一 前言
前一篇介绍了startService启动过程，本篇接着介绍Service中另一种启动方式：bindService过程。bindService过程前一部分在startService中都会得到体现，所以本文只介绍在同一个进程中bindService的流程。即在上一篇的基础上在AndroidManifest.xml中注册MyService时不注册为远程进程：
<service android:name=".MyService">
</service>
然后可以MainActivity.java中通过如下方式即可以bindService：
public class MainActivity extends Activity implements OnClickListener {
...
MyService.MyBinder serverService;
private ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
serverService = ((MyService.MyBinder) service);
serverService. startTask();
}
@Override
public void onServiceDisconnected(ComponentName name) {
serverService = null;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent(MainActivity.this, MyService.class);
bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
}
...
}
接着先给出bindService主流程的时序图：
二 启动流程分析
在MainActivity的里onCreate方法中调用bindService(Intent service)方法时，它实际上是调用ContextWrapper.bindService(Intent service)，然后就从此展示分析。
步骤1.ContextWrapper.bindService
源码位置：/frameworks/base/core/java/android/content/ContextWrapper.java
@Override
public boolean bindService(Intent service, ServiceConnection conn,
int flags) {
return mBase.bindService(service, conn, flags);
}
这个过程与startService类似，mBase的对象类型是Context，它实际上指向了Context的实现类ContextImpl，所以该方法进一步调用ContextImpl.bindService。
步骤2.ContextImpl.bindService
源码位置：/frameworks/base/core/java/android/app/ContextImpl.java
@Override
public boolean bindService(Intent service, ServiceConnection conn,
int flags) {
warnIfCallingFromSystemProcess();
return bindServiceCommon(service, conn, flags, mMainThread.getHandler(),
Process.myUserHandle());
}
ContextImpl的bindService方法内部又调用了自己的startServiceCommon方法
步骤3.ContextImpl.bindServiceCommon
源码位置：/frameworks/base/core/java/android/app/ContextImpl.java
private boolean bindServiceCommon(Intent service, ServiceConnection conn, int flags, Handler
handler, UserHandle user) {
IServiceConnection sd;
if (conn == null) {
throw new IllegalArgumentException("connection is null");
}
if (mPackageInfo != null) {
//把ServiceConnection转成Binder对象，也就是ServiceDispatcher.InnerConnection对象
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);
//接着通过AWS来完成Service的绑定过程
int 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();
}
}
bindServiceCommon方法主要完成如下两件事情：
1.把ServiceConnection转成Binder对象，也就是ServiceDispatcher.InnerConnection对象，这个过程主要是因为绑定服务的过程有可能是跨进程的，因此需要借助Binder才能让远程进程回调onServiceConnected方法，而ServiceDispatcher.InnerConnection就充当Binder这个角色。这个过程由LoadApk的getServiceDispatcher方法中完成的，看下源码：
public final IServiceConnection getServiceDispatcher(ServiceConnection c,
Context context, Handler handler, int flags) {
synchronized (mServices) {
LoadedApk.ServiceDispatcher sd = null;
ArrayMap<ServiceConnection, LoadedApk.ServiceDispatcher> map = mServices.get(context);
if (map != null) {
sd = map.get(c);
}
if (sd == null) {
sd = new ServiceDispatcher(c, context, handler, flags);
if (map == null) {
map = new ArrayMap<ServiceConnection, LoadedApk.ServiceDispatcher>();
mServices.put(context, map);
}
map.put(c, sd);
} else {
sd.validate(context, handler);
}
return sd.getIServiceConnection();
}
}
这个方法中会首先查找ArrayMap的mServices中是否存在与当前ServiceConnection相同的对象，如果不存在就创建一个ServiceDispatcher对象并放入mServices中以便复用。
2.接着通过AWS来完成Service的绑定过程
这个过程调用ActivityManagerNative.getDefault().bindService方法实现，ActivityManagerNative.getDefault()前面两篇文章已经出现多次，会返回一个ActivityManagerService的远程接口，即ActivityManagerProxy接口，然后接着看ActivityManagerProxy.bindService()方法调用的源码。
步骤4.ActivityManagerProxy.bindService
源码位置：/frameworks/base/core/java/android/app/ActivityManagerNative.java的内部类
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);
mRemote.transact(BIND_SERVICE_TRANSACTION, data, reply, 0);
reply.readException();
int res = reply.readInt();
data.recycle();
reply.recycle();
return res;
}
ActivityManagerProxy内部通过Binder对象mRemote调用transact方法向ActivityManagerService发送一个BIND_SERVICE_TRANSACTION进程间通信请求。这样就把绑定Service的操作交给system_server进程的ActivityManagerService处理
步骤5. ActivityManagerService.bindService
