Commits on Aug 22, 2014

1. timers: Avoid linear scan in _unrefActive. …

   Before this change, _unrefActive would keep the unrefList sorted when
   adding a new timer.
   
   Because _unrefActive is called extremely frequently, this linear scan
   (O(n) at worse) would make _unrefActive show high in the list of
   contributors when profiling CPU usage.
   
   This commit changes _unrefActive so that it doesn't try to keep the
   unrefList sorted. The insertion thus happens in constant time.
   
   However, when a timer expires, unrefTimeout has to go through the whole
   unrefList because it's not ordered anymore.
   
   It is usually not large enough to have a significant impact on
   performance because:
   - Most of the time, the timers will be removed before unrefTimeout is
     called because their users (sockets mainly) cancel them when an I/O
     operation takes place.
   - If they're not, it means that some I/O took a long time to happen, and
     the initiator of subsequents I/O operations that would add more timers
     has to wait for them to complete.
   
   With this change, _unrefActive does not show as a significant
   contributor in CPU profiling reports anymore.
   
   Fixes nodejs#8160.

   Julien Gilli committed Aug 22, 2014
   Configuration menu

   • View commit details
   • Copy full SHA for aefb864
   • Browse repository at this point

   Copy the full SHA

   aefb864 View commit details

   Browse the repository at this point in the history