ActivityStackSupervisor-attachApplicationLocked

查看attachApplicationLocked方法

boolean attachApplicationLocked(ProcessRecord app) throws RemoteException {
        final String processName = app.processName;
        boolean didSomething = false;
        for (int displayNdx = mActivityDisplays.size() - 1; displayNdx >= 0; --displayNdx) {
            ArrayList<ActivityStack> stacks = mActivityDisplays.valueAt(displayNdx).mStacks;
            for (int stackNdx = stacks.size() - 1; stackNdx >= 0; --stackNdx) {
                final ActivityStack stack = stacks.get(stackNdx);
                if (!isFrontStack(stack)) {
                    continue;
                }
                ActivityRecord hr = stack.topRunningActivityLocked(null);
                if (hr != null) {
                    if (hr.app == null && app.uid == hr.info.applicationInfo.uid
                            && processName.equals(hr.processName)) {
                        try {
                            if (realStartActivityLocked(hr, app, true, true)) {
                                didSomething = true;
                            }
                        } catch (RemoteException e) {
                            Slog.w(TAG, "Exception in new application when starting activity "
                                  + hr.intent.getComponent().flattenToShortString(), e);
                            throw e;
                        }
                    }
                }
            }
        }
        if (!didSomething) {
            ensureActivitiesVisibleLocked(null, 0);
        }
        return didSomething;
   }

转到realStartActivityLocked方法

inal boolean realStartActivityLocked(ActivityRecord r,
            ProcessRecord app, boolean andResume, boolean checkConfig)
            throws RemoteException {

        if (andResume) {
            r.startFreezingScreenLocked(app, 0);
            mWindowManager.setAppVisibility(r.appToken, true);

            // schedule launch ticks to collect information about slow apps.
            r.startLaunchTickingLocked();
        }

        // Have the window manager re-evaluate the orientation of
        // the screen based on the new activity order.  Note that
        // as a result of this, it can call back into the activity
        // manager with a new orientation.  We don't care about that,
        // because the activity is not currently running so we are
        // just restarting it anyway.
        if (checkConfig) {
            Configuration config = mWindowManager.updateOrientationFromAppTokens(
                    mService.mConfiguration,
                    r.mayFreezeScreenLocked(app) ? r.appToken : null);
            mService.updateConfigurationLocked(config, r, false, false);
        }

        r.app = app;
        app.waitingToKill = null;
        r.launchCount++;
        r.lastLaunchTime = SystemClock.uptimeMillis();

        if (DEBUG_ALL) Slog.v(TAG, "Launching: " + r);

        int idx = app.activities.indexOf(r);
        if (idx < 0) {
            app.activities.add(r);
        }
        mService.updateLruProcessLocked(app, true, null);
        mService.updateOomAdjLocked();

        final TaskRecord task = r.task;
        if (task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE ||
                task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE_PRIV) {
            setLockTaskModeLocked(task, LOCK_TASK_MODE_LOCKED, "mLockTaskAuth==LAUNCHABLE", false);
        }

        final ActivityStack stack = task.stack;
        try {
            if (app.thread == null) {
                throw new RemoteException();
            }
            List<ResultInfo> results = null;
            List<ReferrerIntent> newIntents = null;
            if (andResume) {
                results = r.results;
                newIntents = r.newIntents;
            }
            if (DEBUG_SWITCH) Slog.v(TAG_SWITCH,
                    "Launching: " + r + " icicle=" + r.icicle + " with results=" + results
                    + " newIntents=" + newIntents + " andResume=" + andResume);
            if (andResume) {
                EventLog.writeEvent(EventLogTags.AM_RESTART_ACTIVITY,
                        r.userId, System.identityHashCode(r),
                        task.taskId, r.shortComponentName);
            }
            if (r.isHomeActivity() && r.isNotResolverActivity()) {
                // Home process is the root process of the task.
                mService.mHomeProcess = task.mActivities.get(0).app;
            }
            mService.ensurePackageDexOpt(r.intent.getComponent().getPackageName());
            r.sleeping = false;
            r.forceNewConfig = false;
            mService.showAskCompatModeDialogLocked(r);
            r.compat = mService.compatibilityInfoForPackageLocked(r.info.applicationInfo);
            ProfilerInfo profilerInfo = null;
            if (mService.mProfileApp != null && mService.mProfileApp.equals(app.processName)) {
                if (mService.mProfileProc == null || mService.mProfileProc == app) {
                    mService.mProfileProc = app;
                    final String profileFile = mService.mProfileFile;
                    if (profileFile != null) {
                        ParcelFileDescriptor profileFd = mService.mProfileFd;
                        if (profileFd != null) {
                            try {
                                profileFd = profileFd.dup();
                            } catch (IOException e) {
                                if (profileFd != null) {
                                    try {
                                        profileFd.close();
                                    } catch (IOException o) {
                                    }
                                    profileFd = null;
                                }
                            }
                        }

