Java – 第3页 – 蓝天白云

art和Dalvik的一些知识

分类：Android, Java 阅读 (1,214) 已关闭评论

7月 072020

一、Art的诞生

　　Art是在Android4.4系统中加入的，但是默认是不开启的

　　Art和Dalvik的切换是通过指定一个系统设置项来切换的，见art/Android.mk中.PHONY: use-art下面那一段脚本

　　本文摘录片段

adb shell setprop persist.sys.dalvik.vm.lib.2 libdvm.so
adb shell setprop persist.sys.dalvik.vm.lib.2 libart.so
adb shell setprop persist.sys.dalvik.vm.lib.2 libartd.so

adb shell setprop persist.sys.dalvik.vm.lib.2 libdvm.so

adb shell setprop persist.sys.dalvik.vm.lib.2 libart.so

adb shell setprop persist.sys.dalvik.vm.lib.2 libartd.so

　　libdvm.so是DalvikVm的so库

　　libart.so是Art Vm的so库

　　之所以两个能同时切换，是因为他们都实现了JNI_Create_JavaVm的入口函数。

二、Art的崛起

　　在Android4.4加入Art之后，一直是默认没有开启的，直到Android5.0，DalvikVm彻底被删除，art担当大任

　　可以对比下4.4和5.0源码中dalvik/vm下的代码结构

　　http://androidxref.com/4.4_r1/xref/dalvik/vm/

　　http://androidxref.com/5.0.0_r2/xref/dalvik/vm/

　　可以看到从5.0开始，dalvik的代码已经被删除掉了

Android中art虚拟机启动流程

分类：Android, Java 阅读 (1,811) 已关闭评论

7月 072020

本文基于Android8.1系统进行研究

一、启动zygote

在Linux内核启动完成后，首先启动系统的第一个进程init进程

init进程会读取init.rc中的配置文件

其中有Zygote的配置，init进程将启动zygote进程

zygote的入口在app_main.cpp中的main函数中

二、解析传入参数，调用AndroidRuntime的start方法

在app_main.cpp中的main函数中，首先解析传入的相关参数，并通过如下代码进入ZygoteInit的main函数中

    if (zygote) {
        runtime.start("com.android.internal.os.ZygoteInit", args, zygote);
    }

if (zygote) {

runtime.start("com.android.internal.os.ZygoteInit", args, zygote);

}

runtime是AppRuntime的一个实例，AppRuntim继承自AndroidRuntime

start函数定义在AndroidRuntime中，下面是start函数的注释

/*
 * Start the Android runtime.  This involves starting the virtual machine
 * and calling the "static void main(String[] args)" method in the class
 * named by "className".
 *
 * Passes the main function two arguments, the class name and the specified
 * options string.
*
* 翻译：
* 启动Android运行时，包括启动虚拟机，调用className参数对应的main函数
 */

* Start the Android runtime. This involves starting the virtual machine

* and calling the "static void main(String[] args)" method in the class

* named by "className".

* Passes the main function two arguments, the class name and the specified

* options string.

* 翻译：

* 启动Android运行时，包括启动虚拟机，调用className参数对应的main函数

start函数中的这段代码切入到了startVm函数中

    /* start the virtual machine */
    JniInvocation jni_invocation;
    jni_invocation.Init(NULL);
    JNIEnv* env;
    if (startVm(&mJavaVM, &env, zygote) != 0) {
        return;
    }
    onVmCreated(env);

/* start the virtual machine */

JniInvocation jni_invocation;

jni_invocation.Init(NULL);

JNIEnv* env;

if (startVm(&mJavaVM, &env, zygote) != 0) {

return;

}

onVmCreated(env);

三、startVm函数

这个函数前边也是一堆处理Vm启动参数的逻辑

在函数的最好调用JNI_CreateJavaVM函数通过c++层的库创建虚拟机

四、JNI_CreateJavaVM函数

JNI_CreateJavaVM函数是在art/runtime/java_vm_ext.cc中实现的，代码如下：

// JNI Invocation interface.

extern "C" jint JNI_CreateJavaVM(JavaVM** p_vm, JNIEnv** p_env, void* vm_args) {
  ScopedTrace trace(__FUNCTION__);
  const JavaVMInitArgs* args = static_cast<JavaVMInitArgs*>(vm_args);
  if (JavaVMExt::IsBadJniVersion(args->version)) {
    LOG(ERROR) << "Bad JNI version passed to CreateJavaVM: " << args->version;
    return JNI_EVERSION;
  }
  RuntimeOptions options;
  for (int i = 0; i < args->nOptions; ++i) {
    JavaVMOption* option = &args->options[i];
    options.push_back(std::make_pair(std::string(option->optionString), option->extraInfo));
  }
  bool ignore_unrecognized = args->ignoreUnrecognized;
  if (!Runtime::Create(options, ignore_unrecognized)) {
    return JNI_ERR;
  }

  // Initialize native loader. This step makes sure we have
  // everything set up before we start using JNI.
  android::InitializeNativeLoader();

  Runtime* runtime = Runtime::Current();
  bool started = runtime->Start();
  if (!started) {
    delete Thread::Current()->GetJniEnv();
    delete runtime->GetJavaVM();
    LOG(WARNING) << "CreateJavaVM failed";
    return JNI_ERR;
  }

  *p_env = Thread::Current()->GetJniEnv();
  *p_vm = runtime->GetJavaVM();
  return JNI_OK;
}

// JNI Invocation interface.

extern "C" jint JNI_CreateJavaVM(JavaVM** p_vm, JNIEnv** p_env, void* vm_args) {

ScopedTrace trace(__FUNCTION__);

const JavaVMInitArgs* args = static_cast<JavaVMInitArgs*>(vm_args);

if (JavaVMExt::IsBadJniVersion(args->version)) {

LOG(ERROR) << "Bad JNI version passed to CreateJavaVM: " << args->version;

return JNI_EVERSION;

}

RuntimeOptions options;

for (int i = 0; i < args->nOptions; ++i) {

JavaVMOption* option = &args->options[i];

options.push_back(std::make_pair(std::string(option->optionString), option->extraInfo));

}

bool ignore_unrecognized = args->ignoreUnrecognized;

if (!Runtime::Create(options, ignore_unrecognized)) {

return JNI_ERR;

}

// Initialize native loader. This step makes sure we have

// everything set up before we start using JNI.

android::InitializeNativeLoader();

Runtime* runtime = Runtime::Current();

bool started = runtime->Start();

if (!started) {

delete Thread::Current()->GetJniEnv();

delete runtime->GetJavaVM();

LOG(WARNING) << "CreateJavaVM failed";

return JNI_ERR;

}

*p_env = Thread::Current()->GetJniEnv();

*p_vm = runtime->GetJavaVM();

return JNI_OK;

}

Runtime是在art/runtime/runtime.h中定义的类

Runtime::Current()返回一个静态的Runtime实例，代码如下：

static Runtime* instance_;

1	static Runtime* instance_;

runtime-Start()启动虚拟机

五、其他参考文章

Android ART运行时无缝替换Dalvik虚拟机的过程分析

https://blog.csdn.net/zhu929033262/article/details/77053640

Android虚拟机art流程：从zygote开始梳理art的启动（1）

https://www.shennongblog.com/art-zygote/

Flutter报Could not resolve io.flutter:flutter_embedding_debug问题解决

分类：Android, Java 阅读 (2,961) 已关闭评论

6月 132020

解决办法：

打开build.gradle文件，增加如下maven仓库地址：

文字版：

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
        maven { url "http://download.flutter.io" } //这里增加
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven { url "http://download.flutter.io" } //这里增加
    }
}

buildscript {

ext.kotlin_version = '1.3.50'

repositories {

google()

jcenter()

maven { url "http://download.flutter.io" } //这里增加

}

dependencies {

classpath 'com.android.tools.build:gradle:3.5.0'

classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

}

allprojects {

repositories {

google()

jcenter()

maven { url "http://download.flutter.io" } //这里增加

}

Activity的onSaveInstanceState方法的官方解释

分类：Android, Java 阅读 (1,303) 已关闭评论

6月 032020

基于Android8.1系统源码中的注释翻译

翻译如下：

　　在一个Activity被杀死之前被调用以取出Activity中每个对象实例的状态，这些状态可以在onCreate或者onRestoreInstanceState方法中被重新加载到实例（此方法产生的Bundle将传递到那两个方法）。

