[pgpool-committers: 4139] pgpool: Fix a posible hang during health checking

[Yugo Nagata]

Fix a posible hang during health checking

Helath checking was hang when any data wasn't sent
from backend after connect(2) succeeded. To fix this,
pool_check_fd() returns 1 when select(2) exits with
EINTR due to SIGALRM while health checkking is performed.

Reported and patch provided by harukat and some modification
by Yugo. Per bug #204.

backported from 3.4 or later;
https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commitdiff;h=ed9f2900f1b611f5cfd52e8f758c3616861e60c0

Branch
------
V3_1_STABLE

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=d1be197d655d3a110eefdecaed631cb993288e3b

Modified Files
--------------
main.c               | 2 +-
pool.h               | 1 +
pool_process_query.c | 8 ++++++++
3 files changed, 10 insertions(+), 1 deletion(-)