Hello all, I'm a twisted novice, but I was brought on to a project where twisted is pretty heavily in use. I'm running into all sorts of issues that make me wonder if we're using twisted properly or as it was intended. I have been through the documentation, but I think I need more in-depth answers. So here are a bunch of general questions about twisted. Once I understand this stuff I think I might be able to ask more cogent questions about my specific implementation (or maybe understand why things are the way they are).
1. Is deferToThread running the function in a real python thread? Should this be used (rather than a standard deferred) for any function that might block? 2. I understand that deferreds run "later". However, once a deferred (or a deferToThread) is picked up and run, does it run from start to finish? Can it be interrupted in the middle of the function? How about its callback/errback? Can another deferred jump in for processing in between a deferred and it's callback/errback, or in the middle of processing another deferred? 3. Are there any guarantees regarding the order of execution of deferreds? (I.e., are deferreds processed in the order in which they are created?) 4. Related to #2, and #3, does it make sense to use twisted when requests that are serviced may depend on one another. For example, a client makes a request 'add-A' which is deferred (so that the server can keep processing requests), and immediately afterwards makes a request 'modify-A' (which is also run as a deferred). Can I count on add-A being done so that modify-A doesn't attempt to work on something which hasn't been created yet? 5. Related to all of the above. What If I want to modify a database inside a deferred? Is that incorrect usage? Specifically, if all my requests run as deferred, and they all start a transaction and the beginning, and commit the transaction at the end, will I run into problems due to context switching in the middle of deferreds? (such as one request committing for both requests, starting two transactions in a row, committing twice in a row, and so on.) Thanks in advance. Please let me know if I'm so off that my questions don't even make sense =) -- Uri Please consider the environment before printing this message. http://wwf.panda.org/savepaper/ _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