　　这个方法在一个Activity可能被杀掉之前（不是刚刚被杀之前）被调用，以便于之后某些时候Activity被重新打开时可以恢复它的（某些变量的）状态。比如，如果ActivityB被打开并显示在ActivityA之前（ActivityA被置于后台），在某些时候ActivityA由于系统资源回收被杀掉，AvtivityA将有机会使用此方法来保存用户界面的当前状态，以便当用户回到ActivityA时，用户界面的状态可以在Activity的onCreate或者onRestoreInstanceState中被恢复。

　　不要把这个方法和Activity的生命周期比如onPause和onStop混淆。比如，当从ActivityB退出返回到ActivityA时，onPause和onStop将被调用，但是onSaveInstanceState不会被调用，此时没有必要对ActivityB调用此方法，因为ActivityB将被销毁，并且不会被恢复。另外一个例子，当ActivityB被打开并显示在ActivityA之前时，系统可能会避免调用ActivityA的onSaveInstanceState方法，因为在ActivityB的生命周期内，ActivityA的ui状态可能一直保持完整。

　　大部分UI组件的实例的（状态保存）默认实现是通过对布局中有id属性的view调用view自身的onSaveInstanceState()方法，通过id保存当前有焦点的view（通过view的onRestoreInstanceState来恢复状态）。如果你想使用这个方法来保存某个view的状态，最好使用view自身的onSaveInstanceState来处理，否则每个（Activity中）的view实例都需要你写代码来维护。

　　如果此方法被调用，将在onStop之前发生，但是不能保证肯定是在onPause之后发生。

原文如下：

    /**
     * Called to retrieve per-instance state from an activity before being killed
     * so that the state can be restored in {@link #onCreate} or
     * {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method
     * will be passed to both).
     *
     * <p>This method is called before an activity may be killed so that when it
     * comes back some time in the future it can restore its state.  For example,
     * if activity B is launched in front of activity A, and at some point activity
     * A is killed to reclaim resources, activity A will have a chance to save the
     * current state of its user interface via this method so that when the user
     * returns to activity A, the state of the user interface can be restored
     * via {@link #onCreate} or {@link #onRestoreInstanceState}.
     *
     * <p>Do not confuse this method with activity lifecycle callbacks such as
     * {@link #onPause}, which is always called when an activity is being placed
     * in the background or on its way to destruction, or {@link #onStop} which
     * is called before destruction.  One example of when {@link #onPause} and
     * {@link #onStop} is called and not this method is when a user navigates back
     * from activity B to activity A: there is no need to call {@link #onSaveInstanceState}
     * on B because that particular instance will never be restored, so the
     * system avoids calling it.  An example when {@link #onPause} is called and
     * not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:
     * the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't
     * killed during the lifetime of B since the state of the user interface of
     * A will stay intact.
     *
     * <p>The default implementation takes care of most of the UI per-instance
     * state for you by calling {@link android.view.View#onSaveInstanceState()} on each
     * view in the hierarchy that has an id, and by saving the id of the currently
     * focused view (all of which is restored by the default implementation of
     * {@link #onRestoreInstanceState}).  If you override this method to save additional
     * information not captured by each individual view, you will likely want to
     * call through to the default implementation, otherwise be prepared to save
     * all of the state of each view yourself.
     *
     * <p>If called, this method will occur before {@link #onStop}.  There are
     * no guarantees about whether it will occur before or after {@link #onPause}.
     *
     * @param outState Bundle in which to place your saved state.
     *
     * @see #onCreate
     * @see #onRestoreInstanceState
     * @see #onPause
     */

/**

* Called to retrieve per-instance state from an activity before being killed

* so that the state can be restored in {@link #onCreate} or

* {@link #onRestoreInstanceState} (the {@link Bundle} populated by this method

* will be passed to both).

* <p>This method is called before an activity may be killed so that when it

* comes back some time in the future it can restore its state. For example,

* if activity B is launched in front of activity A, and at some point activity

* A is killed to reclaim resources, activity A will have a chance to save the

* current state of its user interface via this method so that when the user

* returns to activity A, the state of the user interface can be restored

* via {@link #onCreate} or {@link #onRestoreInstanceState}.

* <p>Do not confuse this method with activity lifecycle callbacks such as

* {@link #onPause}, which is always called when an activity is being placed

* in the background or on its way to destruction, or {@link #onStop} which

* is called before destruction. One example of when {@link #onPause} and

* {@link #onStop} is called and not this method is when a user navigates back

* from activity B to activity A: there is no need to call {@link #onSaveInstanceState}

* on B because that particular instance will never be restored, so the

* system avoids calling it. An example when {@link #onPause} is called and

* not {@link #onSaveInstanceState} is when activity B is launched in front of activity A:

* the system may avoid calling {@link #onSaveInstanceState} on activity A if it isn't

* killed during the lifetime of B since the state of the user interface of

* A will stay intact.

* <p>The default implementation takes care of most of the UI per-instance

* state for you by calling {@link android.view.View#onSaveInstanceState()} on each

* view in the hierarchy that has an id, and by saving the id of the currently

* focused view (all of which is restored by the default implementation of

* {@link #onRestoreInstanceState}). If you override this method to save additional

* information not captured by each individual view, you will likely want to

* call through to the default implementation, otherwise be prepared to save

* all of the state of each view yourself.

* <p>If called, this method will occur before {@link #onStop}. There are

* no guarantees about whether it will occur before or after {@link #onPause}.

* @param outState Bundle in which to place your saved state.

* @see #onCreate

* @see #onRestoreInstanceState

* @see #onPause

顶栏phone.StatusBar中makeStatusBarView函数分析（未完）

分类：Android, Java 阅读 (1,720) 已关闭评论

6月 012020

本文基于Android8.1系统

    protected void makeStatusBarView() {
        final Context context = mContext;
        // 用于重新获取mDisplayMetrics和mCurrentDisplaySize
        updateDisplaySize(); // populates mDisplayMetrics
        // 重新加载QSPanel、NotificationPanel等的资源，因为可能configuration可能会有变化
        updateResources();
        updateTheme();

        // 用布局R.layout.super_status_bar填充mStatusBarWindow
        inflateStatusBarWindow(context);
        mStatusBarWindow.setService(this);
        mStatusBarWindow.setOnTouchListener(getStatusBarWindowTouchListener());

