5 messages in com.mysql.lists.perlRe: bug in DBD::MySQL on Ubuntu / Sarge| From | Sent On | Attachments |
|---|---|---|
| Martin Waite | 26 May 2006 06:56 | |
| Patrick Galbraith | 27 May 2006 10:11 | |
| Martin Waite | 28 May 2006 01:18 | |
| Martin Waite | 28 May 2006 02:04 | |
| Martin Waite | 30 May 2006 09:58 |
| Subject: | Re: bug in DBD::MySQL on Ubuntu / Sarge |
|---|---|
| From: | Martin Waite (mar...@datacash.com) |
| Date: | 05/30/2006 09:58:38 AM |
| List: | com.mysql.lists.perl |
Hi,
The problem does indeed look like a Perl problem.
I have done a number of experiments, most notably adding Perl_sv_dump() into the loop around the param array in parse_params. This indicated that the FLAGS in the SV structure change between successive calls.
I can demonstrate this without even using DBD::MySQL:
#! /usr/bin/perl5 -w
use strict; use Devel::Peek;
my $v = '4000930012345671';
print "=" x 20, "Call 1", "=" x 20, "\n"; cancel( $v ); # pPOK flag is set print "=" x 20, "Call 2", "=" x 20, "\n"; cancel( $v ); # bug - pPOK flag is not set
sub cancel { my ( $dcref ) = @_; Dump( substr( $dcref, -11 ) ); }
On perl 5.8.4: we get:
====================Call 1==================== SV = PVLV(0x81635e0) at 0x816addc REFCNT = 1 FLAGS = (PADMY,GMG,SMG,pPOK) IV = 0 NV = 0 PV = 0x8165ae8 "30012345671"\0 CUR = 11 LEN = 12 MAGIC = 0x8165e40 MG_VIRTUAL = &PL_vtbl_substr MG_TYPE = PERL_MAGIC_substr(x) TYPE = x TARGOFF = 5 TARGLEN = 11 TARG = 0x816ad88 SV = PV(0x814cf38) at 0x816ad88 REFCNT = 2 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x816bb50 "4000930012345671"\0 CUR = 16 LEN = 17 ====================Call 2==================== SV = PVLV(0x81635e0) at 0x816addc REFCNT = 1 FLAGS = (PADMY,GMG,SMG) IV = 0 NV = 0 PV = 0x8165ae8 "30012345671"\0 CUR = 11 LEN = 12 MAGIC = 0x8165e40 MG_VIRTUAL = &PL_vtbl_substr MG_TYPE = PERL_MAGIC_substr(x) TYPE = x TARGOFF = 5 TARGLEN = 11 TARG = 0x814cbb8 SV = PV(0x814d0f4) at 0x814cbb8 REFCNT = 2 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x8165d50 "4000930012345671"\0 CUR = 16 LEN = 17
In Call 1, FLAGS includes pPOK, but in call 2, this is missing.
In dbdimp.c, parse_params traverses the param list, and if SvOK(ph->value) is not set, then the parameter is set to NULL. I'm assuming that SvOK() returns true for Call 1 and false for Call 2.
In Perl 5.6.1, the flags for Call 1 are (PADMY,GMG,SMG,pPOK), and for Call 2 are (PADMY,GMG,SMG,POK,pPOK). I don't know why they differ between the calls, but I don't caer because SvOK() returns true for both, and so DBD::MySQL works as expected.
I'll go away now and pester a Perl Internals list somewhere. Do you have any suggestions how I should proceed ? I wouldn't even know what to call this problem.
regards, Martin
Martin Waite wrote:
Hi Patrick,
I have compiled up v 3.0004 on Woody (Perl 5.6.1), and the script works properly.
The problem seems to be tied to the version of Perl that is used.
