Red Hat Bugzilla – Bug 92195
Perl extension hangs on file I/O
Last modified: 2005-11-11 19:59:11 EST
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; .NET
Description of problem:
When working with files(opening, reading, seeking, closing) from within a Perl
C extension, the program will hang during one of the file operations, usually a
fseek. I haven't tested this on RedHat 8 yet, but previous versions of RedHat
prior to that all work with this code on perl v5.8.0. I have condensed the C
code and perl script to the bare minimum to reproduce the error. My
installation of RH9 is a complete install, all available packages are already
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. After unzipping the files, compile the C code using the following command:
gcc -O -c -I/usr/lib/perl5/5.8.0/i386-linux-thread-multi/CORE *.c
The path following -I is where your perl.h,EXTERN.h,and XSUB.h files should be
located by default. The CAtest_wrap.c file may give errors for crypt.h, if that
happens use this instead:
gcc -O -DGNU_SOURCE -c -I/usr/lib/perl5/5.8.0/i386-linux-thread-multi/CORE
2. Link the objects into CAtest.so using the command:
ld -G -o CAtest.so *.o
3. Run the perl script test_4CA.pl
Actual Results: Hangs after displaying "Ok after read".
Expected Results: The program should complete after the "Ok after read"
message and should return control of the shell to the user.
I have noticed that running the perl script with MALLOC_CHECK set seems to
alleviate the hanging, but using that isn't an option on the client end and
would probably degrade performance significantly. You can test this by typing
MALLOC_CHECK_=1 perl test_4CA.pl
Created attachment 92121 [details]
Test code to reproduce error
I just tested the same code on a clean install of RedHat 8.0 and it runs with
no problems, so this is definitely a version 9 issue.
Correction to step 1, -DGNU_SOURCE should actually be -D_GNU_SOURCE. Sorry for
Sorry this bug seems to have been overlooked.
This bug is not a problem with any current Red Hat perl releases.