.
Thread 2 (process 9975):
#0  0x00007fab928c79ff in ?? () from /lib/libc.so.6
#1  0x00007fab928c8276 in free () from /lib/libc.so.6
#2  0x000000000067b5a6 in zend_hash_del_key_or_index ()
#3  0x000000000067358f in zend_unregister_functions ()
#4  0x0000000000674af9 in module_destructor ()
#5  0x000000000067b080 in ?? ()
#6  0x000000000067b338 in zend_hash_graceful_reverse_destroy ()
#7  0x0000000000670a07 in zend_shutdown ()
#8  0x000000000062a0f5 in php_module_shutdown ()
#9  0x00000000006eefbe in main ()
.
Thread 1 (process 9979):
#0  0x00007fab91c794ef in ?? () from /lib/libgcc_s.so.1
#1  0x00007fab91c79e3b in ?? () from /lib/libgcc_s.so.1
#2  0x00007fab91c79f43 in _Unwind_ForcedUnwind () from /lib/libgcc_s.so.1
#3  0x00007fab94517710 in __pthread_unwind () from /lib/libpthread.so.0
#4  0x00007fab94511b05 in pthread_exit () from /lib/libpthread.so.0
#5  0x00007fab8dd1ff3b in ?? ()
#6  0x0000000000000000 in ?? ()