Fix deadlock in LockPatternUtils by using local id.

Activity manager now updates window manager's current user id
directly and immediately rather than waiting for a broadcast
update. Window manager passes this through policy to the
KeyguardViewMediator and into LockPatternUtils. LockPatternUtils
no longer goes to Activity to get the current user id if it finds
that its local id is non-default.

Fixes bug 7193726.

Change-Id: Id5613e7a9fe9e5b49e83c26b74504f587c3998c2

Author: Craig Mautner

core/java/android/view/WindowManagerPolicy.java

@@ -1111,7 +1111,15 @@ interface OnKeyguardExitResult {
      * @param attrs The window's LayoutParams.
      * @return Whether magnification can be applied.
      */
-    public boolean canMagnifyWindow(WindowManager.LayoutParams attrs);
+    public boolean canMagnifyWindowLw(WindowManager.LayoutParams attrs);
+
+    /**
+     * Called when the current user changes. Guaranteed to be called before the broadcast
+     * of the new user id is made to all listeners.
+     *
+     * @param newUserId The id of the incoming user.
+     */
+    public void setCurrentUserLw(int newUserId);
 
     /**
      * Print the WindowManagerPolicy's state into the given stream.

core/java/com/android/internal/widget/LockPatternUtils.java

@@ -22,14 +22,11 @@
 
 import android.app.ActivityManagerNative;
 import android.app.admin.DevicePolicyManager;
-import android.content.BroadcastReceiver;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.IntentFilter;
 import android.content.pm.PackageManager;
 import android.os.Binder;
-import android.os.FileObserver;
 import android.os.IBinder;
 import android.os.Process;
 import android.os.RemoteException;
@@ -45,16 +42,10 @@
 import android.view.View;
 import android.widget.Button;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.RandomAccessFile;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
-import java.util.Arrays;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * Utilities for the lock pattern and its settings.
@@ -134,7 +125,7 @@ public class LockPatternUtils {
     private final ContentResolver mContentResolver;
     private DevicePolicyManager mDevicePolicyManager;
     private ILockSettings mLockSettingsService;
-    private int mCurrentUserId = 0;
+    private int mCurrentUserId = UserHandle.USER_NULL;
 
     public DevicePolicyManager getDevicePolicyManager() {
         if (mDevicePolicyManager == null) {
@@ -233,10 +224,14 @@ public void setCurrentUser(int userId) {
 
     public int getCurrentUser() {
         if (Process.myUid() == Process.SYSTEM_UID) {
+            if (mCurrentUserId != UserHandle.USER_NULL) {
+                // Someone is regularly updating using setCurrentUser() use that value.
+                return mCurrentUserId;
+            }
             try {
                 return ActivityManagerNative.getDefault().getCurrentUser().id;
             } catch (RemoteException re) {
-                return mCurrentUserId;
+                return UserHandle.USER_OWNER;
             }
         } else {
             throw new SecurityException("Only the system process can get the current user");

policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

@@ -71,7 +71,6 @@
 import android.util.Log;
 import android.util.Slog;
 import android.util.SparseArray;
-import android.util.SparseIntArray;
 import android.view.Display;
 import android.view.Gravity;
 import android.view.HapticFeedbackConstants;
@@ -722,6 +721,7 @@ private void cancelPendingScreenshotChordAction() {
     }
 
     private final Runnable mPowerLongPress = new Runnable() {
+        @Override
         public void run() {
             // The context isn't read
             if (mLongPressOnPowerBehavior < 0) {
@@ -4316,7 +4316,8 @@ public void setLastInputMethodWindowLw(WindowState ime, WindowState target) {
         mLastInputMethodTargetWindow = target;
     }
 
-    public boolean canMagnifyWindow(WindowManager.LayoutParams attrs) {
+    @Override
+    public boolean canMagnifyWindowLw(WindowManager.LayoutParams attrs) {
         switch (attrs.type) {
             case WindowManager.LayoutParams.TYPE_INPUT_METHOD:
             case WindowManager.LayoutParams.TYPE_INPUT_METHOD_DIALOG:
@@ -4328,6 +4329,14 @@ public boolean canMagnifyWindow(WindowManager.LayoutParams attrs) {
         return true;
     }
 
+    @Override
+    public void setCurrentUserLw(int newUserId) {
+        if (mKeyguardMediator != null) {
+            mKeyguardMediator.setCurrentUser(newUserId);
+        }
+    }
+
+    @Override
     public void dump(String prefix, PrintWriter pw, String[] args) {
         pw.print(prefix); pw.print("mSafeMode="); pw.print(mSafeMode);
                 pw.print(" mSystemReady="); pw.print(mSystemReady);

policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewMediator.java

@@ -131,7 +131,7 @@ public class KeyguardViewMediator {
     private static final int KEYGUARD_LOCK_AFTER_DELAY_DEFAULT = 5000;
 
