BUG #10888: application is getting hanged in the poll() function of libpq.so.

The following bug has been logged on the website:

Bug reference:      10888
Logged by:          Mitu
Email address:      mitu.verma@ericsson.com
PostgreSQL version: 9.1.3
Operating system:   linux
Description:

Application gets hanged while making a query to the PostgreSql database.

I reproduced the issues on our testbed by making a simple C program which
makes a synchronous connection with the DB.

Pstack is showing the following error when the application is hang (see
below)

Now as it looks that it is getting hanged in the poll() function of
libpq.so.
There are other queries which are running successful on the same server. I
am clueless on how to get it resolved.
I have been advised to make asynchronous connection with the DB for this.
It will be really helpful if you can provide me some inputs on how to solve
this.

>ps -eaf | grep emitver | grep a.out
emitver   7918 26252  0 12:39 pts/21   00:00:00 ./a.out
emitver   9348 22957  0 12:54 pts/20   00:00:00 grep a.out

%sekax144:/workarea/MM/gerrit_clones/emitver/HS64570

>pstack 7918
#0  0x00000031c82dd1a8 in poll () from /lib64/libc.so.6
#1  0x00007f7f520596ef in pqSocketCheck () from
/opt/PostgreSQL/9.1/lib/libpq.so.5
#2  0x00007f7f520597c0 in pqWaitTimed () from
/opt/PostgreSQL/9.1/lib/libpq.so.5
#3  0x00007f7f52058d8e in PQgetResult () from
/opt/PostgreSQL/9.1/lib/libpq.so.5
#4  0x00007f7f52058f5c in PQexecFinish () from
/opt/PostgreSQL/9.1/lib/libpq.so.5
#5  0x0000000000400f77 in main