At 2005-12-03 04:24 PM -0500, you wrote:
The specific problem occurs when objects are reused. I've had situations where a client fails to reply for significantly longer than the timeout period. In that interval, the original CommTrans, AckMgr and RepMgr have been deleted and replaced by new instances. The client finally replies to the original request, and the reply is caught by those new objects! (There is what I think is a very small, but non-zero probability that I'm misinterpreting what I'm seeing.)
From what I can see in the source code, the internal ID is what's set by the builtin 'id' function. I'm printing these at key times and I can see where they're being duplicated. The only time I see this problem occur is when a new object has been created with the same id as a previous object.
Sounds like an object aliasing problem. And I don't think that it's *objects* that are being re-used, but *memory locations* for same-class objects. Don't use the built-in id() function. I'm not sure if this is correct, but it seems to me something like the memory address of the object. When the memory gets re-used, the same ID sometimes recurrs. ***** If you need a unique identifier for your application logic, create and assign it yourself. Don't use the id() function. ***** One possibility is to give each AckMgr/RepMgr pair an auction ID. Create a simple ID generator (object or function). When you create a new AckMgr and RepMgr, get a new ID from the generator and assign it to each one *before* you use it. The AckMgr then could simply ignore any response that doesn't have the expected ID. More generally, I would put the AckMgrs in a dictionary, keyed by the action ID. I would have *one* function/method (ProcessAck) that gets responses and dispatches them to the appropriate AckMgr, or drops them if no matching AckMgr is found. This would make testing, debugging, and tuning easier, too, by providing a single location for instrumentation. - Sam __________________________________________________________ Spinward Stars, LLC Samuel Reynolds Software Consulting and Development 303-805-1446 http://SpinwardStars.com/ sam@SpinwardStars.com