From: "Iñaki Baz Castillo" <redmine@...>
Date: 2011-01-13T01:22:01+09:00
Subject: [ruby-core:34439] [Ruby 1.9-Bug#4272] rb_enc_str_new() causes segmentfault when using threads in parallel


--mimepart_4d2dd5293e641_1dc2b44222a54c9
Content-Type: text/plain
Content-Transfer-Encoding: Quoted-printable
Content-Disposition: inline

Issue #4272 has been updated by I=C3=B1aki Baz Castillo.

File test_bug2.rb added

Yukihiro:
> I could not reproduce your problem

Do you mean under Ruby 1.9.2 64 bits? If so please use a bigger argument =
(ruby test_bug.rb 100000). I've realized that depending on the machine it=
 crashes sooner or later.


> but your script allocates thousands of threads by default.  Each thread=
 consumes at least 1M of memory, so
> that allocating thousands of threads could cause memory starvation, whi=
ch may be the source of your problem.

The segmentfault just occurs when using rb_enc_str_new(). If you edit tes=
t_bug.rb and remove/comment the first iteration with "tester.test_rb_str_=
new" the segmentfault also occurs. And it never occurs if you just leave =
the iteration with "tester.test_rb_str_new".

And more important, I also reproduce *always* the segmentfault using a fi=
xed pool of 20 threads (in EventMachine). And also in this modified test =
script (max 20 threads are created) you can run by loading my attached C =
extension (I attach now test_bug2.rb with this code):

    require "./test_encoding"


    times =3D ( ( ARGV[0] and ARGV[0].to_i > 0 ) ? ARGV[0].to_i : 5000 )
    threads =3D []
    num_threads =3D 20
    tester =3D TestEncoding::Tester.new

    times.times do |num|
      puts "iteration [#{num}]"
      str =3D tester.test_rb_enc_str_new
      threads << Thread.new { }  unless num_threads =3D=3D 0
      num_threads -=3D 1
    end


Using Ruby 1.9.2-<any> produces different segmentfault (randomly, but it =
crashes always in my machines):


1) Crash on Thread.initialize:

iteration [1981]
iteration [1982]
iteration [1983]
iteration [1984]
test_bug.rb:12: [BUG] Segmentation fault
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]

-- control frame ----------
c:0008 p:---- s:0025 b:0025 l:000024 d:000024 CFUNC  :initialize
c:0007 p:---- s:0023 b:0023 l:000022 d:000022 CFUNC  :new
c:0006 p:0063 s:0020 b:0019 l:001f08 d:000018 BLOCK  test_bug.rb:12
c:0005 p:---- s:0015 b:0015 l:000014 d:000014 FINISH
c:0004 p:---- s:0013 b:0013 l:000012 d:000012 CFUNC  :times
c:0003 p:0121 s:0010 b:0010 l:001f08 d:000968 EVAL   test_bug.rb:9
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH
c:0001 p:0000 s:0002 b:0002 l:001f08 d:001f08 TOP   =

---------------------------
-- Ruby level backtrace information -------------------------------------=
---
test_bug.rb:9:in `<main>'
test_bug.rb:9:in `times'
test_bug.rb:12:in `block in <main>'
test_bug.rb:12:in `new'
test_bug.rb:12:in `initialize'

