Use MemoryContext API for regex memory management.
Previously, regex_t objects' memory was managed with malloc() and free()
directly. Switch to palloc()-based memory management instead.
Advantages:
* memory used by cached regexes is now visible with MemoryContext
observability tools
* cleanup can be done automatically in certain failure modes
(something that later commits will take advantage of)
* cleanup can be done in bulk
On the downside, there may be more fragmentation (wasted memory) due to
per-regex MemoryContext objects. This is a problem shared with other
cached objects in PostgreSQL and can probably be improved with later
tuning.
Thanks to Noah Misch for suggesting this general approach, which
unblocks later work on interrupts.
Suggested-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGK3PGKwcKqzoosamn36YW-fsuTdOPPF1i_rtEO%3DnEYKSg%40mail.gmail.com
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/bea3d7e3831fa6a1395eadbad7d97cebc7aa8aee
Modified Files
--------------
src/backend/regex/regprefix.c | 2 +-
src/backend/utils/adt/regexp.c | 57 ++++++++++++++++++++++++++++++------------
src/include/regex/regcustom.h | 6 ++---
3 files changed, 45 insertions(+), 20 deletions(-)