Assertion failure mutex_get_waiters(mutex) == 0 at shutdown

https://bugs.launchpad.net/percona-server/+bug/1291202

Used XtraDB version: Percona XtraDB (http://www.percona.com) 5.6.15-63.0

Starting point is a 15-min concurrent non-deterministic test case and then at shutdown

(gdb) thread apply all bt

Thread 4 (Thread 0x7ff6b89a0700 (LWP 6303)):
#0 0x00007ff6b7b6d9f7 in do_sigwait ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x00007ff6b7b6da79 in sigwait () from /lib/x86_64-linux-gnu/libpthread.so.0
#2 0x000000000058dd56 in signal_hand (arg=0x0)
at /home/elenst/bzr/10.0/sql/mysqld.cc:3298
#3 0x0000000000e8ae9b in pfs_spawn_thread (arg=0x7ff6af775210)
at /home/elenst/bzr/10.0/storage/perfschema/pfs.cc:1853
#4 0x00007ff6b7b65e9a in start_thread ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#5 0x00007ff6b707ccbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#6 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7ff6b89eb780 (LWP 6265)):
#0 0x00007ff6b7b69d84 in pthread_cond_wait@@GLIBC_2.3.2 ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x0000000000f351c5 in safe_cond_wait (cond=0x196d540 <COND_thread_count>,
mp=0x196c480 <LOCK_thread_count>,
file=0xff9860 "/home/elenst/bzr/10.0/include/mysql/psi/mysql_thread.h",
line=1154) at /home/elenst/bzr/10.0/mysys/thr_mutex.c:493
#2 0x0000000000588781 in inline_mysql_cond_wait (
that=0x196d540 <COND_thread_count>, mutex=0x196c480 <LOCK_thread_count>,
--Type <return> to continue, or q <return> to quit--
src_file=0xffb3a8 "/home/elenst/bzr/10.0/sql/mysqld.cc", src_line=5519)
at /home/elenst/bzr/10.0/include/mysql/psi/mysql_thread.h:1154
#3 0x0000000000591977 in mysqld_main (argc=151, argv=0x7ff6b647fac0)
at /home/elenst/bzr/10.0/sql/mysqld.cc:5519
#4 0x0000000000588280 in main (argc=16, argv=0x7fffebcb58d8)
at /home/elenst/bzr/10.0/sql/main.cc:25

