[Android Pro] 分析 Package manager has died

reference to : http://blog.csdn.net/xxooyc/article/details/50162523

这是今天遇到的一个issue,由于Binder造成的。虽然比较简单，还是保持记录下吧。

先来开看一下Crash log:

    E/HpnsService(24810): HPNS Version is 5.0java.lang.RuntimeException: Package manager has died

    E/HpnsService(24810):   at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:111)

    E/HpnsService(24810):   at com.xx.xxx.util.AppUtil.checkInstalledPackageVersionCode(AppUtil.java:568)

    E/HpnsService(24810):   at com.xx.xxx.util.AppUtil.checkAppStatus(AppUtil.java:653)

    E/HpnsService(24810):   at com.xx.xxx.view.AppListView$LoadingAppThread.run(AppListView.java:723)

    E/HpnsService(24810): Caused by: android.os.TransactionTooLargeException

    E/HpnsService(24810):   at android.os.BinderProxy.transactNative(Native Method)

    E/HpnsService(24810):   at android.os.BinderProxy.transact(Binder.java:496)

    E/HpnsService(24810):   at android.content.pm.IPackageManager$Stub$Proxy.getPackageInfo(IPackageManager.java:1786)

    E/HpnsService(24810):   at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:106)

    E/HpnsService(24810):   ... 3 more

为什么会发生Package manager has died？

frameworks/base/core/java/Android/app/ApplicationPackageManager.java:

102    @Override

103    public PackageInfo getPackageInfo(String packageName, int flags)

104            throws NameNotFoundException {

105        try {

106            PackageInfo pi = mPM.getPackageInfo(packageName, flags, mContext.getUserId());

107            if (pi != null) {

108                return pi;

109            }

110        } catch (RemoteException e) {

111            throw new RuntimeException("Package manager has died", e);

112        }

113

114        throw new NameNotFoundException(packageName);

115    }

这是一个Binder调用，造成这个的原因是因为发生了RemoteException。

那为什么友会发生RemoteException？

其实也就是下面的这句Caused by: android.os.TransactionTooLargeException造成的。

为什么会造成TransactionTooLargeException？

frameworks/base/core/jni/android_util_Binder.cpp：

    682        case FAILED_TRANSACTION:

    683            ALOGE("!!! FAILED BINDER TRANSACTION !!!");

    684            // TransactionTooLargeException is a checked exception, only throw from certain methods.

    685            // FIXME: Transaction too large is the most common reason for FAILED_TRANSACTION

    686            //        but it is not the only one.  The Binder driver can return BR_FAILED_REPLY

    687            //        for other reasons also, such as if the transaction is malformed or

    688            //        refers to an FD that has been closed.  We should change the driver

    689            //        to enable us to distinguish these cases in the future.

    690            jniThrowException(env, canThrowRemoteException

    691                    ? "android/os/TransactionTooLargeException"

    692                            : "java/lang/RuntimeException", NULL);

    693            break;

可以看出如果Binder的使用超出了一个进程的限制就会抛出TransactionTooLargeException这个异常。

如果是其他原因造成Binder crash的话就会抛出RuntimeException。

那一个进程的Binder内存限制是多少？

frameworks/native/libs/binder/ProcessState.cpp：

44 #define BINDER_VM_SIZE ((1*1024*1024) - (4096 *2))

这便是一个进程中binder的大小，大约1M。

给Binder分配内存的代码：

    349#if !defined(HAVE_WIN32_IPC)

    350        // mmap the binder, providing a chunk of virtual address space to receive transactions.

    351        mVMStart = mmap(0, BINDER_VM_SIZE, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0);

    352        if (mVMStart == MAP_FAILED) {

    353            // *sigh*

    354            ALOGE("Using /dev/binder failed: unable to mmap transaction memory.\n");

    355            close(mDriverFD);

    356            mDriverFD = -1;

    357        }

通过上面的清理，知道了如果一个进程中使用的Binder内容超过了1M，就会crash.

而如果这时候恰巧在用getPackageManager()做事情，就会提示Package manager has died。

可以事实真的是这样的吗？

写了个demo来证明一下：

    public class MainActivity extends Activity {  

        @Override

        protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_main);

            test();

        }  

        private void test() {

            for (int i = 0; i < 2; i++) {

            new Thread() {

                @Override

                public void run() {

                    int count = 0;

                        List<PackageInfo> list = getPackageManager()

                                .getInstalledPackages(10000);

                        for (PackageInfo info : list) {

                            if(count >=1000){

                                break;

                            }

                            try {

                                PackageInfo pi = getPackageManager()

                                        .getPackageInfo(info.packageName,

                                                PackageManager.GET_ACTIVITIES);

                                Log.e("yanchen", "yanchen threadid:"+Thread.currentThread().getId()

                                        + ",i:" + count++);

                            } catch (NameNotFoundException e) {

                            }

                    }

                }

            }.start();

        }

        }

    }

这个Demo就是同时创建两个线程来进行Binder调用.

运行打印的log:

    E/yanchen (21180): yanchen threadid:4097,i:271

    E/yanchen (21180): yanchen threadid:4097,i:272

    E/yanchen (21180): yanchen threadid:4097,i:273

    E/yanchen (21180): yanchen threadid:4097,i:274

    E/yanchen (21180): yanchen threadid:4097,i:275

    E/yanchen (21180): yanchen threadid:4097,i:276

此时也如预期发生了Crash:

    E/JavaBinder(31244): !!! FAILED BINDER TRANSACTION !!!

    E/AndroidRuntime(31244): FATAL EXCEPTION: Thread-4798

    E/AndroidRuntime(31244): Process: com.example.testdl, PID: 31244

    E/AndroidRuntime(31244): java.lang.RuntimeException: Package manager has died

    E/AndroidRuntime(31244):    at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:155)

    E/AndroidRuntime(31244):    at com.example.testdl.MainActivity$1.run(MainActivity.java:40)

    E/AndroidRuntime(31244): Caused by: android.os.TransactionTooLargeException

    E/AndroidRuntime(31244):    at android.os.BinderProxy.transactNative(Native Method)

    E/AndroidRuntime(31244):    at android.os.BinderProxy.transact(Binder.java:496)

    E/AndroidRuntime(31244):    at android.content.pm.IPackageManager$Stub$Proxy.getPackageInfo(IPackageManager.java:2208)

    E/AndroidRuntime(31244):    at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:150)

    E/AndroidRuntime(31244):    ... 1 more

    D/EnterpriseDeviceManagerService( 3021): isMana

解决方式：

其实只要避免多个线程同时来调用Binder就可以了，毕竟一个线程用了会释放，所以理论上是很难发生的。

修改后的Demo:

    synchronized(MainActivity.class){

        PackageInfo pi = getPackageManager()

                .getPackageInfo(info.packageName,

                        PackageManager.GET_ACTIVITIES);

    }

再次运行就不会Crash了。

巴特西

[Android Pro] 分析 Package manager has died

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