1179657 - Remove PL_DHASHMETER

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Nicholas Nethercote [inactive]]

When PL_DHASHMETER is enabled, we collect lots of stats about each
PLDHashTable. You can then print these out on a per-table basis by calling
PL_DHashTableDumpMeter(), but you have to provide a PLDHashEnumerator function.

This code is unused and totally busted and has been for who knows how long.
(PLDHashStats has two fields named |mSearches|, for example.)

IMO this whole approach isn't a good way of doing stats gathering: it's too
invasive, too prone to breakage, and too awkward to use. A better way is to
just insert temporary, ad hoc fprintf(stderr, ...) calls in the places of
interest and then use simple post-processing to gather counts. I've been doing
this for years, and a while back Brendan -- who I assume is the author of this
code, because it sure feels like his style -- admitted to me that he'd come
around to my opinion on this topic.

Also, this code's presence complicates the removal of PL_DHashTableEnumerate().
It doesn't make removal impossible, but it's yet one more reason to remove it.

Comment 1

[Nicholas Nethercote [inactive]]

Attachment: Remove PL_DHASHMETER

Comment 2

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/486e9c117ecc

Comment 3

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/486e9c117ecc