        // mNotificationPanel用于显示各种各种通知的根Panel
        // TODO: Deal with the ugliness that comes from having some of the statusbar broken out
        // into fragments, but the rest here, it leaves some awkward lifecycle and whatnot.
        mNotificationPanel = (NotificationPanelView) mStatusBarWindow.findViewById(
                R.id.notification_panel);
        // mStackScroller用于显示列表形式的系统通知
        mStackScroller = (NotificationStackScrollLayout) mStatusBarWindow.findViewById(
                R.id.notification_stack_scroller);
        mNotificationPanel.setStatusBar(this);
        mNotificationPanel.setGroupManager(mGroupManager);
        mAboveShelfObserver = new AboveShelfObserver(mStackScroller);
        mAboveShelfObserver.setListener(mStatusBarWindow.findViewById(
                R.id.notification_container_parent));
        mKeyguardStatusBar = (KeyguardStatusBarView) mStatusBarWindow.findViewById(R.id.keyguard_header);

        mNotificationIconAreaController = SystemUIFactory.getInstance()
                .createNotificationIconAreaController(context, this);
        inflateShelf();
        mNotificationIconAreaController.setupShelf(mNotificationShelf);
        Dependency.get(DarkIconDispatcher.class).addDarkReceiver(mNotificationIconAreaController);
        FragmentHostManager.get(mStatusBarWindow)
                .addTagListener(CollapsedStatusBarFragment.TAG, (tag, fragment) -> {
                    CollapsedStatusBarFragment statusBarFragment =
                            (CollapsedStatusBarFragment) fragment;
                    statusBarFragment.initNotificationIconArea(mNotificationIconAreaController);
                    mStatusBarView = (PhoneStatusBarView) fragment.getView();
                    mStatusBarView.setBar(this);
                    mStatusBarView.setPanel(mNotificationPanel);
                    mStatusBarView.setScrimController(mScrimController);
                    mStatusBarView.setBouncerShowing(mBouncerShowing);
                    setAreThereNotifications();
                    checkBarModes();
                }).getFragmentManager()
                .beginTransaction()
                .replace(R.id.status_bar_container, new CollapsedStatusBarFragment(),
                        CollapsedStatusBarFragment.TAG)
                .commit();
        mIconController = Dependency.get(StatusBarIconController.class);

        mHeadsUpManager = new HeadsUpManager(context, mStatusBarWindow, mGroupManager);
        mHeadsUpManager.setBar(this);
        mHeadsUpManager.addListener(this);
        mHeadsUpManager.addListener(mNotificationPanel);
        mHeadsUpManager.addListener(mGroupManager);
        mHeadsUpManager.addListener(mVisualStabilityManager);
        mNotificationPanel.setHeadsUpManager(mHeadsUpManager);
        mNotificationData.setHeadsUpManager(mHeadsUpManager);
        mGroupManager.setHeadsUpManager(mHeadsUpManager);
        mHeadsUpManager.setVisualStabilityManager(mVisualStabilityManager);

        if (MULTIUSER_DEBUG) {
            mNotificationPanelDebugText = (TextView) mNotificationPanel.findViewById(
                    R.id.header_debug_info);
            mNotificationPanelDebugText.setVisibility(View.VISIBLE);
        }

        try {
            boolean showNav = mWindowManagerService.hasNavigationBar();
            if (DEBUG) Log.v(TAG, "hasNavigationBar=" + showNav);
            if (showNav) {
                createNavigationBar();
            }
        } catch (RemoteException ex) {
            // no window manager? good luck with that
        }

        // figure out which pixel-format to use for the status bar.
        mPixelFormat = PixelFormat.OPAQUE;

        // 通知列表框
        mStackScroller.setLongPressListener(getNotificationLongClicker());
        mStackScroller.setStatusBar(this);
        mStackScroller.setGroupManager(mGroupManager);
        mStackScroller.setHeadsUpManager(mHeadsUpManager);
        mGroupManager.setOnGroupChangeListener(mStackScroller);
        mVisualStabilityManager.setVisibilityLocationProvider(mStackScroller);

        // 没有通知提示框
        inflateEmptyShadeView();
        // 清除所有通知提示框
        inflateDismissView();
        mExpandedContents = mStackScroller;

        // 包含多媒体插图、图片的View？不知道是干啥用的
        mBackdrop = (BackDropView) mStatusBarWindow.findViewById(R.id.backdrop);
        mBackdropFront = (ImageView) mBackdrop.findViewById(R.id.backdrop_front);
        mBackdropBack = (ImageView) mBackdrop.findViewById(R.id.backdrop_back);

        // 字面翻译：锁屏壁纸
        if (ENABLE_LOCKSCREEN_WALLPAPER) {
            mLockscreenWallpaper = new LockscreenWallpaper(mContext, this, mHandler);
        }

        mKeyguardIndicationController =
                SystemUIFactory.getInstance().createKeyguardIndicationController(mContext,
                (ViewGroup) mStatusBarWindow.findViewById(R.id.keyguard_indication_area),
                mNotificationPanel.getLockIcon());
        mNotificationPanel.setKeyguardIndicationController(mKeyguardIndicationController);


        mAmbientIndicationContainer = mStatusBarWindow.findViewById(
                R.id.ambient_indication_container);

        // set the initial view visibility
        setAreThereNotifications();

        // TODO: Find better place for this callback.
        mBatteryController.addCallback(new BatteryStateChangeCallback() {
            @Override
            public void onPowerSaveChanged(boolean isPowerSave) {
                mHandler.post(mCheckBarModes);
                if (mDozeServiceHost != null) {
                    mDozeServiceHost.firePowerSaveChanged(isPowerSave);
                }
            }

            @Override
            public void onBatteryLevelChanged(int level, boolean pluggedIn, boolean charging) {
                // noop
            }
        });

        mLightBarController = Dependency.get(LightBarController.class);
        if (mNavigationBar != null) {
            mNavigationBar.setLightBarController(mLightBarController);
        }

        ScrimView scrimBehind = (ScrimView) mStatusBarWindow.findViewById(R.id.scrim_behind);
        ScrimView scrimInFront = (ScrimView) mStatusBarWindow.findViewById(R.id.scrim_in_front);
        View headsUpScrim = mStatusBarWindow.findViewById(R.id.heads_up_scrim);
        mScrimController = SystemUIFactory.getInstance().createScrimController(mLightBarController,
                scrimBehind, scrimInFront, headsUpScrim, mLockscreenWallpaper,
                scrimsVisible -> {
                    if (mStatusBarWindowManager != null) {
                        mStatusBarWindowManager.setScrimsVisible(scrimsVisible);
                    }
                });
        if (mScrimSrcModeEnabled) {
            Runnable runnable = new Runnable() {
                @Override
                public void run() {
                    boolean asSrc = mBackdrop.getVisibility() != View.VISIBLE;
                    mScrimController.setDrawBehindAsSrc(asSrc);
                    mStackScroller.setDrawBackgroundAsSrc(asSrc);
                }
            };
            mBackdrop.setOnVisibilityChangedRunnable(runnable);
            runnable.run();
        }
        mHeadsUpManager.addListener(mScrimController);
        mStackScroller.setScrimController(mScrimController);
        mDozeScrimController = new DozeScrimController(mScrimController, context);

        // Other icons
        mVolumeComponent = getComponent(VolumeComponent.class);

        mNotificationPanel.setUserSetupComplete(mUserSetup);
        if (UserManager.get(mContext).isUserSwitcherEnabled()) {
            createUserSwitcher();
        }

        // 配置快速设置小按钮的面板
        View container = mStatusBarWindow.findViewById(R.id.qs_frame);
        if (container != null) {
            FragmentHostManager fragmentHostManager = FragmentHostManager.get(container);
            ExtensionFragmentListener.attachExtensonToFragment(container, QS.TAG, R.id.qs_frame,
                    Dependency.get(ExtensionController.class).newExtension(QS.class)
                            .withPlugin(QS.class)
                            .withFeature(
                                    PackageManager.FEATURE_AUTOMOTIVE, () -> new CarQSFragment())
                            .withDefault(() -> new QSFragment())
                            .build());
            final QSTileHost qsh = SystemUIFactory.getInstance().createQSTileHost(mContext, this,
                    mIconController);
            mBrightnessMirrorController = new BrightnessMirrorController(mStatusBarWindow,
                    mScrimController);
            fragmentHostManager.addTagListener(QS.TAG, (tag, f) -> {
                QS qs = (QS) f;
                if (qs instanceof QSFragment) {
                    ((QSFragment) qs).setHost(qsh);
                    mQSPanel = ((QSFragment) qs).getQsPanel();
                    mQSPanel.setBrightnessMirror(mBrightnessMirrorController);
                    mKeyguardStatusBar.setQSPanel(mQSPanel);
                }
            });
        }

        mReportRejectedTouch = mStatusBarWindow.findViewById(R.id.report_rejected_touch);
        if (mReportRejectedTouch != null) {
            updateReportRejectedTouchVisibility();
            mReportRejectedTouch.setOnClickListener(v -> {
                Uri session = mFalsingManager.reportRejectedTouch();
                if (session == null) { return; }