                        profilerInfo = new ProfilerInfo(profileFile, profileFd,
                                mService.mSamplingInterval, mService.mAutoStopProfiler);
                    }
                }
            }

            if (andResume) {
                app.hasShownUi = true;
                app.pendingUiClean = true;
            }
            app.forceProcessStateUpTo(mService.mTopProcessState);
            app.thread.scheduleLaunchActivity(new Intent(r.intent), r.appToken,
                    System.identityHashCode(r), r.info, new Configuration(mService.mConfiguration),
                    new Configuration(stack.mOverrideConfig), r.compat, r.launchedFromPackage,
                    task.voiceInteractor, app.repProcState, r.icicle, r.persistentState, results,
                    newIntents, !andResume, mService.isNextTransitionForward(), profilerInfo);

            if ((app.info.privateFlags&ApplicationInfo.PRIVATE_FLAG_CANT_SAVE_STATE) != 0) {
                // This may be a heavy-weight process!  Note that the package
                // manager will ensure that only activity can run in the main
                // process of the .apk, which is the only thing that will be
                // considered heavy-weight.
                if (app.processName.equals(app.info.packageName)) {
                    if (mService.mHeavyWeightProcess != null
                            && mService.mHeavyWeightProcess != app) {
                        Slog.w(TAG, "Starting new heavy weight process " + app
                                + " when already running "
                                + mService.mHeavyWeightProcess);
                    }
                    mService.mHeavyWeightProcess = app;
                    Message msg = mService.mHandler.obtainMessage(
                            ActivityManagerService.POST_HEAVY_NOTIFICATION_MSG);
                    msg.obj = r;
                    mService.mHandler.sendMessage(msg);
                }
            }

        } catch (RemoteException e) {
            if (r.launchFailed) {
                // This is the second time we failed -- finish activity
                // and give up.
                Slog.e(TAG, "Second failure launching "
                      + r.intent.getComponent().flattenToShortString()
                      + ", giving up", e);
                mService.appDiedLocked(app);
                stack.requestFinishActivityLocked(r.appToken, Activity.RESULT_CANCELED, null,
                        "2nd-crash", false);
                return false;
            }

            // This is the first time we failed -- restart process and
            // retry.
            app.activities.remove(r);
            throw e;
        }

        r.launchFailed = false;
        if (stack.updateLRUListLocked(r)) {
            Slog.w(TAG, "Activity " + r
                  + " being launched, but already in LRU list");
        }

        if (andResume) {
            // As part of the process of launching, ActivityThread also performs
            // a resume.
            stack.minimalResumeActivityLocked(r);
        } else {
            // This activity is not starting in the resumed state... which
            // should look like we asked it to pause+stop (but remain visible),
            // and it has done so and reported back the current icicle and
            // other state.
            if (DEBUG_STATES) Slog.v(TAG_STATES,
                    "Moving to STOPPED: " + r + " (starting in stopped state)");
            r.state = STOPPED;
            r.stopped = true;
        }

        // Launch the new version setup screen if needed.  We do this -after-
        // launching the initial activity (that is, home), so that it can have
        // a chance to initialize itself while in the background, making the
        // switch back to it faster and look better.
        if (isFrontStack(stack)) {
            mService.startSetupActivityLocked();
        }

        // Update any services we are bound to that might care about whether
        // their client may have activities.
        mService.mServices.updateServiceConnectionActivitiesLocked(r.app);

        return true;
    }

重点

app.thread.scheduleLaunchActivity(new Intent(r.intent), r.appToken,
                           System.identityHashCode(r), r.info, new Configuration(mService.mConfiguration),
                           new Configuration(stack.mOverrideConfig), r.compat, r.launchedFromPackage,
                           task.voiceInteractor, app.repProcState, r.icicle, r.persistentState, results,
                           newIntents, !andResume, mService.isNextTransitionForward(), profilerInfo);

转到 ActivityThread-scheduleLaunchActivity