Instruments fails to record Points of Interest

Question

Created Aug ’22

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I'm trying to use signposts to help profile C++ code with Instruments (with Xcode 14 beta 5), and it's not working. A section of code in question, which is definitely getting reached, starts like this

static os_log_t sSignpost_log = nullptr;
if (__builtin_available( macOS 10.14, * ))
{
	if (sSignpost_log == nullptr)
	{
		sSignpost_log = os_log_create( "com.frameforge.gscn", "PointsOfInterest" );
	}
	os_signpost_interval_begin( sSignpost_log, 99, "com.frameforge.gscn" );
}

and ends like this

if (__builtin_available( macOS 10.14, * ))
{
	os_signpost_interval_end( sSignpost_log, 99, "com.frameforge.gscn" );
}

In Instruments, I have a Points of Interest instrument, and in the recording options for that instrument, I added 99 and com.frameforge.gscn as a row under "signpost code names". But after recording a run, the Points of Interest instrument always shows "No Data". I tried adding an os_signpost instrument, and it shows some data, but none of mine. What am I missing?

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Answer 1

Developer Tools Engineer OP

Apple

Aug ’22

Hi JWWalker,

You should not have to add anything in the "signpost code name" in the "Points of Interests" recording options, those are for a different type of signpost (kdebug signposts). Signposts logged via os_signpost to the "PointsOfInterest" category should show up by default without you having to do anything. This seems like it should work. Can you try using OS_SIGNPOST_ID_EXCLUSIVE for the signpost id (where you currently have 99) and see whether this makes a difference? Both version should work, but maybe there is a difference in behavior there.

Also, please file a feedback as this should work. If possible, please include the following:

A .trace document you recorded from your target which includes both the "Points of Interest" and the "os_signpost" instrument
A small example project which logs these signposts upon running. It would be great to have this, but if it would be a lot of effort to create it, the feedback + the .trace file is already very valuable.
Information about which Xcode version you used to compile the code, which Instruments you used to profile the target and which OS version the target was running on.

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