On 19 May 2010, at 14:49, Bobby Powers wrote:
yes, that is excellent! any word on performance?
I've not attempted to characterize Mac OS X performance. On FreeBSD at a rough hand-wave on two quad-core systems linked by 10gbps ethernet, I'm seeing slightly lower mean performance with much higher variance, which may be a property of using the GCD userspace thread parts as opposed to the Mac OS X workqueue parts. I hope to have a chance to take a closer look at this in the next couple of weeks, including seeing how Stacey's pthread workqueue stuff works out. This is with no attempts at performance optimization, however. Robert
bobby
On Tue, May 11, 2010 at 11:58 AM, David Leimbach <leimy2k@gmail.com> wrote:
That's just great!
On Tue, May 11, 2010 at 11:48 AM, Robert N. M. Watson <robert@fledge.watson.org> wrote:
Dear all:
I'm pleased to announce a new GCD-related software project, a GCD MPM for Apache. Apache Multi-Processing Modules (MPMs) allow operating systems to provide execution and concurrency structure to Apache: processes, threads, event management primitives, etc. It is intended to illustrate both GCD's programming model and programmability benefits, as well as how GCD can be integrated into a existing large-scale and thread-aware application. A quick skim of the code will bring to light some of its key benefits: a work model integrated with the GCD concurrency framework avoids complex utility libraries to distribute work and manage concurrency, and the integration of C Blocks into the programming language avoids the complexity-overhead of a message passing model. The GCD MPM is experimental and illustrative, but we hope it will also be useful in the future!
The patch and instructions for applying it can be found on the Mac OS X forge web page:
http://libdispatch.macosforge.org/trac/wiki/apache
In the GCD MPM, connections are associated with dispatch queues, which enforce ordered processing of a connection, but allows connections to float across actual OS-provided threads via GCD. The web page says more about the approach, but one interesting observation is that the implementation is around 950 lines of code, vs. the threaded models which come in 1.6x-3x the number of lines.
Thanks to Apple for their support of this project!
Robert Watson University of Cambridge Computer Laboratory _______________________________________________ libdispatch-dev mailing list libdispatch-dev@lists.macosforge.org http://lists.macosforge.org/mailman/listinfo.cgi/libdispatch-dev
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