开启服务
startService()
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// Context.startService() -> ContextImpl.startServiceCommon() -[IPC 到 SystemServer 进程]->
// AMS.startService() -> ActiveServices.startServiceLocked() ->
// [retreiveServiceLocked(): ServiceLookupResult ->] AMS.startServiceInnerLocked() ->
// bringUpServiceLocked(): String
// case1已经启动： -> sendServiceArgsLocked() -> ActivityThread.ApplicationThread.shcheduleServiceArgs() ->
// ActivityThread.handleServiceArgs() -> Service.onStartCommand()
// case2未启动： -> ActivityThread.ApplicationThread.scheduleCreateService() ->
// ActivityThread.handleCreateService() -> Service.onCreate()
stopService()
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// Context.stopService() -> ContextImpl.stopServiceCommon() -[IPC 到 SystemServer 进程]->
// AMS.stopService() -> ActiveServices.stopServiceLocked() ->
// ActivityThread.ApplicationThread.scheduleStopService() -> ActivityThread.handleStopService() ->
// Service.onDestroy()
开启服务小结
- 生命周期
onCreate()->onStartCommand()->onDestroy()
绑定服务
bindService()
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// Context.bindService() ->
// LoadedApk.getServiceDispatcher(): IServiceConnection -> LoadedApk.ServiceDispatcher.getIServiceConnection()
// ServiceDispatcher.InnerConnection
// ContextImpl.bindServiceCommon() -[IPC 到 SystemServer]> AMS.bindService() ->
// ActiveServices.bindServiceLocked() -> retreiveServiceLocked() -> bringUpServiceLocked() ->
// case1 Service 已经创建：sendServiceArgsLocked() -> ActivityThread.ApplicationThread.scheduleServiceArgs() ->
// case2 Service 未创建：realStartServiceLocked() -> ActivityThread.ApplicationThread.scheduleCreateService() ->
// ActivityThread.handleCreateService() -> Service.onCreate()
// requestServiceBindingLocked() -> ActivityThread.ApplicationThread.scheduleBindService() ->
// ActivityThread.handleBindService() -> Service.onBind()
unbindService()
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// Context.unbindService() -> ContextImpl.unbindService() -[IPC 到 SystemServer]->
// AMS.unbindService() -> ActiveServices.unbindServiceLocked() -> removeConnectionLocked() ->
// ActivityThread.ApplicationThread.scheduleUnbindService() -> ActivityThread.handleUnbindService() ->
// Service.onUnbind() ->
// ActiveServices.bringDownServiceIfNeededLocked() -> bringDownServiceLocked() -...-> scheduleStopService() ->
// ActivityThread.handleStopService() -> Service.onDestroy()
绑定服务小结
- 主要提供 c/s 接口，允许组件与 Service 进行交互或者跨进程通讯
- bind 服务的 3 种方式
- 扩展 Binder : 同一个进程内提供服务
- 使用 Messenger : IPC，单线程
- 使用 aidl : IPC，多线程