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java
public int bindService(IApplicationThread caller, IBinder token, Intent service,
String resolvedType, IServiceConnection connection, int flags, String callingPackage,
int userId) throws TransactionTooLargeException {
enforceNotIsolatedCaller("bindService");
// Refuse possible leaked file descriptors
if (service != null && service.hasFileDescriptors() == true) {
throw new IllegalArgumentException("File descriptors passed in Intent");
}
if (callingPackage == null) {
throw new IllegalArgumentException("callingPackage cannot be null");
}
synchronized(this) {
return mServices.bindServiceLocked(caller, token, service,
resolvedType, connection, flags, callingPackage, userId);
}
}
mServices的类型是ActiveServices，ActiveServices是一个AMS的辅助类，管理Service类的启动、绑定和销毁等，因此进一步调用ActiveServices.bindServiceLocked()方法。
步骤6.ActiveServices.bindServiceLocked
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
int bindServiceLocked(IApplicationThread caller, IBinder token, Intent service,
String resolvedType, final IServiceConnection connection, int flags,
String callingPackage, final int userId) throws TransactionTooLargeException {
...
if ((flags&Context.BIND_AUTO_CREATE) != 0) {
s.lastActivity = SystemClock.uptimeMillis();
if (bringUpServiceLocked(s, service.getFlags(), callerFg, false,
permissionsReviewRequired) != null) {
return 0;
}
}
...
}
该方法中调用bringUpServiceLocked方法
步骤7.ActiveServices.bringUpServiceLocked
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
private String bringUpServiceLocked(ServiceRecord r, int intentFlags, boolean execInFg,
boolean whileRestarting, boolean permissionsReviewRequired)
throws TransactionTooLargeException {
//Slog.i(TAG, "Bring up service:");
//r.dump(" ");
if (r.app != null && r.app.thread != null) {
sendServiceArgsLocked(r, execInFg, false);
return null;
}
if (!whileRestarting && r.restartDelay > 0) {
// If waiting for a restart, then do nothing.
return null;
}
if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Bringing up " + r + " " + r.intent);
// We are now bringing the service up, so no longer in the
// restarting state.
if (mRestartingServices.remove(r)) {
r.resetRestartCounter();
clearRestartingIfNeededLocked(r);
}
// Make sure this service is no longer considered delayed, we are starting it now.
if (r.delayed) {
if (DEBUG_DELAYED_STARTS) Slog.v(TAG_SERVICE, "REM FR DELAY LIST (bring up): " + r);
getServiceMap(r.userId).mDelayedStartList.remove(r);
r.delayed = false;
}
// Make sure that the user who owns this service is started. If not,
// we don't want to allow it to run.
if (!mAm.mUserController.hasStartedUserState(r.userId)) {
String msg = "Unable to launch app "
+ r.appInfo.packageName + "/"
+ r.appInfo.uid + " for service "
+ r.intent.getIntent() + ": user " + r.userId + " is stopped";
Slog.w(TAG, msg);
bringDownServiceLocked(r);
return msg;
}
// Service is now being launched, its package can't be stopped.
try {
AppGlobals.getPackageManager().setPackageStoppedState(
r.packageName, false, r.userId);
} catch (RemoteException e) {
} catch (IllegalArgumentException e) {
Slog.w(TAG, "Failed trying to unstop package "
+ r.packageName + ": " + e);
}
final boolean isolated = (r.serviceInfo.flags&ServiceInfo.FLAG_ISOLATED_PROCESS) != 0;
final String procName = r.processName;
ProcessRecord app;
if (!isolated) {
app = mAm.getProcessRecordLocked(procName, r.appInfo.uid, false);
if (DEBUG_MU) Slog.v(TAG_MU, "bringUpServiceLocked: appInfo.uid=" + r.appInfo.uid
+ " app=" + app);
if (app != null && app.thread != null) {
try {
app.addPackage(r.appInfo.packageName, r.appInfo.versionCode, mAm.mProcessStats);
realStartServiceLocked(r, app, execInFg);
return null;
} catch (TransactionTooLargeException e) {
throw e;
} catch (RemoteException e) {
Slog.w(TAG, "Exception when starting service " + r.shortName, e);
}
// If a dead object exception was thrown -- fall through to
// restart the application.