-- C level backtrace information ----------------------------------------=
---
/usr/lib/libruby-1.9.1.so.1.9(rb_vm_bugreport+0x5f) [0x7f10c71c658f]
/usr/lib/libruby-1.9.1.so.1.9(+0x5a7be) [0x7f10c70cd7be]
/usr/lib/libruby-1.9.1.so.1.9(rb_bug+0xa6) [0x7f10c70ce136]
/usr/lib/libruby-1.9.1.so.1.9(+0xf4a75) [0x7f10c7167a75]
/lib/libpthread.so.0(+0xfb40) [0x7f10c6e65b40]
/usr/lib/libruby-1.9.1.so.1.9(+0x6edc8) [0x7f10c70e1dc8]
/usr/lib/libruby-1.9.1.so.1.9(rb_thread_mark+0x4c) [0x7f10c71b1b8c]
/usr/lib/libruby-1.9.1.so.1.9(+0x6e87a) [0x7f10c70e187a]
/usr/lib/libruby-1.9.1.so.1.9(+0x13ea89) [0x7f10c71b1a89]
/usr/lib/libruby-1.9.1.so.1.9(st_foreach+0xb4) [0x7f10c7170284]
/usr/lib/libruby-1.9.1.so.1.9(rb_vm_mark+0x29) [0x7f10c71b1f09]
/usr/lib/libruby-1.9.1.so.1.9(+0x6e87a) [0x7f10c70e187a]
/usr/lib/libruby-1.9.1.so.1.9(+0x6fd98) [0x7f10c70e2d98]
/usr/lib/libruby-1.9.1.so.1.9(rb_newobj+0x47) [0x7f10c70e37c7]
/usr/lib/libruby-1.9.1.so.1.9(rb_data_typed_object_alloc+0x26) [0x7f10c70=
e3886]
/usr/lib/libruby-1.9.1.so.1.9(+0x13f97a) [0x7f10c71b297a]
/usr/lib/libruby-1.9.1.so.1.9(rb_vm_make_proc+0x56) [0x7f10c71b44e6]
/usr/lib/libruby-1.9.1.so.1.9(+0x64be3) [0x7f10c70d7be3]
/usr/lib/libruby-1.9.1.so.1.9(+0x154a92) [0x7f10c71c7a92]
/usr/lib/libruby-1.9.1.so.1.9(+0x149ca5) [0x7f10c71bcca5]
/usr/lib/libruby-1.9.1.so.1.9(+0x154cc8) [0x7f10c71c7cc8]
/usr/lib/libruby-1.9.1.so.1.9(+0x14c93e) [0x7f10c71bf93e]
/usr/lib/libruby-1.9.1.so.1.9(+0x143f61) [0x7f10c71b6f61]
/usr/lib/libruby-1.9.1.so.1.9(+0x148b44) [0x7f10c71bbb44]
/usr/lib/libruby-1.9.1.so.1.9(rb_yield+0x238) [0x7f10c71c2408]
/usr/lib/libruby-1.9.1.so.1.9(+0x96571) [0x7f10c7109571]
/usr/lib/libruby-1.9.1.so.1.9(+0x14c93e) [0x7f10c71bf93e]
/usr/lib/libruby-1.9.1.so.1.9(+0x143f61) [0x7f10c71b6f61]
/usr/lib/libruby-1.9.1.so.1.9(+0x148b44) [0x7f10c71bbb44]
/usr/lib/libruby-1.9.1.so.1.9(rb_iseq_eval_main+0xb1) [0x7f10c71c2c81]
/usr/lib/libruby-1.9.1.so.1.9(+0x5ecca) [0x7f10c70d1cca]
/usr/lib/libruby-1.9.1.so.1.9(ruby_exec_node+0x1d) [0x7f10c70d22ed]
/usr/lib/libruby-1.9.1.so.1.9(ruby_run_node+0x1e) [0x7f10c70d3e3e]
ruby(main+0x4b) [0x40092b]
/lib/libc.so.6(__libc_start_main+0xfe) [0x7f10c6229d8e]
ruby() [0x400819]



2) Crash on Thread#new:

iteration [1780]
iteration [1781]
iteration [1782]
iteration [1783]
test_bug.rb:12: [BUG] Segmentation fault
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]

-- control frame ----------
c:0007 p:---- s:0023 b:0023 l:000022 d:000022 CFUNC  :new
c:0006 p:0063 s:0020 b:0019 l:000048 d:000018 BLOCK  test_bug.rb:12
c:0005 p:---- s:0015 b:0015 l:000014 d:000014 FINISH
c:0004 p:---- s:0013 b:0013 l:000012 d:000012 CFUNC  :times
c:0003 p:0121 s:0010 b:0010 l:000048 d:0011b8 EVAL   test_bug.rb:9
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH
c:0001 p:0000 s:0002 b:0002 l:000048 d:000048 TOP   =

---------------------------
-- Ruby level backtrace information -------------------------------------=
---
test_bug.rb:9:in `<main>'
test_bug.rb:9:in `times'
test_bug.rb:12:in `block in <main>'
test_bug.rb:12:in `new'

