- From: Glenn Maynard <glenn@zewt.org>
- Date: Wed, 9 Mar 2011 16:35:57 -0500
- To: Boris Zbarsky <bzbarsky@mit.edu>
- Cc: Chris Marrin <cmarrin@apple.com>, Web Applications Working Group WG <public-webapps@w3.org>
On Wed, Mar 9, 2011 at 3:40 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote: > On 3/9/11 1:54 PM, Glenn Maynard wrote: >> >> Any system with memory protection can interrupt on write, which makes >> copy-on-write very close to free, as long as you can page-align the >> buffer. > > That's a pretty serious caveat, though. And you're assuming that memory > meta-operations like "set up a custom write interrupt handler for this page" > are free, which is not exactly the case as I understand it. I don't think the presence of an MMU is a serious caveat for an optional optimization (even an important one), and you only need to set it up when it turns into a COW buffer, not before each access. Either way I agree with a direct zero-copy based API rather than building on COW. No sense introducing this complexity to implementations if it won't actually make the API better. -- Glenn Maynard
Received on Wednesday, 9 March 2011 21:36:30 UTC