Bug #4123: thread-safe problem in libxml_ruby.so

• Status: Third Party's Issue
• Assignee: -
• Target version: 1.9.2
• ruby -v: 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]

[tracy_trend (tracy qin)]

=begin
Hi,

We set up a rails webservice app using libxml_ruby.so, Hash.from_xml funtion.
This Webserive server works as one process and start new thread to handle each request. But crash always happens at the second call.

rails reported stacktrace as below: (also attached as "libxml_AbortStacktrace.txt"

-- Ruby level backtrace information ----------------------------------------
/usr/local/lib/ruby/1.9.1/webrick/server.rb:183:in block in start_thread' /usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:70:in run'
/usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:111:in service' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/handler/webrick.rb:50:in service'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/content_length.rb:13:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.4/lib/rails/rack/log_tailer.rb:17:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in each'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in block in call' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.4/lib/rails/rack/static.rb:31:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:108:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/reloader.rb:34:in run'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:114:in block in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/lock.rb:11:in call'
internal:prelude:10:in synchronize' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/lock.rb:11:in block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/failsafe.rb:26:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/session/cookie_store.rb:93:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/params_parser.rb:15:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/head.rb:9:in call' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:28:in call' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:9:in cache'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in cache' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:29:in block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:29:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:130:in block in build_middleware_stack'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:121:in _call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:87:in dispatch'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:436:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:443:in recognize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/core_ext/string/inflections.rb:162:in constantize' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:371:in constantize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:371:in each' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:372:in block in constantize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:372:in const_get' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:80:in const_missing_with_dependencies'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:425:in load_missing_constant' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:379:in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in new_constants_in'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in block in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in load'
/var/webapps/ws_ui/app/controllers/v20/stats_controller.rb:1:in <top (required)>' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:96:in const_missing'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:425:in load_missing_constant' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:379:in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in new_constants_in'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in block in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in load'
/var/webapps/ws_ui/app/controllers/application_controller.rb:7:in <top (required)>' /var/webapps/ws_ui/app/controllers/application_controller.rb:9:in class:ApplicationController'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in helper' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in each'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:120:in block in helper' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in helper'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in each' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:126:in block in helper'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:136:in require_dependency' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:224:in depend_on'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:373:in load_file'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:312:in loadable_constants_for_path' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:312:in collect'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:313:in block in loadable_constants_for_path' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:313:in expand_path'

-- C level backtrace information -------------------------------------------
ruby(rb_vm_bugreport+0x68) [0x52bc38]
ruby [0x566a01]
ruby(rb_bug+0xee) [0x566b09]
ruby [0x4b3850]
/lib64/libpthread.so.0 [0x2af6da3fab10]
/lib64/libc.so.6 [0x2af6daf40485]
/lib64/libc.so.6 [0x2af6daf42a6c]
/lib64/libc.so.6(__libc_malloc+0x6e) [0x2af6daf44cde]
ruby [0x41e4ae]
ruby(ruby_xmalloc2+0x64) [0x41e68d]
ruby [0x4c005d]
ruby(rb_str_new+0x24) [0x4c02b8]
ruby(rb_usascii_str_new+0x1d) [0x4c02d7]
ruby(rb_file_expand_path+0x40) [0x5702c7]
ruby(rb_file_s_expand_path+0x26) [0x570304]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby [0x540018]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby(rb_iseq_eval+0x2d) [0x529391]
ruby [0x56ad05]
ruby [0x56af4a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x522aaf]
ruby [0x523d7f]
ruby [0x523cd5]
ruby(rb_funcall+0x201) [0x523f8a]
ruby [0x4fb60e]
ruby [0x4fbe1f]
ruby(rb_const_get+0x27) [0x4fbe8d]
ruby [0x51e650]
ruby [0x517741]
ruby [0x5289a5]
ruby(rb_iseq_eval+0x2d) [0x529391]
ruby [0x56ad05]
ruby [0x56af4a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x522aaf]
ruby [0x523d7f]
ruby [0x523cd5]
ruby(rb_funcall+0x201) [0x523f8a]
ruby [0x4fb60e]
ruby [0x4fbe1f]
ruby(rb_const_get_at+0x27) [0x4fbeb6]
ruby [0x44cb0a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby(rb_vm_invoke_proc+0xfd) [0x5277c5]
ruby [0x41afa1]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby(rb_vm_invoke_proc+0xfd) [0x5277c5]
ruby [0x52cfef]
ruby [0x52c16b]
/lib64/libpthread.so.0 [0x2af6da3f273d]
/lib64/libc.so.6(clone+0x6d) [0x2af6dafa3d1d]

[NOTE]
You may have encountered a bug in the Ruby interpreter or extension libraries.
Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html

Aborted (core dumped)

Then we recompile ruby in debug mode and accquire below calldump. (also attached as libxml_coredump.txt)