     /**
-     * How long we'll wait for the {@link KeyguardViewCallback#keyguardDoneDrawing()}
+     * How long we'll wait for the {@link ViewMediatorCallback#keyguardDoneDrawing()}
      * callback before unblocking a call to {@link #setKeyguardEnabled(boolean)}
      * that is reenabling the keyguard.
      */
@@ -297,7 +297,7 @@ public interface ViewMediatorCallback {
 
         @Override
         public void onUserSwitched(int userId) {
-            mLockPatternUtils.setCurrentUser(userId);
+            // Note that the mLockPatternUtils user has already been updated from setCurrentUser.
             synchronized (KeyguardViewMediator.this) {
                 resetStateLocked();
             }
@@ -465,6 +465,7 @@ public KeyguardViewMediator(Context context, LockPatternUtils lockPatternUtils)
 
         mLockPatternUtils = lockPatternUtils != null
                 ? lockPatternUtils : new LockPatternUtils(mContext);
+        mLockPatternUtils.setCurrentUser(UserHandle.USER_OWNER);
 
         WindowManager wm = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
 
@@ -890,6 +891,14 @@ public boolean isSecure() {
             || KeyguardUpdateMonitor.getInstance(mContext).isSimPinSecure();
     }
 
+    /**
+     * Update the newUserId. Call while holding WindowManagerService lock.
+     * @param newUserId The id of the incoming user.
+     */
+    public void setCurrentUser(int newUserId) {
+        mLockPatternUtils.setCurrentUser(newUserId);
+    }
+
     private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {

services/java/com/android/server/am/ActivityManagerService.java

@@ -13969,6 +13969,8 @@ public boolean switchUser(int userId) {
                 mUserLru.remove(userIdInt);
                 mUserLru.add(userIdInt);
 
+                mWindowManager.setCurrentUser(userId);
+
                 final UserStartedState uss = mStartedUsers.get(userId);
 
                 mHandler.removeMessages(REPORT_USER_SWITCH_MSG);
@@ -14007,7 +14009,7 @@ public void performReceive(Intent intent, int resultCode,
                 if (!haveActivities) {
                     startHomeActivityLocked(userId);
                 }
-            
+
                 sendUserSwitchBroadcastsLocked(oldUserId, userId);
             }
         } finally {

services/java/com/android/server/wm/WindowManagerService.java

@@ -292,9 +292,6 @@ public void onReceive(Context context, Intent intent) {
             if (DevicePolicyManager.ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED.equals(action)) {
                 mKeyguardDisableHandler.sendEmptyMessage(
                     KeyguardDisableHandler.KEYGUARD_POLICY_CHANGED);
-            } else if (Intent.ACTION_USER_SWITCHED.equals(action)) {
-                final int newUserId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
-                mCurrentUserId = newUserId;
             }
         }
     };
@@ -811,8 +808,6 @@ private WindowManagerService(Context context, PowerManagerService pm,
         // Track changes to DevicePolicyManager state so we can enable/disable keyguard.
         IntentFilter filter = new IntentFilter();
         filter.addAction(DevicePolicyManager.ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED);
-        // Track user switching.
-        filter.addAction(Intent.ACTION_USER_SWITCHED);
         mContext.registerReceiver(mBroadcastReceiver, filter);
 
         mHoldingScreenWakeLock = pmc.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK
@@ -5396,6 +5391,13 @@ public void setInputFilter(IInputFilter filter) {
         mInputManager.setInputFilter(filter);
     }
 
+    public void setCurrentUser(final int newUserId) {
+        synchronized (mWindowMap) {
+            mCurrentUserId = newUserId;
+            mPolicy.setCurrentUserLw(newUserId);
+        }
+    }
+
     public void enableScreenAfterBoot() {
         synchronized(mWindowMap) {
             if (DEBUG_BOOT) {

services/java/com/android/server/wm/WindowState.java

@@ -518,11 +518,11 @@ MagnificationSpec getWindowMagnificationSpecLocked() {
         MagnificationSpec spec = mDisplayContent.mMagnificationSpec;
         if (spec != null && !spec.isNop()) {
             if (mAttachedWindow != null) {
-                if (!mPolicy.canMagnifyWindow(mAttachedWindow.mAttrs)) {
+                if (!mPolicy.canMagnifyWindowLw(mAttachedWindow.mAttrs)) {
                     return null;
                 }
             }
-            if (!mPolicy.canMagnifyWindow(mAttrs)) {
+            if (!mPolicy.canMagnifyWindowLw(mAttrs)) {
                 return null;
             }
         }