Fixes in close() in BinaryDictionary.

Avoid using 'synchronized' in finalizer as well.

bug: 3340837
Change-Id: I9b28f54e4490ecb844ba33a379f71b625e4246a2

3 files changed, 32 insertions, 12 deletions

diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index f7e67673a..813f7d32f 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -42,6 +42,7 @@ public class BinaryDictionary extends Dictionary {
 
     private static final int TYPED_LETTER_MULTIPLIER = 2;
 
+    private static final BinaryDictionary sInstance = new BinaryDictionary();
     private int mDicTypeId;
     private int mNativeDict;
     private long mDictLength;
@@ -59,16 +60,24 @@ public class BinaryDictionary extends Dictionary {
         }
     }
 
+    private BinaryDictionary() {
+    }
+
     /**
-     * Create a dictionary from a raw resource file
+     * Initialize a dictionary from a raw resource file
      * @param context application context for reading resources
      * @param resId the resource containing the raw binary dictionary
+     * @return initialized instance of BinaryDictionary
      */
-    public BinaryDictionary(Context context, int resId, int dicTypeId) {
-        if (resId != 0) {
-            loadDictionary(context, resId);
+    public static BinaryDictionary initDictionary(Context context, int resId, int dicTypeId) {
+        synchronized (sInstance) {
+            sInstance.closeInternal();
+            if (resId != 0) {
+                sInstance.loadDictionary(context, resId);
+                sInstance.mDicTypeId = dicTypeId;
+            }
         }
-        mDicTypeId = dicTypeId;
+        return sInstance;
     }
 
     private native int openNative(String sourceDir, long dictOffset, long dictSize,
@@ -104,6 +113,8 @@ public class BinaryDictionary extends Dictionary {
     @Override
     public void getBigrams(final WordComposer codes, final CharSequence previousWord,
             final WordCallback callback, int[] nextLettersFrequencies) {
+        if (mNativeDict == 0) return;
+
         char[] chars = previousWord.toString().toCharArray();
         Arrays.fill(mOutputChars_bigrams, (char) 0);
         Arrays.fill(mFrequencies_bigrams, 0);
@@ -135,6 +146,8 @@ public class BinaryDictionary extends Dictionary {
     @Override
     public void getWords(final WordComposer codes, final WordCallback callback,
             int[] nextLettersFrequencies) {
+        if (mNativeDict == 0) return;
+
         final int codesSize = codes.size();
         // Won't deal with really long words.
         if (codesSize > MAX_WORD_LENGTH - 1) return;
@@ -179,6 +192,10 @@ public class BinaryDictionary extends Dictionary {
 
     @Override
     public synchronized void close() {
+        closeInternal();
+    }
+
+    private void closeInternal() {
         if (mNativeDict != 0) {
             closeNative(mNativeDict);
             mNativeDict = 0;
@@ -188,7 +205,10 @@ public class BinaryDictionary extends Dictionary {
 
     @Override
     protected void finalize() throws Throwable {
-        close();
-        super.finalize();
+        try {
+            closeInternal();
+        } finally {
+            super.finalize();
+        }
     }
 }
diff --git a/java/src/com/android/inputmethod/latin/InputLanguageSelection.java b/java/src/com/android/inputmethod/latin/InputLanguageSelection.java
index faee38eda..a9f2c2c22 100644
--- a/java/src/com/android/inputmethod/latin/InputLanguageSelection.java
+++ b/java/src/com/android/inputmethod/latin/InputLanguageSelection.java
@@ -107,7 +107,7 @@ public class InputLanguageSelection extends PreferenceActivity {
         res.updateConfiguration(conf, res.getDisplayMetrics());
 
         int mainDicResId = LatinIME.getMainDictionaryResourceId(res);
-        BinaryDictionary bd = new BinaryDictionary(this, mainDicResId, Suggest.DIC_MAIN);
+        BinaryDictionary bd = BinaryDictionary.initDictionary(this, mainDicResId, Suggest.DIC_MAIN);
 
         // Is the dictionary larger than a placeholder? Arbitrarily chose a lower limit of
         // 4000-5000 words, whereas the LARGE_DICTIONARY is about 20000+ words.
diff --git a/java/src/com/android/inputmethod/latin/Suggest.java b/java/src/com/android/inputmethod/latin/Suggest.java
index 9ea9c2f3e..a8454b23e 100644
--- a/java/src/com/android/inputmethod/latin/Suggest.java
+++ b/java/src/com/android/inputmethod/latin/Suggest.java
@@ -103,7 +103,7 @@ public class Suggest implements Dictionary.WordCallback {
     private int mCorrectionMode = CORRECTION_BASIC;
 
     public Suggest(Context context, int dictionaryResId) {
-        mMainDict = new BinaryDictionary(context, dictionaryResId, DIC_MAIN);
+        mMainDict = BinaryDictionary.initDictionary(context, dictionaryResId, DIC_MAIN);
         initPool();
     }
 
@@ -127,7 +127,7 @@ public class Suggest implements Dictionary.WordCallback {
     }
 
     public boolean hasMainDictionary() {
-        return mMainDict.getSize() > LARGE_DICTIONARY_THRESHOLD;
+        return mMainDict != null && mMainDict.getSize() > LARGE_DICTIONARY_THRESHOLD;
     }
 
     public int getApproxMaxWordLength() {
@@ -276,7 +276,7 @@ public class Suggest implements Dictionary.WordCallback {
                     mHaveCorrection = true;
                 }
             }
-            mMainDict.getWords(wordComposer, this, mNextLettersFrequencies);
+            if (mMainDict != null) mMainDict.getWords(wordComposer, this, mNextLettersFrequencies);
             if ((mCorrectionMode == CORRECTION_FULL || mCorrectionMode == CORRECTION_FULL_BIGRAM)
                     && mSuggestions.size() > 0 && mPriorities.length > 0) {
                 // TODO: when the normalized score of the first suggestion is nearly equals to
@@ -496,7 +496,7 @@ public class Suggest implements Dictionary.WordCallback {
     }
 
     public boolean isValidWord(final CharSequence word) {
-        if (word == null || word.length() == 0) {
+        if (word == null || word.length() == 0 || mMainDict == null) {
             return false;
         }
         return mMainDict.isValidWord(word)