                StringWriter message = new StringWriter();
                message.write("Build info: ");
                message.write(SystemProperties.get("ro.build.description"));
                message.write("\nSerial number: ");
                message.write(SystemProperties.get("ro.serialno"));
                message.write("\n");

                PrintWriter falsingPw = new PrintWriter(message);
                FalsingLog.dump(falsingPw);
                falsingPw.flush();

                startActivityDismissingKeyguard(Intent.createChooser(new Intent(Intent.ACTION_SEND)
                                .setType("*/*")
                                .putExtra(Intent.EXTRA_SUBJECT, "Rejected touch report")
                                .putExtra(Intent.EXTRA_STREAM, session)
                                .putExtra(Intent.EXTRA_TEXT, message.toString()),
                        "Share rejected touch report")
                                .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK),
                        true /* onlyProvisioned */, true /* dismissShade */);
            });
        }

        PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
        if (!pm.isScreenOn()) {
            mBroadcastReceiver.onReceive(mContext, new Intent(Intent.ACTION_SCREEN_OFF));
        }
        mGestureWakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK,
                "GestureWakeLock");
        mVibrator = mContext.getSystemService(Vibrator.class);
        int[] pattern = mContext.getResources().getIntArray(
                R.array.config_cameraLaunchGestureVibePattern);
        mCameraLaunchGestureVibePattern = new long[pattern.length];
        for (int i = 0; i < pattern.length; i++) {
            mCameraLaunchGestureVibePattern[i] = pattern[i];
        }

        // receive broadcasts
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(DevicePolicyManager.ACTION_SHOW_DEVICE_MONITORING_DIALOG);
        context.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL, filter, null, null);

        IntentFilter demoFilter = new IntentFilter();
        if (DEBUG_MEDIA_FAKE_ARTWORK) {
            demoFilter.addAction(ACTION_FAKE_ARTWORK);
        }
        demoFilter.addAction(ACTION_DEMO);
        context.registerReceiverAsUser(mDemoReceiver, UserHandle.ALL, demoFilter,
                android.Manifest.permission.DUMP, null);

        // listen for USER_SETUP_COMPLETE setting (per-user)
        mDeviceProvisionedController.addCallback(mUserSetupObserver);
        mUserSetupObserver.onUserSetupChanged();

        // disable profiling bars, since they overlap and clutter the output on app windows
        ThreadedRenderer.overrideProperty("disableProfileBars", "true");

        // Private API call to make the shadows look better for Recents
        ThreadedRenderer.overrideProperty("ambientRatio", String.valueOf(1.5f));
    }

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protected void makeStatusBarView() {

final Context context = mContext;

// 用于重新获取mDisplayMetrics和mCurrentDisplaySize

updateDisplaySize(); // populates mDisplayMetrics

// 重新加载QSPanel、NotificationPanel等的资源，因为可能configuration可能会有变化

updateResources();

updateTheme();

// 用布局R.layout.super_status_bar填充mStatusBarWindow

inflateStatusBarWindow(context);

mStatusBarWindow.setService(this);

mStatusBarWindow.setOnTouchListener(getStatusBarWindowTouchListener());

// mNotificationPanel用于显示各种各种通知的根Panel

// TODO: Deal with the ugliness that comes from having some of the statusbar broken out

// into fragments, but the rest here, it leaves some awkward lifecycle and whatnot.

mNotificationPanel = (NotificationPanelView) mStatusBarWindow.findViewById(

R.id.notification_panel);

// mStackScroller用于显示列表形式的系统通知

mStackScroller = (NotificationStackScrollLayout) mStatusBarWindow.findViewById(

R.id.notification_stack_scroller);

mNotificationPanel.setStatusBar(this);

mNotificationPanel.setGroupManager(mGroupManager);

mAboveShelfObserver = new AboveShelfObserver(mStackScroller);

mAboveShelfObserver.setListener(mStatusBarWindow.findViewById(

R.id.notification_container_parent));

mKeyguardStatusBar = (KeyguardStatusBarView) mStatusBarWindow.findViewById(R.id.keyguard_header);

mNotificationIconAreaController = SystemUIFactory.getInstance()

.createNotificationIconAreaController(context, this);

inflateShelf();

mNotificationIconAreaController.setupShelf(mNotificationShelf);

Dependency.get(DarkIconDispatcher.class).addDarkReceiver(mNotificationIconAreaController);

FragmentHostManager.get(mStatusBarWindow)

.addTagListener(CollapsedStatusBarFragment.TAG, (tag, fragment) -> {

CollapsedStatusBarFragment statusBarFragment =

(CollapsedStatusBarFragment) fragment;

statusBarFragment.initNotificationIconArea(mNotificationIconAreaController);

mStatusBarView = (PhoneStatusBarView) fragment.getView();

mStatusBarView.setBar(this);

mStatusBarView.setPanel(mNotificationPanel);

mStatusBarView.setScrimController(mScrimController);

mStatusBarView.setBouncerShowing(mBouncerShowing);

setAreThereNotifications();

checkBarModes();

}).getFragmentManager()

.beginTransaction()

.replace(R.id.status_bar_container, new CollapsedStatusBarFragment(),

CollapsedStatusBarFragment.TAG)

.commit();

mIconController = Dependency.get(StatusBarIconController.class);

mHeadsUpManager = new HeadsUpManager(context, mStatusBarWindow, mGroupManager);

mHeadsUpManager.setBar(this);

mHeadsUpManager.addListener(this);

mHeadsUpManager.addListener(mNotificationPanel);

mHeadsUpManager.addListener(mGroupManager);

mHeadsUpManager.addListener(mVisualStabilityManager);

mNotificationPanel.setHeadsUpManager(mHeadsUpManager);

mNotificationData.setHeadsUpManager(mHeadsUpManager);

mGroupManager.setHeadsUpManager(mHeadsUpManager);

mHeadsUpManager.setVisualStabilityManager(mVisualStabilityManager);

if (MULTIUSER_DEBUG) {

mNotificationPanelDebugText = (TextView) mNotificationPanel.findViewById(

R.id.header_debug_info);

mNotificationPanelDebugText.setVisibility(View.VISIBLE);

}

try {

boolean showNav = mWindowManagerService.hasNavigationBar();

if (DEBUG) Log.v(TAG, "hasNavigationBar=" + showNav);

if (showNav) {

createNavigationBar();

}

} catch (RemoteException ex) {

// no window manager? good luck with that

}

// figure out which pixel-format to use for the status bar.

mPixelFormat = PixelFormat.OPAQUE;

// 通知列表框

mStackScroller.setLongPressListener(getNotificationLongClicker());

mStackScroller.setStatusBar(this);

mStackScroller.setGroupManager(mGroupManager);

mStackScroller.setHeadsUpManager(mHeadsUpManager);

mGroupManager.setOnGroupChangeListener(mStackScroller);

mVisualStabilityManager.setVisibilityLocationProvider(mStackScroller);

// 没有通知提示框

inflateEmptyShadeView();

// 清除所有通知提示框

inflateDismissView();

mExpandedContents = mStackScroller;

// 包含多媒体插图、图片的View？不知道是干啥用的

mBackdrop = (BackDropView) mStatusBarWindow.findViewById(R.id.backdrop);

mBackdropFront = (ImageView) mBackdrop.findViewById(R.id.backdrop_front);

mBackdropBack = (ImageView) mBackdrop.findViewById(R.id.backdrop_back);

// 字面翻译：锁屏壁纸

if (ENABLE_LOCKSCREEN_WALLPAPER) {

mLockscreenWallpaper = new LockscreenWallpaper(mContext, this, mHandler);

