• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Zeroing out instance variables
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Zeroing out instance variables


  • Subject: Re: Zeroing out instance variables
  • From: "Paul Sanders" <email@hidden>
  • Date: Sat, 17 Apr 2010 14:14:20 +0100

> Yep, it's a big win.  Even if the default allocator does something
> similar (and I think you're right that a linked list of free blocks of
> a given size is maintained by the malloc code, or something of that
> sort), this scheme avoids a fair handful of method calls and function
> calls per object, and so it wins big even just with that.  I can't
> remember what the degree of speedup was (I put this scheme in several
> months ago now), but it was quite substantial.

http://www.mikeash.com/pyblog/performance-comparisons-of-common-operations.html

According to which, alloc + init + release costs about the same as 35-40 method calls.

The code I posted could cache [MyClass class] if (as I do) you like to leave the asserts in your release code.  And it works, of course, because the isA pointer in all instances of a particular class is the same.

Paul Sanders.
_______________________________________________

Cocoa-dev mailing list (email@hidden)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

  • Follow-Ups:
    • Re: Zeroing out instance variables
      • From: Ben Haller <email@hidden>
References: 
 >Zeroing out instance variables (From: Ben Haller <email@hidden>)
 >Re: Zeroing out instance variables (From: Graham Cox <email@hidden>)
 >Re: Zeroing out instance variables (From: Ben Haller <email@hidden>)

  • Prev by Date: Launch app with params as front process and wait?
  • Next by Date: Re: Zeroing out instance variables
  • Previous by thread: Re: Zeroing out instance variables
  • Next by thread: Re: Zeroing out instance variables
  • Index(es):
    • Date
    • Thread