android 启动应用启动过程

android启动总览.png

1. applist 中点击应用

iconClickListener对象是从launcher传递进去
AllAppsGridAdapter构造方法

  public AllAppsGridAdapter(Launcher launcher, AlphabeticalAppsList apps, View.OnClickListener
            iconClickListener, View.OnLongClickListener iconLongClickListener) {
        Resources res = launcher.getResources();
        mLauncher = launcher;
        mApps = apps;
        mEmptySearchMessage = res.getString(R.string.all_apps_loading_message);
        mGridSizer = new GridSpanSizer();
        mGridLayoutMgr = new AppsGridLayoutManager(launcher);
        mGridLayoutMgr.setSpanSizeLookup(mGridSizer);
        mLayoutInflater = LayoutInflater.from(launcher);
        mIconClickListener = iconClickListener;
        mIconLongClickListener = iconLongClickListener;
        if (FeatureFlags.LAUNCHER3_PHYSICS) {
            mSpringAnimationHandler = new SpringAnimationHandler<>(
                    SpringAnimationHandler.Y_DIRECTION, new AllAppsSpringAnimationFactory());
        }
    }
    

2. Launcher

launcher onclick 方法介绍

    /**
     * Launches the intent referred by the clicked shortcut.
     *
     * @param v The view representing the clicked shortcut.
     */
    public void onClick(View v) {
     // Make sure that rogue clicks don't get through while allapps is launching, or after the
        // view has detached (it's possible for this to happen if the view is removed mid touch).
        if (v.getWindowToken() == null) {
            return;
        }

        if (!mWorkspace.isFinishedSwitchingState()) {
            return;
        }

        if (v instanceof Workspace) {
            if (mWorkspace.isInOverviewMode()) {
                getUserEventDispatcher().logActionOnContainer(LauncherLogProto.Action.Type.TOUCH,
                        LauncherLogProto.Action.Direction.NONE,
                        LauncherLogProto.ContainerType.OVERVIEW, mWorkspace.getCurrentPage());
                showWorkspace(true);
            }
            return;
        }

        if (v instanceof CellLayout) {
            if (mWorkspace.isInOverviewMode()) {
                int page = mWorkspace.indexOfChild(v);
                getUserEventDispatcher().logActionOnContainer(LauncherLogProto.Action.Type.TOUCH,
                        LauncherLogProto.Action.Direction.NONE,
                        LauncherLogProto.ContainerType.OVERVIEW, page);
                mWorkspace.snapToPageFromOverView(page);
                showWorkspace(true);
            }
            return;
        }

        Object tag = v.getTag();
        if (tag instanceof ShortcutInfo) {
            onClickAppShortcut(v);
        } else if (tag instanceof FolderInfo) {
            if (v instanceof FolderIcon) {
                onClickFolderIcon(v);
            }
        } else if ((v instanceof PageIndicator) ||
            (v == mAllAppsButton && mAllAppsButton != null)) {
            onClickAllAppsButton(v);
        } else if (tag instanceof AppInfo) {
            startAppShortcutOrInfoActivity(v);
        } else if (tag instanceof LauncherAppWidgetInfo) {
            if (v instanceof PendingAppWidgetHostView) {
                onClickPendingWidget((PendingAppWidgetHostView) v);
            }
        }
   
    }

   private void startAppShortcutOrInfoActivity(View v) {
        ItemInfo item = (ItemInfo) v.getTag();
        Intent intent;
        if (item instanceof PromiseAppInfo) {
            PromiseAppInfo promiseAppInfo = (PromiseAppInfo) item;
            intent = promiseAppInfo.getMarketIntent();
        } else {
            intent = item.getIntent();
        }
        if (intent == null) {
            throw new IllegalArgumentException("Input must have a valid intent");
        }
        boolean success = startActivitySafely(v, intent, item);
        getUserEventDispatcher().logAppLaunch(v, intent); // TODO for discovered apps b/35802115

        if (success && v instanceof BubbleTextView) {
            mWaitingForResume = (BubbleTextView) v;
            mWaitingForResume.setStayPressed(true);
        }
    }
    
