Re: observing process blocked on find_or_construct

From: Murali Kishore (bmuralikishore_at_[hidden])
Date: 2025-01-28 12:16:50

Thanks Peter Dimov, i have added logic unlock in signal handler, now i am
not seeing this issue.

I am seeing one more issue, if i call construct object and do work and
clear in loop of ~30000, i see following error while construct call.

43 #0  set_bits (b=0, n=...) at /x86/include/boost/interp
rocess/offset_ptr.hpp:728
44 #1  set_color (c=<optimized out>, n=...) at /x86/inclu
de/boost/intrusive/detail/rbtree_node.hpp:167
45 #2
boost::intrusive::rbtree_algorithms<boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void,
long, uns    igned long, 0ul>, true> >::rebalance_after_insertion
(header=..., p=...) at
/x86/include/boost/intrusive/rbtree_algorithms.hpp:558
46 #3  0x0000000001c3ba5d in
insert_equal<boost::intrusive::detail::key_nodeptr_comp<std::less<boost::interprocess::rbtree_best
_fit<boost::interprocess::mutex_family>::block_ctrl>,
boost::intrusive::bhtraits<boost::interprocess::rbtree_best_fit<boost:
:interprocess::mutex_family>::block_ctrl,
boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void>,
true>,     (boost::intrusive::link_mode_type)0, boost::intrusive::dft_tag,
3u>, boost::move_detail::identity<boost::interprocess::rbtr
ee_best_fit<boost::interprocess::mutex_family>::block_ctrl> > > (comp=...,
new_node=..., hint=..., header=...) at
/x86/include/boost/intrusive/rbtree_algorithms.hpp:388
47 #4
boost::intrusive::bstree_impl<boost::intrusive::bhtraits<boost::interprocess::rbtree_best_fit<boost::interprocess::mutex
_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>,
0ul>::block_ctrl, boost::intrusive::rbtree_node_tr
aits<boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>,
true>, (boost::intrusive::link_mode_type)0, boost::int    rusive::dft_tag,
3u>, void, void, unsigned long, true, (boost::intrusive::algo_types)5,
void>::insert_equal (this=this_at_entry    =0x7fcdf86f5038, hint=...,
value=...) at /x86/include/    boost/intrusive/bstree.hpp:1085
48 #5  0x0000000001c3e9f5 in insert (value=..., hint=...,
this=0x7fcdf86f5038) at /x86/include/boost/intrusive/set.hpp:752
49 #6
boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,
boost::interprocess::offset_ptr<void, long, unsi    gned long, 0ul>,
0ul>::priv_check_and_allocate (this=this_at_entry=0x7fcdf86f5010,
nunits=nunits_at_entry=10, block=0x7fcdf87429c0    ,
received_size=@0x7fcdfb5f5730: 149) at /x86/include/
boost/interprocess/mem_algo/rbtree_best_fit.hpp:1282
50 #7  0x0000000001c4c7ac in priv_allocate (backwards_multiple=1,
reuse_ptr=<synthetic pointer>, prefer_in_recvd_out_size=@0x7f
cdfb5f5730: 149, limit_size=<optimized out>, command=1,
this=0x7fcdf86f5010) at
/x86/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp:977
51 #8
boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family,
boost::interprocess::offset_ptr<void, long, unsi    gned long, 0ul>,
0ul>::allocate (this=this_at_entry=0x7fcdf86f5010, nbytes=<optimized out>) at
/x86/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp:673
52 #9  0x0000000001c4cc85 in allocate (nbytes=<optimized out>,
this=0x7fcdf86f5010) at
/x86/include/boost/interprocess/segment_manager.hpp:177

let me know what can cause this kind of issue.
Regards,
Murali

On Thu, Jan 23, 2025 at 11:35 PM Peter Dimov <pdimov_at_[hidden]> wrote:

> Murali Kishore wrote:
> > Hi ,
> >
> > We are trying interprocess scenario, one process created shared memory
> > objects and killed and second process open the object using
> find_or_construct
> > seeing this process blocked at getting lock.
> >
> > bt as shown below,
> > #0  __lll_lock_wait () at
> > ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
> > #1  0x00007fa6b6733eb6 in _L_lock_941 () from /lib64/libpthread.so.0
> > #2  0x00007fa6b6733daf in __GI___pthread_mutex_lock
> > (mutex=mutex_at_entry=0x7fa6b198b070)
> > at ../nptl/pthread_mutex_lock.c:113
> > #3  0x0000000001bc3822 in lock (this=0x7fa6b198b070) at
> > /x86/include/boost/interprocess/sync/posix/recursive_mutex.hpp:90
>
> Detecting mutexes held by dead processes requires the so-called
> POSIX robust mutexes. I can see in the Interprocess source code
> that those are enabled when the macro
> BOOST_INTERPROCESS_POSIX_ROBUST_MUTEXES is defined.
>
> This macro is defined automatically
>
> #if (_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L)
>
>
> https://github.com/boostorg/interprocess/blob/29cee9c6067f1d20ddb6421af15977e7bbaa3a18/include/boost/interprocess/detail/workaround.hpp#L81-L83
>
> but I suppose you can also try defining it manually and see if that helps,
> because _XOPEN_SOURCE and _POSIX_C_SOURCE are also user macros
> and you probably aren't defining any of them.
>
>
>

-- 
Regards,
Murali Kishore