[ruby-dev:9916] Re: deadlock detection problem

小松です。

In the message of [ruby-dev:9853] Re: deadlock detection problem
    on 2000/5/25 22:02:28 Katsuyuki Komatsu <[e-mail]> wrote:
|昨日 (2000-05-24) のcommitでdeadlockが出力されるように
|なっていたのですが、今日 (2000-05-25) のcommitで
|またハングするようになってしまいました。

今日 (2000-05-30) のcommitでdeadlockが検出されるように
なったのですが、繰り返し実行していると4〜5回に1回ぐらいの
割合でcore dumpするようになってしまいました。

正常なときはdeadlockの行が1行しか出ないことを考えると、
deadlockの処理中のdeadlockの扱い、あるいはdeadlock中に
deadlockが起きることがよろしくないような気がします。

% ruby -v
ruby 1.5.4 (2000-05-30) [sparc-solaris2.5.1]
% ruby ruby-list-15168.rb ruby-list-15168.rb
require "thread"

q = Queue.new

Thread.start {
  while gets
    q.push $_
  end
}

while TRUE
  while line = q.pop
    print line
  end
end
deadlock 0xf42b0: 2:0 (main) - /usr/local/lib/ruby/1.5/thread.rb:178:
deadlock 0xf42b0: 2:0 (main) - /usr/local/lib/ruby/1.5/thread.rb:184:
/usr/local/lib/ruby/1.5/thread.rb:184: [BUG] Segmentation fault
異常終了 (コアダンプしました。)
% gdb ruby core
GNU gdb 5.0
Copyright 2000 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "sparc-sun-solaris2.5.1"...

warning: core file may not match specified executable file.
Core was generated by `ruby ruby-list-15168.rb ruby-list-15168.rb'.
Program terminated with signal 6, Abort.
Reading symbols from /usr/lib/libdl.so.1...done.
Loaded symbols for /usr/lib/libdl.so.1
Reading symbols from /usr/lib/libm.so.1...done.
Loaded symbols for /usr/lib/libm.so.1
Reading symbols from /usr/lib/libc.so.1...done.
Loaded symbols for /usr/lib/libc.so.1
Reading symbols from /usr/platform/SUNW,Ultra-2/lib/libc_psr.so.1...done.
Loaded symbols for /usr/platform/SUNW,Ultra-2/lib/libc_psr.so.1
#0  0xef6f9cb4 in kill () from /usr/lib/libc.so.1
(gdb) bt
#0  0xef6f9cb4 in kill () from /usr/lib/libc.so.1
#1  0xef6bf914 in abort () from /usr/lib/libc.so.1
#2  0x8cfa4 in rb_bug (fmt=0x9f538 "Segmentation fault") at ../error.c:162
#3  0x72128 in sigsegv (sig=11) at ../signal.c:376
#4  <signal handler called>
#5  st_lookup (table=0x0, key=0x1131 <Address 0x1131 out of bounds>, 
    value=0xeffff1fc) at ../st.c:253
#6  0x1ad00 in search_method (klass=930944, id=4401, origin=0xeffff27c)
    at ../eval.c:242
#7  0x1adb4 in rb_get_method_body (klassp=0xeffff36c, idp=0xeffff30c, 
    noexp=0xeffff310) at ../eval.c:263
#8  0x28a98 in rb_call (klass=930944, recv=931616, mid=4401, argc=0, argv=0x0, 
    scope=1) at ../eval.c:4210
#9  0x28f84 in rb_funcall (recv=931616, mid=4401, n=0) at ../eval.c:4307
#10 0x1bcf8 in get_backtrace (info=931616) at ../eval.c:838
#11 0x1bde8 in error_print () at ../eval.c:860
#12 0x1ccdc in ruby_run () at ../eval.c:1114
#13 0x1a764 in main (argc=0, argv=0xeffff74c, envp=0xeffff75c) at ../main.c:48
(gdb) frame 5
#5  st_lookup (table=0x0, key=0x1131 <Address 0x1131 out of bounds>, 
    value=0xeffff1fc) at ../st.c:253
253	    hash_val = do_hash(key, table);
(gdb) up
#6  0x1ad00 in search_method (klass=930944, id=4401, origin=0xeffff27c)
    at ../eval.c:242
242	    while (!st_lookup(RCLASS(klass)->m_tbl, id, &body)) {
(gdb) print *((struct RClass *)klass)
$1 = {basic = {flags = 0, klass = 930920}, iv_tbl = 0x0, m_tbl = 0x0, 
  super = 0}
(gdb) up
#7  0x1adb4 in rb_get_method_body (klassp=0xeffff36c, idp=0xeffff30c, 
    noexp=0xeffff310) at ../eval.c:263
263	    if ((body = search_method(klass, id, &origin)) == 0 || !body->nd_body) {
(gdb) up
#8  0x28a98 in rb_call (klass=930944, recv=931616, mid=4401, argc=0, argv=0x0, 
    scope=1) at ../eval.c:4210
4210	    else if ((body = rb_get_method_body(&klass, &id, &noex)) == 0) {
(gdb) up
#9  0x28f84 in rb_funcall (recv=931616, mid=4401, n=0) at ../eval.c:4307
4307	    return rb_call(CLASS_OF(recv), recv, mid, n, argv, 1);
(gdb) print *((struct RClass *)recv)
$2 = {basic = {flags = 0, klass = 930944}, iv_tbl = 0x124f18, m_tbl = 0x0, 
  super = 0}
(gdb) up
#10 0x1bcf8 in get_backtrace (info=931616) at ../eval.c:838
838	    return rb_funcall(info, rb_intern("backtrace"), 0);
(gdb) up
#11 0x1bde8 in error_print () at ../eval.c:860
860		errat = get_backtrace(ruby_errinfo);
(gdb) up
#12 0x1ccdc in ruby_run () at ../eval.c:1114
1114		    error_print();
(gdb) up
#13 0x1a764 in main (argc=0, argv=0xeffff74c, envp=0xeffff75c) at ../main.c:48
48	    ruby_run();
(gdb) up
Initial frame selected; you cannot go up.
(gdb) quit
% 

--
小松克行 / Katsuyuki Komatsu <[e-mail]>