[pgpool-committers: 7333] pgpool: Use single shared memory segment for all shared variables in Pg

[Muhammad Usama]

Use single shared memory segment for all shared variables in Pgpool parent process

Shared memory segments is a limited resource and opening too many segments
should be avoided.
Also the default limit for on some operating systems like
OS/X (kern.sysv.shmmni: 32) is very small that you have to increase
shmmni just to run Pgpool-II.
So to avoid creating too many shared memory segments, the commit creates a
single shared memory segment big enough to hold all required shared memory
and put all shared memory variables within that segment one after the other.

Branch
------
V4_2_STABLE

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=3dc4cb2ac191b3f11e42f5e6336f60ffcd8c853e
Author: Muhammad Usama <m.usama at highgo.ca>

Modified Files
--------------
src/config/pool_config.c                    |  32 ++++----
src/config/pool_config.l                    |   5 --
src/include/pool.h                          |   2 +
src/include/query_cache/pool_memqcache.h    |   1 +
src/include/watchdog/wd_internal_commands.h |   2 +-
src/include/watchdog/wd_ipc_conn.h          |   1 +
src/main/pgpool_main.c                      | 112 ++++++++++++++++------------
src/query_cache/pool_memqcache.c            |  36 +++++++--
src/utils/pool_shmem.c                      |  55 ++++++++++++++
src/watchdog/wd_internal_commands.c         |  15 +++-
src/watchdog/wd_ipc_conn.c                  |   7 +-
src/watchdog/wd_lifecheck.c                 |   8 +-
12 files changed, 191 insertions(+), 85 deletions(-)