Re:WordPress 3.6 arrives with better post locking, built-in ...
by jacques_chester on Friday August 02, 2013 @12:24AM
(#6145310)
It's non-blocking on the page load, but it still ties up an additional PHP instance.
On page load (that is, when WP actually runs), WP fires off a non-blocking HTTP request to itself. This runs at maximum once per minute, and shouldn't actually run if you're using Super Cache or similar and hit a cache page.