===============
#0 0x00002b7acf490265 in raise () from /lib64/libc.so.6
#1 0x00002b7acf491d10 in abort () from /lib64/libc.so.6
#2 0x0000000000566b0e in rb_bug (fmt=0x5a70ff "Segmentation fault") at error.c:253
#3 0x00000000004b3850 in sigsegv (sig=11, info=0x1243afd0, ctx=0x1243aea0) at signal.c:613
#4
#5 0x00002b7acf4d1d26 in _int_free () from /lib64/libc.so.6
#6 0x00002b7acf4d276b in free () from /lib64/libc.so.6
#7 0x000000000041e602 in vm_xfree (objspace=0xf6f7b70, ptr=0x11f91c60) at gc.c:732
#8 0x000000000041e78b in ruby_xfree (x=0x11f91c60) at gc.c:780
#9 0x00000000004dfe5c in time_free (tobj=0x11f91c60) at time.c:1806
#10 0x000000000042232f in run_final (objspace=0xf6f7b70, obj=283873120) at gc.c:2605
#11 0x00000000004204a5 in finalize_list (objspace=0xf6f7b70, p=0x10eb8f60) at gc.c:1808
#12 0x00000000004223a4 in finalize_deferred (objspace=0xf6f7b70) at gc.c:2621
#13 0x00000000004223bb in gc_finalize_deferred (objspace=0xf6f7b70) at gc.c:2628
#14 0x00000000004223dd in rb_gc_finalize_deferred () at gc.c:2635
#15 0x000000000052e73e in rb_threadptr_execute_interrupts_rec (th=0x11b3c230, sched_depth=0) at thread.c:1295
#16 0x000000000052e837 in rb_threadptr_execute_interrupts (th=0x11b3c230) at thread.c:1323
#17 0x000000000051f44f in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c4e8, num=1, blockptr=0x0, flag=0, id=7072, me=0xf7d2b60, recv=259309440)
at vm_insnhelper.c:669
#18 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#19 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#20 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088c618, self=265666400, argc=1, argv=0x40ccabc8, blockptr=0x0, cref=0x0)
at vm.c:557
#21 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccabc8) at vm.c:587
#22 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccabc8) at vm_eval.c:731
#23 0x0000000000524153 in rb_yield (val=264390920) at vm_eval.c:741
#24 0x0000000000540018 in rb_ary_collect (ary=272006520) at array.c:2166
#25 0x000000000051f998 in call_cfunc (func=0x53ff4d <rb_ary_collect>, recv=272006520, len=0, argc=0, argv=0x2aaab078ec18) at vm_insnhelper.c:317
#26 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088c5f0, num=0, recv=272006520, blockptr=0x2aaab088c618, me=0xf7aeb30)
at vm_insnhelper.c:401
#27 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c5f0, num=0, blockptr=0x2aaab088c618, flag=0, id=1536, me=0xf7aeb30, recv=272006520)
at vm_insnhelper.c:523
#28 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#29 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#30 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088c8d8, self=271841760, argc=1, argv=0x40ccbd48, blockptr=0x0, cref=0x0)
at vm.c:557
#31 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccbd48) at vm.c:587
#32 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccbd48) at vm_eval.c:731
#33 0x0000000000524153 in rb_yield (val=263084440) at vm_eval.c:741
#34 0x000000000053d736 in rb_ary_each (ary=263072400) at array.c:1427
#35 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=263072400, len=0, argc=0, argv=0x2aaab078eab0) at vm_insnhelper.c:317
#36 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088c8b0, num=0, recv=263072400, blockptr=0x2aaab088c8d8, me=0xf7addc0)
at vm_insnhelper.c:401
#37 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c8b0, num=0, blockptr=0x2aaab088c8d8, flag=0, id=424, me=0xf7addc0, recv=263072400)
at vm_insnhelper.c:523
#38 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#39 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#40 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088ca38, self=271841760, argc=1, argv=0x40ccceb8, blockptr=0x0, cref=0x0)
at vm.c:557
#41 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccceb8) at vm.c:587
#42 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccceb8) at vm_eval.c:731
#43 0x0000000000524153 in rb_yield (val=3956750) at vm_eval.c:741
#44 0x000000000053d736 in rb_ary_each (ary=263093600) at array.c:1427
#45 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=263093600, len=0, argc=0, argv=0x2aaab078ea20) at vm_insnhelper.c:317
#46 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088ca10, num=0, recv=263093600, blockptr=0x2aaab088ca38, me=0xf7addc0)
at vm_insnhelper.c:401
#47 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088ca10, num=0, blockptr=0x2aaab088ca38, flag=0, id=424, me=0xf7addc0, recv=263093600)
at vm_insnhelper.c:523
#48 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#49 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#50 0x0000000000529391 in rb_iseq_eval (iseqval=272926200) at vm.c:1372
#51 0x000000000056ad05 in rb_load_internal (fname=280717600, wrap=0) at load.c:302
#52 0x000000000056af4a in rb_f_load (argc=1, argv=0x2aaab078e9a8) at load.c:375
#53 0x000000000051f980 in call_cfunc (func=0x56ae8b <rb_f_load>, recv=265666400, len=-1, argc=1, argv=0x2aaab078e9a8) at vm_insnhelper.c:314
#54 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088cbc8, num=1, recv=265666400, blockptr=0x0, me=0xfd96140) at vm_insnhelper.c:401
#55 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088cbc8, num=1, blockptr=0x0, flag=8, id=34488, me=0xfd96140, recv=265666400)
at vm_insnhelper.c:523
#56 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#57 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#58 0x0000000000522aaf in vm_call0 (th=0x11b3c230, recv=259360280, id=1144, argc=1, argv=0x40ccf2a0, me=0xfc62580) at vm_eval.c:66
#59 0x0000000000523d7f in rb_call0 (recv=259360280, mid=1144, argc=1, argv=0x40ccf2a0, scope=CALL_FCALL, self=6) at vm_eval.c:235
#60 0x0000000000523cd5 in rb_call (recv=259360280, mid=1144, argc=1, argv=0x40ccf2a0, scope=CALL_FCALL) at vm_eval.c:438
#61 0x0000000000523f8a in rb_funcall (recv=259360280, mid=1144, n=1) at vm_eval.c:637
#62 0x00000000004fb60e in const_missing (klass=259360280, id=88005) at variable.c:1360
#63 0x00000000004fbe1f in rb_const_get_0 (klass=259360280, id=88005, exclude=0, recurse=1) at variable.c:1600
#64 0x00000000004fbe8d in rb_const_get (klass=259360280, id=88005) at variable.c:1614
