What are synchronizing strategies for Prevayler?

Question

Prevayler guarantees that all the writes ( through its transactions) are synchronized. But what about reads?

Is it right that dirty reads are possible if no explic

Answer 1

The recommended way is to use JMatch Query and Prevayler.execute(Query). Either directly or by using subclassing.

The returned results must be either primitive values or immutable objects. If you plan to return mutable objects you should subclass JMatch Query to do these deep copies. This way you get a system that locks every sensible read with other (sensible) reads and writes. This can speed up and simplify development, especially for developers without multithreaded programming expirience.

If you need more performance under high concurrent load, which is supposed to be a rare case, you indeed can use described above fine grained locking - using "synchronized" and java.util.concurrent.

See this discussion for more details.

Answer 2

It's been a really long time since I looked at Prevayler (I used it in a POC project about 6 or 7 years ago). I am pretty sure that if doing all your reads and writes through Prevayler no further synchronization is required - certainly I didn't need to in what I did, and that had multiple threads using the datastore.