Boost Python，传播c++回调到Python导致分段错误

我在c++中有以下侦听器，它接收一个Python对象来传播回调。

class PyClient {
    private:
        std::vector<DipSubscription *> subs;
        subsFactory *sub;
        class GeneralDataListener: public SubscriptionListener {
            private:
                PyClient * client;
            public:
                GeneralDataListener(PyClient *c):client(c){
                    client->pyListener.attr("log_message")("Handler created");
                }
                void handleMessage(Subscription *sub, Data &message) {
                    // Lock the execution of this method
                    PyGILState_STATE state = PyGILState_Ensure();
                    client->pyListener.attr("log_message")("Data received for topic");
                    ...
                    // This method ends modifying the value of the Python object
                    topicEntity.attr("save_value")(valueKey, extractDipValue(valueKey.c_str(), message))
                    // Release the lock
                    PyGILState_Release(state);
                }
                void connected(Subscription *sub) {
                    client->pyListener.attr("connected")(sub->getTopicName());
                }
                void disconnected(Subscription *sub, char* reason) {
                    std::string s_reason(reason);
                    client->pyListener.attr("disconnected")(sub->getTopicName(), s_reason);
                }
                void handleException(Subscription *sub, Exception &ex) {
                    client->pyListener.attr("handle_exception")(sub->getTopicName())(ex.what());
                }
        };
        GeneralDataListener *handler;
    public:
        python::object pyListener;

        PyClient(python::object pyList): pyListener(pyList) {
            std::ostringstream iss;
            iss << "Listener" << getpid();
            sub = Sub::create(iss.str().c_str());
            createSubscriptions();
        }
        ~PyClient() {
            for (unsigned int i = 0; i < subs.size(); i++) {
                if (subs[i] == NULL) {
                    continue;
                }
                sub->destroySubscription(subs[i]);
            }
        }
};

BOOST_PYTHON_MODULE(pytest)
{
    // There is no need to expose more methods as will be used as callbacks
    Py_Initialize();
    PyEval_InitThreads();
    python::class_<PyClient>("PyClient",     python::init<python::object>())
        .def("pokeHandler", &PyClient::pokeHandler);
};

然后，我有了我的Python程序，就像这样:

import sys
import time
import pytest

class Entity(object):
    def __init__(self, entity, mapping):
        self.entity = entity
        self.mapping = mapping
        self.values = {}
        for field in mapping:
            self.values[field] = ""
        self.updated = False
    def save_value(self, field, value):
        self.values[field] = value
        self.updated = True

class PyListener(object):
    def __init__(self):
        self.listeners = 0
        self.mapping = ["value"]
        self.path_entity = {}
        self.path_entity["path/to/node"] = Entity('Name', self.mapping)
    def connected(self, topic):
        print "%s topic connected" % topic
    def disconnected(self, topic, reason):
        print "%s topic disconnected, reason: %s" % (topic, reason)
    def handle_message(self, topic):
        print "Handling message from topic %s" % topic
    def handle_exception(self, topic, exception):
        print "Exception %s in topic %s" % (exception, topic)
    def log_message(self, message):
       print message
    def sample(self):
        for path, entity in self.path_entity.iteritems():
            if not entity.updated:
                return False
            sample = " ".join([entity.values[field] for field in dip_entity.mapping])
            print "%d %s %d %s" % (0, entity.entity, 4324, sample)
            entity.updated = False
        return True

if __name__ == "__main__":
    sys.settrace(trace)
    py_listener = PyListener()
    sub = pytest.PyClient(py_listener)
    while True:
        if py_listener.sample():
            break

所以，最后，我的问题似乎是，当我开始在Python程序中运行while True时，脚本会卡住检查实体是否更新，并且随机地，当c++侦听器试图调用回调时，我得到一个分段错误。

如果我只是尝试时间也是一样的。在python脚本中休眠并按时间调用sample。我知道如果我从c++代码中调用sample就可以解决这个问题，但是这个脚本将由其他Python模块运行，这些模块将调用给定特定延迟的sample方法。因此，预期的功能将是c++更新实体的值，而Python脚本只读取它们。

我已经用gdb调试了这个错误，但是我得到的堆栈跟踪并没有太多的解释:

#0  0x00007ffff7a83717 in PyFrame_New () from /lib64/libpython2.7.so.1.0
#1  0x00007ffff7af58dc in PyEval_EvalFrameEx () from /lib64/libpython2.7.so.1.0
#2  0x00007ffff7af718d in PyEval_EvalCodeEx () from /lib64/libpython2.7.so.1.0
#3  0x00007ffff7af7292 in PyEval_EvalCode () from /lib64/libpython2.7.so.1.0
#4  0x00007ffff7b106cf in run_mod () from /lib64/libpython2.7.so.1.0
#5  0x00007ffff7b1188e in PyRun_FileExFlags () from /lib64/libpython2.7.so.1.0
#6  0x00007ffff7b12b19 in PyRun_SimpleFileExFlags () from /lib64/libpython2.7.so.1.0
#7  0x00007ffff7b23b1f in Py_Main () from /lib64/libpython2.7.so.1.0
#8  0x00007ffff6d50af5 in __libc_start_main () from /lib64/libc.so.6
#9  0x0000000000400721 in _start ()

如果用sys调试。在Python中trace分段错误前的最后一行总是在样例方法中，但它可能会有所不同。

我不知道如何解决这个沟通问题，所以任何正确方向的建议都将不胜感激。

编辑修改PyDipClient对PyClient的引用

正在发生的事情是我从Python主方法启动程序，如果然后c++侦听器尝试回调Python侦听器，它会因分割错误错误而崩溃，我认为创建的唯一线程是当我创建订阅时，但那是来自库内部的代码，我不知道是如何工作的。

如果我删除Python侦听器的所有回调，并强制Python的方法(如调用pokehandler)，一切都工作得很好。