#65 0x000000000051e650 in vm_get_ev_const (th=0x11b3c230, iseq=0x12601510, orig_klass=4, id=88005, is_defined=0) at vm_insnhelper.c:1196
#66 0x0000000000517741 in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:223
#67 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#68 0x0000000000529391 in rb_iseq_eval (iseqval=281036160) at vm.c:1372
#69 0x000000000056ad05 in rb_load_internal (fname=282078760, wrap=0) at load.c:302
#70 0x000000000056af4a in rb_f_load (argc=1, argv=0x2aaab078e7e8) at load.c:375
#71 0x000000000051f980 in call_cfunc (func=0x56ae8b <rb_f_load>, recv=265666400, len=-1, argc=1, argv=0x2aaab078e7e8) at vm_insnhelper.c:314
#72 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088cf38, num=1, recv=265666400, blockptr=0x0, me=0xfd96140) at vm_insnhelper.c:401
#73 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088cf38, num=1, blockptr=0x0, flag=8, id=34488, me=0xfd96140, recv=265666400)
at vm_insnhelper.c:523
#74 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#75 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#76 0x0000000000522aaf in vm_call0 (th=0x11b3c230, recv=282348640, id=1144, argc=1, argv=0x40cd1630, me=0x100a4d00) at vm_eval.c:66
#77 0x0000000000523d7f in rb_call0 (recv=282348640, mid=1144, argc=1, argv=0x40cd1630, scope=CALL_FCALL, self=6) at vm_eval.c:235
#78 0x0000000000523cd5 in rb_call (recv=282348640, mid=1144, argc=1, argv=0x40cd1630, scope=CALL_FCALL) at vm_eval.c:438
#79 0x0000000000523f8a in rb_funcall (recv=282348640, mid=1144, n=1) at vm_eval.c:637
#80 0x00000000004fb60e in const_missing (klass=282348640, id=124773) at variable.c:1360
#81 0x00000000004fbe1f in rb_const_get_0 (klass=282348640, id=124773, exclude=1, recurse=0) at variable.c:1600
#82 0x00000000004fbeb6 in rb_const_get_at (klass=282348640, id=124773) at variable.c:1620
#83 0x000000000044cb0a in rb_mod_const_get (argc=2, argv=0x2aaab078e660, mod=282348640) at object.c:1695
#84 0x000000000051f980 in call_cfunc (func=0x44ca55 <rb_mod_const_get>, recv=282348640, len=-1, argc=2, argv=0x2aaab078e660) at vm_insnhelper.c:314
#85 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d1f8, num=2, recv=282348640, blockptr=0x0, me=0xf767b70) at vm_insnhelper.c:401
#86 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d1f8, num=2, blockptr=0x0, flag=0, id=1112, me=0xf767b70, recv=282348640)
at vm_insnhelper.c:523
#87 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#88 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#89 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088d328, self=261961800, argc=1, argv=0x40cd2998, blockptr=0x0, cref=0x0)
at vm.c:557
#90 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40cd2998) at vm.c:587
#91 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40cd2998) at vm_eval.c:731
#92 0x0000000000524153 in rb_yield (val=282361960) at vm_eval.c:741
#93 0x000000000053d736 in rb_ary_each (ary=282362240) at array.c:1427
#94 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=282362240, len=0, argc=0, argv=0x2aaab078e620) at vm_insnhelper.c:317
#95 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d300, num=0, recv=282362240, blockptr=0x2aaab088d328, me=0xf7addc0)
at vm_insnhelper.c:401
#96 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d300, num=0, blockptr=0x2aaab088d328, flag=0, id=424, me=0xf7addc0, recv=282362240)
at vm_insnhelper.c:523
#97 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#98 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#99 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x127510b0, self=291970880, argc=1, argv=0x2aaab078e4f0, blockptr=0x0, cref=0x0)
at vm.c:557
#100 0x00000000005277c5 in rb_vm_invoke_proc (th=0x11b3c230, proc=0x127510b0, self=291970880, argc=1, argv=0x2aaab078e4f0, blockptr=0x0) at vm.c:603
---Type to continue, or q to quit---
#101 0x000000000041afa1 in proc_call (argc=1, argv=0x2aaab078e4f0, procval=282451640) at proc.c:556
#102 0x000000000051f980 in call_cfunc (func=0x41aefc <proc_call>, recv=282451640, len=-1, argc=1, argv=0x2aaab078e4f0) at vm_insnhelper.c:314
#103 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d618, num=1, recv=282451640, blockptr=0x0, me=0xf7f0f00) at vm_insnhelper.c:401
#104 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d618, num=1, blockptr=0x0, flag=0, id=5912, me=0xf7f0f00, recv=282451640)
at vm_insnhelper.c:523
#105 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#106 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#107 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088dd20, self=295023880, argc=1, argv=0x40cd4d68, blockptr=0x0, cref=0x0)
at vm.c:557
#108 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40cd4d68) at vm.c:587
#109 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40cd4d68) at vm_eval.c:731
#110 0x0000000000524153 in rb_yield (val=295023400) at vm_eval.c:741
#111 0x000000000053d736 in rb_ary_each (ary=295023360) at array.c:1427
#112 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=295023360, len=0, argc=0, argv=0x2aaab078e218) at vm_insnhelper.c:317
#113 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088dcf8, num=0, recv=295023360, blockptr=0x2aaab088dd20, me=0xf7addc0)
at vm_insnhelper.c:401
#114 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088dcf8, num=0, blockptr=0x2aaab088dd20, flag=0, id=424, me=0xf7addc0, recv=295023360)
at vm_insnhelper.c:523
#115 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#116 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#117 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x119b71e0, self=294980880, argc=0, argv=0x10db1988, blockptr=0x0, cref=0x0)
at vm.c:557
#118 0x00000000005277c5 in rb_vm_invoke_proc (th=0x11b3c230, proc=0x119b71e0, self=294980880, argc=0, argv=0x10db1988, blockptr=0x0) at vm.c:603
#119 0x000000000052cfef in thread_start_func_2 (th=0x11b3c230, stack_start=0x40cd6120) at thread.c:441
#120 0x000000000052c16b in thread_start_func_1 (th_ptr=0x11b3c230) at thread_pthread.c:369
#121 0x00002b7ace98273d in start_thread () from /lib64/libpthread.so.0
#122 0x00002b7acf533d1d in clone () from /lib64/libc.so.6

