On Wed, Feb 17, 2010 at 3:36 AM, <strasser@uni-bremen.de> wrote:
Zitat von Bob Walters <bob.s.walters@gmail.com>:
The use of macros for these loops should be optional. For that matter, the loops are optional. In my library, a user can employ pessimistic locking conventions to ensure no chance of an isolation_exception, and in the process, would not need the retry loop.
how do you handle deadlocks?
even pessimistic RDBMS require a retry-logic on the user's part in case of a deadlock, how do you avoid that?
Because I'm using entry-level locking, it is possible to write the algorithms so that all changes occurring in parallel threads happen in an agreed-upon order resulting in deadlock-free execution. For example, sorting all the keys of modified or deleted entries prior to performing those operations. I concede that in practice, most users won't do that, unless their algorithms are so contentious that the effort is warranted. So yes, I need deadlock handling, and for that, the standard retry loop / exception handling is appropriate.