regards, Martin
Martin Waite wrote:
Hi Patrick,
I have changed the cancel subroutine to print out the substr expression:
sub cancel { my ( $dcref ) = @_; print "DCREF: $dcref\n"; print "update update_bug set status = 5 where k = ? ", substr( $dcref, -11 ), "\n"; $dbh->do( "update update_bug set status = 5 where k = ?", undef, substr( $dcref, -11 ) ); }
The output from the program now is:
martin@chadwick:~$ perl -w ~/ed/adhoc/update-bug DCREF: 4000930012345671 update update_bug set status = 5 where k = ? 30012345671 DCREF: 4000930012345671 update update_bug set status = 5 where k = ? 30012345671 DCREF: 4000930012345671 update update_bug set status = 5 where k = ? 30012345671 DCREF: 4000930012345671 update update_bug set status = 5 where k = ? 30012345671
Which is what I'd expect, however the query log still shows:
4655 Query SET AUTOCOMMIT=1 4655 Query drop table if exists update_bug 4655 Query create table update_bug( k int not null primary key, status int not null ) 4655 Query update update_bug set status = 5 where k = '30012345671' 4655 Query update update_bug set status = 5 where k = '30012345671' 4655 Query update update_bug set status = 5 where k = '30012345671' 4655 Query update update_bug set status = 5 where k = NULL 4655 Query update update_bug set status = 5 where k = NULL 4655 Query update update_bug set status = 5 where k = NULL 4655 Quit
I have raised this issue through the MySQL Network, and they have raised a bug. They tried the script on Suse, and the same problem appears.
I have downloaded the latest DBD (3.0004) and the problem still applies (this linked against the 5.0.20a client libraries). Poking around in dbdimp.c, I noticed that a whole lot of debug switches on if you set dbis->debug to 2, so in mysql_st_internal_execute, I set dbis->debug to 2, but then the problem goes away. Very frustrating. (By the way, what is the proper way to set debugging on ?)
My plan of action is to attempt to compile the woody DBD (v1.22 !) on sarge/perl 5.8.4 and see if that works - but the version might be too old to work with the new Perl. Probably easier to compile the newest DBD on woody against Perl 5.6 and see if the problem follows with it.
I notice in the release email for DBD 3.0004 that you say threading must be switched off on Solaris. The version of Perl on sarge / ubuntu has threading switched on. I don't know how much of this is relevant, but below I include the output of Perl -V for the two hosts the script fails on (Sarge and Ubuntu), and the one it works on (Woody).
regards, Martin
sarge: perl -V Summary of my perl5 (revision 5 version 8 subversion 4) configuration: Platform: osname=linux, osvers=2.6.15, archname=i386-linux-thread-multi uname='linux ninsei 2.6.15 #1 smp preempt sat jan 7 12:47:52 pst 2006 i686 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i386-linux -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.4 -Dsitearch=/usr/local/lib/perl/5.8.4 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.4 -Dd_dosuid -des' hint=recommended, useposix=true, d_sigaction=define usethreads=define use5005threads=undef useithreads=define usemultiplicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2', cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include' ccversion='', gccversion='3.3.5 (Debian 1:3.3.5-13)', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=4, prototype=define Linker and Libraries: ld='cc', ldflags =' -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=/lib/libc-2.3.2.so, so=so, useshrplib=true, libperl=libperl.so.5.8.4 gnulibc_version='2.3.2' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'
Characteristics of this binary (from libperl): Compile-time options: MULTIPLICITY USE_ITHREADS USE_LARGE_FILES PERL_IMPLICIT_CONTEXT Built under linux Compiled at Jan 12 2006 14:54:46 @INC: /etc/perl /usr/local/lib/perl/5.8.4 /usr/local/share/perl/5.8.4 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.8 /usr/share/perl/5.8 /usr/local/lib/site_perl .
Ubuntu: perl -V
Summary of my perl5 (revision 5 version 8 subversion 4) configuration: Platform: osname=linux, osvers=2.6.8.1, archname=i386-linux-thread-multi uname='linux terranova 2.6.8.1 #1 smp sat feb 26 13:03:40 utc 2005 i686 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i386-linux -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.4 -Dsitearch=/usr/local/lib/perl/5.8.4 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.4 -Dd_dosuid -des' hint=recommended, useposix=true, d_sigaction=define usethreads=define use5005threads=undef useithreads=define usemultiplicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2', cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -I/usr/local/include' ccversion='', gccversion='3.3.4 (Debian 1:3.3.4-9ubuntu5)', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=4, prototype=define Linker and Libraries: ld='cc', ldflags =' -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=/lib/libc-2.3.2.so, so=so, useshrplib=true, libperl=libperl.so.5.8.4 gnulibc_version='2.3.2' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'
Characteristics of this binary (from libperl): Compile-time options: MULTIPLICITY USE_ITHREADS USE_LARGE_FILES PERL_IMPLICIT_CONTEXT Built under linux Compiled at Mar 9 2005 11:10:00 @INC: /etc/perl /usr/local/lib/perl/5.8.4 /usr/local/share/perl/5.8.4 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.8 /usr/share/perl/5.8 /usr/local/lib/site_perl .