Since we doubt it seems to be a thread safe problem with libxml_ruby.so , a simple test script is used (attached as testthreadxml.rb), and it seems it runs very unstable. sometimes, it throw below exception.

================
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/xml_mini.rb:15:in rescue in parse': parse delegated to backend.parse, but backend is nil: ActiveSupport::XmlMini (RuntimeError) from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/xml_mini.rb:12:in parse'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/core_ext/hash/conversions.rb:164:in from_xml' from testthreadxml.rb:12:in block in '

===============
problem never happen in ruby1.8.6 though.

would you help on such issue? thank you!
=end

[tracy_trend (tracy qin)]

=begin
HI,

Just make a further test based on the testthreadxml.rb.

Change file

/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/xml_mini.rb

From
XmlMini.backend = 'REXML'

To:
XmlMini.backend = 'LibXML'

Run testthreadxml.rb twice, crash would happen and same coredump can be seen.

Libxml version:
libxml-ruby (1.1.4)

Best wishes,
-Tracy

-----Original Message-----
From: tracy qin [mailto:[e-mail]]
Sent: 2010年12月6日 16:26
To: [e-mail]
Subject: [Ruby 1.9-Bug#4123][Open] thread-safe problem in libxml_ruby.so

Bug #4123: thread-safe problem in libxml_ruby.so
http://redmine.ruby-lang.org/issues/show/4123

Author: tracy qin
Status: Open, Priority: Normal
Category: lib, Target version: 1.9.2
ruby -v: 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]

Hi,

We set up a rails webservice app using libxml_ruby.so, Hash.from_xml funtion.
This Webserive server works as one process and start new thread to handle each request. But crash always happens at the second call.

rails reported stacktrace as below: (also attached as "libxml_AbortStacktrace.txt"