}

mKeyguardIndicationController =

SystemUIFactory.getInstance().createKeyguardIndicationController(mContext,

(ViewGroup) mStatusBarWindow.findViewById(R.id.keyguard_indication_area),

mNotificationPanel.getLockIcon());

mNotificationPanel.setKeyguardIndicationController(mKeyguardIndicationController);

mAmbientIndicationContainer = mStatusBarWindow.findViewById(

R.id.ambient_indication_container);

// set the initial view visibility

setAreThereNotifications();

// TODO: Find better place for this callback.

mBatteryController.addCallback(new BatteryStateChangeCallback() {

@Override

public void onPowerSaveChanged(boolean isPowerSave) {

mHandler.post(mCheckBarModes);

if (mDozeServiceHost != null) {

mDozeServiceHost.firePowerSaveChanged(isPowerSave);

}

@Override

public void onBatteryLevelChanged(int level, boolean pluggedIn, boolean charging) {

// noop

}

});

mLightBarController = Dependency.get(LightBarController.class);

if (mNavigationBar != null) {

mNavigationBar.setLightBarController(mLightBarController);

}

ScrimView scrimBehind = (ScrimView) mStatusBarWindow.findViewById(R.id.scrim_behind);

ScrimView scrimInFront = (ScrimView) mStatusBarWindow.findViewById(R.id.scrim_in_front);

View headsUpScrim = mStatusBarWindow.findViewById(R.id.heads_up_scrim);

mScrimController = SystemUIFactory.getInstance().createScrimController(mLightBarController,

scrimBehind, scrimInFront, headsUpScrim, mLockscreenWallpaper,

scrimsVisible -> {

if (mStatusBarWindowManager != null) {

mStatusBarWindowManager.setScrimsVisible(scrimsVisible);

}

});

if (mScrimSrcModeEnabled) {

Runnable runnable = new Runnable() {

@Override

public void run() {

boolean asSrc = mBackdrop.getVisibility() != View.VISIBLE;

mScrimController.setDrawBehindAsSrc(asSrc);

mStackScroller.setDrawBackgroundAsSrc(asSrc);

}

};

mBackdrop.setOnVisibilityChangedRunnable(runnable);

runnable.run();

}

mHeadsUpManager.addListener(mScrimController);

mStackScroller.setScrimController(mScrimController);

mDozeScrimController = new DozeScrimController(mScrimController, context);

// Other icons

mVolumeComponent = getComponent(VolumeComponent.class);

mNotificationPanel.setUserSetupComplete(mUserSetup);

if (UserManager.get(mContext).isUserSwitcherEnabled()) {

createUserSwitcher();

}

// 配置快速设置小按钮的面板

View container = mStatusBarWindow.findViewById(R.id.qs_frame);

if (container != null) {

FragmentHostManager fragmentHostManager = FragmentHostManager.get(container);

ExtensionFragmentListener.attachExtensonToFragment(container, QS.TAG, R.id.qs_frame,

Dependency.get(ExtensionController.class).newExtension(QS.class)

.withPlugin(QS.class)

.withFeature(

PackageManager.FEATURE_AUTOMOTIVE, () -> new CarQSFragment())

.withDefault(() -> new QSFragment())

.build());

final QSTileHost qsh = SystemUIFactory.getInstance().createQSTileHost(mContext, this,

mIconController);

mBrightnessMirrorController = new BrightnessMirrorController(mStatusBarWindow,

mScrimController);

fragmentHostManager.addTagListener(QS.TAG, (tag, f) -> {

QS qs = (QS) f;

if (qs instanceof QSFragment) {

((QSFragment) qs).setHost(qsh);

mQSPanel = ((QSFragment) qs).getQsPanel();

mQSPanel.setBrightnessMirror(mBrightnessMirrorController);

mKeyguardStatusBar.setQSPanel(mQSPanel);

}

});

}

mReportRejectedTouch = mStatusBarWindow.findViewById(R.id.report_rejected_touch);

if (mReportRejectedTouch != null) {

updateReportRejectedTouchVisibility();

mReportRejectedTouch.setOnClickListener(v -> {

Uri session = mFalsingManager.reportRejectedTouch();

if (session == null) { return; }

StringWriter message = new StringWriter();

message.write("Build info: ");

message.write(SystemProperties.get("ro.build.description"));

message.write("\nSerial number: ");

message.write(SystemProperties.get("ro.serialno"));

message.write("\n");

PrintWriter falsingPw = new PrintWriter(message);

FalsingLog.dump(falsingPw);

falsingPw.flush();

startActivityDismissingKeyguard(Intent.createChooser(new Intent(Intent.ACTION_SEND)

.setType("*/*")

.putExtra(Intent.EXTRA_SUBJECT, "Rejected touch report")

.putExtra(Intent.EXTRA_STREAM, session)

.putExtra(Intent.EXTRA_TEXT, message.toString()),

"Share rejected touch report")

.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK),

true /* onlyProvisioned */, true /* dismissShade */);

});

}

PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);

if (!pm.isScreenOn()) {

mBroadcastReceiver.onReceive(mContext, new Intent(Intent.ACTION_SCREEN_OFF));

}

mGestureWakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK,

"GestureWakeLock");

mVibrator = mContext.getSystemService(Vibrator.class);

int[] pattern = mContext.getResources().getIntArray(

R.array.config_cameraLaunchGestureVibePattern);

mCameraLaunchGestureVibePattern = new long[pattern.length];

for (int i = 0; i < pattern.length; i++) {

mCameraLaunchGestureVibePattern[i] = pattern[i];

}

// receive broadcasts

IntentFilter filter = new IntentFilter();

filter.addAction(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);

filter.addAction(Intent.ACTION_SCREEN_OFF);

filter.addAction(DevicePolicyManager.ACTION_SHOW_DEVICE_MONITORING_DIALOG);

context.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL, filter, null, null);

IntentFilter demoFilter = new IntentFilter();

if (DEBUG_MEDIA_FAKE_ARTWORK) {

demoFilter.addAction(ACTION_FAKE_ARTWORK);

}

demoFilter.addAction(ACTION_DEMO);

context.registerReceiverAsUser(mDemoReceiver, UserHandle.ALL, demoFilter,

android.Manifest.permission.DUMP, null);

// listen for USER_SETUP_COMPLETE setting (per-user)

mDeviceProvisionedController.addCallback(mUserSetupObserver);

mUserSetupObserver.onUserSetupChanged();

// disable profiling bars, since they overlap and clutter the output on app windows

ThreadedRenderer.overrideProperty("disableProfileBars", "true");

// Private API call to make the shadows look better for Recents

ThreadedRenderer.overrideProperty("ambientRatio", String.valueOf(1.5f));

}

Android8.1系统源码中如何判断一个ServiceRecord对应的服务是运行状态

分类：Android, Java 阅读 (1,314) 已关闭评论

5月 282020

        if (r.app != null && r.app.thread != null) {
            // If service is currently running.
            return true;
        }

if (r.app != null && r.app.thread != null) {

// If service is currently running.

return true;

}

ActiveServices.bindServiceLocked代码分析

分类：Android, Java 阅读 (1,172) 已关闭评论

5月 282020

    int bindServiceLocked(IApplicationThread caller, IBinder token, Intent service,
            String resolvedType, final IServiceConnection connection, int flags,
            String callingPackage, final int userId) throws TransactionTooLargeException {
        if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "bindService: " + service
                + " type=" + resolvedType + " conn=" + connection.asBinder()
                + " flags=0x" + Integer.toHexString(flags));
        // 获取调用bindService的进程信息，如果进程信息不存在，则报异常。为什么会不存在？
        final ProcessRecord callerApp = mAm.getRecordForAppLocked(caller);
        if (callerApp == null) {
            throw new SecurityException(
                    "Unable to find app for caller " + caller
                    + " (pid=" + Binder.getCallingPid()
                    + ") when binding service " + service);
        }

