[Monetdb-developers] memory problems (black smoke) from the [HEAD]

Jan Flokstra flokstra at cs.utwente.nl
Tue Jan 30 15:13:14 CET 2007


We (Henning and I) are currently experiencing some strange problems with the
HEAD of Pathfinder. It looks like there is a problem with memory management in
Pathfinder. On our 64 bit SuSe9.3 system crashes every time we do a second
query through the Mapi interface.

* start Mserver, run mil_start();
* then run through the MapiClient interface 2 times the query "1+1"
Now the Mserver crashes and gdb gives:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1107310944 (LWP 4579)]
0x00002aaaac67e3d2 in memcpy () from /lib64/tls/libc.so.6
(gdb) where
#0  0x00002aaaac67e3d2 in memcpy () from /lib64/tls/libc.so.6
#1  0x00002aaab6546150 in ?? ()
#2  0x00002aaab4c31c02 in mem_realloc (pa=<value optimized out>, p=0x0,
n=2048) at mem.c:133
#3  0x00002aaab4c31c4e in PFrealloc_ (n=<value optimized out>,
mem=<value optimized out>, file=0x2aaab4d1212c "array.c",
    func=0x2aaab4d120fc "PFarray_at", line=128) at mem.c:165
#4  0x00002aaab4c3130b in PFarray_at (a=0x2aaab6546970, i=1) at array.c:128
#5  0x00002aaab4c32d28 in PFqname (ns={prefix = 0x0, uri = 0x0},
loc=0x0) at qname.c:188
#6  0x00002aaab4b98730 in PFty_xs_anyAttribute () at types.c:675
#7  0x00002aaab4b99f81 in PFfun_xquery_fo () at xquery_fo.c:122
#8  0x00002aaab4b797a0 in PFcompile_MonetDB (xquery=0xff83b9 "1+1\n",
url=0xff83b9 "1+1\n", prologue=0x42002a08, query=0x42002960,
    epilogue=0x42002a18, options=<value optimized out>) at compile.c:730
#9  0x00002aaab4b76e22 in xquery_compile_exec (ctx=0x6227b8,
url=0xff83b9 "1+1\n", is_url=0, prologue=0x42002a08, query=0x42002a10,
    epilogue=0x42002a18, nsurl=0x0) at pathfinder.mx:3586
#10 0x00002aaab4b78207 in xquery_prepare (ctx=0x6227b8, usec=18557579,
query=0xff83b9 "1+1\n") at pathfinder.mx:4911
#11 0x00002aaab4b794ee in xquery_client_engine (fc=0x2aaab4fc1ad8) at
pathfinder.mx:5054
#12 0x00002aaab4ebf882 in mapi_client_engine (FC=<value optimized out>)
at mapi.mx:509
#13 0x00002aaaabfcd84f in start_thread () from /lib64/tls/libpthread.so.0
#14 0x00002aaaac6c6703 in clone () from /lib64/tls/libc.so.6
#15 0x0000000000000000 in ?? ()
#16 0x0000000000000000 in ?? ()
#17 0x0000000000000000 in ?? ()
#18 0x0000000000000000 in ?? ()
[ etc etc etc]

On my 32 bit SuSE 9.3 system it crashes already in the first query:

* start Mserver, run mil_start();

teehuis software/SCRIPTS> MapiClient -p 50123 -lx
xquery>1+1
more>MAPI  = monetdb at localhost:50123
QUERY = 1+1
ERROR = !tree matching: NULL pointer passed to PFnormalize_label
        !
        !# halted in normalize.brg (PFnormalize_label), line 3649
xquery>

Anybody any idea what changed lately. I heard that JanR was planning some 
changes in the memory allocator,

JanF.





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