On Fri, Dec 11, 2009 at 10:29 AM, Robert O'Callahan <rob...@ocallahan.org>wrote:
> On Fri, Dec 11, 2009 at 2:30 AM, Jeremy Orlow <jor...@chromium.org> wrote: > >> CanvasRenderingContext2Ds would never need to be shared between threads >> because they're "cloned" when passed...so is your concern that the libraries >> are only meant to ever be used from one thread? Maybe I'm being naive, but >> it would surprise me if that turned out to be an issue. > > > In Gecko we build cairo configured to only be usable from one thread. This > reduces locking overhead around global caches. We could change that > decision, but that would impose a small penalty on normal rendering, so it's > a trade-off. > > Resizing images was just one use. I could easily imagine apps wanting to >> generate more complex images on background threads without needing to >> implement things like spline drawing, pattern filling, and text themselves. >> > > Drawing text on a worker thread means making CSS font parsing, associated > font objects, text shaping, and bidi processing all usable from multiple > threads. That would be a much bigger problem for us than the actual > drawing... > Good point. Maybe that could be in a future version if it proved itself useful.
