enum class MessagePumpType {
// This type of pump only supports tasks and timers.
DEFAULT,
// This type of pump also supports native UI events (e.g., Windows
// messages).
UI,
// User provided implementation of MessagePump interface
CUSTOM,
// This type of pump also supports asynchronous IO.
IO,
};
enum class ThreadType : int {
// Suitable for threads that have the least urgency and lowest priority, and
// can be interrupted or delayed by other types.
kBackground,
// Suitable for threads that are less important than normal type, and can be
// interrupted or delayed by threads with kDefault type.
kUtility,
// Suitable for threads that produce user-visible artifacts but aren't
// latency sensitive. The underlying platform will try to be economic
// in its usage of resources for this thread, if possible.
kResourceEfficient,
// Default type. The thread priority or quality of service will be set to
// platform default. In Chrome, this is suitable for handling user
// interactions (input), only display and audio can get a higher priority.
kDefault,
// Suitable for display critical threads, ie. threads critical to compositing
// and presenting the foreground content.
kDisplayCritical,
// Suitable for low-latency, glitch-resistant audio.
kRealtimeAudio,
kMaxValue = kRealtimeAudio,
};wWinMain()
content::ContentMain()
content::ContentMainRunner::Initialize();
content::ContentMainDelegate::BasicStartupComplete();
tracing::TracingSamplerProfiler::CreateOnMainThread(); // LoaderLockSampler 线程，负责周期性检测 DllMain 锁
sandbox::policy::Sandbox::Initialize(); // BrokerEvent 线程，负责监听 Job 对象
content::ContentMainRunner::Run();
content::ContentMainRunnerImpl::RunBrowser();
base::ThreadPoolInstance::Start(); // ThreadPoolServiceThread 线程，负责转发异步事件到目标线程
// ThreadPoolForegroundWorker 线程（若干）
// ThreadPoolBackgroundWorker 线程（若干）
content::BrowserTaskExecutor::CreateIOThread(); // Chrome_IOThread 线程，负责异步 IO// electron
BaseWindow -> Widget
WebContentsView -> View
WebContents