        ActivityRecord activity = null;
        // 这个token对应的是ContextImpl中的getActivityToken()，如果在一个Service中bind其他的Service，这个token是不是就是null了？
        if (token != null) {
            // 在Activity栈中看是否有调用的Activity，如果没有，则返回
            activity = ActivityRecord.isInStackLocked(token);
            if (activity == null) {
                Slog.w(TAG, "Binding with unknown activity: " + token);
                return 0;
            }
        }

        int clientLabel = 0;
        PendingIntent clientIntent = null;
        final boolean isCallerSystem = callerApp.info.uid == Process.SYSTEM_UID;

        // 这里看不太懂
        if (isCallerSystem) {
            // Hacky kind of thing -- allow system stuff to tell us
            // what they are, so we can report this elsewhere for
            // others to know why certain services are running.
            service.setDefusable(true);
            clientIntent = service.getParcelableExtra(Intent.EXTRA_CLIENT_INTENT);
            if (clientIntent != null) {
                clientLabel = service.getIntExtra(Intent.EXTRA_CLIENT_LABEL, 0);
                if (clientLabel != 0) {
                    // There are no useful extras in the intent, trash them.
                    // System code calling with this stuff just needs to know
                    // this will happen.
                    service = service.cloneFilter();
                }
            }
        }

        // 把要绑定的服务看作一个Activity？后面还有相关的判断
        if ((flags&Context.BIND_TREAT_LIKE_ACTIVITY) != 0) {
            // 检查权限，如果没有权限会直接报异常结束函数
            mAm.enforceCallingPermission(android.Manifest.permission.MANAGE_ACTIVITY_STACKS,
                    "BIND_TREAT_LIKE_ACTIVITY");
        }

        // 如果要请求管理白名单，但又不是系统应用，则报异常
        if ((flags & Context.BIND_ALLOW_WHITELIST_MANAGEMENT) != 0 && !isCallerSystem) {
            throw new SecurityException(
                    "Non-system caller " + caller + " (pid=" + Binder.getCallingPid()
                    + ") set BIND_ALLOW_WHITELIST_MANAGEMENT when binding service " + service);
        }

        // 调用者在前台？
        final boolean callerFg = callerApp.setSchedGroup != ProcessList.SCHED_GROUP_BACKGROUND;
        final boolean isBindExternal = (flags & Context.BIND_EXTERNAL_SERVICE) != 0;

        //ServiceLookupResult包含一个ServiceRecord成员和一个权限字符串
        ServiceLookupResult res =
            retrieveServiceLocked(service, resolvedType, callingPackage, Binder.getCallingPid(),
                    Binder.getCallingUid(), userId, true, callerFg, isBindExternal);
        if (res == null) {
            return 0;
        }
        if (res.record == null) {
            return -1;
        }
        ServiceRecord s = res.record;

        boolean permissionsReviewRequired = false;

        // 是否需要让用户预览所需权限，这一段没仔细看
        // If permissions need a review before any of the app components can run,
        // we schedule binding to the service but do not start its process, then
        // we launch a review activity to which is passed a callback to invoke
        // when done to start the bound service's process to completing the binding.
        if (mAm.mPermissionReviewRequired) {
            if (mAm.getPackageManagerInternalLocked().isPermissionsReviewRequired(
                    s.packageName, s.userId)) {

                permissionsReviewRequired = true;

                // Show a permission review UI only for binding from a foreground app
                if (!callerFg) {
                    Slog.w(TAG, "u" + s.userId + " Binding to a service in package"
                            + s.packageName + " requires a permissions review");
                    return 0;
                }

                final ServiceRecord serviceRecord = s;
                final Intent serviceIntent = service;

                RemoteCallback callback = new RemoteCallback(
                        new RemoteCallback.OnResultListener() {
                    @Override
                    public void onResult(Bundle result) {
                        synchronized(mAm) {
                            final long identity = Binder.clearCallingIdentity();
                            try {
                                if (!mPendingServices.contains(serviceRecord)) {
                                    return;
                                }
                                // If there is still a pending record, then the service
                                // binding request is still valid, so hook them up. We
                                // proceed only if the caller cleared the review requirement
                                // otherwise we unbind because the user didn't approve.
                                if (!mAm.getPackageManagerInternalLocked()
                                        .isPermissionsReviewRequired(
                                                serviceRecord.packageName,
                                                serviceRecord.userId)) {
                                    try {
                                        bringUpServiceLocked(serviceRecord,
                                                serviceIntent.getFlags(),
                                                callerFg, false, false);
                                    } catch (RemoteException e) {
                                        /* ignore - local call */
                                    }
                                } else {
                                    unbindServiceLocked(connection);
                                }
                            } finally {
                                Binder.restoreCallingIdentity(identity);
                            }
                        }
                    }
                });

                final Intent intent = new Intent(Intent.ACTION_REVIEW_PERMISSIONS);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                        | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
                intent.putExtra(Intent.EXTRA_PACKAGE_NAME, s.packageName);
                intent.putExtra(Intent.EXTRA_REMOTE_CALLBACK, callback);

                if (DEBUG_PERMISSIONS_REVIEW) {
                    Slog.i(TAG, "u" + s.userId + " Launching permission review for package "
                            + s.packageName);
                }

                mAm.mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        mAm.mContext.startActivityAsUser(intent, new UserHandle(userId));
                    }
                });
            }
        }

        final long origId = Binder.clearCallingIdentity();

        try {
            // 检查这个服务是不是在要重启的列表（还有个这个列表？）里，如果是就移除
            if (unscheduleServiceRestartLocked(s, callerApp.info.uid, false)) {
                if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "BIND SERVICE WHILE RESTART PENDING: "
                        + s);
            }

            // 是否有自动创建标志
            if ((flags&Context.BIND_AUTO_CREATE) != 0) {
                s.lastActivity = SystemClock.uptimeMillis();
                // 如果已连接这个服务的连接都没有BIND_AUTO_CREATE标志
                if (!s.hasAutoCreateConnections()) {
                    // This is the first binding, let the tracker know.
                    ServiceState stracker = s.getTracker();
                    if (stracker != null) {
                        stracker.setBound(true, mAm.mProcessStats.getMemFactorLocked(),
                                s.lastActivity);
                    }
                }
            }

            // 和ActivityManagerService联系起来？
            mAm.startAssociationLocked(callerApp.uid, callerApp.processName, callerApp.curProcState,
                    s.appInfo.uid, s.name, s.processName);
            // Once the apps have become associated, if one of them is caller is ephemeral
            // the target app should now be able to see the calling app
            mAm.grantEphemeralAccessLocked(callerApp.userId, service,
                    s.appInfo.uid, UserHandle.getAppId(callerApp.uid));

            AppBindRecord b = s.retrieveAppBindingLocked(service, callerApp);
            ConnectionRecord c = new ConnectionRecord(b, activity,
                    connection, flags, clientLabel, clientIntent);

            IBinder binder = connection.asBinder();
            ArrayList<ConnectionRecord> clist = s.connections.get(binder);
            if (clist == null) {
                clist = new ArrayList<ConnectionRecord>();
                s.connections.put(binder, clist);
            }
            clist.add(c);
            b.connections.add(c);
            if (activity != null) {
                if (activity.connections == null) {
                    activity.connections = new HashSet<ConnectionRecord>();
                }
                activity.connections.add(c);
            }
            b.client.connections.add(c);
            if ((c.flags&Context.BIND_ABOVE_CLIENT) != 0) {
                b.client.hasAboveClient = true;
            }
            if ((c.flags&Context.BIND_ALLOW_WHITELIST_MANAGEMENT) != 0) {
                s.whitelistManager = true;
            }
            if (s.app != null) {
                updateServiceClientActivitiesLocked(s.app, c, true);
            }
            clist = mServiceConnections.get(binder);
            if (clist == null) {
                clist = new ArrayList<ConnectionRecord>();
                mServiceConnections.put(binder, clist);
            }
            clist.add(c);