-- Ruby level backtrace information ----------------------------------------
/usr/local/lib/ruby/1.9.1/webrick/server.rb:183:in block in start_thread' /usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:70:in run'
/usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:111:in service' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/handler/webrick.rb:50:in service'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/content_length.rb:13:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.4/lib/rails/rack/log_tailer.rb:17:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in each'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in block in call' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.4/lib/rails/rack/static.rb:31:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:108:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/reloader.rb:34:in run'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:114:in block in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/lock.rb:11:in call'
internal:prelude:10:in synchronize' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/lock.rb:11:in block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/failsafe.rb:26:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/session/cookie_store.rb:93:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/params_parser.rb:15:in call' /usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.0.1/lib/rack/head.rb:9:in call' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in call'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:28:in call' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:9:in cache'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in cache' /usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:29:in block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/activerecord-2.3.4/lib/active_record/query_cache.rb:29:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:130:in block in build_middleware_stack'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:121:in _call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/dispatcher.rb:87:in dispatch'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:436:in call' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:443:in recognize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/core_ext/string/inflections.rb:162:in constantize' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:371:in constantize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:371:in each' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:372:in block in constantize'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/inflector.rb:372:in const_get' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:80:in const_missing_with_dependencies'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:425:in load_missing_constant' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:379:in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in new_constants_in'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in block in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in load'
/var/webapps/ws_ui/app/controllers/v20/stats_controller.rb:1:in <top (required)>' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:96:in const_missing'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:425:in load_missing_constant' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:379:in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in new_constants_in'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in block in load_file' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:380:in load'
/var/webapps/ws_ui/app/controllers/application_controller.rb:7:in <top (required)>' /var/webapps/ws_ui/app/controllers/application_controller.rb:9:in class:ApplicationController'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in helper' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in each'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:120:in block in helper' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in helper'
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:115:in each' /usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.4/lib/action_controller/helpers.rb:126:in block in helper'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:136:in require_dependency' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:224:in depend_on'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:259:in require_or_load' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:373:in load_file'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:312:in loadable_constants_for_path' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:312:in collect'
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:313:in block in loadable_constants_for_path' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:313:in expand_path'

-- C level backtrace information -------------------------------------------
ruby(rb_vm_bugreport+0x68) [0x52bc38]
ruby [0x566a01]
ruby(rb_bug+0xee) [0x566b09]
ruby [0x4b3850]
/lib64/libpthread.so.0 [0x2af6da3fab10]
/lib64/libc.so.6 [0x2af6daf40485]
/lib64/libc.so.6 [0x2af6daf42a6c]
/lib64/libc.so.6(__libc_malloc+0x6e) [0x2af6daf44cde] ruby [0x41e4ae]
ruby(ruby_xmalloc2+0x64) [0x41e68d]
ruby [0x4c005d]
ruby(rb_str_new+0x24) [0x4c02b8]
ruby(rb_usascii_str_new+0x1d) [0x4c02d7]
ruby(rb_file_expand_path+0x40) [0x5702c7]
ruby(rb_file_s_expand_path+0x26) [0x570304] ruby [0x51f980] ruby [0x51f853] ruby [0x51ec2b] ruby [0x519abd] ruby [0x5289a5] ruby [0x52763f] ruby [0x5276c6] ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby [0x540018]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby(rb_iseq_eval+0x2d) [0x529391]
ruby [0x56ad05]
ruby [0x56af4a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x522aaf]
ruby [0x523d7f]
ruby [0x523cd5]
ruby(rb_funcall+0x201) [0x523f8a]
ruby [0x4fb60e]
ruby [0x4fbe1f]
ruby(rb_const_get+0x27) [0x4fbe8d]
ruby [0x51e650]
ruby [0x517741]
ruby [0x5289a5]
ruby(rb_iseq_eval+0x2d) [0x529391]
ruby [0x56ad05]
ruby [0x56af4a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x522aaf]
ruby [0x523d7f]
ruby [0x523cd5]
ruby(rb_funcall+0x201) [0x523f8a]
ruby [0x4fb60e]
ruby [0x4fbe1f]
ruby(rb_const_get_at+0x27) [0x4fbeb6]
ruby [0x44cb0a]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby(rb_vm_invoke_proc+0xfd) [0x5277c5]
ruby [0x41afa1]
ruby [0x51f980]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby [0x5276c6]
ruby [0x52417f]
ruby(rb_yield+0x39) [0x524153]
ruby(rb_ary_each+0x8a) [0x53d736]
ruby [0x51f998]
ruby [0x51f853]
ruby [0x51ec2b]
ruby [0x519abd]
ruby [0x5289a5]
ruby [0x52763f]
ruby(rb_vm_invoke_proc+0xfd) [0x5277c5]
ruby [0x52cfef]
ruby [0x52c16b]
/lib64/libpthread.so.0 [0x2af6da3f273d]
/lib64/libc.so.6(clone+0x6d) [0x2af6dafa3d1d]

[NOTE]
You may have encountered a bug in the Ruby interpreter or extension libraries.
Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html

