Re: [aspell-devel] 0.60 hangs at pthread_mutex_lock

[James Lee]

On 27/04/04, 17:26:07, Kevin Atkinson <address@hidden> wrote regarding Re: 
[aspell-devel] 0.60 hangs at pthread_mutex_lock :

> > > > Both get_cache_data methods in cache_t.hpp call the mutex lock
> > > > a second time without unlocking. The first lock is on entry and
> > > > the second from copy. This happens when the lock of n is the
> > > > same as that of cache. The mutex will not unlock as the thread
> > > > locked it itself, hence the thread thread blocks on the second
> > > > lock.
> >
> > > Could I have a test cast that will trigger the problem?
> >
> > A case. Pan via gtkspell as mentioned above - fails every time.

> So I should Pan so I can find the problem?

Yes, if that what it takes. I had to compile them both too.



> Can I at least have a backtrace?

#0  0xdeedb3e8 in _lwp_sema_wait () from /usr/lib/libc.so.1
#1  0xdef6971d in _park () from /usr/lib/libthread.so.1
#2  0xdef69543 in _swtch () from /usr/lib/libthread.so.1
#3  0xdef6aa9c in _mutex_adaptive_lock () from /usr/lib/libthread.so.1
#4  0xdef6b3e5 in pthread_mutex_lock () from /usr/lib/libthread.so.1
#5  0xdfaa47ac in acommon::Mutex::lock() (this=0xdfb51c60) at 
common/lock.hpp:38
#6  0xdfaa3894 in acommon::Lock::Lock(acommon::Mutex*) (this=0x80452a0, 
l=0xdfb51c60) at common/lock.hpp:60
#7  0xdfa476b9 in acommon::Cacheable::copy() const (this=0x8397118) at 
common/cache.cpp:13
#8  0xdfacba91 in acommon::PosibErr<acommon::Decode*> 
acommon::get_cache_data<acommon::Decode>(acommon::GlobalCache<acommon::Dec
ode>*, acommon::Decode::CacheConfig*, acommon::Decode::CacheKey const&) 
(cache=0xdfb51c60, config=0x838c750, address@hidden) at 
common/cache-t.hpp:61
#9  0xdfac3614 in acommon::PosibErr<void> 
acommon::setup<acommon::Decode>(acommon::CachePtr<acommon::Decode>&, 
acommon::GlobalCache<acommon::Decode>*, acommon::Decode::CacheConfig*, 
acommon::Decode::CacheKey const&) (address@hidden, cache=0xdfb51c60, 
config=0x838c750, address@hidden) at common/cache.hpp:71
#10 0xdfa5dcb5 in acommon::Convert::init(acommon::Config const&, 
acommon::ParmString, acommon::ParmString) (this=0x839c978, address@hidden, 
in={str_ = 0x8396ed0 "iso-8859-1", size_ = 4294967295}, out={str_ = 
0x8396f60 "utf-8", size_ = 4294967295}) at common/convert.cpp:924
#11 0xdfa5e726 in acommon::Convert::init_norm_to(acommon::Config const&, 
acommon::ParmString, acommon::ParmString) (this=0x839c978, address@hidden, 
in={str_ = 0x8396ed0 "iso-8859-1", size_ = 4294967295}, out={str_ = 
0x8396f60 "utf-8", size_ = 4294967295}) at common/convert.cpp:973
#12 0xdfa5d12f in acommon::internal_new_convert(acommon::Config const&, 
acommon::ParmString, acommon::ParmString, bool, acommon::Normalize) 
(address@hidden, in={str_ = 0x8396ed0 "iso-8859-1", size_ = 4294967295}, 
out={str_ = 0x8396f60 "utf-8", size_ = 4294967295}, if_needed=true, 
norm=NormTo) at common/convert.cpp:881
#13 0xdfa6d7bf in acommon::new_convert_if_needed(acommon::Config const&, 
acommon::ParmString, acommon::ParmString, acommon::Normalize) 
(address@hidden, in={str_ = 0x8396fa8 "iso-8859-1", size_ = 10}, out={str_ 
= 0xdfafd21c "utf-8", size_ = 4294967295}, n=NormTo) at 
common/convert.hpp:222
#14 0xdfadef3b in acommon::ConvObj::setup(acommon::Config const&, 
acommon::ParmString, acommon::ParmString, acommon::Normalize) 
(this=0x80457e0, address@hidden, from={str_ = 0x8396fa8 "iso-8859-1", size_ 
= 10}, to={str_ = 0xdfafd21c "utf-8", size_ = 4294967295}, norm=NormTo) 
at common/convert.hpp:233
#15 0xdfaf598c in acommon::Conv::setup(acommon::Config const&, 
acommon::ParmString, acommon::ParmString, acommon::Normalize) 
(this=0x80457c0, address@hidden, from={str_ = 0x8396fa8 "iso-8859-1", size_ 
= 10}, to={str_ = 0xdfafd21c "utf-8", size_ = 4294967295}, norm=NormTo) 
at common/convert.hpp:317
#16 0xdfa88f1b in aspeller::Language::set_lang_defaults(acommon::Config&) 
const (this=0x8394680, address@hidden) at 
modules/speller/default/language.cpp:308