            // bringUpServiceLocked这里是启动service的地方，调用路径bringUpServiceLocked->realStartServiceLocked->
            // app.thread.scheduleCreateService->ActivityThread.scheduleCreateService->ActivityThread.handleCreateService，如果启动成功则返回0
            if ((flags&Context.BIND_AUTO_CREATE) != 0) {
                s.lastActivity = SystemClock.uptimeMillis();
                if (bringUpServiceLocked(s, service.getFlags(), callerFg, false,
                        permissionsReviewRequired) != null) {
                    return 0;
                }
            }

            if (s.app != null) {
                if ((flags&Context.BIND_TREAT_LIKE_ACTIVITY) != 0) {
                    s.app.treatLikeActivity = true;
                }
                if (s.whitelistManager) {
                    s.app.whitelistManager = true;
                }
                // This could have made the service more important.
                mAm.updateLruProcessLocked(s.app, s.app.hasClientActivities
                        || s.app.treatLikeActivity, b.client);
                mAm.updateOomAdjLocked(s.app, true);
            }

            if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Bind " + s + " with " + b
                    + ": received=" + b.intent.received
                    + " apps=" + b.intent.apps.size()
                    + " doRebind=" + b.intent.doRebind);

            if (s.app != null && b.intent.received) {
                // 如果服务已经运行，则立刻发布connection
                // Service is already running, so we can immediately
                // publish the connection.
                try {
                    c.conn.connected(s.name, b.intent.binder, false);
                } catch (Exception e) {
                    Slog.w(TAG, "Failure sending service " + s.shortName
                            + " to connection " + c.conn.asBinder()
                            + " (in " + c.binding.client.processName + ")", e);
                }

                // If this is the first app connected back to this binding,
                // and the service had previously asked to be told when
                // rebound, then do so.
                if (b.intent.apps.size() == 1 && b.intent.doRebind) {
                    requestServiceBindingLocked(s, b.intent, callerFg, true);
                }
            } else if (!b.intent.requested) {
                requestServiceBindingLocked(s, b.intent, callerFg, false);
            }

            getServiceMapLocked(s.userId).ensureNotStartingBackgroundLocked(s);

        } finally {
            Binder.restoreCallingIdentity(origId);
        }

        return 1;
    }

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int bindServiceLocked(IApplicationThread caller, IBinder token, Intent service,

String resolvedType, final IServiceConnection connection, int flags,

String callingPackage, final int userId) throws TransactionTooLargeException {

if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "bindService: " + service

+ " type=" + resolvedType + " conn=" + connection.asBinder()

+ " flags=0x" + Integer.toHexString(flags));

// 获取调用bindService的进程信息，如果进程信息不存在，则报异常。为什么会不存在？

final ProcessRecord callerApp = mAm.getRecordForAppLocked(caller);

if (callerApp == null) {

throw new SecurityException(

"Unable to find app for caller " + caller

+ " (pid=" + Binder.getCallingPid()

+ ") when binding service " + service);

}

ActivityRecord activity = null;

// 这个token对应的是ContextImpl中的getActivityToken()，如果在一个Service中bind其他的Service，这个token是不是就是null了？

if (token != null) {

// 在Activity栈中看是否有调用的Activity，如果没有，则返回

activity = ActivityRecord.isInStackLocked(token);

if (activity == null) {

Slog.w(TAG, "Binding with unknown activity: " + token);

return 0;

}

int clientLabel = 0;

PendingIntent clientIntent = null;

final boolean isCallerSystem = callerApp.info.uid == Process.SYSTEM_UID;

// 这里看不太懂

if (isCallerSystem) {

// Hacky kind of thing -- allow system stuff to tell us

// what they are, so we can report this elsewhere for

// others to know why certain services are running.

service.setDefusable(true);

clientIntent = service.getParcelableExtra(Intent.EXTRA_CLIENT_INTENT);

if (clientIntent != null) {

clientLabel = service.getIntExtra(Intent.EXTRA_CLIENT_LABEL, 0);

if (clientLabel != 0) {

// There are no useful extras in the intent, trash them.

// System code calling with this stuff just needs to know

// this will happen.

service = service.cloneFilter();

}

// 把要绑定的服务看作一个Activity？后面还有相关的判断

if ((flags&Context.BIND_TREAT_LIKE_ACTIVITY) != 0) {

// 检查权限，如果没有权限会直接报异常结束函数

mAm.enforceCallingPermission(android.Manifest.permission.MANAGE_ACTIVITY_STACKS,

"BIND_TREAT_LIKE_ACTIVITY");

}

// 如果要请求管理白名单，但又不是系统应用，则报异常

if ((flags & Context.BIND_ALLOW_WHITELIST_MANAGEMENT) != 0 && !isCallerSystem) {

throw new SecurityException(

"Non-system caller " + caller + " (pid=" + Binder.getCallingPid()

+ ") set BIND_ALLOW_WHITELIST_MANAGEMENT when binding service " + service);

}

// 调用者在前台？

final boolean callerFg = callerApp.setSchedGroup != ProcessList.SCHED_GROUP_BACKGROUND;

final boolean isBindExternal = (flags & Context.BIND_EXTERNAL_SERVICE) != 0;

//ServiceLookupResult包含一个ServiceRecord成员和一个权限字符串

ServiceLookupResult res =

retrieveServiceLocked(service, resolvedType, callingPackage, Binder.getCallingPid(),

Binder.getCallingUid(), userId, true, callerFg, isBindExternal);

if (res == null) {

return 0;

}

if (res.record == null) {

return -1;

}

ServiceRecord s = res.record;

boolean permissionsReviewRequired = false;

// 是否需要让用户预览所需权限，这一段没仔细看

// If permissions need a review before any of the app components can run,

// we schedule binding to the service but do not start its process, then

// we launch a review activity to which is passed a callback to invoke

// when done to start the bound service's process to completing the binding.

if (mAm.mPermissionReviewRequired) {

if (mAm.getPackageManagerInternalLocked().isPermissionsReviewRequired(

s.packageName, s.userId)) {

permissionsReviewRequired = true;

// Show a permission review UI only for binding from a foreground app

if (!callerFg) {

Slog.w(TAG, "u" + s.userId + " Binding to a service in package"

+ s.packageName + " requires a permissions review");

return 0;

}

final ServiceRecord serviceRecord = s;

final Intent serviceIntent = service;

RemoteCallback callback = new RemoteCallback(

new RemoteCallback.OnResultListener() {

@Override

public void onResult(Bundle result) {

synchronized(mAm) {

final long identity = Binder.clearCallingIdentity();

try {

if (!mPendingServices.contains(serviceRecord)) {

return;

}

// If there is still a pending record, then the service

// binding request is still valid, so hook them up. We

// proceed only if the caller cleared the review requirement

// otherwise we unbind because the user didn't approve.

if (!mAm.getPackageManagerInternalLocked()

.isPermissionsReviewRequired(

serviceRecord.packageName,

serviceRecord.userId)) {

try {

bringUpServiceLocked(serviceRecord,

serviceIntent.getFlags(),

callerFg, false, false);

} catch (RemoteException e) {

/* ignore - local call */

}

} else {

unbindServiceLocked(connection);

}

} finally {

Binder.restoreCallingIdentity(identity);

}

});

final Intent intent = new Intent(Intent.ACTION_REVIEW_PERMISSIONS);

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK

| Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);

intent.putExtra(Intent.EXTRA_PACKAGE_NAME, s.packageName);

intent.putExtra(Intent.EXTRA_REMOTE_CALLBACK, callback);

if (DEBUG_PERMISSIONS_REVIEW) {

Slog.i(TAG, "u" + s.userId + " Launching permission review for package "

+ s.packageName);

}

mAm.mHandler.post(new Runnable() {

@Override

public void run() {

mAm.mContext.startActivityAsUser(intent, new UserHandle(userId));

}

});

}

final long origId = Binder.clearCallingIdentity();

try {

// 检查这个服务是不是在要重启的列表（还有个这个列表？）里，如果是就移除

if (unscheduleServiceRestartLocked(s, callerApp.info.uid, false)) {

if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "BIND SERVICE WHILE RESTART PENDING: "

+ s);

}

// 是否有自动创建标志

if ((flags&Context.BIND_AUTO_CREATE) != 0) {

s.lastActivity = SystemClock.uptimeMillis();

// 如果已连接这个服务的连接都没有BIND_AUTO_CREATE标志

if (!s.hasAutoCreateConnections()) {

// This is the first binding, let the tracker know.