     public boolean startActivitySafely(View v, Intent intent, ItemInfo item) {
                ...
      try {
            if (Utilities.ATLEAST_MARSHMALLOW
                    && (item instanceof ShortcutInfo)
                    && (item.itemType == Favorites.ITEM_TYPE_SHORTCUT
                     || item.itemType == Favorites.ITEM_TYPE_DEEP_SHORTCUT)
                    && !((ShortcutInfo) item).isPromise()) {
                // Shortcuts need some special checks due to legacy reasons.
                startShortcutIntentSafely(intent, optsBundle, item);
            } else if (user == null || user.equals(Process.myUserHandle())) {
                // Could be launching some bookkeeping activity
                startActivity(intent, optsBundle);
            } else {
                LauncherAppsCompat.getInstance(this).startActivityForProfile(
                        intent.getComponent(), user, intent.getSourceBounds(), optsBundle);
            }
            return true;
        } catch (ActivityNotFoundException|SecurityException e) {
            Toast.makeText(this, R.string.activity_not_found, Toast.LENGTH_SHORT).show();
            Log.e(TAG, "Unable to launch. tag=" + item + " intent=" + intent, e);
        }
                ...
     }
     

3. Activity startActivity最终调用startActivityForResult流程

/**
     * @hide
     */
    @Override
    public void startActivityForResult(
            String who, Intent intent, int requestCode, @Nullable Bundle options) {
        Uri referrer = onProvideReferrer();
        if (referrer != null) {
            intent.putExtra(Intent.EXTRA_REFERRER, referrer);
        }
        options = transferSpringboardActivityOptions(options);
        Instrumentation.ActivityResult ar =
            mInstrumentation.execStartActivity(
                this, mMainThread.getApplicationThread(), mToken, who,
                intent, requestCode, options);
        if (ar != null) {
            mMainThread.sendActivityResult(
                mToken, who, requestCode,
                ar.getResultCode(), ar.getResultData());
        }
        cancelInputsAndStartExitTransition(options);
    }
    

4. Instrumentation

  */
    public ActivityResult execStartActivity(
            Context who, IBinder contextThread, IBinder token, String resultWho,
            Intent intent, int requestCode, Bundle options, UserHandle user) {
                            ...
           try {
            intent.migrateExtraStreamToClipData();
            intent.prepareToLeaveProcess(who);
            int result = ActivityManager.getService()
                .startActivityAsUser(whoThread, who.getBasePackageName(), intent,
                        intent.resolveTypeIfNeeded(who.getContentResolver()),
                        token, resultWho,
                        requestCode, 0, null, options, user.getIdentifier());
            checkStartActivityResult(result, intent);
        } catch (RemoteException e) {
            throw new RuntimeException("Failure from system", e);
        }
                            ...
            
            }

5. ActivityManagerservice

  @Override
    public final int startActivityAsUser(IApplicationThread caller, String callingPackage,
            Intent intent, String resolvedType, IBinder resultTo, String resultWho, int requestCode,
            int startFlags, ProfilerInfo profilerInfo, Bundle bOptions, int userId) {
        enforceNotIsolatedCaller("startActivity");
        userId = mUserController.handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(),
                userId, false, ALLOW_FULL_ONLY, "startActivity", null);
        // TODO: Switch to user app stacks here.
        return mActivityStarter.startActivityMayWait(caller, -1, callingPackage, intent,
                resolvedType, null, null, resultTo, resultWho, requestCode, startFlags,
                profilerInfo, null, null, bOptions, false, userId, null, "startActivityAsUser");
    }

6. ActivityStarter

    final int startActivityMayWait(IApplicationThread caller, int callingUid,
            String callingPackage, Intent intent, String resolvedType,
            IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
            IBinder resultTo, String resultWho, int requestCode, int startFlags,
            ProfilerInfo profilerInfo, WaitResult outResult,
            Configuration globalConfig, Bundle bOptions, boolean ignoreTargetSecurity, int userId,
            TaskRecord inTask, String reason) {
   
            
            final ActivityRecord[] outRecord = new ActivityRecord[1];
            int res = startActivityLocked(caller, intent, ephemeralIntent, resolvedType,
                    aInfo, rInfo, voiceSession, voiceInteractor,
                    resultTo, resultWho, requestCode, callingPid,
                    callingUid, callingPackage, realCallingPid, realCallingUid, startFlags,
                    options, ignoreTargetSecurity, componentSpecified, outRecord, inTask,
                    reason);
            