Thread 2 (Thread 0x7ff6b63ff700 (LWP 6274)):
#0 0x00007ff6b7b6a0fe in pthread_cond_timedwait@@GLIBC_2.3.2 ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x0000000000f354c9 in safe_cond_timedwait (
cond=0x2192e80 <COND_checkpoint>, mp=0x2192dc0 <LOCK_checkpoint>,
abstime=0x7ff6b63fed60,
file=0x11114b0 "/home/elenst/bzr/10.0/include/mysql/psi/mysql_thread.h",
line=1191) at /home/elenst/bzr/10.0/mysys/thr_mutex.c:547
#2 0x0000000000a60641 in inline_mysql_cond_timedwait (
that=0x2192e80 <COND_checkpoint>, mutex=0x2192dc0 <LOCK_checkpoint>,
abstime=0x7ff6b63fed60,
src_file=0x11114e8 "/home/elenst/bzr/10.0/storage/maria/ma_servicethread.c", src_line=119) at /home/elenst/bzr/10.0/include/mysql/psi/mysql_thread.h:1191
#3 0x0000000000a60b27 in my_service_thread_sleep (
control=0x17ab0d0 <checkpoint_control>, sleep_time=30000000000)
at /home/elenst/bzr/10.0/storage/maria/ma_servicethread.c:118
--Type <return> to continue, or q <return> to quit--
#4 0x0000000000a5570e in ma_checkpoint_background (arg=0x1e)
at /home/elenst/bzr/10.0/storage/maria/ma_checkpoint.c:709
#5 0x0000000000e8ae9b in pfs_spawn_thread (arg=0x7ff6b645a210)
at /home/elenst/bzr/10.0/storage/perfschema/pfs.cc:1853
#6 0x00007ff6b7b65e9a in start_thread ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#7 0x00007ff6b707ccbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#8 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7ff6b5bb5700 (LWP 6669)):
#0 0x00007ff6b7b6af8c in pthread_kill ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x0000000000f2ea18 in my_write_core (sig=6)
at /home/elenst/bzr/10.0/mysys/stacktrace.c:457
#2 0x00000000008444cf in handle_fatal_signal (sig=6)
at /home/elenst/bzr/10.0/sql/signal_handler.cc:262
#3 <signal handler called>
#4 0x00007ff6b6fbf425 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#5 0x00007ff6b6fc2b8b in abort () from /lib/x86_64-linux-gnu/libc.so.6
#6 0x0000000000ca29e4 in mutex_free_func (mutex=0x7ff6af522988)
at /home/elenst/bzr/10.0/storage/xtradb/sync/sync0sync.cc:371
#7 0x0000000000ca263c in pfs_mutex_free_func (mutex=0x7ff6af522988)
at /home/elenst/bzr/10.0/storage/xtradb/include/sync0sync.ic:585
--Type <return> to continue, or q <return> to quit--
#8 0x0000000000ca4cec in sync_close ()
at /home/elenst/bzr/10.0/storage/xtradb/sync/sync0sync.cc:1642
#9 0x0000000000c9d33d in innobase_shutdown_for_mysql ()
at /home/elenst/bzr/10.0/storage/xtradb/srv/srv0start.cc:3081
#10 0x0000000000b4d6d9 in innobase_end (hton=0x7ff6b645ee70,
type=HA_PANIC_CLOSE)
at /home/elenst/bzr/10.0/storage/xtradb/handler/ha_innodb.cc:3817
#11 0x0000000000845dd8 in ha_finalize_handlerton (plugin=0x7ff6b1ff57f8)
at /home/elenst/bzr/10.0/sql/handler.cc:440
#12 0x000000000066017b in plugin_deinitialize (plugin=0x7ff6b1ff57f8,
ref_check=true) at /home/elenst/bzr/10.0/sql/sql_plugin.cc:1169
#13 0x0000000000660541 in reap_plugins ()
at /home/elenst/bzr/10.0/sql/sql_plugin.cc:1242
#14 0x0000000000662416 in plugin_shutdown ()
at /home/elenst/bzr/10.0/sql/sql_plugin.cc:1904
#15 0x000000000058b555 in clean_up (print_message=true)
at /home/elenst/bzr/10.0/sql/mysqld.cc:2015
#16 0x000000000058b304 in unireg_end ()
at /home/elenst/bzr/10.0/sql/mysqld.cc:1922
#17 0x000000000058b226 in kill_server (sig_ptr=0x0)
at /home/elenst/bzr/10.0/sql/mysqld.cc:1850
#18 0x000000000058b243 in kill_server_thread (arg=0x7ff6b899fd60)
at /home/elenst/bzr/10.0/sql/mysqld.cc:1873
--Type <return> to continue, or q <return> to quit--
#19 0x0000000000e8ae9b in pfs_spawn_thread (arg=0x7ff6a342a1d0)
at /home/elenst/bzr/10.0/storage/perfschema/pfs.cc:1853
#20 0x00007ff6b7b65e9a in start_thread ()
from /lib/x86_64-linux-gnu/libpthread.so.0
#21 0x00007ff6b707ccbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#22 0x0000000000000000 in ?? ()

(gdb)
#6 0x0000000000ca29e4 in mutex_free_func (mutex=0x7ff6af522988)
at /home/elenst/bzr/10.0/storage/xtradb/sync/sync0sync.cc:371
371 ut_a(mutex_get_waiters(mutex) == 0);
(gdb) p *mutex
$1 = {event = 0x7ff6b1749580, lock_word = 0 '\000', waiters = 1, list =

{ prev = 0x0, next = 0x7ff6af5228f8}

,
file_name = 0x1192040 "/home/elenst/bzr/10.0/storage/xtradb/buf/buf0lru.cc",
line = 2293, level = 145,
cfile_name = 0x118c0f8 "/home/elenst/bzr/10.0/storage/xtradb/buf/buf0buf.cc", cline = 1288, count_os_wait = 2, thread_id = 18446744073709551615,
magic_n = 979585, ib_mutex_type = 0,
cmutex_name = 0x118c9d2 "&buf_pool->free_list_mutex", pfs_psi = 0x0}