bindservice流程

本文主要是介绍bindservice流程，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

bindservice流程

android.app.ContextImpl#bindService

@Override
public boolean bindService(Intent service, ServiceConnection conn,int flags) {warnIfCallingFromSystemProcess();return bindServiceCommon(service, conn, flags, mMainThread.getHandler(),Process.myUserHandle());
}private boolean bindServiceCommon(Intent service, ServiceConnection conn, int flags, Handlerhandler, UserHandle user) {IServiceConnection sd;if (conn == null) {throw new IllegalArgumentException("connection is null");}if (mPackageInfo != null) {sd = mPackageInfo.getServiceDispatcher(conn, getOuterContext(), handler, flags);} else {throw new RuntimeException("Not supported in system context");}validateServiceIntent(service);try {IBinder token = getActivityToken();if (token == null && (flags&BIND_AUTO_CREATE) == 0 && mPackageInfo != null&& mPackageInfo.getApplicationInfo().targetSdkVersion< android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {flags |= BIND_WAIVE_PRIORITY;}service.prepareToLeaveProcess(this);// 1. 这里是调用了服务端的bindServiceint res = ActivityManagerNative.getDefault().bindService(mMainThread.getApplicationThread(), getActivityToken(), service,service.resolveTypeIfNeeded(getContentResolver()),sd, flags, getOpPackageName(), user.getIdentifier());if (res < 0) {throw new SecurityException("Not allowed to bind to service " + service);}return res != 0;} catch (RemoteException e) {throw e.rethrowFromSystemServer();}
}

ActivityManagerProxy代理的真正的是ActivityManagerNative子类ActivityManagerService

android.app.ActivityManagerProxy#bindService

public int bindService(IApplicationThread caller, IBinder token,Intent service, String resolvedType, IServiceConnection connection,int flags,  String callingPackage, int userId) throws RemoteException {Parcel data = Parcel.obtain();Parcel reply = Parcel.obtain();data.writeInterfaceToken(IActivityManager.descriptor);data.writeStrongBinder(caller != null ? caller.asBinder() : null);data.writeStrongBinder(token);service.writeToParcel(data, 0);data.writeString(resolvedType);data.writeStrongBinder(connection.asBinder());data.writeInt(flags);data.writeString(callingPackage);data.writeInt(userId);// 2. 代理调接口跟服务端通信,这里走到服务端mRemote.transact(BIND_SERVICE_TRANSACTION, data, reply, 0);reply.readException();int res = reply.readInt();data.recycle();reply.recycle();return res;
}

public abstract class ActivityManagerNative extends Binder implements IActivityManager

@Override
public boolean onTransact(int code, Parcel data, Parcel reply, int flags)throws RemoteException {// 4. 子类调用了父类的onTransactcase BIND_SERVICE_TRANSACTION: {data.enforceInterface(IActivityManager.descriptor);IBinder b = data.readStrongBinder();IApplicationThread app = ApplicationThreadNative.asInterface(b);IBinder token = data.readStrongBinder();Intent service = Intent.CREATOR.createFromParcel(data);String resolvedType = data.readString();b = data.readStrongBinder();int fl = data.readInt();String callingPackage = data.readString();int userId = data.readInt();IServiceConnection conn = IServiceConnection.Stub.asInterface(b);// 5. 这里调用了子类中的bindService不是代理类中的int res = bindService(app, token, service, resolvedType, conn, fl,callingPackage, userId);reply.writeNoException();reply.writeInt(res);return true;}
}

com.android.server.am.ActivityManagerService extends ActivityManagerNative

@Override
public boolean onTransact(int code, Parcel data, Parcel reply, int flags)throws RemoteException {try {// 3. 这里会调用父类的onTransact方法return super.onTransact(code, data, reply, flags);} catch (RuntimeException e) {// The activity manager only throws security exceptions, so let's// log all others.if (!(e instanceof SecurityException)) {Slog.wtf(TAG, "Activity Manager Crash", e);}throw e;}
}public int bindService(IApplicationThread caller, IBinder token, Intent service,String resolvedType, IServiceConnection connection, int flags, String callingPackage,int userId) throws TransactionTooLargeException {enforceNotIsolatedCaller("bindService");// 6. 执行绑定服务的操作synchronized(this) {return mServices.bindServiceLocked(caller, token, service,resolvedType, connection, flags, callingPackage, userId);}
}