Startup box represents the parent process’s (Browser process) startup procedure
Zygote
after Browser process startup, Zygote process is created
Fork
Zygote process is forked in order to create Renderer process(es)
Loop
MainMessageLoop
is used to process events for a particular thread
puts the incoming messages, tasks to a queue
pops a task from the queue and starts it
strong relationship with the IPC communication framework
has task reentrancy protection
second task cannot be started until first task finishes
IPC / Mojo
framework which is used for inter-process communication
connects directly to the MainMessageLoop
provides communication channels through which the messages can be sent
message creating, sending and receiving
asynchronous message handling
TaskAnnotator
all incoming tasks are going through a TaskAnnotator which annotates the task before the execution
implements common debug annotations for posted tasks. This includes data such as task origins, queueing durations and memory usage.
runs a previously queued task
callback
this box represents system or message related callbacks
Scheduler
package which contains multiple classes regarding task schedule
TaskQueueManager
The task queue manager provides N task queues and a selector interface for choosing which task queue to service next. Each task queue consists of two sub queues
Incoming task queue
Work queue
blink::HTMLDocumentParser
parse the HTML document
build the DOM tree
autofill
AutofillAgent deals with Autofill related communications between WebKit and the browser
there is one AutofillAgent per RenderFrame
Autofill encompasses:
single text field suggestions, that we usually refer to as Autocomplete,
password form fill, referred to as Password Autofill, and
entire form fill based on one field entry, referred to as Form Autofill.
icu
ICU stands for International Components for Unicode
library which provides Unicode and Globalization support for software applications
in the current context icu is used for regular expression pattern matching to determine if an autofill matches a specific regular expression
content::ResourceDispatcher
this class serves as a communication interface to the ResourceDispatcherHost in the browser process
it can be used from any child process.
dispatches incoming messages
blink::TimerBase
basic Timer
blink::FrameLoader
controls a load of a specific frame (page)
blink::EventHandler
handle events like selection, drag and drop, gesture, mouse move, mouse press or release
perform hit test
blink::EventDispatcher
dispatches simple events, scoped events or simulated clicks
blink::Document
blink::DocumentLoader is responsible for the loading of the Document
after CSS style applying (blink::StyleResolver) and Layout calculation the paint layers and graphics layers are updated
media::DecoderStream
wraps a DemuxerStream and a list of Decoders and provides decoded output to its client (e.g. Audio/VideoRendererImpl).
blink::ScriptRunner
class for executing JavaScript instructions
content::RenderThread
a thread which is used for rendering tasks in Renderer and Zygote process (only one can be present at a time)
blink::V8Initializer
has only static methods in order to initialize v8 context
on the main thread
on a worker thread
extensions
reusable extensions module
it implements the core parts of Chrome's extension system, and can be used with any host of the 'content' module.
blink::WorkerThread
thread which can execute specific tasks
tasks can be posted to a worker
calls WorkerScriptController::initializeContextifNeeded in order to execute JavaScript via V8
Compositor (cc)
uses multiple backing stores to cache and group chunks of the render tree
avoids unnecessary repainting
primary compositing tasks
determine how to group contents into backing stores (i.e. composited layers)
paint the contents of each composited layer
draw the composited layers to make a final image
paints the layer contents to display lists
handles layer updates
Skia
Blink’s drawing library
the rasterization calls specific Skia functions in order to get the canvas drawn correctly
drawColor, drawPicture, drawRect, fillRect, etc.
blink::ImageDecoder
ImageDecoder is a base for all format-specific decoders (e.g. JPEGImageDecoder). This base manages the ImageFrame cache.
content::WebGraphicsContext3DCommandBuffer
3D graphic related methods
forwards instructions to the GpuChannelHost which
encapsulates an IPC channel between the client and one GPU process
on the GPU process side there's a corresponding GpuChannel
every method can be called on any thread with a message loop, except for the IO thread
RasterTask
task, which performs rasterization
tasks are represented as a task graph
edges: dependencies
node: tasks, priority is assigned to them
items in the display list are drawn to the surface
rasterization calls gpu::gles2::QueryTracker methods in order to create queries to the GPU
gpu::gles2
QueryTracker
tracks queries for client side of command buffer.
QueryManager
keeps track of the queries and their state as Queries are not shared there is one QueryManager per context.
sends queries to content::CommandBufferProxyImpl
client side proxy that forwards messages synchronously to a CommandBufferStub
