Change the way that LWLocks for extensions are allocated

Enterprise / PostgreSQL - Robert Haas [postgresql.org] - 4 February 2016 15:43 UTC

The previous RequestAddinLWLocks() method had several disadvantages. First, the locks would be in the main tranche; we've recently decided that it's useful for LWLocks used for separate purposes to have separate tranche IDs. Second, there wasn't any correlation between what code called RequestAddinLWLocks() and what code called LWLockAssign(); when multiple modules are in use, it could become quite difficult to troubleshoot problems where LWLockAssign() ran out of locks. To fix, create a concept of named LWLock tranches which can be used either by extension or by core code.

Amit Kapila and Robert Haas

c1772ad Change the way that LWLocks for extensions are allocated.
contrib/pg_stat_statements/pg_stat_statements.c | 4 +-
doc/src/sgml/xfunc.sgml | 9 +-
src/backend/postmaster/postmaster.c | 6 +
src/backend/storage/lmgr/lwlock.c | 212 +++++++++++++++++++----
src/include/pg_config_manual.h | 5 -
src/include/storage/lwlock.h | 22 ++-
src/tools/pgindent/typedefs.list | 2 +
7 files changed, 210 insertions(+), 50 deletions(-)

Upstream: git.postgresql.org


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