}
} else {
// If this service runs in an isolated process, then each time
// we call startProcessLocked() we will get a new isolated
// process, starting another process if we are currently waiting
// for a previous process to come up. To deal with this, we store
// in the service any current isolated process it is running in or
// waiting to have come up.
app = r.isolatedProc;
}
// Not running -- get it started, and enqueue this service record
// to be executed when the app comes up.
if (app == null && !permissionsReviewRequired) {
if ((app=mAm.startProcessLocked(procName, r.appInfo, true, intentFlags,
"service", r.name, false, isolated, false)) == null) {
String msg = "Unable to launch app "
+ r.appInfo.packageName + "/"
+ r.appInfo.uid + " for service "
+ r.intent.getIntent() + ": process is bad";
Slog.w(TAG, msg);
bringDownServiceLocked(r);
return msg;
}
if (isolated) {
r.isolatedProc = app;
}
}
if (!mPendingServices.contains(r)) {
mPendingServices.add(r);
}
if (r.delayedStop) {
// Oh and hey we've already been asked to stop!
r.delayedStop = false;
if (r.startRequested) {
if (DEBUG_DELAYED_STARTS) Slog.v(TAG_SERVICE,
"Applying delayed stop (in bring up): " + r);
stopServiceLocked(r);
}
}
return null;
}
前言中举的例子假设MySerivce是一个与MainActivity所在app属于同一个进程，因此，此时MySerivce所在进程已启动，会直接走realStartServiceLocked方法，
如果Service所在进程未启动，则会调用mAm.startProcessLocked方法，而这个过程在上一篇文章已经跟踪过代码，对应上一篇文章的步骤8-16，本篇就不重复分析这个过程。
步骤8.ActiveServices.realStartServiceLocked
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
private final void realStartServiceLocked(ServiceRecord r,
ProcessRecord app, boolean execInFg) throws RemoteException {
...
boolean created = false;
try {
if (LOG_SERVICE_START_STOP) {
String nameTerm;
int lastPeriod = r.shortName.lastIndexOf('.');
nameTerm = lastPeriod >= 0 ? r.shortName.substring(lastPeriod) : r.shortName;
EventLogTags.writeAmCreateService(
r.userId, System.identityHashCode(r), nameTerm, r.app.uid, r.app.pid);
}
synchronized (r.stats.getBatteryStats()) {
r.stats.startLaunchedLocked();
}
mAm.notifyPackageUse(r.serviceInfo.packageName,
PackageManager.NOTIFY_PACKAGE_USE_SERVICE);
app.forceProcessStateUpTo(ActivityManager.PROCESS_STATE_SERVICE);
//1.创建Service
app.thread.scheduleCreateService(r, r.serviceInfo,
mAm.compatibilityInfoForPackageLocked(r.serviceInfo.applicationInfo),
app.repProcState);
r.postNotification();
created = true;
} catch (DeadObjectException e) {
Slog.w(TAG, "Application dead when creating service " + r);
mAm.appDiedLocked(app);
throw e;
} finally {
if (!created) {
// Keep the executeNesting count accurate.
final boolean inDestroying = mDestroyingServices.contains(r);
serviceDoneExecutingLocked(r, inDestroying, inDestroying);
// Cleanup.
if (newService) {
app.services.remove(r);
r.app = null;
}
// Retry.
if (!inDestroying) {
scheduleServiceRestartLocked(r, false);
}
}
}
if (r.whitelistManager) {
app.whitelistManager = true;
}
//2.请求绑定Service
requestServiceBindingsLocked(r, execInFg);
updateServiceClientActivitiesLocked(app, null, true);
...