Aborted (core dumped)

Then we recompile ruby in debug mode and accquire below calldump. (also attached as libxml_coredump.txt)

===============
#0 0x00002b7acf490265 in raise () from /lib64/libc.so.6
#1 0x00002b7acf491d10 in abort () from /lib64/libc.so.6
#2 0x0000000000566b0e in rb_bug (fmt=0x5a70ff "Segmentation fault") at error.c:253
#3 0x00000000004b3850 in sigsegv (sig=11, info=0x1243afd0, ctx=0x1243aea0) at signal.c:613
#4
#5 0x00002b7acf4d1d26 in _int_free () from /lib64/libc.so.6
#6 0x00002b7acf4d276b in free () from /lib64/libc.so.6
#7 0x000000000041e602 in vm_xfree (objspace=0xf6f7b70, ptr=0x11f91c60) at gc.c:732
#8 0x000000000041e78b in ruby_xfree (x=0x11f91c60) at gc.c:780
#9 0x00000000004dfe5c in time_free (tobj=0x11f91c60) at time.c:1806 #10 0x000000000042232f in run_final (objspace=0xf6f7b70, obj=283873120) at gc.c:2605
#11 0x00000000004204a5 in finalize_list (objspace=0xf6f7b70, p=0x10eb8f60) at gc.c:1808
#12 0x00000000004223a4 in finalize_deferred (objspace=0xf6f7b70) at gc.c:2621
#13 0x00000000004223bb in gc_finalize_deferred (objspace=0xf6f7b70) at gc.c:2628
#14 0x00000000004223dd in rb_gc_finalize_deferred () at gc.c:2635
#15 0x000000000052e73e in rb_threadptr_execute_interrupts_rec (th=0x11b3c230, sched_depth=0) at thread.c:1295
#16 0x000000000052e837 in rb_threadptr_execute_interrupts (th=0x11b3c230) at thread.c:1323
#17 0x000000000051f44f in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c4e8, num=1, blockptr=0x0, flag=0, id=7072, me=0xf7d2b60, recv=259309440)
at vm_insnhelper.c:669
#18 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#19 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145 #20 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088c618, self=265666400, argc=1, argv=0x40ccabc8, blockptr=0x0, cref=0x0)
at vm.c:557
#21 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccabc8) at vm.c:587
#22 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccabc8) at vm_eval.c:731
#23 0x0000000000524153 in rb_yield (val=264390920) at vm_eval.c:741
#24 0x0000000000540018 in rb_ary_collect (ary=272006520) at array.c:2166
#25 0x000000000051f998 in call_cfunc (func=0x53ff4d <rb_ary_collect>, recv=272006520, len=0, argc=0, argv=0x2aaab078ec18) at vm_insnhelper.c:317
#26 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088c5f0, num=0, recv=272006520, blockptr=0x2aaab088c618, me=0xf7aeb30)
at vm_insnhelper.c:401
#27 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c5f0, num=0, blockptr=0x2aaab088c618, flag=0, id=1536, me=0xf7aeb30, recv=272006520)
at vm_insnhelper.c:523
#28 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#29 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145 #30 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088c8d8, self=271841760, argc=1, argv=0x40ccbd48, blockptr=0x0, cref=0x0)
at vm.c:557
#31 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccbd48) at vm.c:587
#32 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccbd48) at vm_eval.c:731
#33 0x0000000000524153 in rb_yield (val=263084440) at vm_eval.c:741
#34 0x000000000053d736 in rb_ary_each (ary=263072400) at array.c:1427
#35 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=263072400, len=0, argc=0, argv=0x2aaab078eab0) at vm_insnhelper.c:317
#36 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088c8b0, num=0, recv=263072400, blockptr=0x2aaab088c8d8, me=0xf7addc0)
at vm_insnhelper.c:401
#37 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088c8b0, num=0, blockptr=0x2aaab088c8d8, flag=0, id=424, me=0xf7addc0, recv=263072400)
at vm_insnhelper.c:523
#38 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#39 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145 #40 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088ca38, self=271841760, argc=1, argv=0x40ccceb8, blockptr=0x0, cref=0x0)
at vm.c:557
#41 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40ccceb8) at vm.c:587
#42 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40ccceb8) at vm_eval.c:731
#43 0x0000000000524153 in rb_yield (val=3956750) at vm_eval.c:741
#44 0x000000000053d736 in rb_ary_each (ary=263093600) at array.c:1427
#45 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=263093600, len=0, argc=0, argv=0x2aaab078ea20) at vm_insnhelper.c:317
#46 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088ca10, num=0, recv=263093600, blockptr=0x2aaab088ca38, me=0xf7addc0)
at vm_insnhelper.c:401
#47 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088ca10, num=0, blockptr=0x2aaab088ca38, flag=0, id=424, me=0xf7addc0, recv=263093600)
