RFC: DTrace probes for debugging or testing in userland programs

[Adrian Chadd]

On 19 December 2016 at 16:04, Jordan Hubbard <jkh at mail.turbofuzz.com> wrote:
>
> On Dec 19, 2016, at 12:27 PM, Adrian Chadd <adrian.chadd at gmail.com> wrote:
>
> So although I like the sentiment, I don't think using dtrace for
> program logging is the right answer.  I like what apple did to wrap
> the program logging stuff so people didn't just write their own
> libraries (hi!) and so there's a unified-ish way to interact with
> apple programs. I think we could do with that.
>
>
> Thanks!
>
> We did a number of other things with ASL (Apple System Logger) which I miss
> very much today and would hope to see in any FreeBSD equivalent:
>
> 1. We structured all log data into dictionaries, so every application and/or
> subsystem within that application can add its own “tags” without squashing
> other key information.  This also unified the character encoding format, so
> some applications were no longer logging in ISO-Latin1, others in UTF-8 and
> yet others in SHIFT-JIS.
>
> 2.  There’s also a logging database, as one of the many possible “output
> sinks”, so searches / queries are fast (and there’s an API for querying and
> managing its contents).
>
> 3. We added client-side and server side logging filters, so you can “crank
> an application up” or shut its mouth without having to make any code
> changes.
>
> 4. It’s all thread-safe.

Hm. Where's the ASL source hiding? I'm kinda hoping it's light weight
enough to port over without porting a lot of other stuff, but I am
also afraid it's Apple.. :)



-adrian