| Subject: | Tk::IO broken under Windows, partial diagnosis, need help |
| Date: | Tue, 26 Jun 2018 13:41:28 -0400 |
| To: | bug-Tk [...] rt.cpan.org |
| From: | tlhackque <tlhackque [...] yahoo.com> |
Tk::IO does not work under windows.
The first issue is that the exec code starts with:
my $pid = open($fh,'-|');
As documented here: https://perldoc.perl.org/perlfork.html
this isn't supported under windows.
I applied the obvious work-around (actually, several variants):
my $wr;
pipe( $fh, $wr ) or die( "pipe: $!\n" );
my $pid = fork;
die( "fork $!" ) unless( defined $pid );
if ($pid)
{
close( $wr );
...
else
{
# make STDERR same as STDOUT here
setpgrp;
open( STDOUT, '>&=' . fileno( $wr ) ) or die( "Child open $!\n" );
exec(@_) || die 'Cannot exec ',join(' ',@_),":$!";
However, this wins:
panic: restartop
'Free to wrong pool 8a59d70 not dc8090 at C:/Perl64/site/lib/Tk.pm
line 251.
apparently from the child process.
This seems odd, since the exec should not run down Perl.
In fact, if the ONLY statement in the child is the exec, it still dies.
If I put a sleep before the exec, the crash happens after the timeout.
This indicates that it's not the setpgrp or the open of STDOUT in the
child that
triggers/detects the corruption, but something impacted by the exec.
I'm not enough of an XS person to debug further, but I would like this
to work.
Also, I tried exec'ing several programs; from echo to another Perl
program; nothing changes.
The real target is a perl script - but it knows nothing about tk.
This work done under Windows 10, Activestate Perl 5.26.1 (full -V follows).
Tk version 0804.034 Tk::IO 4.006.
Thanks in advance.
Here is my entire patched version (I simply overload the Tk::IO::exec
function:
package Tl::IO;
our @ISA = ( qw/Tk::IO/ );
sub exec
{
my $fh = shift;
# my $pid = open($fh,'-|');
my $wr;
pipe( $fh, $wr ) or die( "pipe: $!\n" );
my $pid = fork;
die( "fork $!" ) unless( defined $pid );
if ($pid)
{
close( $wr );
${*$fh} = '' unless (defined ${*$fh});
${*$fh}{'-exec'} = [@_];
${*$fh}{'-pid'} = $pid;
if (exists ${*$fh}{-linecommand})
{
my $w = ${*$fh}{-widget};
$w = 'Tk' unless (defined $w);
$w->fileevent($fh,'readable',[$fh,'readable']);
${*$fh}{_readable} = $w;
}
else
{
require Tk::Pretty;
croak Tk::Pretty::Pretty(\%{*$fh});
}
return $pid;
}
else
{
# make STDERR same as STDOUT here
setpgrp;
open( STDOUT, '>&=' . fileno( $wr ) ) or die( "Child open $!\n" );
sleep( 20 );
exec(@_) || die 'Cannot exec ',join(' ',@_),":$!";
}
}
Summary of my perl5 (revision 5 version 26 subversion 1) configuration:
Platform:
osname=MSWin32
osvers=6.1
archname=MSWin32-x64-multi-thread
uname=''
config_args='undef'
hint=recommended
useposix=true
d_sigaction=undef
useithreads=define
usemultiplicity=define
use64bitint=define
use64bitall=undef
uselongdouble=undef
usemymalloc=n
default_inc_excludes_dot=define
bincompat5005=undef
Compiler:
cc='C:\Perl64\site\bin\gcc.exe'
ccflags =' -s -O2 -DWIN32 -DWIN64 -DCONSERVATIVE
-DPERL_TEXTMODE_SCRIPTS -DUSE_SITECUSTOMIZE -DPERL_IMPLICIT_CONTEXT
-DPERL_IMPLICIT_SYS -fwrapv -fno-strict-aliasing -mms-bitfields'
optimize='-s -O2'
cppflags='-DWIN32'
ccversion=''
gccversion='4.6.3'
gccosandvers=''
intsize=4
longsize=4
ptrsize=8
doublesize=8
byteorder=12345678
doublekind=3
d_longlong=define
longlongsize=8
d_longdbl=define
longdblsize=16
longdblkind=3
ivtype='long long'
ivsize=8
nvtype='double'
nvsize=8
Off_t='long long'
lseeksize=8
alignbytes=8
prototype=define
Linker and Libraries:
ld='C:\Perl64\site\bin\g++.exe'
ldflags ='-s -static-libgcc -static-libstdc++ -L"C:\Perl64\lib\CORE"
-L"C:\MinGW\x86_64-w64-mingw32\lib"'
libpth=C:\MinGW\x86_64-w64-mingw32\lib
libs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32
-ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr
-lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
perllibs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool
-lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid
-lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
libc=
so=dll
useshrplib=true
libperl=libperl526.a
gnulibc_version=''
Dynamic Linking:
dlsrc=dl_win32.xs
dlext=dll
d_dlsymun=undef
ccdlflags=' '
cccdlflags=' '
lddlflags='-mdll -s -static-libgcc -static-libstdc++
-L"C:\Perl64\lib\CORE" -L"C:\MinGW\x86_64-w64-mingw32\lib"'
Characteristics of this binary (from libperl):
Compile-time options:
HAS_TIMES
HAVE_INTERP_INTERN
MULTIPLICITY
PERLIO_LAYERS
PERL_COPY_ON_WRITE
PERL_DONT_CREATE_GVSV
PERL_IMPLICIT_CONTEXT
PERL_IMPLICIT_SYS
PERL_MALLOC_WRAP
PERL_OP_PARENT
PERL_PRESERVE_IVUV
USE_64_BIT_INT
USE_ITHREADS
USE_LARGE_FILES
USE_LOCALE
USE_LOCALE_COLLATE
USE_LOCALE_CTYPE
USE_LOCALE_NUMERIC
USE_LOCALE_TIME
USE_PERLIO
USE_PERL_ATOF
USE_SITECUSTOMIZE
Locally applied patches:
ActivePerl Build 2601 [404865]
Built under MSWin32
Compiled at Dec 11 2017 12:23:25
@INC:
C:/Perl64/site/lib
C:/Perl64/lib