ECPG still having thread problems on Linux

From: Philip Yarra <philip(at)utiba(dot)com>
To: pgsql-interfaces(at)postgresql(dot)org
Subject: ECPG still having thread problems on Linux
Date: 2003-06-24 08:25:32
Message-ID: 200306241825.32527.philip@utiba.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-interfaces

Hi all, it looks like Lee's ECPG (and libpq) thread-safety patches
have been applied, and configure --with-threads is also added. I
have been doing some testing.

On FreeBSD 4.8, the attached sample app runs without a problem.

However, I still encounter a threading problem on Linux (RedHat 7.3).

I have done the following:
1) cvs update
2) ./configure --with-threads && make && su -c "make install"
3) compiled cn.pgc as follows:
a) ecpg -t cn.pgc
b) gcc -I/usr/local/pgsql/include -L/usr/local/pgsql/lib \
-lecpg -lpgtypes -pthread cn.c
4) ./a.out - one thread runs to completion (inserts 5 records),
the other hangs (manages one insert, then blocks forever)

Using gdb, I attached to the thread that has locked up, and the backtrace
looks like this:

(gdb) backtrace
#0 0x420e0187 in poll () from /lib/i686/libc.so.6
#1 0x4007d8cc in pqSocketPoll () from /usr/local/pgsql/lib/libpq.so.3
#2 0x4007d7ed in pqSocketCheck () from /usr/local/pgsql/lib/libpq.so.3
#3 0x4007d71f in pqWaitTimed () from /usr/local/pgsql/lib/libpq.so.3
#4 0x4007d6f5 in pqWait () from /usr/local/pgsql/lib/libpq.so.3
#5 0x4007bb53 in PQgetResult () from /usr/local/pgsql/lib/libpq.so.3
#6 0x4007bcbb in PQexec () from /usr/local/pgsql/lib/libpq.so.3
#7 0x40026d81 in ECPGexecute () from /usr/local/pgsql/lib/libecpg.so.4
#8 0x4002724c in ECPGdo () from /usr/local/pgsql/lib/libecpg.so.4
#9 0x08048927 in ins2 ()
#10 0x40043faf in pthread_start_thread () from /lib/i686/libpthread.so.0

Can anyone shed some light on why the behaviour differs between these two
platforms?

Also, perhaps someone other there with access to a different Linux setup
(maybe a more recent build than RedHat 7.3, or a different distro) could try
this app themselves to help verify if this is something that's stuffed on
that release. I think I can rule out this problem being a quirk of my
particular setup, as 3 different machines (all running RH7.3) give identical
results.

Build env:
Linux 2.4.18-3
gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-113)

Regards, Philip Yarra.

Attachment Content-Type Size
cn.pgc text/x-csrc 1.4 KB

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Dave Page 2003-06-24 08:26:08 Re: ftp mirror
Previous Message Karel Zak 2003-06-24 08:04:13 Re: TO_CHAR SO SLOW???

Browse pgsql-interfaces by date

  From Date Subject
Next Message The Hermit Hacker 2003-06-25 02:46:24 libpgtcl and pgtclsh
Previous Message Nic Ferrier 2003-06-24 00:46:18 emarsden's pg.scm for guile (with some extensions)