   }

startActivityLocked 又继续调用startctivity

    int startActivityLocked(IApplicationThread caller, Intent intent, Intent ephemeralIntent,
         String resolvedType, ActivityInfo aInfo, ResolveInfo rInfo,
         IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
         IBinder resultTo, String resultWho, int requestCode, int callingPid, int callingUid,
         String callingPackage, int realCallingPid, int realCallingUid, int startFlags,
         ActivityOptions options, boolean ignoreTargetSecurity, boolean componentSpecified,
         ActivityRecord[] outActivity, TaskRecord inTask, String reason) {

     if (TextUtils.isEmpty(reason)) {
         throw new IllegalArgumentException("Need to specify a reason.");
     }
     mLastStartReason = reason;
     mLastStartActivityTimeMs = System.currentTimeMillis();
     mLastStartActivityRecord[0] = null;

     mLastStartActivityResult = startActivity(caller, intent, ephemeralIntent, resolvedType,
             aInfo, rInfo, voiceSession, voiceInteractor, resultTo, resultWho, requestCode,
             callingPid, callingUid, callingPackage, realCallingPid, realCallingUid, startFlags,
             options, ignoreTargetSecurity, componentSpecified, mLastStartActivityRecord,
             inTask);

     if (outActivity != null) {
         // mLastStartActivityRecord[0] is set in the call to startActivity above.
         outActivity[0] = mLastStartActivityRecord[0];
     }

     // Aborted results are treated as successes externally, but we must track them internally.
     return mLastStartActivityResult != START_ABORTED ? mLastStartActivityResult : START_SUCCESS;
 }
 
  /** DO NOT call this method directly. Use {@link #startActivityLocked} instead. */
 private int startActivity(IApplicationThread caller, Intent intent, Intent ephemeralIntent,
         String resolvedType, ActivityInfo aInfo, ResolveInfo rInfo,
         IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
         IBinder resultTo, String resultWho, int requestCode, int callingPid, int callingUid,
         String callingPackage, int realCallingPid, int realCallingUid, int startFlags,
         ActivityOptions options, boolean ignoreTargetSecurity, boolean componentSpecified,
         ActivityRecord[] outActivity, TaskRecord inTask) {
         
         // 。。。。省略部分代码。。。。
         
                 return startActivity(r, sourceRecord, voiceSession, voiceInteractor, startFlags, true,
             options, inTask, outActivity);
         }
         
         
         
 private int startActivity(final ActivityRecord r, ActivityRecord sourceRecord,
         IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
         int startFlags, boolean doResume, ActivityOptions options, TaskRecord inTask,
         ActivityRecord[] outActivity) {
     int result = START_CANCELED;
     try {
         mService.mWindowManager.deferSurfaceLayout();
         result = startActivityUnchecked(r, sourceRecord, voiceSession, voiceInteractor,
                 startFlags, doResume, options, inTask, outActivity);
     } finally {
         // If we are not able to proceed, disassociate the activity from the task. Leaving an
         // activity in an incomplete state can lead to issues, such as performing operations
         // without a window container.
         if (!ActivityManager.isStartResultSuccessful(result)
                 && mStartActivity.getTask() != null) {
             mStartActivity.getTask().removeActivity(mStartActivity);
         }
         mService.mWindowManager.continueSurfaceLayout();
     }

     postStartActivityProcessing(r, result, mSupervisor.getLastStack().mStackId,  mSourceRecord,
             mTargetStack);

     return result;
 }
 

• 关键的应用启动模式的设定

        // Note: This method should only be called from {@link startActivity}.
    private int startActivityUnchecked(final ActivityRecord r, ActivityRecord sourceRecord,
            IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
            int startFlags, boolean doResume, ActivityOptions options, TaskRecord inTask,
            ActivityRecord[] outActivity) {
                ............
                
