Commit 33bf533c authored by Bartek Fabiszewski's avatar Bartek Fabiszewski
Browse files

Simplify synchronized db access, avoid potential race condition

parent be2e3c3a

app/src/main/java/net/fabiszewski/ulogger/DbAccess.java

+19 −15
Original line number Diff line number Diff line
@@ -16,8 +16,6 @@ import android.database.sqlite.SQLiteDatabase; 
import android.location.Location;

import android.util.Log;



import java.util.concurrent.atomic.AtomicInteger;



/**

 * Gateway class for database access

 *
@@ -25,14 +23,13 @@ import java.util.concurrent.atomic.AtomicInteger; 


class DbAccess {



    private static final AtomicInteger openCount = new AtomicInteger();

    private static int openCount;

    private static DbAccess sInstance;



    private static SQLiteDatabase db;

    private static DbHelper mDbHelper;

    private static final String TAG = DbAccess.class.getSimpleName();





    /**

     * Private constructor

     */
@@ -54,12 +51,15 @@ class DbAccess { 
     * Opens database

     * @param context Context

     */

    synchronized void open(Context context) {

        if(openCount.incrementAndGet() == 1) {

    void open(Context context) {

        synchronized (DbAccess.class) {

            if (openCount++ == 0) {

                if (Logger.DEBUG) { Log.d(TAG, "[open]"); }

                mDbHelper = DbHelper.getInstance(context.getApplicationContext());

                db = mDbHelper.getWritableDatabase();

            }

        }

    }



    /**

     * Write location to database.
@@ -323,8 +323,11 @@ class DbAccess { 
    /**

     * Closes database

     */

    synchronized void close() {

        if(openCount.decrementAndGet() == 0) {

    void close() {

        synchronized (DbAccess.class) {

            if (--openCount == 0) {

                if (Logger.DEBUG) { Log.d(TAG, "[close]"); }



                if (db != null) {

                    db.close();

                }
@@ -333,5 +336,6 @@ class DbAccess { 
                }

            }

        }

    }



}

app/src/main/java/net/fabiszewski/ulogger/DbHelper.java

+1 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ class DbHelper extends SQLiteOpenHelper { 
     * @param context Context

     * @return DbHelper instance

     */

    public static synchronized DbHelper getInstance(Context context) {

    static DbHelper getInstance(Context context) {



        if (sInstance == null) {

            sInstance = new DbHelper(context.getApplicationContext());