Java Concurrency: Alternative to Multi Threading (working with non thread safe environment)

Question

I am working with a 3rd party proprietary library (no source code) which creates instances of a non thread safe component. Does this mean that I shouldn't use multiple threads to run jobs in parallel? Running each job in it's own JVM crossed my mind but is overkill.

Then I read the article here

http://cscarioni.blogspot.com/2011/09/alternatives-to-threading-in-java-stm.html

Is it recommended to follow that article's advice? What other alternatives exist out there?

Response to Martin James:

Vendor tells me that there is only one thread in which multiple instances of the component exist (Factory pattern to create the component instance) and each instance is independently controllable from it's API.

So does this mean that I can still use multiple threads while controlling each component instances running in one big thread?

Answer 1

No, it does not mean this. It means that you should care about data protection yourself. One possible way is to synchronize access to that library in code that calls it (your code). Other possible way is using immutable objects (for example make private copy of non-threadsafe data structure every time you want to work with it).

Other way is to design your application that way that the code that works with certain object always run in the same thread. It does not mean that code that is working with other object (even of the same class) cannot run int other thread. So, the system is multi-threaded but no data clashes are created.

Answer 2

'Vendor tells me that there is only one thread in which multiple instances of the componenet exist (Factory pattern to create the component instance) and each instance is independently controllable from it's API.'

That is not exactly 100% clear. What I think it means is:

1) Creation of components is not thread-safe. Maybe they are all stored internally in a non-threadsafe container. Presumably, destruction of the components is not thread-safe either.

2) Once created, the components are 'independently controllable' - this suggests strongly that they are thread-safe.

That's my take on it so far. Maybe your vendor could confirm it, just to be sure, before you proceed any further with a design.