DTrace-compatible request_rec for Solaris and Leopard

[Jeff Trawick <tr...@gmail.com>]

See
http://svn.apache.org/viewvc/httpd/httpd/trunk/ap.d?view=markup&pathrev=723565,
which has a mapping for some 64-bit build.  That needs some help in
portability and auto-generation.
In case it helps anyone DTracing Apache, attached is a request_rec mapping
which matches trunk that is ready to use with Solaris and Leopard on x86
(32-bit and 64-bit).  (I have a slightly different one for the 2.2.x branch
as well.)  See the hints for dtrace command-line parameters near the top.
 Handling the alignment differences between C-on-ia32 and D (the DTrace
language) are the worst part of the exercise.

It is very possible that having the offsets and sizes (or name of compatible
DTrace data types) available to DTrace scripts is all that is needed.
 Meanwhile, if the request_rec alignment/padding were cleaned up for 2.4 it
should be straightforward for someone to use a script to generate offsets
for request_rec fields which match their build of Apache.  (The script would
generate a C program via apxs which uses offsetof() to output definitions
that a DTrace script could use.

Is anybody out there DTracing Apache?

Any thoughts on having field offsets instead of structure definitions
available to scripts, in case the former can be provided in a more
maintainable manner?

-- 
Born in Roswell... married an alien...