}
该方法内部要完成如下两件事情：
1.创建Service，这个过程与上一篇文章startService的步骤17-21对应，本文也就不再分析。
2.请求绑定Service，本文接着重点分析Service创建成功后的绑定的流程。
步骤9-步骤14与上一篇startService文章的步骤17-21类似，可自行查看其过程，接着看requestServiceBindingsLocked请求绑定Service过程
步骤15.ActiveServices.requestServiceBindingsLocked
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
private final void requestServiceBindingsLocked(ServiceRecord r, boolean execInFg)
throws TransactionTooLargeException {
for (int i=r.bindings.size()-1; i>=0; i--) {
IntentBindRecord ibr = r.bindings.valueAt(i);
if (!requestServiceBindingLocked(r, ibr, execInFg, false)) {
break;
}
}
}
private final boolean requestServiceBindingLocked(ServiceRecord r, IntentBindRecord i,
boolean execInFg, boolean rebind) throws TransactionTooLargeException {
if (r.app == null || r.app.thread == null) {
// If service is not currently running, can't yet bind.
return false;
}
if ((!i.requested || rebind) && i.apps.size() > 0) {
try {
bumpServiceExecutingLocked(r, execInFg, "bind");
r.app.forceProcessStateUpTo(ActivityManager.PROCESS_STATE_SERVICE);
r.app.thread.scheduleBindService(r, i.intent.getIntent(), rebind,
r.app.repProcState);
if (!rebind) {
i.requested = true;
}
i.hasBound = true;
i.doRebind = false;
} catch (TransactionTooLargeException e) {
// Keep the executeNesting count accurate.
if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Crashed while binding " + r, e);
final boolean inDestroying = mDestroyingServices.contains(r);
serviceDoneExecutingLocked(r, inDestroying, inDestroying);
throw e;
} catch (RemoteException e) {
if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Crashed while binding " + r);
// Keep the executeNesting count accurate.
final boolean inDestroying = mDestroyingServices.contains(r);
serviceDoneExecutingLocked(r, inDestroying, inDestroying);
return false;
}
}
return true;
}
可知，requestServiceBindingLocked内部又通过r.app.thread调用scheduleBindService方法，而app.thread这个对象在前两篇文章也出现多次，其在ApplicationThreadNative实现初始化后返回ApplicationThreadProxy对象。接着看ApplicationThreadProxy.scheduleBindService源码：
步骤16. ApplicationThreadProxy.scheduleBindService
源码位置：frameworks/base/core/java/android/app/ApplicationThreadNative.java的内部类
public final void scheduleBindService(IBinder token, Intent intent, boolean rebind,
int processState) throws RemoteException {
Parcel data = Parcel.obtain();
data.writeInterfaceToken(IApplicationThread.descriptor);
data.writeStrongBinder(token);
intent.writeToParcel(data, 0);
data.writeInt(rebind ? 1 : 0);
data.writeInt(processState);
mRemote.transact(SCHEDULE_BIND_SERVICE_TRANSACTION, data, null,
IBinder.FLAG_ONEWAY);
data.recycle();
}
ApplicationThreadProxy内部通过Binder对象mRemote调用transact方法向ApplicationThread发送一个SCHEDULE_BIND_SERVICE_TRANSACTION进程间通信请求。这样就把绑定Service的操作交给system_server进程的ApplicationThread处理
步骤17.ActivityThread$ApplicationThread.scheduleBindService
源码位置：/frameworks/base/core/java/android/app/ActivityThread.java的内部类
boolean rebind, int processState) {
updateProcessState(processState, false);
BindServiceData s = new BindServiceData();
s.token = token;
s.intent = intent;
s.rebind = rebind;
if (DEBUG_SERVICE)
Slog.v(TAG, "scheduleBindService token=" + token + " intent=" + intent + " uid="
+ Binder.getCallingUid() + " pid=" + Binder.getCallingPid());
sendMessage(H.BIND_SERVICE, s);
}
步骤18.ActivityThread.sendMessage
源码位置：
/frameworks/base/core/java/android/app/ActivityThread.java
private void sendMessage(int what, Object obj, int arg1, int arg2, boolean async) {
if (DEBUG_MESSAGES) Slog.v(
TAG, "SCHEDULE " + what + " " + mH.codeToString(what)
+ ": " + arg1 + " / " + obj);
Message msg = Message.obtain();
msg.what = what;
msg.obj = obj;
msg.arg1 = arg1;
msg.arg2 = arg2;
if (async) {
msg.setAsynchronous(true);
}
mH.sendMessage(msg);
}
mH是一个H对象，类H是ActivityThread的内部类，并继承了Handler。接着在handleMessage方法中看BIND_SERVICE类型消息的处理
步骤19.ActivityThread$H.handleMessage
源码位置：
/frameworks/base/core/java/android/app/ActivityThread.java内部类H
public void handleMessage(Message msg) {
...
case BIND_SERVICE:
Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "serviceBind");
handleBindService((BindServiceData)msg.obj);
Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
break;
...
