[ruby-dev:5047] Re: Ruby 1.3.1-990210

渡辺哲也です。

thread と GC のタイミングで core してしまうようで
す。少々バックトレースが長いのですが、よろしくお願
いします。

■ 確認スクリプト

このスクリプトで現象を起こす場合、1.upto(10) do の 
「10」の部分を調整してください。

Pentium II 450MHz で 10
Pentium 166MHz    で  3

という感じでした。

8 個 thread を作成します。このときスレッドの実行時
間を表示すると次のような感じです。ここでは、5 つ実
行に成功しましたが、落ちました。

0.042370
0.039530
0.137694
0.221117
0.058355

ループの回数を調整する場合に、一つの基準にしてみて
ください。

#! /usr/local/bin/ruby
# /home/tetsu/src/ruby/bug/th.rb
# Created: February 10,1999 Wednesday 13:48:51
# Author: tetsu(WATANABE Tetsuya)
# $Id$
# usage:

class Benchmark
  def initialize
    @bench = []
    @s = nil
  end
  
  def start
    @s = Time.now
  end

  def stop
    @bench.push((Time.now - @s).to_f)
    @s = nil
  end

  def to_s
    sum = 0.0
    @bench.each do |a|
      sum += a
    end
    sprintf('%f', sum / @bench.size)
  end
end

arr = []

1.upto(8) do
  b = Benchmark.new
  th = Thread.start {
    b.start
# P6 450MHz
    1.upto(10) do
# P5 166MHz   1.upto(3) do
      str = ''
      str += 'seed' * 100
      j = str.split('')
    end
    b.stop
    print b, "\n"
  }
  arr.push(th)
end

arr.each { |t|
  if t and t.alive?
    t.join
  end
}

exit

■ デバックのために埋め込んだコード

確認のために、次のコードを埋め込みました。

------------------------------
--- gc.c.org    Tue Feb  9 15:08:20 1999
+++ gc.c        Fri Feb 12 14:43:22 1999
@@ -553,8 +553,10 @@
            int i, len = obj->as.array.len;
            VALUE *ptr = obj->as.array.ptr;
 
-           for (i=0; i < len; i++)
+           for (i=0; i < len; i++) {
+               fprintf(stderr, "*ptr(0x%0x) i(%d) len(%d:%d)\n", *ptr, i, len, obj->as.array.len); /* tetsu */
                rb_gc_mark(*ptr++);
+           }
        }
        break;
 
------------------------------

■ 上記の結果

出力結果の後半のみ

------------------------------
*ptr(0x40120844) i(396) len(400:400)
*ptr(0x40120808) i(397) len(400:400)
*ptr(0x401207cc) i(398) len(400:400)
*ptr(0x40120790) i(399) len(400:400)
*ptr(0x40120394) i(2) len(4:4)
*ptr(0x128) i(3) len(4:4)
th.rb:43: [BUG] Segmentation fault
------------------------------

