What about multithreading in Android SQLite?

Question

In my app I\'ve got to implement some UI and Sync service. It runs in the background and updates data. Sync service is not very simple, it uses multithreading.

So, here

Answer 1

Well, reading the documentation my previous answer seems incorrect. I have a single(ton) SQLiteOpenHelper, so it seems all connections are the same. Even the readable ones are the same as the writable connections.

So I am going to skip calling getReadableDatabase, and use getWritableDatabase only. Then I am going to keep a counter, to make sure the database get closed once and only once.

Since the SQLiteOpenHelper serializes the writes, everything should be fine this way. I will just have to keep track of the connection, to make sure I dont keep one open at the end.

So in my DbHelper class I now have:

private int activeDatabaseCount = 0;
public synchronized SQLiteDatabase openDatabase() {
    SQLiteDatabase connection = getWritableDatabase(); // always returns the same connection instance
    activeDatabaseCount++;
    return connection; 
}
public synchronized void closeDatabase(SQLiteDatabase connection) {
    activeDatabaseCount--;
    if (activeDatabaseCount == 0) {
        if (connection != null) {
            if (connection.isOpen()) {
                connection.close();
            }
        }
    }
}