Peter's right: as far as I understand, parsing, rendering, and script execution are all expected to take place on a single thread of execution. This includes any calls across multiple pages, which is why we place "connected" same-site pages (those in the same unit of related browsing contexts) in the same process. If one page calls a function in another page, we don't want to allow data races.
For more info on the decisions we've made about which pages go to which process, see: http://dev.chromium.org/developers/design-documents/process-models We also have a Eurosys 2009 paper on the topic: http://www.cs.washington.edu/homes/creis/publications/eurosys-2009.pdf Hope that helps, Charlie On Mon, Jan 4, 2010 at 7:10 PM, Peter Kasting <pkast...@google.com> wrote: > On Mon, Jan 4, 2010 at 6:55 PM, Fady Samuel <fadysam...@gmail.com> wrote: > >> So a script cannot execute concurrently with the traversal of the DOM >> tree? Could this be a performance bottleneck? > > > Pretty much nothing in the renderer can execute concurrently with other > things in the renderer. There have been academic papers published about > trying to parallelize parts of web rendering, and some though experiments > from various smart Mozilla and WebKit folks, but from what I've seen it's > not promising. The web wasn't really designed with thread- or process-level > parallelism on the part of the UA in mind. (Witness, for example, the > horror of sync XHR, or how difficult it is to make alert()s not be > renderer-modal.) > > In particular, it's fairly well-defined that script sees a coherent state > as it executes, so unless you can solve the halting problem, there are > pretty severe limits on how much you could parallelize script execution with > other stuff. > > PK > > -- > Chromium Developers mailing list: chromium-dev@googlegroups.com > View archives, change email options, or unsubscribe: > http://groups.google.com/group/chromium-dev > -- Chromium Developers mailing list: chromium-dev@googlegroups.com View archives, change email options, or unsubscribe: http://groups.google.com/group/chromium-dev