}
绑定过程又调用ActivityThread.handleBindService方法来实现
步骤20.ActivityThread.handleBindService
源码位置：
/frameworks/base/core/java/android/app/ActivityThread.java
private void handleBindService(BindServiceData data) {
Service s = mServices.get(data.token);
if (DEBUG_SERVICE)
Slog.v(TAG, "handleBindService s=" + s + " rebind=" + data.rebind);
if (s != null) {
try {
data.intent.setExtrasClassLoader(s.getClassLoader());
data.intent.prepareToEnterProcess();
try {
if (!data.rebind) {
IBinder binder = s.onBind(data.intent);
ActivityManagerNative.getDefault().publishService(
data.token, data.intent, binder);
} else {
s.onRebind(data.intent);
ActivityManagerNative.getDefault().serviceDoneExecuting(
data.token, SERVICE_DONE_EXECUTING_ANON, 0, 0);
}
ensureJitEnabled();
} catch (RemoteException ex) {
throw ex.rethrowFromSystemServer();
}
} catch (Exception e) {
if (!mInstrumentation.onException(s, e)) {
throw new RuntimeException(
"Unable to bind to service " + s
+ " with " + data.intent + ": " + e.toString(), e);
}
}
}
}
首先方法会先判断Service是否重复绑定，如果不是rebind，Service会执行Service.onBind方法即步骤21，然后再告诉AMS.publishService即步骤22
步骤21.Service.onBind
即回调执行MyService中的onBind方法
public class MyService extends Service {
private Binder mBinder = new MyBinder();
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
class MyBinder extends Binder {
public void startTask() {
// 执行具体的任务
}
}
}
步骤22. ActivityManagerProxy.publishService
源码位置：
/frameworks/base/core/java/android/app/ActivityManagerNative.java的内部类
public void publishService(IBinder token,
Intent intent, IBinder service) throws RemoteException {
Parcel data = Parcel.obtain();
Parcel reply = Parcel.obtain();
data.writeInterfaceToken(IActivityManager.descriptor);
data.writeStrongBinder(token);
intent.writeToParcel(data, 0);
data.writeStrongBinder(service);
mRemote.transact(PUBLISH_SERVICE_TRANSACTION, data, reply, 0);
reply.readException();
data.recycle();
reply.recycle();
}
ActivityManagerProxy内部通过Binder对象mRemote调用transact方法向ActivityManagerService发送一个PUBLISH_SERVICE_TRANSACTION进程间通信请求。这样就把绑定Service的操作交给system_server进程的ActivityManagerService处理
步骤23. ActivityManagerService.publishService
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java
public void publishService(IBinder token, Intent intent, IBinder service) {
// Refuse possible leaked file descriptors
if (intent != null && intent.hasFileDescriptors() == true) {
throw new IllegalArgumentException("File descriptors passed in Intent");
}
synchronized(this) {
if (!(token instanceof ServiceRecord)) {
throw new IllegalArgumentException("Invalid service token");
}
mServices.publishServiceLocked((ServiceRecord)token, intent, service);
}
}
mServices的类型是ActiveServices，因此进一步调用ActiveServices.publishServiceLocked()方法。
步骤24. ActiveServices.publishServiceLocked
源码位置：
/frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
void publishServiceLocked(ServiceRecord r, Intent intent, IBinder service) {
final long origId = Binder.clearCallingIdentity();
try {
if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "PUBLISHING " + r
+ " " + intent + ": " + service);
if (r != null) {
Intent.FilterComparison filter
= new Intent.FilterComparison(intent);
IntentBindRecord b = r.bindings.get(filter);
if (b != null && !b.received) {
b.binder = service;
b.requested = true;
b.received = true;
for (int conni=r.connections.size()-1; conni>=0; conni--) {
ArrayList<ConnectionRecord> clist = r.connections.valueAt(conni);
for (int i=0; i<clist.size(); i++) {