-- C level backtrace information ----------------------------------------=
---
/usr/lib/libruby-1.9.1.so.1.9(rb_vm_bugreport+0x5f) [0x7f53d34ec58f]
/usr/lib/libruby-1.9.1.so.1.9(+0x5a7be) [0x7f53d33f37be]
/usr/lib/libruby-1.9.1.so.1.9(rb_bug+0xa6) [0x7f53d33f4136]
/usr/lib/libruby-1.9.1.so.1.9(+0xf4a75) [0x7f53d348da75]
/lib/libpthread.so.0(+0xfb40) [0x7f53d318bb40]
/usr/lib/libruby-1.9.1.so.1.9(+0x6edc8) [0x7f53d3407dc8]
/usr/lib/libruby-1.9.1.so.1.9(rb_thread_mark+0x4c) [0x7f53d34d7b8c]
/usr/lib/libruby-1.9.1.so.1.9(+0x6e87a) [0x7f53d340787a]
/usr/lib/libruby-1.9.1.so.1.9(+0x13ea89) [0x7f53d34d7a89]
/usr/lib/libruby-1.9.1.so.1.9(st_foreach+0xb4) [0x7f53d3496284]
/usr/lib/libruby-1.9.1.so.1.9(rb_vm_mark+0x29) [0x7f53d34d7f09]
/usr/lib/libruby-1.9.1.so.1.9(+0x6e87a) [0x7f53d340787a]
/usr/lib/libruby-1.9.1.so.1.9(+0x6fd98) [0x7f53d3408d98]
/usr/lib/libruby-1.9.1.so.1.9(+0x70b4c) [0x7f53d3409b4c]
/usr/lib/libruby-1.9.1.so.1.9(+0x1403af) [0x7f53d34d93af]
/usr/lib/libruby-1.9.1.so.1.9(rb_thread_alloc+0x66) [0x7f53d34e9286]
/usr/lib/libruby-1.9.1.so.1.9(+0x154cb8) [0x7f53d34edcb8]
/usr/lib/libruby-1.9.1.so.1.9(+0x14c93e) [0x7f53d34e593e]
/usr/lib/libruby-1.9.1.so.1.9(+0x143f61) [0x7f53d34dcf61]
/usr/lib/libruby-1.9.1.so.1.9(+0x148b44) [0x7f53d34e1b44]
/usr/lib/libruby-1.9.1.so.1.9(rb_yield+0x238) [0x7f53d34e8408]
/usr/lib/libruby-1.9.1.so.1.9(+0x96571) [0x7f53d342f571]
/usr/lib/libruby-1.9.1.so.1.9(+0x14c93e) [0x7f53d34e593e]
/usr/lib/libruby-1.9.1.so.1.9(+0x143f61) [0x7f53d34dcf61]
/usr/lib/libruby-1.9.1.so.1.9(+0x148b44) [0x7f53d34e1b44]
/usr/lib/libruby-1.9.1.so.1.9(rb_iseq_eval_main+0xb1) [0x7f53d34e8c81]
/usr/lib/libruby-1.9.1.so.1.9(+0x5ecca) [0x7f53d33f7cca]
/usr/lib/libruby-1.9.1.so.1.9(ruby_exec_node+0x1d) [0x7f53d33f82ed]
/usr/lib/libruby-1.9.1.so.1.9(ruby_run_node+0x1e) [0x7f53d33f9e3e]
ruby(main+0x4b) [0x40092b]
/lib/libc.so.6(__libc_start_main+0xfe) [0x7f53d254fd8e]
ruby() [0x400819]


3) Sometimes it crashes on "times.times do".


However as I said, in same machine using Ruby 1.9.1 it doesn't crash.

My system data:
- AMD Phenom(tm) II X4 965 Processor
- Ubuntu 10.10 64 bits
- gcc-4.4 =

- Ruby 1.9.2-p0, 1.9.2-p136, and snapshot version (2011-01-12)
- 4GB RAM
----------------------------------------
http://redmine.ruby-lang.org/issues/show/4272

----------------------------------------
http://redmine.ruby-lang.org

--mimepart_4d2dd5293e641_1dc2b44222a54c9
Content-Type: application/x-ruby; name=test_bug2.rb
Content-Transfer-Encoding: Base64
Content-Disposition: attachment; filename=test_bug2.rb

cmVxdWlyZSAiLi90ZXN0X2VuY29kaW5nIgoKdGltZXMgPSAoICggQVJHVlsw
XSBhbmQgQVJHVlswXS50b19pID4gMCApID8gQVJHVlswXS50b19pIDogNTAw
MCApCnRocmVhZHMgPSBbXQpudW1fdGhyZWFkcyA9IDIwCnRlc3RlciA9IFRl
c3RFbmNvZGluZzo6VGVzdGVyLm5ldwoKdGltZXMudGltZXMgZG8gfG51bXwK
ICBwdXRzICJpdGVyYXRpb24gWyN7bnVtfV0iCiAgcyA9IHRlc3Rlci50ZXN0
X3JiX2VuY19zdHJfbmV3CiAgdGhyZWFkcyA8PCBUaHJlYWQubmV3IHsgfSAg
dW5sZXNzIG51bV90aHJlYWRzID09IDAKICBudW1fdGhyZWFkcyAtPSAxCmVu
ZAo=

--mimepart_4d2dd5293e641_1dc2b44222a54c9--