At 16:13 Uhr -0700 4.9.2001, Randal L. Schwartz wrote:
>I don't think Cache::Cache has enough logic for an "atomic
>read-modify-write" in any of its modes to implement (for example) a
>web hit counter. It has only "atomic write". The "last write wins"
>strategy is fine for caching, but not for transacting, so I can see
>why Rob is a bit puzzled.
>
>It'd be nice if we could build a generic "atomic read-modify-write",
>but now we're back to Apache::Session, which in spite of its name
>works fine away from Apache. :)
>
>Caching. An area of interest of mine, but I still don't seem to get
>around to really writing the framework I want, so all I can do is keep
>lobbing grenades into the parts I don't want. :) :) Sorry guys. :)
What about my IPC::FsSharevars? I've once mentioned it on this list,
but I don't have the time to read all list mail, so maybe I've missed
some conclusions following the discussion from last time.
I've still not used it under heavy traffic, but it's supposed to
offer transaction safety, while allowing concurrent access to
different variables from even the same session (it locks each
variable independantly, and allows both shared and exclusive locks).
Still, it has been written for my fastcgi framework, not mod_perl,
but should work under the latter too I think (you'll have to load it
in a startup.pl script since it registers the pid of the parent
process so it can send signals to the whole process group (should be
easy to change to use the ppid of the process instead)).
http://www.eile.ethz.ch/download/
Write me if you have any issues with it (and I'm eager to hear about
success stories =)).
Christian