 ActivityStack.logStartActivity(
     EventLogTags.AM_CREATE_ACTIVITY, mStartActivity, mStartActivity.getTask());
        mTargetStack.mLastPausedActivity = null;

        sendPowerHintForLaunchStartIfNeeded(false /* forceSend */, mStartActivity);

        mTargetStack.startActivityLocked(mStartActivity, topFocused, newTask, mKeepCurTransition,
                mOptions);
        if (mDoResume) {
            final ActivityRecord topTaskActivity =
                    mStartActivity.getTask().topRunningActivityLocked();
            if (!mTargetStack.isFocusable()
                    || (topTaskActivity != null && topTaskActivity.mTaskOverlay
                    && mStartActivity != topTaskActivity)) {
                // If the activity is not focusable, we can't resume it, but still would like to
                // make sure it becomes visible as it starts (this will also trigger entry
                // animation). An example of this are PIP activities.
                // Also, we don't want to resume activities in a task that currently has an overlay
                // as the starting activity just needs to be in the visible paused state until the
                // over is removed.
                mTargetStack.ensureActivitiesVisibleLocked(null, 0, !PRESERVE_WINDOWS);
                // Go ahead and tell window manager to execute app transition for this activity
                // since the app transition will not be triggered through the resume channel.
                mWindowManager.executeAppTransition();
            } else {
                // If the target stack was not previously focusable (previous top running activity
                // on that stack was not visible) then any prior calls to move the stack to the
                // will not update the focused stack.  If starting the new activity now allows the
                // task stack to be focusable, then ensure that we now update the focused stack
                // accordingly.
                if (mTargetStack.isFocusable() && !mSupervisor.isFocusedStack(mTargetStack)) {
                    mTargetStack.moveToFront("startActivityUnchecked");
                }
                mSupervisor.resumeFocusedStackTopActivityLocked(mTargetStack, mStartActivity,
                        mOptions);
            }
                
                ...........
          
            }
            
  

7. ActivityStackSupervisor

    boolean resumeFocusedStackTopActivityLocked() {
        return resumeFocusedStackTopActivityLocked(null, null, null);
    }

    boolean resumeFocusedStackTopActivityLocked(
            ActivityStack targetStack, ActivityRecord target, ActivityOptions targetOptions) {

        if (!readyToResume()) {
            return false;
        }

        if (targetStack != null && isFocusedStack(targetStack)) {
            return targetStack.resumeTopActivityUncheckedLocked(target, targetOptions);
        }

        final ActivityRecord r = mFocusedStack.topRunningActivityLocked();
        if (r == null || r.state != RESUMED) {
            mFocusedStack.resumeTopActivityUncheckedLocked(null, null);
        } else if (r.state == RESUMED) {
            // Kick off any lingering app transitions form the MoveTaskToFront operation.
            mFocusedStack.executeAppTransition(targetOptions);
        }

• 调用resumeTopActivityUncheckedLocked -> resumeTopActivityInnerLocked();最终回调ActivityStackSupervisor 的 startSpecificActivityLocked
  最后贴出核心片段，在此判定是新起进程，还是创建直接创建activity

 void startSpecificActivityLocked(ActivityRecord r,
            boolean andResume, boolean checkConfig) {
        // Is this activity's application already running?
        ProcessRecord app = mService.getProcessRecordLocked(r.processName,
                r.info.applicationInfo.uid, true);

        r.getStack().setLaunchTime(r);
    //  判断当前该应用进程是否存在
        if (app != null && app.thread != null) {
            try {
                if ((r.info.flags&ActivityInfo.FLAG_MULTIPROCESS) == 0
                        || !"android".equals(r.info.packageName)) {
                    // Don't add this if it is a platform component that is marked
                    // to run in multiple processes, because this is actually
                    // part of the framework so doesn't make sense to track as a
                    // separate apk in the process.
                    app.addPackage(r.info.packageName, r.info.applicationInfo.versionCode,
                            mService.mProcessStats);
                }
                // 存在起界面
                realStartActivityLocked(r, app, andResume, checkConfig);
                return;
            } catch (RemoteException e) {
                Slog.w(TAG, "Exception when starting activity "
                        + r.intent.getComponent().flattenToShortString(), e);
            }

            // If a dead object exception was thrown -- fall through to
            // restart the application.
        }

    // 不存在则新建进程
        mService.startProcessLocked(r.processName, r.info.applicationInfo, true, 0,
                "activity", r.intent.getComponent(), false, false, true);
    }

进程存在的情况下启动应用流程
android 应用启动流程分析（二）