I am having issues when I am running an AsyncTask that performs a long delete action on the local SQLite database. If the user rotates the screen, then the Activity is recreated and a new connection to the database is created, while the AsyncTask is running.
I know that SQLite supports multiple reading and one writing at a time, and this will be the case, so I do not understand why it crashes when opening the database as readable while deleting is done...
The failure is the next:
04-26 12:54:21.839: I/Database(3925): sqlite returned: error code = 5, msg = database is locked
04-26 12:54:21.839: E/Database(3925): SELECT locale FROM android_metadata failed
04-26 12:54:21.839: E/Database(3925): Failed to setLocale() when constructing, closing the database
04-26 12:54:21.839: E/Database(3925): android.database.sqlite.SQLiteException: database is locked
04-26 12:54:21.839: E/Database(3925): at android.database.sqlite.SQLiteDatabase.native_setLocale(Native Method)
04-26 12:54:21.839: E/Database(3925): at android.database.sqlite.SQLiteDatabase.setLocale(SQLiteDatabase.java:1967)
04-26 12:54:21.839: E/Database(3925): at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1835)
04-26 12:54:21.839: E/Database(3925): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:820)
04-26 12:54:21.839: E/Database(3925): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:197)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:172)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.openReadableDatabaseWithForeignKeySupport(DatabaseManager.java:180)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.open(DatabaseManager.java:157)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.persistence.DatabaseManager.<init>(DatabaseManager.java:147)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.openerp.models.ConnectionProfile$ConnectionProfileManager.<init>(ConnectionProfile.java:138)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.activities.SelectConnectionProfile.fillData(SelectConnectionProfile.java:71)
04-26 12:54:21.839: E/Database(3925): at com.caumons.trainingdininghall.activities.SelectConnectionProfile.onResume(SelectConnectionProfile.java:66)
04-26 12:54:21.839: E/Database(3925): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1149)
04-26 12:54:21.839: E/Database(3925): at android.app.Activity.performResume(Activity.java:3833)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2085)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2110)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1643)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2796)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.access$1600(ActivityThread.java:117)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:932)
04-26 12:54:21.839: E/Database(3925): at android.os.Handler.dispatchMessage(Handler.java:99)
04-26 12:54:21.839: E/Database(3925): at android.os.Looper.loop(Looper.java:123)
04-26 12:54:21.839: E/Database(3925): at android.app.ActivityThread.main(ActivityThread.java:3647)
04-26 12:54:21.839: E/Database(3925): at java.lang.reflect.Method.invokeNative(Native Method)
04-26 12:54:21.839: E/Database(3925): at java.lang.reflect.Method.invoke(Method.java:507)
04-26 12:54:21.839: E/Database(3925): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-26 12:54:21.839: E/Database(3925): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-26 12:54:21.839: E/Database(3925): at dalvik.system.NativeStart.main(Native Method)
I coded the following workaround, but I think this is not very polite:
private void openReadableDatabaseWithForeignKeySupport() {
try {
mDatabase = mDatabaseHelper.getReadableDatabase();
mDatabase.execSQL("PRAGMA foreign_keys = ON");
} catch (SQLiteException e) {
/*
* If there is an exception because the database is locked,
* we will retry until it is free and can be opened.
* */
Log.d(getClass().getName(), e.toString());
openReadableDatabaseWithForeignKeySupport(); // Recursive call
}
}
The most curious is that what seems to fail is the setLocale() method called automatically by Android, but the docs says that:
setLocale() Sets the locale for this database. Does nothing if this database has the NO_LOCALIZED_COLLATORS flag set or was opened read only.
Any help will be much appreciated! :)