Woody: perl -V Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration: Platform: osname=linux, osvers=2.4.28-es, archname=i386-linux uname='linux gluck 2.4.28-es #1 smp wed jan 12 09:55:22 est 2005 i686 unknown ' config_args='-Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i386-linux -Dprefix=/usr -Dprivlib=/usr/share/perl/5.6.1 -Darchlib=/usr/lib/perl/5.6.1 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.6.1 -Dsitearch=/usr/local/lib/perl/5.6.1 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Duseshrplib -Dlibperl=libperl.so.5.6.1 -Dd_dosuid -des' hint=recommended, useposix=true, d_sigaction=define usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef Compiler: cc='cc', ccflags ='-DDEBIAN -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2', cppflags='-DDEBIAN -fno-strict-aliasing -I/usr/local/include' ccversion='', gccversion='2.95.4 20011002 (Debian prerelease)', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=4, usemymalloc=n, prototype=define Linker and Libraries: ld='cc', ldflags =' -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib libs=-lgdbm -ldb -ldl -lm -lc -lcrypt perllibs=-ldl -lm -lc -lcrypt libc=/lib/libc-2.2.5.so, so=so, useshrplib=true, libperl=libperl.so.5.6.1 Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'
Characteristics of this binary (from libperl): Compile-time options: USE_LARGE_FILES Built under linux Compiled at Mar 18 2005 16:57:39 @INC: /usr/local/lib/perl/5.6.1 /usr/local/share/perl/5.6.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.6.1 /usr/share/perl/5.6.1 /usr/local/lib/site_perl/i386-linux /usr/local/lib/site_perl .
Patrick Galbraith wrote:
Martin,
It doesn't look like a DBD::mysql problem to me. It has something to do with the script. What does the output of program show? Perhaps print out "print substr($dcref, -11) . "\n"; prior to each call of do to see that it's actually passing the value to the driver. Or, try it without the substring call. Try some variation to see if the problem is in the value being passed to do.
regards,
Patrick
Martin Waite wrote:
Hi,
I have come across a problem in DBD::MySQL while porting code from Woody to Sarge and Ubuntu (both hoary and breezy).
The following script creates a simple test table and attempts to perform 6 updates. The first 3 updates work correctly, but in the final 3 updates, the key is erroneously taken as NULL:
#! /usr/bin/perl5 -w
use strict; use DBI;
my $dbh = DBI->connect( "dbi:mysql:test:host=chadwick:port=3306", 'testuser', 'test', {RaiseError=>1, PrintError=>0} );
$dbh->do( "drop table if exists update_bug" ); $dbh->do( "create table update_bug( k int not null primary key, status int not null )" );
my $v = '4000930012345671';
$dbh->do( "update update_bug set status = 5 where k = ?", undef, substr( $v, -11 ) ); # OK $dbh->do( "update update_bug set status = 5 where k = ?", undef, substr( $v, -11 ) ); # OK
cancel( $v ); # OK cancel( $v ); # bug - k is NULL cancel( $v ); # bug - k is NULL cancel( $v ); # bug - k is NULL
sub cancel { my ( $dcref ) = @_; print "DCREF: $dcref\n"; $dbh->do( "update update_bug set status = 5 where k = ?", undef, substr( $dcref, -11 ) ); }
In the Query log of the 4.1.11 database we're connecting to, we see:
060526 14:24:52 4605 Connect testuser@chadwick on test 4605 Query SET AUTOCOMMIT=1 4605 Query drop table if exists update_bug 4605 Query create table update_bug( k int not null primary key, status int not null ) 4605 Query update update_bug set status = 5 where k = '30012345671' 4605 Query update update_bug set status = 5 where k = '30012345671' 4605 Query update update_bug set status = 5 where k = '30012345671' 4605 Query update update_bug set status = 5 where k = NULL 4605 Query update update_bug set status = 5 where k = NULL 4605 Query update update_bug set status = 5 where k = NULL 4605 Quit
The problem seems to be related to the fact that a substring expression is passed as an argument to DBI::do, but only when the DBI::do is called within a subroutine.
I'm stumped here. Is this a bug in Perl or DBD::MySQL, or just the versions on Sarge and Ubuntu ?
regards, Martin