promises for Chromium
• C++ Promise/Future/Coroutine in Chromium
• Java task scheduling
• Scheduling resource responses with right priority
• Refactor EventQueue
• Looking into scrolling lag
• Better scheduling metrics
• Scheduler architecture 2.0
• Task Scheduler - Message Loop integration and migration
• Supporting per-frame priorities in Blink Scheduler
• Simplifying scheduler interfaces
• Using dedicated workers for background work
• Untangling spaghetti of platform/scheduler/
• Better layering for platform/scheduler/
• Keyed Service scheduling

2017

• Improved load time scheduling
• Wake-up based throttling
• Background tabs & offscreen frames
• BeginFrame sequence numbers + acknowledgements
• Background tab use cases
• Activity traits
• Blink and Task Scheduler integration
• Lifecycle use cases
• Task execution policies in Blink
• Capturing task type metadata
• Further per-frame scheduler work
• Better tracing for Blink Scheduler
• Scheduling architecture roadmap: one pager
• RendererMainThreadLoad metrics
• State of the throttling
• Background tabs & offscreen frames
• Prototyping cooperative scheduling
• Cooperative scheduling in Blink

2016

• Time-based renderer task throttling
• V8 Performance Mode
• Isolating performance of third-party iframes
• Folly of Scheduling (BlinkOn 6)
• Rendering pipeline throttling (BlinkOn 6)
• Power usage impact of render pipeline throttling
• The future of TaskRunnerHandles
• Improved policy for blocking expensive tasks
• scheduler-dev performance metrics
• FrameBlamer
• Virtual time in Blink
• Browser I/O scheduler (Lucky Luke)

2015

• Virtual time in Headless Chrome
• Task traits
• Compositor and Display Scheduling presentation from scheduling summit
• Simplifying Task Management in Chromium
• Outline of known work needed to fix resize
• Blink spatial scheduling
• Throttling Blink's rendering pipeline for hidden content
• Scheduling to avoid checkerboard in Chrome
• State of GPU scheduling
• Scheduling architecture diagram
• Event dispatch diagram
• Proxying MessageLoop tasks to the Scheduler
• Scheduling JS timer execution
• PSA: How to write reliable layout tests
• Long Idle Tasks: Coupling wagons to the Blink Midnight Train
• Cooperative scheduling in Javascript

2014

• Blink Scheduler talk at BlinkOn 3
• Blink Scheduler
• Blink Scheduler refactoring (moving from Blink to content)
• Idle Tasks in the Blink Scheduler
• Resource loading tasks and the Blink Scheduler
• Blink Scheduler friendly HTMLDocumentParser
• Trustable Future Sync Points
• Unified VSync Scheduling
• VSync-Aligned Buffered Input
• London Perf Summit - Chrome Scheduling
• GPU Service Scheduling Latency
• Related
  • Sync Point Shader Arguments
  • Asynchronous Shader Input from the CPU
  • T-Sync Display Interface
  • Surfaces
  • Better Video Frame Scheduling

2013

• Synthetic Scheduler Tests
• Chrome Frame Synchronization
• Chrome Scheduling Overhaul Phase 1
• Chrome Scheduling Overhaul Phase 2
• Improved vsync scheduling for Chrome on Android
• ZilCh

Miscellaneous

• Rendering for “Glass Time”
• Motion Vectors: An interface between Render and Input Systems
• Begin Frame / VSync Design Diagram