Re: Locking in PHP (Question for PHP Gurus)

Cabbar Duzayak wrote:

Hi All, I am using PHP on Apache/Linux with mod_php4. I need to implement a lazy cache for some resource which should be updated say every 1 hour in a way that the first person who arrives after an hour will be updating the cache. As you can imagine, I need to implement a write lock in this case, the idea is:

Why? As long as you do an atomic replace of the cache data, you shouldn't have any problems. You may have 2 requests both trying to create the new cache entry, but that is much cleaner than having to deal with locking. Do a tempnam() to get a temp file to write to and then do a rename() if this is a filesystem thing. Basically avoid locking at all costs in a web app. -Rasmus