[squeak-dev] FileStreams Limit
unique75 at web.de
Thu Feb 17 16:48:07 UTC 2022
I am on a Mac :-)
And the 4 times faster VisualWorks code is running on same Mac :-)
> Am 17.02.2022 um 17:45 schrieb Levente Uzonyi <leves at caesar.elte.hu>:
> On Thu, 17 Feb 2022, Jörg Belger wrote:
>> Funny, I commented out some things (red) in #open:forWrite:. Now the profiler is telling me that „String new: 1“ tools 97.4%… Really? Or is this a profiler bug?
> It's a limitation of the profiler. That profiler uses sampling and is implemented entirely in Smalltalk, so it can only measure message sends.
> What happens with your code is that after the #asVmPathName send a primitive is invoked (#primOpen:writable:), and that is not a real message send.
> Then inlined code comes (#ifNil:), which is also not a send.
> Then assignments come which are also not sends.
> The first actual send is String >> #new:.
> So, the profiler will count everything that happend before that send and after #asVmPathName towards String >> #new:, which is why you see such high number there.
> Since you know that String >> #new: with argument 1 is not expected to take too long, and the same applies to #ifNil: and the assignments, you can be sure that the time is spent in #primOpen:writable:, which is primitiveFileOpen in FilePlugin. And that is known to be quite slow on Windows presumably due to anti-virus measures.
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