[PATCH] [RFC] profiler updates

I have an incomplete patch to fix bug 1961 (CPU profiler crashing squid
whenever AIO or other threads are used).

So far I have a timer class whose constructor/destructor perform the
timer setup and stats recording. That is attached.

The old profiler was done in a way which allowed live run-time snapshot
cachemgr report to be taken without stopping any timers. I've hooked
these classes into that reporting structure, but at present they will
result in the snapshots only recording *finished* timers, not the
currently active incomplete ones.

I'm thinking keeping the stack/list of timers from the old design but
only using it to dump a list of "currently incomplete" function calls
instead of using it to add incremental bits of timers to the report.

Does anyone have any other inspirational thoughts about how to keep
that kind of detail peeking using these classes in a multi-threaded soup
of code?

Amos