#17 0xdfa7329f in 
aspeller::Dictionary::set_check_lang(acommon::ParmString, 
acommon::Config&) (this=0x83925a8, l={str_ = 0x8394638 "\en", size_ = 
4294967295}, address@hidden) at modules/speller/default/data.cpp:98
#18 0xdfa6881f in (anonymous 
namespace)::ReadOnlyDict::load(acommon::ParmString, acommon::Config&, 
aspeller::LocalDictList*, aspeller::SpellerImpl*, aspeller::LocalDictInfo 
const*) (this=0x83925a8, f0={str_ = 0x8390550 
"/opt/csw/lib/asp\ell/\en-only.rws", size_ = 31}, address@hidden) at 
modules/speller/default/readonly_ws.cpp:353
#19 0xdfa754bf in aspeller::add_data_set(acommon::ParmString, 
acommon::Config&, aspeller::LocalDict&, aspeller::LocalDictList*, 
aspeller::SpellerImpl*, aspeller::LocalDictInfo const*, 
acommon::ParmString, unsigned) (fn={str_ = 0x838d9bd "\en-only.rws", 
size_ = 11}, address@hidden, address@hidden, new_dicts=0x8046390, 
speller=0x838d5d0, local_info=0x8045d50, dir={str_ = 0x838c630 
"/opt/csw/lib/asp\ell", size_ = 19}, allowed=255) at 
modules/speller/default/data.cpp:444
#20 0xdfa76821 in (anonymous 
namespace)::MultiDictImpl::load(acommon::ParmString, acommon::Config&, 
aspeller::LocalDictList*, aspeller::SpellerImpl*, aspeller::LocalDictInfo 
const*) (this=0x838d910, fn={str_ = 0x838c678 
"/opt/csw/lib/asp\ell/\en_GB.multi", size_ = 31}, address@hidden, 
new_dicts=0x8046390, speller=0x838d5d0, li=0x0) at 
modules/speller/default/multi_ws.cpp:65
#21 0xdfa754bf in aspeller::add_data_set(acommon::ParmString, 
acommon::Config&, aspeller::LocalDict&, aspeller::LocalDictList*, 
aspeller::SpellerImpl*, aspeller::LocalDictInfo const*, 
acommon::ParmString, unsigned) (fn={str_ = 0x837f450 
"/opt/csw/lib/asp\ell/\en_GB.multi", size_ = 31}, address@hidden, 
address@hidden, new_dicts=0x8046390, speller=0x838d5d0, local_info=0x0, 
dir={str_ = 0x0, size_ = 4294967295}, allowed=255) at 
modules/speller/default/data.cpp:444
#22 0xdfa7f871 in aspeller::SpellerImpl::setup(acommon::Config*) 
(this=0x838d5d0, c=0x838c750) at modules/speller/default/speller_impl.cpp:435
#23 0xdfaa0374 in acommon::new_speller(acommon::Config*) (c0=0x838bc68) 
at lib/find_speller.cpp:403
#24 0xdfaa0ebf in new_aspell_speller (config=0x838bc68) at 
lib/speller-c.cpp:26
#25 0xdfb73704 in gtkspell_set_language_internal (spell=0x838a4e0, 
lang=0x8047f42 "\en_GB", error=0x0) at gtkspell.c:429
#26 0xdfb7397b in gtkspell_new_attach (view=0x838b310, lang=0x0, 
error=0x0) at gtkspell.c:520
#27 0xdfb73d25 in gtkspell_attach (view=0x838b310) at deprecated.c:34
#28 0x0808caaf in create_body_pane_nolock (mw=0x8380f08) at 
message-window.c:1989
#29 0x0808a5f9 in create_post_info_pane (mw=0x8380f08) at 
message-window.c:1123
#30 0x0808ce41 in message_post_window_create (compose=0x8380f08) at 
message-window.c:2039
#31 0x0808d318 in message_window_new (message=0x0, type=NNTP_POST) at 
message-window.c:2152
#32 0x0808cccb in message_post_window () at message-window.c:2019
#33 0x0806b961 in pan_action_do (action=ACTION_COMPOSE_NEW) at 
action.c:89
#34 0x0808341a in toolbar_cb (button=0x8266a10, user_data=0x0) at 
gui.c:1152
#35 0xdf4c4d87 in g_cclosure_marshal_VOID__VOID () from 
/opt/csw/lib/libgobject-2.0.so.0
#36 0xdf4b0bd1 in g_object_steal_data () from 
/opt/csw/lib/libgobject-2.0.so.0
#37 0xdf4ead4c in ?? () from /opt/csw/lib/libgobject-2.0.so.0
#38 0xdf4a8eac in g_closure_invoke () from 
/opt/csw/lib/libgobject-2.0.so.0
#39 0x08046990 in ?? ()





> > The key to the problem is the lock of the cache is the same as that
> > of n, n being the object return from the cache by find. I can't
> > tell if this is the error or what is intended.
> >
> > An avoidance tactic is to unlock the mutex explicitly, then it can
> > be unlock after the find and before the copy.

> I'm still not exactly sure where the problem is.  A patch to fix the
> problem will be most welcome.

I can see the problem (as described twice above) but I don't know if
it is correct that the lock is shared, hence which problem should be
fixed? The cache or the lock?