at vm_insnhelper.c:523
#48 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#49 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145 #50 0x0000000000529391 in rb_iseq_eval (iseqval=272926200) at vm.c:1372
#51 0x000000000056ad05 in rb_load_internal (fname=280717600, wrap=0) at load.c:302
#52 0x000000000056af4a in rb_f_load (argc=1, argv=0x2aaab078e9a8) at load.c:375
#53 0x000000000051f980 in call_cfunc (func=0x56ae8b <rb_f_load>, recv=265666400, len=-1, argc=1, argv=0x2aaab078e9a8) at vm_insnhelper.c:314
#54 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088cbc8, num=1, recv=265666400, blockptr=0x0, me=0xfd96140) at vm_insnhelper.c:401
#55 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088cbc8, num=1, blockptr=0x0, flag=8, id=34488, me=0xfd96140, recv=265666400)
at vm_insnhelper.c:523
#56 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#57 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#58 0x0000000000522aaf in vm_call0 (th=0x11b3c230, recv=259360280, id=1144, argc=1, argv=0x40ccf2a0, me=0xfc62580) at vm_eval.c:66
#59 0x0000000000523d7f in rb_call0 (recv=259360280, mid=1144, argc=1, argv=0x40ccf2a0, scope=CALL_FCALL, self=6) at vm_eval.c:235 #60 0x0000000000523cd5 in rb_call (recv=259360280, mid=1144, argc=1, argv=0x40ccf2a0, scope=CALL_FCALL) at vm_eval.c:438
#61 0x0000000000523f8a in rb_funcall (recv=259360280, mid=1144, n=1) at vm_eval.c:637
#62 0x00000000004fb60e in const_missing (klass=259360280, id=88005) at variable.c:1360
#63 0x00000000004fbe1f in rb_const_get_0 (klass=259360280, id=88005, exclude=0, recurse=1) at variable.c:1600
#64 0x00000000004fbe8d in rb_const_get (klass=259360280, id=88005) at variable.c:1614
#65 0x000000000051e650 in vm_get_ev_const (th=0x11b3c230, iseq=0x12601510, orig_klass=4, id=88005, is_defined=0) at vm_insnhelper.c:1196
#66 0x0000000000517741 in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:223
#67 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#68 0x0000000000529391 in rb_iseq_eval (iseqval=281036160) at vm.c:1372
#69 0x000000000056ad05 in rb_load_internal (fname=282078760, wrap=0) at load.c:302 #70 0x000000000056af4a in rb_f_load (argc=1, argv=0x2aaab078e7e8) at load.c:375
#71 0x000000000051f980 in call_cfunc (func=0x56ae8b <rb_f_load>, recv=265666400, len=-1, argc=1, argv=0x2aaab078e7e8) at vm_insnhelper.c:314
#72 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088cf38, num=1, recv=265666400, blockptr=0x0, me=0xfd96140) at vm_insnhelper.c:401
#73 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088cf38, num=1, blockptr=0x0, flag=8, id=34488, me=0xfd96140, recv=265666400)
at vm_insnhelper.c:523
#74 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#75 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#76 0x0000000000522aaf in vm_call0 (th=0x11b3c230, recv=282348640, id=1144, argc=1, argv=0x40cd1630, me=0x100a4d00) at vm_eval.c:66
#77 0x0000000000523d7f in rb_call0 (recv=282348640, mid=1144, argc=1, argv=0x40cd1630, scope=CALL_FCALL, self=6) at vm_eval.c:235
#78 0x0000000000523cd5 in rb_call (recv=282348640, mid=1144, argc=1, argv=0x40cd1630, scope=CALL_FCALL) at vm_eval.c:438
#79 0x0000000000523f8a in rb_funcall (recv=282348640, mid=1144, n=1) at vm_eval.c:637 #80 0x00000000004fb60e in const_missing (klass=282348640, id=124773) at variable.c:1360
#81 0x00000000004fbe1f in rb_const_get_0 (klass=282348640, id=124773, exclude=1, recurse=0) at variable.c:1600
#82 0x00000000004fbeb6 in rb_const_get_at (klass=282348640, id=124773) at variable.c:1620
#83 0x000000000044cb0a in rb_mod_const_get (argc=2, argv=0x2aaab078e660, mod=282348640) at object.c:1695
#84 0x000000000051f980 in call_cfunc (func=0x44ca55 <rb_mod_const_get>, recv=282348640, len=-1, argc=2, argv=0x2aaab078e660) at vm_insnhelper.c:314
#85 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d1f8, num=2, recv=282348640, blockptr=0x0, me=0xf767b70) at vm_insnhelper.c:401
#86 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d1f8, num=2, blockptr=0x0, flag=0, id=1112, me=0xf767b70, recv=282348640)
at vm_insnhelper.c:523
#87 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#88 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#89 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088d328, self=261961800, argc=1, argv=0x40cd2998, blockptr=0x0, cref=0x0)
at vm.c:557
#90 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40cd2998) at vm.c:587