ConnectionRecord c = clist.get(i);
if (!filter.equals(c.binding.intent.intent)) {
if (DEBUG_SERVICE) Slog.v(
TAG_SERVICE, "Not publishing to: " + c);
if (DEBUG_SERVICE) Slog.v(
TAG_SERVICE, "Bound intent: " + c.binding.intent.intent);
if (DEBUG_SERVICE) Slog.v(
TAG_SERVICE, "Published intent: " + intent);
continue;
}
if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Publishing to: " + c);
try {
c.conn.connected(r.name, service);
} catch (Exception e) {
Slog.w(TAG, "Failure sending service " + r.name +
" to connection " + c.conn.asBinder() +
" (in " + c.binding.client.processName + ")", e);
}
}
}
}
serviceDoneExecutingLocked(r, mDestroyingServices.contains(r), false);
}
} finally {
Binder.restoreCallingIdentity(origId);
}
}
代码比较长，其内部核心调用其实是 c.conn.connected(r.name, service);c的类型是ConnectionRecord，c.conn的类型就是步骤3中讨论的ServiceDispatcher.InnerConnection，接着就看看InnerConnection内部的调用情况。
步骤25. LoadedApk$ServiceDispatcher$InnerConnection.connected
源码位置：
/frameworks/base/core/java/android/app/LoadedApk.java
LoadedApk.ServiceDispatcher sd = mDispatcher.get();
if (sd != null) {
sd.connected(name, service);
}
方法内部又调用了ServiceDispatcher.connected
步骤26. LoadedApk$ServiceDispatcher.connected
源码位置：
/frameworks/base/core/java/android/app/LoadedApk.java
public void connected(ComponentName name, IBinder service) {
if (mActivityThread != null) {
mActivityThread.post(new RunConnection(name, service, 0));
} else {
doConnected(name, service);
}
}
mActivityThread是ActivityThread中的H，所以之后会通过H这个handler post一个Connection Runnable：
private final class RunConnection implements Runnable {
RunConnection(ComponentName name, IBinder service, int command) {
mName = name;
mService = service;
mCommand = command;
}
public void run() {
if (mCommand == 0) {
doConnected(mName, mService);
} else if (mCommand == 1) {
doDeath(mName, mService);
}
}
final ComponentName mName;
final IBinder mService;
final int mCommand;
}
其内部调用了ServiceDispatcher.doConnected方法。
步骤27. LoadedApk$ServiceDispatcher.doConnected
源码位置：
/frameworks/base/core/java/android/app/LoadedApk.java
public void doConnected(ComponentName name, IBinder service) {
ServiceDispatcher.ConnectionInfo old;
ServiceDispatcher.ConnectionInfo info;
synchronized (this) {
if (mForgotten) {
// We unbound before receiving the connection; ignore
// any connection received.
return;
}
old = mActiveConnections.get(name);
if (old != null && old.binder == service) {
// Huh, already have this one. Oh well!
return;
}
if (service != null) {
// A new service is being connected... set it all up.
info = new ConnectionInfo();
info.binder = service;
info.deathMonitor = new DeathMonitor(name, service);
try {
service.linkToDeath(info.deathMonitor, 0);
mActiveConnections.put(name, info);
} catch (RemoteException e) {
// This service was dead before we got it... just
// don't do anything with it.
mActiveConnections.remove(name);
return;
}
} else {
// The named service is being disconnected... clean up.
mActiveConnections.remove(name);
}
if (old != null) {
old.binder.unlinkToDeath(old.deathMonitor, 0);
}
}
// If there was an old service, it is now disconnected.
if (old != null) {
mConnection.onServiceDisconnected(name);
}
// If there is a new service, it is now connected.
if (service != null) {
mConnection.onServiceConnected(name, service);
}
}
ServiceDispatcher在步骤3时保存了客户端的ServiceConnection对象，因此，最终在doConnected方法真正执行了ServiceConnection中的onServiceConnected方法，完成最终绑定的过程，整个bindService过程就完成了。
