[pgpool-committers: 2086] pgpool: Fix reset query stuck problem.

[Tatsuo Ishii]

Fix reset query stuck problem.

It is reported that reset query (DISCARD ALL etc.) occasionally does
not finish and pgpool child remain waiting for reply from backend thus
client cannot connect to pgpool (for example
http://www.pgpool.net/mantisbt/view.php?id=107).  The cause of problem
is not identified yet but if client suddenly closes connection to
pgpool in the middle of query processing, backend may not accept the
reset queries because they are not ready for query.

The fix is, if frontend closes connection in unexpected way, query
process loop immediately returns with new state:
POOL_END_WITH_FRONTEND_ERROR and pgpool closes connection to
PostgreSQL then goes back to new connection request waiting loop.

Branch
------
V3_1_STABLE

Details
-------
http://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=41bf6d767f17d47ed2d87a53ee42c4779333341b

Modified Files
--------------
child.c              |    5 ++++-
pool.h               |    3 ++-
pool_proto_modules.c |    2 +-
3 files changed, 7 insertions(+), 3 deletions(-)