Android :: Thread-safety When Creating Methods - Activities Which Interact With SQLite Database

Sep 20, 2010

I am creating an app which allows for many different Activities to be started from a TabActivity(up to ~25). Most of the activities require data from the sqlite database, so when onCreate is run, an AsyncTask creates an SQLiteOpenHelper object(which will open a readable/writable database), runs a query, data is retrieved, and everything is then closed.

I was just testing messing around to see if i could break something, so i added every Activityto the TabActivity's TabHost. I then started mashing each tab as quickly as possible.

I noticed that very quickly i began to see in the LogCat: Caused by: android.database.sqlite.SQLiteException: database is locked: BEGIN EXCLUSIVE; and the app proceeded to die.

Typically there will only be about 4-6 tabs(i can just limit the user anyway) for the TabHost. I haven't been able to break anything with a small amount of tabs to mash, but i am still worried that maybe i am accessing the database in a poor way.

How can i prevent my SQLiteDatabase objects to cause a lock?

If i create a ContentProvider will that eliminate the possibility of database locking?

Do you have any suggestions for changes I could make for accessing data from an SQLiteDatabase?

I ended up taking the approach of using the Application class and storing 1 SQLiteOpenHelper and trying my best to keep it synchronized. This seems to be working great - i put all my 25 activities in the TabHost and mashed away on them with no errors.

I am calling ((SQLiteDbApplication)getApplication()).setDbHelper(new DBHelper(this, Constants.DB_NAME, null, Constants.DB_VERSION_CODE)); method(shown below) in every onCreate() in my activities

Any further suggestions to this approach or to the changes i made using this Application class?

CODE:...................

Android :: thread-safety when creating methods - activities which interact with SQLite database


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