tree: 86551e7d9747a4e5ee379345ddf65bcc1f7e3fa2 [path history] [tgz]
  1. DEPS
  2. README.md
  3. catalog/
  4. file/
  5. navigation/
  6. shell/
  7. tracing/
  8. ui/
  9. video_capture/
services/README.md

Chrome Foundation Services

Overview

This directory contains Chrome Foundation Services. If you think of Chrome as a “portable OS,” Chrome Foundation Services can be thought of as that OS' foundational “system services” layer.

Roughly each subdirectory here corresponds to a service that:

  • is a client of //services/shell with its own unique Identity.
  • could logically run a standalone process for security/performance isolation benefits depending on the constraints of the host OS.

Service Directory Structure

Individual services are structured like so:

//services/foo/                   <-- Implementation code, may have subdirs.
              /public/    
                     /cpp/        <-- C++ client libraries (optional)
                     /interfaces/ <-- Mojom interfaces

Dependencies

Code within //services may only depend on each other via each other's /public/ directories, i.e. implementation code cannot be shared directly.

Service code should also take care to tightly limit the dependencies on static libraries from outside of //services. Dependencies to large platform layers like //content, //chrome or //third_party/WebKit must be avoided.

Physical Packaging

Note that while it may be possible to build a discrete physical package (DSO) for each service, products consuming these services may package them differently, e.g. by combining them into a single package.

High-level Design Doc

https://docs.google.com/document/d/15I7sQyQo6zsqXVNAlVd520tdGaS8FCicZHrN0yRu-oU/edit#heading=h.p37l9e7o0io5

Relationship to other top-level directories in //

Services can be thought of as integrators of library code from across the Chromium repository, most commonly //base and //mojo (obviously) but for each service also //components, //ui, etc in accordance with the functionality they provide.

Not everything in //components is automatically a service in its own right. Think of //components as sort of like a //lib. Individual //components can define, implement and use mojom interfaces, but only //services have unique identities with the Mojo Shell.