On Fri, Jan 08, 2010 at 12:29:18AM +0200, Igor Stasenko wrote:
2010/1/7 Alexandre Bergel <alexandre@bergel.eu>:
Hi!
I am currently working on a new profiler for Pharo. The idea is to graphically renders a profiling using Mondrian. I hope to release it soon. When discussing with an expert in the field (Walter Binder), the question about time grain was raised. I am partly based on MessageTally, which has a millisecond grain. Anyone is aware of a finer grain? At the level of nanosecond? Does it makes sense since there is no JIT (yet)?
AFAIK, there's no primitives in VM, which provide timing with nanosecond precision.
Also, the accuracy of the #millisecondClockValue available to the image is different on different platforms. I haven't checked lately, but I think the Windows VM is good pretty much to the nearest millisecond, while Linux is more variable. Not sure about OS X or other unixy platforms. So even if you are dealing with times that are measured to millisecond precision, the accuracy may be less depending on the underlying platform and VM. Dave