RuntimeException: Package manager has died

原文出处：http://blog.csdn.net/xxooyc/article/details/50162523，（部分修改）

bug描述

W/System.err: java.lang.RuntimeException: Package manager has died
W/System.err: at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:122)
W/System.err: at com.qq.googleplay.common.utils.AppUtil.isInstalled(AppUtil.java:73)
W/System.err: at com.qq.googleplay.manager.DownloadManager.getDownLoadInfo(DownloadManager.java:182)
W/System.err: at com.qq.googleplay.ui.fragment.HomeFragment$HomeAdapter$1.run(HomeFragment.java:179)
W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
W/System.err: at java.lang.Thread.run(Thread.java:818)

出现bug的代码

 /*** 判断包是否安装** @param context* @param packageName* @return*/public static boolean isInstalled(Context context, String packageName) {PackageManager manager = context.getPackageManager();try {manager.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);return true;} catch (PackageManager.NameNotFoundException e) {return false;}}

bug分析

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

@Override
public PackageInfo getPackageInfo(String packageName, int flags)  throws NameNotFoundException {  try {  PackageInfo pi = mPM.getPackageInfo(packageName, flags, mContext.getUserId());  if (pi != null) {  return pi;  }  } catch (RemoteException e) {  throw new RuntimeException("Package manager has died", e);  }  throw new NameNotFoundException(packageName);
}

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

Caused by: android.os.TransactionTooLargeException

W/System.err: Caused by: android.os.TransactionTooLargeException
W/System.err: at android.os.BinderProxy.transactNative(Native Method)
W/System.err: at android.os.BinderProxy.transact(Binder.java:507)
W/System.err: at android.content.pm.IPackageManager$Stub$Proxy.getPackageInfo(IPackageManager.java:1806)
W/System.err: at android.app.ApplicationPackageManager.getPackageInfo(ApplicationPackageManager.java:117)

frameworks/base/core/jni/android_util_Binder.cpp

case FAILED_TRANSACTION:
ALOGE("!!! FAILED BINDER TRANSACTION !!!");
// TransactionTooLargeException is a checked exception, only throw from certain methods.
// FIXME: Transaction too large is the most common reason for FAILED_TRANSACTION
//        but it is not the only one.  The Binder driver can return BR_FAILED_REPLY
//        for other reasons also, such as if the transaction is malformed or
//        refers to an FD that has been closed.  We should change the driver
//        to enable us to distinguish these cases in the future.
jniThrowException(env, canThrowRemoteException  ? "android/os/TransactionTooLargeException"  : "java/lang/RuntimeException", NULL);
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：

#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：

#if !defined(HAVE_WIN32_IPC)
// mmap the binder, providing a chunk of virtual address space to receive transactions.
mVMStart = mmap(0, BINDER_VM_SIZE, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0);
if (mVMStart == MAP_FAILED) {  // *sigh*  ALOGE("Using /dev/binder failed: unable to mmap transaction memory.\n");  close(mDriverFD);  mDriverFD = -1;
}

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