dclerk Memory Corruption

Sun Sep 6 11:33:14 PDT 2020

Have you pinned down the point in the programming that triggers this 
error?  There are situations that can trigger faults.

1. Not enough Memory.  You can adjust the PFTOKSIZE, PFAUTOKSIZE, 
PFFORMTOKSIZE  to better allocate memory.

PFTOKSIZE   Default 20000
PFAUTOKSIZE  Default 20000
PFFORMTOKSIZE Default 15000

If you have programming that does not use Automatic processing or it is 
small, reduce the PFAUTOKSIZE to 10000.  Form tok applies to calls and 
forms that need to load processing.  If you use CALL command review the 
sizes of the processing to make sure it is not needing more room.

Planning the token sizes takes into account two things, in my 
experience.  1) how big the processing table is 2) how many variables 
and arrays are used.  The second one of these is the most difficult to 
guess but if you are using big arrays or lots of variables give yourself 
ample room for all that memory.  Define variable lengths whenever 
possible to make sure space is good.  I often set this to 100000 or more.

I will share a discovery I made on this.  I had a dummy variable called 
ab which was not defined.  It was printing on a form and was assigned 
different values on each form.  I kept crashing memory on this form, on 
a Unix computer which then writes a memory dump.  I looked at the dump 
and discovered values for this variable over and over.  What filepro 
does with an undefined variable is to grab new memory each time a value 
is assigned.  If you give the variable a defined length, then it assigns 
that variable to one place in memory and just updates it each time the 
value is changed.  So a small thing like an undefined variable can cause 
a memory issue.

Just my thoughts.  I am waiting for a process to run so I can get away 
from my computer, and it has so I am out of here.  I hope this helps.

Nancy

On 8/28/2020 1:44 PM, Seijyaku via Filepro-list wrote:
> I'm working on a server running dclerk version 5.0.14D4 that is occasionally showing the error below in some of the logs. Any input on what might be causing this or how to resolve it?
>
> \x07,
> *** Error in `dclerk': malloc(): memory corruption (fast): 0x08b0c2c8 ***,
> ======= Backtrace: =========,
> /lib/libc.so.6(+0x77dfc)[0xf7ddfdfc],
> /lib/libc.so.6(+0x7ae98)[0xf7de2e98],
> /lib/libc.so.6(__libc_malloc+0x9a)[0xf7de496a],
> dclerk[0x80b1e4e],
> dclerk[0x80b18e6],
> dclerk[0x80b15f1],
> dclerk[0x80b1e02],
> dclerk[0x80ae0af],
> dclerk[0x80af2f4],
> dclerk[0x80aec39],
> dclerk[0x80a95ad],
> [0xf7f8bec0],
> dclerk[0x80daa1d],
> dclerk[0x80daf33],
> dclerk[0x80d90d7],
> dclerk[0x80d301b],
> dclerk[0x80d66cd],
> dclerk[0x80d61ef],
> dclerk[0x80d6178],
> dclerk[0x8070610],
> dclerk[0x8061017],
> dclerk[0x805fbb2],
> dclerk[0x805e65f],
> dclerk[0x805e907],
> dclerk[0x8071bc2],
> dclerk[0x804f2e7],
> dclerk[0x804e230],
> /lib/libc.so.6(__libc_start_main+0xf3)[0xf7d822a3],
> ======= Memory map: ========,
> 08048000-080f2000 r-xp 00000000 08:02 1614140597 /opt/filepro/dclerk,
> 080f2000-08104000 rwxp 000aa000 08:02 1614140597 /opt/filepro/dclerk,
> 08104000-08113000 rwxp 00000000 00:00 0 ,
> 08aa0000-08b2a000 rwxp 00000000 00:00 0 [heap],
> f7b00000-f7b21000 rwxp 00000000 00:00 0 ,
> f7b21000-f7c00000 ---p 00000000 00:00 0 ,
> f7cae000-f7cc7000 r-xp 00000000 08:02 1611440773 /usr/lib/libgcc_s-4.8.5-20150702.so.1,
> f7cc7000-f7cc8000 r-xp 00018000 08:02 1611440773 /usr/lib/libgcc_s-4.8.5-20150702.so.1,
> f7cc8000-f7cc9000 rwxp 00019000 08:02 1611440773 /usr/lib/libgcc_s-4.8.5-20150702.so.1,
> f7cd5000-f7d43000 rwxp 00000000 00:00 0 ,
> f7d43000-f7d53000 rwxs 00000000 00:01 2 /SYSVf102e0ed (deleted),
> f7d53000-f7d5e000 r-xp 00000000 08:02 1611347286 /usr/lib/libnss_files-2.17.so,
> f7d5e000-f7d5f000 r-xp 0000a000 08:02 1611347286 /usr/lib/libnss_files-2.17.so,
> f7d5f000-f7d60000 rwxp 0000b000 08:02 1611347286 /usr/lib/libnss_files-2.17.so,
> f7d60000-f7d68000 rwxp 00000000 00:00 0 ,
> f7d68000-f7f2c000 r-xp 00000000 08:02 1611317456 /usr/lib/libc-2.17.so,
> f7f2c000-f7f2d000 ---p 001c4000 08:02 1611317456 /usr/lib/libc-2.17.so,
> f7f2d000-f7f2f000 r-xp 001c4000 08:02 1611317456 /usr/lib/libc-2.17.so,
> f7f2f000-f7f30000 rwxp 001c6000 08:02 1611317456 /usr/lib/libc-2.17.so,
> f7f30000-f7f33000 rwxp 00000000 00:00 0 ,
> f7f33000-f7f73000 r-xp 00000000 08:02 1611317464 /usr/lib/libm-2.17.so,
> f7f73000-f7f74000 r-xp 0003f000 08:02 1611317464 /usr/lib/libm-2.17.so,
> f7f74000-f7f75000 rwxp 00040000 08:02 1611317464 /usr/lib/libm-2.17.so,
> f7f75000-f7f78000 r-xp 00000000 08:02 1610785783 /usr/lib/libtermcap.so.2.0.8,
> f7f78000-f7f79000 r-xp 00002000 08:02 1610785783 /usr/lib/libtermcap.so.2.0.8,
> f7f79000-f7f7a000 rwxp 00003000 08:02 1610785783 /usr/lib/libtermcap.so.2.0.8,
> f7f85000-f7f87000 rwxp 00000000 00:00 0 ,
> f7f87000-f7f8b000 r--p 00000000 00:00 0 [vvar],
> f7f8b000-f7f8d000 r-xp 00000000 00:00 0 [vdso],
> f7f8d000-f7faf000 r-xp 00000000 08:02 1610615685 /usr/lib/ld-2.17.so,
> f7faf000-f7fb0000 r-xp 00021000 08:02 1610615685 /usr/lib/ld-2.17.so,
> f7fb0000-f7fb1000 rwxp 00022000 08:02 1610615685 /usr/lib/ld-2.17.so,
> ffa8e000-ffab0000 rwxp 00000000 00:00 0 [stack],
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-- 
Nancy Palmquist         MOS & filePro Training Available
Virtual Software Systems    Web Based Training and Consulting
PHONE: (412) 835-9417           Web site:  http://www.vss3.com

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