■ バックトレース

上記修正のため、gc.c は行番号がずれています。

#0  0x40076e01 in __kill ()
#1  0x40076c2f in raise (sig=6) at ../sysdeps/posix/raise.c:27
#2  0x40077e3f in abort () at ../sysdeps/generic/abort.c:83
#3  0x8096274 in rb_check_type (x=134892599, t=-1073761060) at error.c:154
#4  0x8083cb1 in sigsegv (sig=11) at signal.c:333
#5  <signal handler called>
#6  rb_gc_mark (ptr=0x128) at gc.c:394
#7  0x805f527 in rb_gc_mark (ptr=0x40122d4c) at gc.c:558
#8  0x805f5d7 in rb_gc_mark (ptr=0x40130d34) at gc.c:609
#9  0x805936d in blk_mark (data=0x80db378) at eval.c:5215
#10 0x805f568 in rb_gc_mark (ptr=0x401241d8) at gc.c:576
#11 0x805ee53 in mark_entry (key=8325, value=1074938328) at gc.c:346
#12 0x8085ef1 in st_foreach (table=0x80b5ff8, func=0x805ee48 <mark_entry>, arg=0x0) at st.c:434
#13 0x805ee6f in rb_mark_tbl (tbl=0x80b5ff8) at gc.c:355
#14 0x805f578 in rb_gc_mark (ptr=0x40130d20) at gc.c:580
#15 0x805ee53 in mark_entry (key=2809, value=1074990368) at gc.c:346
#16 0x8085ef1 in st_foreach (table=0x80b6300, func=0x805ee48 <mark_entry>, arg=0x0) at st.c:434
#17 0x805ee6f in rb_mark_tbl (tbl=0x80b6300) at gc.c:355
#18 0x805f578 in rb_gc_mark (ptr=0x40130ce4) at gc.c:580
#19 0x805f4d8 in rb_gc_mark (ptr=0x40130cd0) at gc.c:546
#20 0x805f4d8 in rb_gc_mark (ptr=0x40130cbc) at gc.c:546
#21 0x805f2c0 in rb_gc_mark (ptr=0x40130cf8) at gc.c:541
#22 0x805f2c0 in rb_gc_mark (ptr=0x4012ee80) at gc.c:541
#23 0x805f2c0 in rb_gc_mark (ptr=0x4012ee94) at gc.c:541
#24 0x805f2c0 in rb_gc_mark (ptr=0x4010006c) at gc.c:541
#25 0x805ee0e in mark_locations_array (x=0xbfffbb04, n=1) at gc.c:319
#26 0x805fc16 in rb_gc_mark_frame (frame=0xbfffba78) at gc.c:838
#27 0x805fc6a in rb_gc () at gc.c:897
#28 0x805ed3d in rb_newobj () at gc.c:265
#29 0x8078629 in match_alloc () at re.c:366
#30 0x80789a9 in rb_reg_search (reg=1074932748, str=1074790568, start=1, reverse=0) at re.c:486
#31 0x80892a0 in rb_str_split_method (argc=1, argv=0xbfffbb04, str=1074790568) at string.c:2057
#32 0x8056401 in call_cfunc (func=0x8089040 <rb_str_split_method>, recv=1074790568, len=-1, argc=1, 
    argv=0xbfffbb04) at eval.c:3609
#33 0x8056882 in rb_call0 (klass=1074982548, recv=1074790568, id=4041, argc=1, argv=0xbfffbb04, 
    body=0x4012e764, nosuper=1) at eval.c:3748
#34 0x8056ea4 in rb_call (klass=1074982548, recv=1074790568, mid=4041, argc=1, argv=0xbfffbb04, scope=0)
    at eval.c:3933
#35 0x80531bc in rb_eval (self=1074986828, node=0x401232c4) at eval.c:2160
#36 0x8053ab2 in rb_eval (self=1074986828, node=0x40123328) at eval.c:2303
#37 0x8051dfa in rb_eval (self=1074986828, node=0x4012329c) at eval.c:1695
#38 0x805561e in rb_yield_0 (val=13, self=1074986828, klass=0) at eval.c:3159
#39 0x8055773 in rb_yield (val=13) at eval.c:3200
#40 0x806a776 in fix_upto (from=3, to=21) at numeric.c:1321
#41 0x8056415 in call_cfunc (func=0x806a740 <fix_upto>, recv=3, len=1, argc=1, argv=0xbfffc960)
    at eval.c:3615
#42 0x8056882 in rb_call0 (klass=1074967948, recv=3, id=3897, argc=1, argv=0xbfffc960, body=0x4012b050, 
    nosuper=1) at eval.c:3748
#43 0x8056ea4 in rb_call (klass=1074967948, recv=3, mid=3897, argc=1, argv=0xbfffc960, scope=0)
    at eval.c:3933
#44 0x80531bc in rb_eval (self=1074986828, node=0x401234f4) at eval.c:2160
#45 0x8052492 in rb_eval (self=1074986828, node=0x40123274) at eval.c:1901
#46 0x8051dfa in rb_eval (self=1074986828, node=0x40123238) at eval.c:1695
#47 0x805561e in rb_yield_0 (val=1074923288, self=1074986828, klass=0) at eval.c:3159
#48 0x805bca7 in rb_thread_yield (arg=0, th=0x8128d18) at eval.c:6785
#49 0x805bb08 in rb_thread_create_0 (fn=0x805bc84 <rb_thread_yield>, arg=0x0, klass=1074970148)
    at eval.c:6735
#50 0x805bcd7 in rb_thread_start (klass=1074970148) at eval.c:6795
#51 0x805640b in call_cfunc (func=0x805bcac <rb_thread_start>, recv=1074970148, len=0, argc=0, argv=0x0)
    at eval.c:3612
#52 0x8056882 in rb_call0 (klass=1074970128, recv=1074970148, id=5457, argc=0, argv=0x0, body=0x4012bdd4, 
    nosuper=1) at eval.c:3748
#53 0x8056ea4 in rb_call (klass=1074970128, recv=1074970148, mid=5457, argc=0, argv=0x0, scope=0)
    at eval.c:3933
#54 0x80531bc in rb_eval (self=1074986828, node=0x401235bc) at eval.c:2160
#55 0x8052492 in rb_eval (self=1074986828, node=0x401230f8) at eval.c:1901
#56 0x8053ab2 in rb_eval (self=1074986828, node=0x401235e4) at eval.c:2303
#57 0x8051dfa in rb_eval (self=1074986828, node=0x401230bc) at eval.c:1695
#58 0x805561e in rb_yield_0 (val=11, self=1074986828, klass=0) at eval.c:3159
#59 0x8055773 in rb_yield (val=11) at eval.c:3200
#60 0x806a776 in fix_upto (from=3, to=17) at numeric.c:1321
#61 0x8056415 in call_cfunc (func=0x806a740 <fix_upto>, recv=3, len=1, argc=1, argv=0xbfffeac0)
    at eval.c:3615
#62 0x8056882 in rb_call0 (klass=1074967948, recv=3, id=3897, argc=1, argv=0xbfffeac0, body=0x4012b050, 
    nosuper=1) at eval.c:3748
#63 0x8056ea4 in rb_call (klass=1074967948, recv=3, mid=3897, argc=1, argv=0xbfffeac0, scope=0)
    at eval.c:3933
#64 0x80531bc in rb_eval (self=1074986828, node=0x40123698) at eval.c:2160
#65 0x8052492 in rb_eval (self=1074986828, node=0x40123008) at eval.c:1901
#66 0x8051dfa in rb_eval (self=1074986828, node=0x40122fe0) at eval.c:1695
#67 0x8050702 in eval_node (self=1074986828) at eval.c:961
#68 0x80507b7 in ruby_run () at eval.c:990
#69 0x804f78c in main (argc=2, argv=0xbffff80c, envp=0xbffff818) at main.c:39

--
WATANABE Tetsuya
 e-mail: [e-mail]
         [e-mail]