FindBugs: Fix a synchronized method warning in HttpAuthDatabase.java.

android_webview/java/src/org/chromium/android_webview/HttpAuthDatabase.java

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.android_webview;
 
 import android.content.ContentValues;
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
@@ skipping 34 matching lines @@
     private static final String HTTPAUTH_HOST_COL = "host";
     private static final String HTTPAUTH_REALM_COL = "realm";
     private static final String HTTPAUTH_USERNAME_COL = "username";
     private static final String HTTPAUTH_PASSWORD_COL = "password";
 
     /**
      * Initially false until the background thread completes.
      */
     private boolean mInitialized = false;
 
+    private final Object mInitializedLock = new Object();
+
     /**
      * Create an instance of HttpAuthDatabase for the named file, and kick-off background
      * initialization of that database.
      *
      * @param context the Context to use for opening the database
      * @param databaseFile Name of the file to be initialized.
      */
     public HttpAuthDatabase(final Context context, final String databaseFile) {
         new Thread() {
             @Override
             public void run() {
                 initOnBackgroundThread(context, databaseFile);
             }
         }.start();
     }
 
     /**
      * Initializes the databases and notifies any callers waiting on waitForInit.
      *
      * @param context the Context to use for opening the database
      * @param databaseFile Name of the file to be initialized.
      */
-    private synchronized void initOnBackgroundThread(Context context, String databaseFile) {
-        if (mInitialized) {
-            return;
+    private void initOnBackgroundThread(Context context, String databaseFile) {
+        synchronized (mInitializedLock) {
+            if (mInitialized) {
+                return;
+            }
+
+            initDatabase(context, databaseFile);
+
+            // Thread done, notify.
+            mInitialized = true;
+            notifyAll();
         }
-
-        initDatabase(context, databaseFile);
-
-        // Thread done, notify.
-        mInitialized = true;
-        notifyAll();
     }
 
     /**
      * Opens the database, and upgrades it if necessary.
      *
      * @param context the Context to use for opening the database
      * @param databaseFile Name of the file to be initialized.
      */
     private void initDatabase(Context context, String databaseFile) {
         try {
@@ skipping 34 matching lines @@
         mDatabase.setVersion(DATABASE_VERSION);
     }
 
     /**
      * Waits for the background initialization thread to complete and check the database creation
      * status.
      *
      * @return true if the database was initialized, false otherwise
      */
     private boolean waitForInit() {
-        synchronized (this) {
+        synchronized (mInitializedLock) {
             while (!mInitialized) {
                 try {
                     wait();

[boliu, 2014/02/04 23:26:25]

This needs to be mInitializedLock.wait() I think.

[Lei Zhang, 2014/02/05 00:50:42]

Thanks. Done.

                 } catch (InterruptedException e) {
                     Log.e(LOGTAG, "Caught exception while checking initialization", e);
                 }
             }
         }
         return mDatabase != null;
     }
 
     /**
      * Sets the HTTP authentication password. Tuple (HTTPAUTH_HOST_COL, HTTPAUTH_REALM_COL,
@@ skipping 85 matching lines @@
     /**
      * Clears the HTTP authentication password database.
      */
     public void clearHttpAuthUsernamePassword() {
         if (!waitForInit()) {
             return;
         }
         mDatabase.delete(HTTPAUTH_TABLE_NAME, null, null);
     }
 }