Federico,
Sorry for the belated reply.
I'll look into this issue and see if indeed the pointer is stale. Do you
have a test script I could use to reproduce this? Another thing you can
also do is use server side prepared statements in the latest driver. It
doesn't use ParseParam (which does the statement parsing). It lets the
server do this work.
Thanks!
Patrick
Federico Giannici wrote:
It seems to me that there is some kind of memory access problem with
DBI or DBD-Mysql.
I'm using OpenBSD 3.9-stable amd64. On OpenBSD 3.3 i386 the problem
didn't appeared. As you may know, recent version of OpenBSD have a new
kind of memory handling that make the programs segfault when they try
to access no (longer) allocated memory.
I'm using DBI 1.45 and DBD-Mysql 2.9008. I tried DBI 1.52 and
DBD-Mysql 3.0006, but the problems were more frequent, so I remained
to the old versions.
Here is the problem: frequently some "do" commands cause perl to crash
with signal 11. The crashes seems to depend on a lot of factors. For
example, loading more libraries could make the program to start
working. I think it depends on the structure of the memory allocated
to the program.
Here is the "bt" output of the core dump:
#0 0x000000005260a736 in mysql_st_internal_execute (h=0x4713b6e0,
statement=0x479b7140, attribs=0x4aa5fd40, numParams=0, params=0x0,
cdaPtr=0x7f7ffffc8610, svsock=0x43c90498, use_mysql_use_result=0)
at dbdimp.c:1654
#1 0x0000000052612da3 in XS_DBD__mysql__db_do (cv=0x40970b20) at
mysql.xs:222
#2 0x0000000050ddf07b in XS_DBI_dispatch () from
/usr/local/libdata/perl5/site_perl/amd64-openbsd/auto/DBI/DBI.so
#3 0x000000004a5a1c47 in Perl_pp_entersub () at
/usr/src/gnu/usr.bin/perl/pp_hot.c:2890
#4 0x000000004a60899e in Perl_runops_standard () at
/usr/src/gnu/usr.bin/perl/run.c:37
#5 0x000000004a5f744d in S_run_body (oldscope=1) at
/usr/src/gnu/usr.bin/perl/perl.c:1936
#6 0x000000004a5f7231 in perl_run (my_perl=0x45356258) at
/usr/src/gnu/usr.bin/perl/perl.c:1855
#7 0x0000000000401afe in main ()
I have found the problem is caused by accessing
"imp_dbh->bind_type_guessing" for the call to ParseParam() inside
mysql_st_internal_execute().
I have verified that "imp_dbh" is NOT null, but trying to access any
member make the program segfault. So maybe the pointer is a stale one?
I have not enough knowledge of DBI to make more debugging.
Bye.
