| Subject: | Anomalous SEGV during destruction |
I've had a long running problem I've had a hard time isolating, and I'm triaging the little I have here in the event its useful.
And it only happens Multiple open transactions in multiple namespaces sharing the same ENV
If I tease them out into seperate ENVs, or if I create transactions only prior to making any changes ( ie: Opentxn, write, commit, continue .... instead of opentxn, ( do stuff ), closetxn at EXIT ) then the problem goes away, but both have reasonable performance penalties.
Unfortunately, I can't provide a concise test case that emulates this behaviour, only a very complicated stack of confusing parts that conspire to make the problem manifest:
If I modify that script to have
single_txn => 1,
And return %args unmodified from xnamespace, then the problem occurs every time the script terminates, wether it created new entries or simply ran read-only.
| Subject: | backtrace.txt |
Thread 1 (process 910291):
#0 0x00007fffecf0fee9 in mdb_txn_commit (txn=0x91) at mdb.c:2942
rc = <optimized out>
i = <optimized out>
env = <optimized out>
__FUNCTION__ = "mdb_txn_commit"
#1 0x00007fffecf0ff00 in mdb_txn_commit (txn=0x7b2fb60) at mdb.c:2946
rc = <optimized out>
i = <optimized out>
env = <optimized out>
__FUNCTION__ = "mdb_txn_commit"
#2 0x00007fffecf0ff00 in mdb_txn_commit (txn=0x1c4e530) at mdb.c:2946
rc = <optimized out>
i = <optimized out>
env = <optimized out>
__FUNCTION__ = "mdb_txn_commit"
#3 0x00007fffed11d654 in XS_LMDB__Txn__commit (cv=<optimized out>) at LMDB.c:1030
txn = <optimized out>
RETVAL = <optimized out>
targ = 0x1791308
sp = <optimized out>
ax = 1
mark = <optimized out>
items = <optimized out>
#4 0x00000000004c3827 in Perl_pp_entersub () at pp_hot.c:2784
markix = <optimized out>
sp = <optimized out>
sv = 0x17d0aa0
gv = 0x17912d8
cv = 0x17d0aa0
cx = <optimized out>
gimme = 1
hasargs = <optimized out>
#5 0x00000000004bce43 in Perl_runops_standard () at run.c:41
op = <optimized out>
#6 0x000000000043c92b in Perl_call_sv (sv=sv@entry=0x1782b28, flags=<optimized out>, flags@entry=45) at perl.c:2727
sp = <optimized out>
myop = {op_next = 0x0, op_sibling = 0x0, op_ppaddr = 0x0, op_targ = 0, op_type = 0, op_opt = 0, op_slabbed = 0, op_savefree = 0, op_static = 0,
op_folded = 0, op_lastsib = 0, op_spare = 0, op_flags = 65 'A', op_private = 0 '\000', op_first = 0x0, op_other = 0x7fffffffc780}
method_unop = {op_next = 0x7fffffffc890, op_sibling = 0x4b4abb <Perl_hv_common_key_len+43>, op_ppaddr = 0x0, op_targ = 0, op_type = 0, op_opt = 0,
op_slabbed = 0, op_savefree = 0, op_static = 0, op_folded = 0, op_lastsib = 0, op_spare = 0, op_flags = 0 '\000', op_private = 0 '\000',
op_first = 0x446122 <Perl_gv_fetchmeth_pvn+306>}
method_svop = {op_next = 0x7d3db8, op_sibling = 0x9, op_ppaddr = 0x58b662, op_targ = 0, op_type = 368, op_opt = 0, op_slabbed = 1, op_savefree = 1,
op_static = 0, op_folded = 1, op_lastsib = 0, op_spare = 0, op_flags = 185 '\271', op_private = 1 '\001', op_sv = 0x9}
oldmark = 0
retval = 0
oldscope = 6
oldcatch = false
ret = <optimized out>
oldop = 0x1b23b30
cur_env = {je_prev = 0x7fffffffcac0, je_buf = {{__jmpbuf = {140737488340864, 603917217558303656, 24652584, 0, 15569528, 24652584, 603917217218565032,
-603916680868654168}, __mask_was_saved = 0, __saved_mask = {__val = {8209552, 8, 5819933, 137438953504, 4294967296, 8209552, 8281856, 8282064, 0,
12498329130309844224, 8209552, 28681456, 7, 0, 5893883, 25146552}}}}, je_ret = 0, je_mustcatch = false}
#7 0x00000000004ce96a in S_curse (sv=sv@entry=0x1a69ba0, check_refcnt=check_refcnt@entry=true) at sv.c:6688
destructor = 0x1782b28
sp = <optimized out>
stash = 0x1782408
#8 0x00000000004cf2af in Perl_sv_clear (orig_sv=orig_sv@entry=0x1c205d8) at sv.c:6312
stash = <optimized out>
type = 7
sv_type_details = <optimized out>
iter_sv = 0x17fb3c8
next_sv = 0x0
sv = 0x1a69ba0
hash_index = 8
#9 0x00000000004cf662 in Perl_sv_free2 (sv=0x1c205d8, rc=<optimized out>) at sv.c:6789
No locals.
