Is the .net DbProviderFactory thread safe?

Question

I'm refactoring some old code based on DbProviderFactory to take advantage of connection pooling, but I ran into a simple question: Is the object returned by DbProviderFactories.GetFactory() thread-safe?

The code now is this:

DbProviderFactory factory = DbProviderFactories.GetFactory("Provider String from config");
var connection = factory.CreateConnection();
connection.ConnectionString = "connection string from config";

etc, etc. But this is done once PER THREAD. Obviously not what I'd want.

I wondered if I can use the "factory" object everywhere? Can I create multiple connections in different threads from the same DbProviderFactory object? Can I create DbAdapter classes, again, from the same factory?

As stupid as it is, the MSDN doc for even the concrete sub-classes don't say if you can do this. For example the msdn doc for SqlClientFactory for the CreateDataAdapter() method doesn't say if it's thread-safe or not. A few different guides on the internet have about just opening an instance of SqlConnection and it'll do thread-pooling, which is fine, but if you then do this:

SqlConnection connection = new SqlConnection("my connection string);
DbDataAdapter adapt = DbProviderFactories.GetFactory(connection).CreateDataAdapter();

Is that thread-safe? How many of those factories exist? What does that GetFactory method there return across threads? Always the same object? Or not? My existing code that I'm modifying uses DbDataAdapter s heavily, so I don't really want to change all of that too.

So is it thread-safe to take the factory and use it from multiple threads?

Answer 1

MSDN says:-

Thread Safety:

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.