#91 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40cd2998) at vm_eval.c:731
#92 0x0000000000524153 in rb_yield (val=282361960) at vm_eval.c:741
#93 0x000000000053d736 in rb_ary_each (ary=282362240) at array.c:1427
#94 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=282362240, len=0, argc=0, argv=0x2aaab078e620) at vm_insnhelper.c:317
#95 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d300, num=0, recv=282362240, blockptr=0x2aaab088d328, me=0xf7addc0)
at vm_insnhelper.c:401
#96 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d300, num=0, blockptr=0x2aaab088d328, flag=0, id=424, me=0xf7addc0, recv=282362240)
at vm_insnhelper.c:523
#97 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#98 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#99 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x127510b0, self=291970880, argc=1, argv=0x2aaab078e4f0, blockptr=0x0, cref=0x0)
at vm.c:557
#100 0x00000000005277c5 in rb_vm_invoke_proc (th=0x11b3c230, proc=0x127510b0, self=291970880, argc=1, argv=0x2aaab078e4f0, blockptr=0x0) at vm.c:603 ---Type to continue, or q to quit---
#101 0x000000000041afa1 in proc_call (argc=1, argv=0x2aaab078e4f0, procval=282451640) at proc.c:556
#102 0x000000000051f980 in call_cfunc (func=0x41aefc <proc_call>, recv=282451640, len=-1, argc=1, argv=0x2aaab078e4f0) at vm_insnhelper.c:314
#103 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088d618, num=1, recv=282451640, blockptr=0x0, me=0xf7f0f00) at vm_insnhelper.c:401
#104 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088d618, num=1, blockptr=0x0, flag=0, id=5912, me=0xf7f0f00, recv=282451640)
at vm_insnhelper.c:523
#105 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#106 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#107 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x2aaab088dd20, self=295023880, argc=1, argv=0x40cd4d68, blockptr=0x0, cref=0x0)
at vm.c:557
#108 0x00000000005276c6 in vm_yield (th=0x11b3c230, argc=1, argv=0x40cd4d68) at vm.c:587
#109 0x000000000052417f in rb_yield_0 (argc=1, argv=0x40cd4d68) at vm_eval.c:731 #110 0x0000000000524153 in rb_yield (val=295023400) at vm_eval.c:741
#111 0x000000000053d736 in rb_ary_each (ary=295023360) at array.c:1427
#112 0x000000000051f998 in call_cfunc (func=0x53d6ac <rb_ary_each>, recv=295023360, len=0, argc=0, argv=0x2aaab078e218) at vm_insnhelper.c:317
#113 0x000000000051f853 in vm_call_cfunc (th=0x11b3c230, reg_cfp=0x2aaab088dcf8, num=0, recv=295023360, blockptr=0x2aaab088dd20, me=0xf7addc0)
at vm_insnhelper.c:401
#114 0x000000000051ec2b in vm_call_method (th=0x11b3c230, cfp=0x2aaab088dcf8, num=0, blockptr=0x2aaab088dd20, flag=0, id=424, me=0xf7addc0, recv=295023360)
at vm_insnhelper.c:523
#115 0x0000000000519abd in vm_exec_core (th=0x11b3c230, initial=0) at insns.def:1006
#116 0x00000000005289a5 in vm_exec (th=0x11b3c230) at vm.c:1145
#117 0x000000000052763f in invoke_block_from_c (th=0x11b3c230, block=0x119b71e0, self=294980880, argc=0, argv=0x10db1988, blockptr=0x0, cref=0x0)
at vm.c:557
#118 0x00000000005277c5 in rb_vm_invoke_proc (th=0x11b3c230, proc=0x119b71e0, self=294980880, argc=0, argv=0x10db1988, blockptr=0x0) at vm.c:603
#119 0x000000000052cfef in thread_start_func_2 (th=0x11b3c230, stack_start=0x40cd6120) at thread.c:441 #120 0x000000000052c16b in thread_start_func_1 (th_ptr=0x11b3c230) at thread_pthread.c:369
#121 0x00002b7ace98273d in start_thread () from /lib64/libpthread.so.0
#122 0x00002b7acf533d1d in clone () from /lib64/libc.so.6 ===============

Since we doubt it seems to be a thread safe problem with libxml_ruby.so , a simple test script is used (attached as testthreadxml.rb), and it seems it runs very unstable. sometimes, it throw below exception.

================
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/xml_mini.rb:15:in rescue in parse': parse delegated to backend.parse, but backend is nil: ActiveSupport::XmlMini (RuntimeError) from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/xml_mini.rb:12:in parse'
from /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.4/lib/active_support/core_ext/hash/conversions.rb:164:in from_xml' from testthreadxml.rb:12:in block in '

===============
problem never happen in ruby1.8.6 though.

would you help on such issue? thank you!

---

http://redmine.ruby-lang.org

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=end

[naruse (Yui NARUSE)]

• Status changed from Open to Third Party's Issue

=begin
It seems that libxml-ruby makes a wronb object and crashes when GC collect it.
=end