#10 0x00000000004f2e75 in S_SvREFCNT_dec_NN (sv=<optimized out>) at inline.h:134
rc = <optimized out>
#11 Perl_free_tmps () at scope.c:159
sv = <optimized out>
myfloor = -1
#12 0x00000000004bd075 in Perl_pp_nextstate () at pp_hot.c:52
No locals.
#13 0x00000000004bce43 in Perl_runops_standard () at run.c:41
op = <optimized out>
#14 0x000000000043c92b in Perl_call_sv (sv=sv@entry=0x1355f80, flags=<optimized out>, flags@entry=13) at perl.c:2727
sp = <optimized out>
myop = {op_next = 0x0, op_sibling = 0x0, op_ppaddr = 0x0, op_targ = 0, op_type = 0, op_opt = 0, op_slabbed = 0, op_savefree = 0, op_static = 0,
op_folded = 0, op_lastsib = 0, op_spare = 0, op_flags = 65 'A', op_private = 0 '\000', op_first = 0x0, op_other = 0x7fffffffca80}
method_unop = {op_next = 0x7fffffffcb70, op_sibling = 0x446122 <Perl_gv_fetchmeth_pvn+306>, op_ppaddr = 0x0, op_targ = 140733193388032, op_type = 304,
op_opt = 0, op_slabbed = 0, op_savefree = 1, op_static = 1, op_folded = 1, op_lastsib = 0, op_spare = 1, op_flags = 208 '\320', op_private = 0 '\000',
op_first = 0x40}
method_svop = {op_next = 0x1488278, op_sibling = 0xf, op_ppaddr = 0x200000000, op_targ = 11815455031309, op_type = 64, op_opt = 0, op_slabbed = 1,
op_savefree = 0, op_static = 1, op_folded = 1, op_lastsib = 1, op_spare = 1, op_flags = 42 '*', op_private = 1 '\001', op_sv = 0x8}
oldmark = 0
retval = 0
oldscope = 2
oldcatch = false
ret = <optimized out>
oldop = 0x0
cur_env = {je_prev = 0x7fffffffcc20, je_buf = {{__jmpbuf = {140737488341632, 603917217593955240, 20275072, 0, 30560752, 0, 603917217520554920,
-603916680868654168}, __mask_was_saved = 0, __saved_mask = {__val = {28674712, 23316960, 0, 4925082, 0, 12498329130309844224, 0, 0,
140733193388032, 8235024, 30287872, 30287944, 0, 4944424, 188685160, 0}}}}, je_ret = 0, je_mustcatch = false}
#15 0x000000000043e912 in Perl_call_list (oldscope=1, paramList=0xab1ec8) at perl.c:4825
atsv = <optimized out>
oldline = 0
cv = 0x1355f80
len = 28443200
ret = <optimized out>
cur_env = {je_prev = 0x7fffffffcd40, je_buf = {{__jmpbuf = {11214536, 603917217413600168, 4319508, 140737488342896, 0, 0, 603917217591858088,
-603916682310052952}, __mask_was_saved = 0, __saved_mask = {__val = {24390464, 0, 140737488342272, 5196359, 2, 0, 4308823400, 5001422, 0,
28649312, 30560768, 8220592, 30560752, 30560752, 30560752, 140737488342376}}}}, je_ret = 0, je_mustcatch = false}
#16 0x000000000043fef1 in perl_destruct (my_perl=<optimized out>) at perl.c:574
cur_env = {je_prev = 0x7d1200 <PL_start_env>, je_buf = {{__jmpbuf = {69, 603917217507972008, 4319508, 140737488342896, 0, 0, 603917217411503016,
-603916682534186072}, __mask_was_saved = 0, __saved_mask = {__val = {0, 4830937, 0, 0, 140737488342608, 0, 140737488342608, 4439136,
140737488342896, 4457444, 0, 4469852, 603917217507972008, 8589922168, 8196608, 0}}}}, je_ret = 0, je_mustcatch = false}
x = <optimized out>
destruct_level = 0 '\000'
hv = <optimized out>
i = <optimized out>
#17 0x000000000041e8d4 in main (argc=2, argv=0x7fffffffcf78, env=0x7fffffffcf90) at perlmain.c:125
exitstatus = <optimized out>
i = <optimized out>
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