ServiceState stracker = s.getTracker();

if (stracker != null) {

stracker.setBound(true, mAm.mProcessStats.getMemFactorLocked(),

s.lastActivity);

}

// 和ActivityManagerService联系起来？

mAm.startAssociationLocked(callerApp.uid, callerApp.processName, callerApp.curProcState,

s.appInfo.uid, s.name, s.processName);

// Once the apps have become associated, if one of them is caller is ephemeral

// the target app should now be able to see the calling app

mAm.grantEphemeralAccessLocked(callerApp.userId, service,

s.appInfo.uid, UserHandle.getAppId(callerApp.uid));

AppBindRecord b = s.retrieveAppBindingLocked(service, callerApp);

ConnectionRecord c = new ConnectionRecord(b, activity,

connection, flags, clientLabel, clientIntent);

IBinder binder = connection.asBinder();

ArrayList<ConnectionRecord> clist = s.connections.get(binder);

if (clist == null) {

clist = new ArrayList<ConnectionRecord>();

s.connections.put(binder, clist);

}

clist.add(c);

b.connections.add(c);

if (activity != null) {

if (activity.connections == null) {

activity.connections = new HashSet<ConnectionRecord>();

}

activity.connections.add(c);

}

b.client.connections.add(c);

if ((c.flags&Context.BIND_ABOVE_CLIENT) != 0) {

b.client.hasAboveClient = true;

}

if ((c.flags&Context.BIND_ALLOW_WHITELIST_MANAGEMENT) != 0) {

s.whitelistManager = true;

}

if (s.app != null) {

updateServiceClientActivitiesLocked(s.app, c, true);

}

clist = mServiceConnections.get(binder);

if (clist == null) {

clist = new ArrayList<ConnectionRecord>();

mServiceConnections.put(binder, clist);

}

clist.add(c);

// bringUpServiceLocked这里是启动service的地方，调用路径bringUpServiceLocked->realStartServiceLocked->

// app.thread.scheduleCreateService->ActivityThread.scheduleCreateService->ActivityThread.handleCreateService，如果启动成功则返回0

if ((flags&Context.BIND_AUTO_CREATE) != 0) {

s.lastActivity = SystemClock.uptimeMillis();

if (bringUpServiceLocked(s, service.getFlags(), callerFg, false,

permissionsReviewRequired) != null) {

return 0;

}

if (s.app != null) {

if ((flags&Context.BIND_TREAT_LIKE_ACTIVITY) != 0) {

s.app.treatLikeActivity = true;

}

if (s.whitelistManager) {

s.app.whitelistManager = true;

}

// This could have made the service more important.

mAm.updateLruProcessLocked(s.app, s.app.hasClientActivities

|| s.app.treatLikeActivity, b.client);

mAm.updateOomAdjLocked(s.app, true);

}

if (DEBUG_SERVICE) Slog.v(TAG_SERVICE, "Bind " + s + " with " + b

+ ": received=" + b.intent.received

+ " apps=" + b.intent.apps.size()

+ " doRebind=" + b.intent.doRebind);

if (s.app != null && b.intent.received) {

// 如果服务已经运行，则立刻发布connection

// Service is already running, so we can immediately

// publish the connection.

try {

c.conn.connected(s.name, b.intent.binder, false);

} catch (Exception e) {

Slog.w(TAG, "Failure sending service " + s.shortName

+ " to connection " + c.conn.asBinder()

+ " (in " + c.binding.client.processName + ")", e);

}

// If this is the first app connected back to this binding,

// and the service had previously asked to be told when

// rebound, then do so.

if (b.intent.apps.size() == 1 && b.intent.doRebind) {

requestServiceBindingLocked(s, b.intent, callerFg, true);

}

} else if (!b.intent.requested) {

requestServiceBindingLocked(s, b.intent, callerFg, false);

}

getServiceMapLocked(s.userId).ensureNotStartingBackgroundLocked(s);

} finally {

Binder.restoreCallingIdentity(origId);

}

return 1;

}

TextView点击事件分发流程

分类：Android, Java 阅读 (1,059) 已关闭评论

5月 262020

本文基于Android8.1系统源码分析

本文以TextView为例描述一下，点击事件的分发流程

如下图：

Android8.1去除user模式下允许usb设备连接提示框

分类：Android, Java 阅读 (2,097) 已关闭评论

5月 262020

去除下图所示提示框：

修改文件：frameworks/base/services/usb/java/com/android/server/usb/UsbDebuggingManager.java

增加import头

import android.os.IBinder;
import android.os.ServiceManager;
import android.util.Log;
import android.hardware.usb.IUsbManager;
import android.hardware.usb.UsbManager;

import android.os.IBinder;

import android.os.ServiceManager;

import android.util.Log;

import android.hardware.usb.IUsbManager;

import android.hardware.usb.UsbManager;

在处理MESSAGE_ADB_CONFIRM消息那一段，把startConfirmation(key, mFingerprints);去掉，改成如下代码

                case MESSAGE_ADB_CONFIRM: {
                    if ("trigger_restart_min_framework".equals(
                            SystemProperties.get("vold.decrypt"))) {
                        Slog.d(TAG, "Deferring adb confirmation until after vold decrypt");
                        if (mThread != null) {
                            mThread.sendResponse("NO");
                        }
                        break;
                    }
                    String key = (String)msg.obj;
                    String fingerprints = getFingerprints(key);
                    if ("".equals(fingerprints)) {
                        if (mThread != null) {
                            mThread.sendResponse("NO");
                        }
                        break;
                    }

                    try {
                        IBinder b = ServiceManager.getService(Context.USB_SERVICE);
                        IUsbManager service = IUsbManager.Stub.asInterface(b);
                        service.allowUsbDebugging(true, key);
                    } catch (Exception e) {
                        Log.e(TAG, "Unable to notify Usb service", e);
                    }
        
                    mFingerprints = fingerprints;
                    //去掉startConfirmation函数
                    //startConfirmation(key, mFingerprints);
                    break;
                }

case MESSAGE_ADB_CONFIRM: {

if ("trigger_restart_min_framework".equals(

SystemProperties.get("vold.decrypt"))) {

Slog.d(TAG, "Deferring adb confirmation until after vold decrypt");

if (mThread != null) {

mThread.sendResponse("NO");

}

break;

}

String key = (String)msg.obj;

String fingerprints = getFingerprints(key);

if ("".equals(fingerprints)) {

if (mThread != null) {

mThread.sendResponse("NO");

}

break;

}

try {

IBinder b = ServiceManager.getService(Context.USB_SERVICE);

IUsbManager service = IUsbManager.Stub.asInterface(b);

service.allowUsbDebugging(true, key);

} catch (Exception e) {

Log.e(TAG, "Unable to notify Usb service", e);

}

mFingerprints = fingerprints;

//去掉startConfirmation函数

//startConfirmation(key, mFingerprints);

break;

}

Android组件绘制流程

分类：Android, Java 阅读 (908) 已关闭评论

5月 212020

首先是在ViewRootImpl.java中的performTraversals中开始的？

最主要的有三个子函数

performMeasure、performLayout、performDraw

这三个函数分别对应View中的onMeasure、onLayout、onDraw

onMeasure是为了计算view的宽度和高度

最后使用setMeasuredDimension设置view的宽度和高度

onLayout是为了给子组件设置尺寸和位置(如果组件是个容器？)

onDraw是具体的窗体绘制函数

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