比如说，有两个模型同时加载，很容易崩溃。
跟踪的时候会发现，在deserialize()的地方出错。
如果用gdb看，错误有时是这样的：
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `./gh_manager thread false 1'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f7378dfa984 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
[Current thread is 1 (Thread 0x7f7345066700 (LWP 18369))]
(gdb) backtrace
#0 0x00007f7378dfa984 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#1 0x00007f7378e83106 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#2 0x00007f7378dff1a7 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#3 0x00007f7378dffe3b in _PyObject_GC_Malloc ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#4 0x00007f7378dffeed in _PyObject_GC_New ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#5 0x00007f7378ea43f8 in PyWrapper_New ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#6 0x00007f7378ea55d7 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#7 0x00007f7378e372b3 in PyObject_Call ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#8 0x00007f7378dd539c in PyEval_EvalFrameEx ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#9 0x00007f7378f0e11c in PyEval_EvalCodeEx ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#10 0x00007f7378e643b0 in ?? ()
from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0
#11 0x00007f7378e372b3 in PyObject_Call ()
---Type to continue, or q to quit---q
from /usr/lib/x86_64-linux-gnu/libpytQuit
