主要观点总结
本文介绍了插件化开发在Android技术中的应用，提到了Flutter等技术的发展，以及插件化技术的适用场景。作者个人经历了从学习Android基础到源码的过程，并探索了插件化开发的相关知识。文章详细描述了startActivity方法的调用链、AMS与ActivityThread的交互，以及插件Dex的加载和资源加载的过程。同时，提到了So加载的问题，以及Service的加载与AMS的交互。最后，作者分享了个人对插件化开发的思考和学习经历，并给出了Vapp项目的地址。
关键观点总结
关键观点1: 插件化开发背景与意义
从Android技术的概念提出到Flutter等技术的发展，插件化技术一直是Android进步的重要方向。
关键观点2: 插件化技术适用场景
适用于大型应用模块化拆分、按需加载功能和第三方服务集成等场景。
关键观点3: 插件化开发探索
作者个人经历了从Android基础到源码的学习，并探索了插件化开发的相关知识。
关键观点4: startActivity方法调用链
描述了startActivity方法的调用链，以及AMS与ActivityThread的交互。
关键观点5: 插件Dex加载
介绍了插件Dex的加载过程，包括双亲委派模型、Dex文件解析和类加载流程。
关键观点6: 资源加载
讨论了资源加载的问题，如资源冲突等，并提供了解决思路。
关键观点7: So加载
提出了So加载的问题，并提供了解决方案，如预加载So文件。
关键观点8: Service加载
介绍了Service的加载与AMS的交互，并给出了相关代码示例。
关键观点9: 学习经历与项目分享
作者分享了个人对插件化开发的思考和学习经历，并给出了Vapp项目的地址。
正文
5428
}
else
{
5429
//
Note
we
want
to
go
through
this
method
for
compatibility
with
5430
//
existing
applications
that
may
have
overridden
it.
5431
mParent.startActivityFromChild(this
,
intent
,
requestCode);
5432
}
5433
}
5434
}
主要的代码就是这个玩意了 ：mInstrumentation.execStartActivity
1710 public ActivityResult execStartActivity(
1711 Context who, IBinder contextThread, IBinder token, Activity target,
1712 Intent intent, int requestCode, Bundle options) {
1713 IApplicationThread whoThread = (IApplicationThread) contextThread;
1714 Uri referrer = target != null ? target.onProvideReferrer() : null;
1715 if (referrer != null) {
1716 intent.putExtra(Intent.EXTRA_REFERRER, referrer);
1717 }
1718 if (mActivityMonitors != null) {
1719 synchronized (mSync) {
1720 final int N = mActivityMonitors.size();
1721 for (int i=0; i i++) {
1722 final ActivityMonitor am = mActivityMonitors.get(i);
1723 ActivityResult result = null;
1724 if (am.ignoreMatchingSpecificIntents()) {
1725 result = am.onStartActivity(intent);
1726 }
1727 if (result != null) {
1728 am.mHits++;
1729 return result;
1730 } else if (am.match(who, null, intent)) {
1731 am.mHits++;
1732 if (am.isBlocking()) {
1733 return requestCode >= 0 ? am.getResult() : null;
1734 }
1735 break;
1736 }
1737 }
1738 }
1739 }
1740 try {
1741 intent.migrateExtraStreamToClipData(who);
1742 intent.prepareToLeaveProcess(who);
1743 int result = ActivityTaskManager.getService().startActivity(whoThread,
1744 who.getOpPackageName(), who.getAttributionTag(), intent,
1745 intent.resolveTypeIfNeeded(who.getContentResolver()), token,
1746 target != null ? target.mEmbeddedID : null, requestCode, 0, null, options);
1747 checkStartActivityResult(result, intent);
1748 } catch (RemoteException e) {
1749 throw new RuntimeException("Failure from system", e);
1750 }
1751 return null;
1752 }
这里就调用 ActivityTaskManager.getService().startActivity方法了，这里就开始 与 ams沟通，
AMS 的内部就不记录了。
后面会调用 ActivityThread的 H 对象进行沟通。
@Override
public void scheduleTransaction(ClientTransaction transaction) {
mH.sendMessage(H.EXECUTE_TRANSACTION, transaction);
}
case EXECUTE_TRANSACTION:
2213 final ClientTransaction transaction = (ClientTransaction) msg.obj;
2214 mTransactionExecutor.execute(transaction);
2215 if (isSystem()) {
2216
2217
2218
2219 transaction.recycle();
2220 }
2221
我查看了TransactionExecutor 的类
