Update by multi-thread about ormlite-android HOT 5 CLOSED

This is pretty wild. What database are you using? Are you always updating items?

from ormlite-android.

Hi, It's an Android app. a single assetDao via OrmLiteSqliteOpenHelper across the app.
createOrUpdate always returns success but no rows in the DB.. it's quite weird.

before update
1 a
2 b
3 c
4 d
5 f
...

after update
1 a'
2 b'
5 f'
...

// below code is run by around 10 threads at the same time.
// it parses data (tens of assets) and always update same table via the assetDao.
mAssetDao.callBatchTasks(new Callable() {
@OverRide
public Object call() throws Exception {
for (int i = 0; i < jsonAssets.length(); i++) {
JSONObject jsonAsset = jsonAssets.getJSONObject(i);
Asset asset = new Asset();
parseAsset(asset, jsonAsset);
mAssetDao.createOrUpdate(asset);
}
return null;
}
});

from ormlite-android.

Sorry for the delay. Can you write a junit test that reproduces this? We are getting ready to [finally] push 4.49 and I'd like to make sure this isn't an issue.

from ormlite-android.

Ok, I understand this now and it makes sense. Multiple threads cannot use the callBatchTasks(...) at the same time because there is a single database connection and the transactions are getting screwed up. I just added the following to the javadocs:

NOTE: Depending on your underlying database implementation and whether or not you are working with a single database connection, you may need to synchronize around calls to this method otherwise the database transactions that are used may clash when called simultaneously from multiple threads. You may also need to synchronize other calls to transactions and dao.setAutoCommit(...).

from ormlite-android.

Related to #34

from ormlite-android.