Oh ok it makes sense now. Thank you for the heads up On 18 August 2015 at 15:36, Howard Chu <[email protected]> wrote:
> Simon Majou wrote: > >> This is version 0.9.16 >> >> I used sample-bdb.txt for instance, with the DUP_SORT option, and the >> mdb_put >> with the MDB_RESERVED flags, and execute it 2 times. The first run >> (creation) >> is ok, the second (update) gets the seg fault. >> > > DUPSORT and RESERVED are incompatible. RESERVED means you're not providing > a data value, only a length. DUPSORT sorts *values* - since you didn't > provide a valid value, it probably chased a pointer off into space. > > >> I ran it in gdb and got the stack : >> #0 mdb_cursor_set (mc=mc@entry=0x7fffffffdb40, key=key@entry >> =0x7fffffffdda0, >> data=data@entry=0x7fffffffd800, op=op@entry=MDB_SET, >> exactp=exactp@entry=0x7fffffffd7f0) at mdb.c:5867 >> #1 0x00007ffff7bd024c in mdb_cursor_put (mc=0x7fffffffdb40, >> key=0x7fffffffdda0, data=0x7fffffffd8f0, flags=32768) at mdb.c:6391 >> #2 0x00007ffff7bd095f in mdb_cursor_put (mc=0x7fffffffd9b0, >> key=0x7fffffffdd90, data=0x7fffffffdda0, flags=<optimized out>) >> at mdb.c:6780 >> #3 0x00007ffff7bd29b2 in mdb_put (txn=<optimized out>, dbi=<optimized >> out>, >> key=0x7fffffffdd90, data=0x7fffffffdda0, flags=65536) at mdb.c:8611 >> #4 0x0000000000400ccf in main (argc=1, argv=0x7fffffffded8) at >> sample-mdb.c:43 >> >> It seems the mp_lower value of the page is set to 0 instead of a value >> inside >> the page. >> >> On 18 August 2015 at 13:58, Howard Chu <[email protected] <mailto: >> [email protected]>> >> wrote: >> >> Simon Majou wrote: >> >> Hello, >> >> I wonder, why do I get a Segmentation fault when I use mdb_put >> with >> MDB_RESERVE on a key that already exists ? >> >> >> Have no idea. Provide some more details and maybe we can guess. >> >> LMDB version? stack trace from SEGV? What's the size of the existing >> record, what's the size of the new record? Show sample code that >> demonstrates the problem? >> >> -- >> -- Howard Chu >> CTO, Symas Corp. http://www.symas.com >> Director, Highland Sun http://highlandsun.com/hyc/ >> Chief Architect, OpenLDAP http://www.openldap.org/project/ >> >> >> >> >> -- >> >> Best regards, >> >> Simon >> > > > -- > -- Howard Chu > CTO, Symas Corp. http://www.symas.com > Director, Highland Sun http://highlandsun.com/hyc/ > Chief Architect, OpenLDAP http://www.openldap.org/project/ > -- Best regards, Simon