205 private void performLifecycleSequence(ActivityClientRecord r, IntArray path,
206 ClientTransaction transaction) {
207 final int size = path.size();
208 for (int i = 0, state; i < size; i++) {
209 state = path.get(i);
210 if (DEBUG_RESOLVER) {
211 Slog.d(TAG, tId(transaction) + "Transitioning activity: "
212 + getShortActivityName(r.token, mTransactionHandler)
213 + " to state: " + getStateName(state));
214 }
215 switch (state) {
216 case ON_CREATE:
217 mTransactionHandler.handleLaunchActivity(r, mPendingActions,
218 null );
219 break;
220 case ON_START:
221 mTransactionHandler.handleStartActivity(r, mPendingActions,
222 null );
223 break;
224 case ON_RESUME:
225 mTransactionHandler.handleResumeActivity(r, false ,
226 r.isForward, "LIFECYCLER_RESUME_ACTIVITY");
227 break;
228 case ON_PAUSE:
229 mTransactionHandler.handlePauseActivity(r, false ,
230 false , 0 , mPendingActions,
231 "LIFECYCLER_PAUSE_ACTIVITY");
232 break;
233 case ON_STOP:
234 mTransactionHandler.handleStopActivity(r, 0 ,
235 mPendingActions, false ,
236 "LIFECYCLER_STOP_ACTIVITY");
237 break;
238 case ON_DESTROY:
239 mTransactionHandler.handleDestroyActivity(r, false ,
240 0 , false ,
241 "performLifecycleSequence. cycling to:" + path.get(size - 1));
242 break;
243 case ON_RESTART:
244 mTransactionHandler.performRestartActivity(r, false );
245 break;
246 default:
247 throw new IllegalArgumentException("Unexpected lifecycle state: " + state);
248 }
249 }
250 }
这里就进入
mTransactionHandler.handleLaunchActivity(r, mPendingActions,
218 null );
/**
3758 * Extended implementation of activity launch. Used when server requests a launch or relaunch.
3759 */
3760 @Override
3761 public Activity handleLaunchActivity(ActivityClientRecord r,
3762 PendingTransactionActions pendingActions, Intent customIntent) {
3763 // If we are getting ready to gc after going to the background, well
3764 // we are back active so skip it.
3765 unscheduleGcIdler();
3766 mSomeActivitiesChanged = true;
3767
3768 if (r.profilerInfo != null) {
3769 mProfiler.setProfiler(r.profilerInfo);
3770 mProfiler.startProfiling();
3771 }
3772
3773 if (r.mPendingFixedRotationAdjustments != null) {
3774 // The rotation adjustments must be applied before handling configuration, so process
3775 // level display metrics can be adjusted.
3776 overrideApplicationDisplayAdjustments(r.token, adjustments ->
3777 adjustments.setFixedRotationAdjustments(r.mPendingFixedRotationAdjustments));
3778 }
3779
3780 // Make sure we are running with the most recent config.
3781 mConfigurationController.handleConfigurationChanged(null, null);
3782
3783 if (localLOGV) Slog.v(
3784 TAG, "Handling launch of " + r);
3785
3786 // Initialize before creating the activity
3787 if (ThreadedRenderer.sRendererEnabled
3788 && (r.activityInfo.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0) {
3789 HardwareRenderer.preload();
3790 }
3791 WindowManagerGlobal.initialize();
3792
3793 // Hint the GraphicsEnvironment that an activity is launching on the process.
3794 GraphicsEnvironment.hintActivityLaunch();
3795
