Assign a child slot to every postmaster child process Previously, only backends, autovacuum workers, and background workers had an entry in the PMChildFlags array. With this commit, all postmaster child processes, including all the aux processes, have an entry. Dead-end backends still don't get an entry, though, and other processes that don't touch shared memory will never mark their PMChildFlags entry as active.
We now maintain separate freelists for different kinds of child processes. That ensures that there are always slots available for autovacuum and background workers. Previously, pre-authentication backends could prevent autovacuum or background workers from starting up, by using up all the slots. The code to manage the slots in the postmaster process is in a new pmchild.c source file. Because postmaster.c is just so large. Assigning pmsignal slot numbers is now pmchild.c's responsibility. This replaces the PMChildInUse array in pmsignal.c. Some of the comments in postmaster.c still talked about the "stats process", but that was removed in commit 5891c7a8ed. Fix those while we're at it. Reviewed-by: Andres Freund <and...@anarazel.de> Discussion: https://www.postgresql.org/message-id/a102f15f-eac4-4ff2-af02-f9ff209ec...@iki.fi Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/a78af0427015449269fb7d9d8c6057cfcb740149 Modified Files -------------- src/backend/bootstrap/bootstrap.c | 8 + src/backend/postmaster/Makefile | 1 + src/backend/postmaster/launch_backend.c | 3 + src/backend/postmaster/meson.build | 1 + src/backend/postmaster/pmchild.c | 285 +++++++++ src/backend/postmaster/postmaster.c | 912 ++++++++++++---------------- src/backend/postmaster/syslogger.c | 6 +- src/backend/storage/ipc/pmsignal.c | 89 +-- src/backend/storage/lmgr/proc.c | 12 +- src/backend/tcop/postgres.c | 6 + src/include/postmaster/bgworker_internals.h | 2 +- src/include/postmaster/postmaster.h | 45 ++ src/include/postmaster/syslogger.h | 2 +- src/include/storage/pmsignal.h | 4 +- src/tools/pgindent/typedefs.list | 3 +- 15 files changed, 785 insertions(+), 594 deletions(-)
