> Whenever the queue is empty, the queue emptier WAITs. But if the > queue is storage constrained, it can fill up. What does the > queue filler do then?
There are at least two types of queues; static queues, where all of the elements are pre-allocated/formatted by the queue owner and dynamic queues where the queue elements are provided by the caller. The former case is notoriously inflexible and difficult to size adequately to avoid full queues and service denial. The latter case adds a little complexity in the termination and cleanup cases, but in most other respects is more flexible and a better design choice. In terms of performance it's a wash. They both typically use Compare and Stop :-) to add/remove queue items so neither one is going to be blazing fast, but then again there's no free lunch with serialization. My own choice is PLO which is certainly a slooooow instruction, but it is flexible enough to use to manage singly linked and doubly linked queues in both 31 and 64 bit forms. It's the only thing (other than a lock/latch/enq) that will allow you to add or remove an entry from anywhere in the queue atomically. CS and CDS can't do that. CC ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
