• 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: OSAtomic
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: OSAtomic

  • Subject: Re: OSAtomic
  • From: Greg Parker <email@hidden>
  • Date: Mon, 18 Jan 2010 11:30:57 -0800
On Jan 18, 2010, at 11:04 AM, Derek Darwin Lists wrote:
> I believe you are misreading/mistranslating the x86 assembly implementation of OSAtomicAnd32. The compare and swap operation (cmpxchg) in the "commpage" will populate GPR EAX with the value in memory on a mismatch, so the loop on failure will restart with the "latest" value of the memory operand after the failed comparison.

That's right. You can't do that with C code and OSAtomicCompareAndSwap(), but x86 OSAtomicAnd32() is built atop other assembly code that is not identical to OSAtomicCompareAndSwap().


--
Greg Parker     email@hidden     Runtime Wrangler


 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Darwin-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden
  • Follow-Ups:
    • Re: OSAtomic
      • From: Ariel Burton <email@hidden>
References: 
 >OSAtomic (From: email@hidden)
 >Re: OSAtomic (From: Derek Darwin Lists <email@hidden>)

  • Prev by Date: Re: OSAtomic
  • Next by Date: Re: OSAtomic
  • Previous by thread: Re: OSAtomic
  • Next by thread: Re: OSAtomic
  • Index(es):
    • Date
    • Thread