------- Comment #18 from dave at hiauly1 dot hia dot nrc dot ca 2006-10-07
18:56 -------
Subject: Re: [4.2 Regression] Timeouts in libstdc++, libjava and libgomp
testsuites
> ------- Comment #16 from bkoz at gcc dot gnu dot org 2006-10-06 09:52 -------
> When you get to "break here" this is what your mutex should look like in gdb:
Well, we don't actually get to "break here". The program hangs in
xactly the same way as 23591_thread-1:
(gdb) bt
#0 *__GI___pthread_mutex_lock (mutex=0x4010ee00) at mutex.c:99
#1 0x400679e4 in locale (this=0x4010dae4)
at
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/libstdc++-v3/include/hppa-linux/bits/gthr-default.h:549
#2 0x40062984 in Init (this=<value optimized out>)
at
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/libstdc++-v3/include/streambuf:462
#3 0x4007ca28 in __static_initialization_and_destruction_0 (
__initialize_p=<value optimized out>, __priority=0)
at
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/libstdc++-v3/include/iostream:77
#4 0x400eb140 in __do_global_ctors_aux ()
from
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/./libstdc++-v3/src/.libs/libstdc++.so.6
#5 0x40051924 in _init ()
from
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/./libstdc++-v3/src/.libs/libstdc++.so.6
...
(gdb) p *mutex
$9 = {__m_reserved = 0, __m_count = 0, __m_owner = 0x0, __m_kind = 0,
__m_lock = {__spinlock = {lock = {0, 0, 0, 0}}, __status = 0}}
(gdb) p &locale_mutex
$10 = (__gnu_cxx::__mutex *) 0x4010ee00
(gdb) p mutex
$11 = (pthread_mutex_t *) 0x4010ee00
As can be seen, this occurs running constructors from _init (). There
are several other calls to __GI___pthread_mutex_lock with properly
initialized mutexes prior to the one shown above which isn't properly
initialized. A properly initialized mutex looks like:
(gdb) p *mutex
$13 = {__m_reserved = 0, __m_count = 0, __m_owner = 0x0, __m_kind = 0,
__m_lock = {__spinlock = {lock = {1, 1, 1, 1}}, __status = 0}}
There are two earlier calls to __GI___pthread_mutex_lock from locale.
The first is here:
(gdb) bt
#0 *__GI___pthread_mutex_lock (mutex=0x402e1cb0) at mutex.c:99
#1 0x402ca258 in __pthread_once (once_control=0x4010dff8,
[EMAIL PROTECTED]: 0x40067568 <std::locale::_S_initialize_once()>)
at mutex.c:301
#2 0x40067620 in std::locale::_S_initialize ()
at
/home/dave/gnu/gcc-4.2/objdir/hppa-linux/libstdc++-v3/include/hppa-linux/bits/gthr-default.h:516
#3 0x4006797c in locale (this=0x402e1cb0)
at ../../../../gcc/libstdc++-v3/src/locale_init.cc:209
...
(gdb) info symbol 0x402e1cb0
once_masterlock in section .data
(gdb) p mutex
$14 = (pthread_mutex_t *) 0x402e1cb0
(gdb) p *mutex
$15 = {__m_reserved = 0, __m_count = 0, __m_owner = 0x0, __m_kind = 0,
__m_lock = {__spinlock = {lock = {1, 1, 1, 1}}, __status = 0}}
once_masterlock appears to be statically initialized.
>From locale_init.cc:
locale::locale() throw() : _M_impl(0)
{
_S_initialize();
__gnu_cxx::__scoped_lock sentry(locale_mutex);
_S_global->_M_add_reference();
_M_impl = _S_global;
}
It appears we hang at the "once_masterlock" line. We never get to
the next line.
Dave
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29118
