&引用；访问冲突读取位置“；包装c+时+；带Cython的api 我在Python中使用一个包装器，用C++编写的API。api本身是本地安装在我的计算机上的Windows（7）应用程序的c库/api的包装器。我可以访问C++ API源代码而不是C库。我使用Python 2.7.5（即VS 9.0）中的distutils构建Cython模块，并尝试了3.4.1（即VS 10.0）两种32位安装

访问模块时出现的情况是，弹出窗口显示

python.exe已停止工作

，然后按close时

进程结束，退出代码为-1073741819（0xC0000005）

。调试时（我使用Visual Studio 2012），我在python.exe中的0x64ED1EB2（apiclient10m.dll）处得到：

未处理的异常：0xC0000005:访问冲突读取位置0x7C03B776

。有时，我还会在python.exe中的0x1E0EFECF（python27.dll）处获得

未处理的异常：0xC0000005:访问冲突写入位置0x5753422C。

这取决于我调用api的方式

我认为它与C++中定义的对象“Objistt”相关，并被发送到C库进行更新。然后用C++读取这个对象，然后将INT发送回Cython。当返回某个内存位置时，调用堆栈中的某个地方存在不允许的访问

这就是它看起来的样子：

mymodule.pyx:

# distutils: language = c++
# distutils: extra_compile_args = ["/EHsc"]
# distutils: sources = [connection.cpp, object.cpp]
# distutils: include_dirs=['C:\\Program Files (x86)\\App\\api']
# distutils: library_dirs=['C:\\Program Files (x86)\\App\\api']

from libcpp.string cimport string
from cython.operator cimport dereference as deref

cdef extern from "connection.h" namespace "pvcs":

    cdef cppclass connection:
        connection() except +
        ...

cdef class PyConnection:

    cdef connection *_cpp_connection_instance    # Pointer to wrapped connection instance

    def __cinit__(self):
        self._cpp_connection_instance = new connection()

    def __dealloc__(self):
        del self._cpp_connection_instance

cdef extern from "object.h" namespace "pvcs":

    cdef int get_baseline_uid(connection c, string spec)

def get_uid(PyConnection connection, bytes specification):
    return get_baseline_uid(
        deref(connection._cpp_connection_instance), specification)

namespace pvcs {
  class connection {
    public:
      connection();
      ~connection();

  int get_baseline_uid(connection & c, std::string & spec) {
    ObjStruct os = { 0 };

    //Fills the struct os with the information
    if(InitSpec(c.uid(), const_cast<char *>(spec.c_str()), BASELINE, &os) == 1) {
      int uid = os.uid;
      ObjFree(&os);
      return uid;  // Somewhere after this point the error occurs.
    }
    return -1;
  }

typedef struct ObjStruct
{
    int         uid;
    int         objType;
    int         typeUid;
    _TCHAR      typeName[(L_TYPE_NAME + 1)*CHARSIZEMAX];
    _TCHAR      productId[(L_PRODUCT_ID + 1)*CHARSIZEMAX];
    _TCHAR      objId[(MAX_L_ID + 1)*CHARSIZEMAX];
    _TCHAR      variant[(L_VARIANT + 1)*CHARSIZEMAX];
    _TCHAR      revision[(L_REVISION + 1)*CHARSIZEMAX];
    _TCHAR      description[(L_DESCRIPTION + 1)*CHARSIZEMAX];
    _TCHAR      userName[(L_USER + 1)*CHARSIZEMAX];
    _TCHAR      status[(L_STATUS + 1)*CHARSIZEMAX];
    _TCHAR      dateTime[(L_DATE_TIME + 1)*CHARSIZEMAX];
    _TCHAR      isExtracted;
    int         noAttrs;        /* The number of attributes for this object. */
    ObjAttrStruct *attrs;   /* Pointer to the array of attributes. */
    int         specUid;
}   ObjStruct;

extern int APIFUN CCONV InitSpec(int, _TCHAR*, int, PcmsObjStruct*);

from distutils.core import setup
from Cython.Build import cythonize

METADATA = {'name': 'mymodule', 
            'ext_modules': cythonize("mymodule.pyx"),}

if __name__ == '__main__':
    metadata = METADATA.copy()
    setup(**metadata)

get_uid方法是失败的方法

c++api:

# distutils: language = c++
# distutils: extra_compile_args = ["/EHsc"]
# distutils: sources = [connection.cpp, object.cpp]
# distutils: include_dirs=['C:\\Program Files (x86)\\App\\api']
# distutils: library_dirs=['C:\\Program Files (x86)\\App\\api']

from libcpp.string cimport string
from cython.operator cimport dereference as deref

cdef extern from "connection.h" namespace "pvcs":

    cdef cppclass connection:
        connection() except +
        ...

cdef class PyConnection:

    cdef connection *_cpp_connection_instance    # Pointer to wrapped connection instance

    def __cinit__(self):
        self._cpp_connection_instance = new connection()

    def __dealloc__(self):
        del self._cpp_connection_instance

cdef extern from "object.h" namespace "pvcs":

    cdef int get_baseline_uid(connection c, string spec)

def get_uid(PyConnection connection, bytes specification):
    return get_baseline_uid(
        deref(connection._cpp_connection_instance), specification)

namespace pvcs {
  class connection {
    public:
      connection();
      ~connection();

  int get_baseline_uid(connection & c, std::string & spec) {
    ObjStruct os = { 0 };

    //Fills the struct os with the information
    if(InitSpec(c.uid(), const_cast<char *>(spec.c_str()), BASELINE, &os) == 1) {
      int uid = os.uid;
      ObjFree(&os);
      return uid;  // Somewhere after this point the error occurs.
    }
    return -1;
  }

typedef struct ObjStruct
{
    int         uid;
    int         objType;
    int         typeUid;
    _TCHAR      typeName[(L_TYPE_NAME + 1)*CHARSIZEMAX];
    _TCHAR      productId[(L_PRODUCT_ID + 1)*CHARSIZEMAX];
    _TCHAR      objId[(MAX_L_ID + 1)*CHARSIZEMAX];
    _TCHAR      variant[(L_VARIANT + 1)*CHARSIZEMAX];
    _TCHAR      revision[(L_REVISION + 1)*CHARSIZEMAX];
    _TCHAR      description[(L_DESCRIPTION + 1)*CHARSIZEMAX];
    _TCHAR      userName[(L_USER + 1)*CHARSIZEMAX];
    _TCHAR      status[(L_STATUS + 1)*CHARSIZEMAX];
    _TCHAR      dateTime[(L_DATE_TIME + 1)*CHARSIZEMAX];
    _TCHAR      isExtracted;
    int         noAttrs;        /* The number of attributes for this object. */
    ObjAttrStruct *attrs;   /* Pointer to the array of attributes. */
    int         specUid;
}   ObjStruct;

extern int APIFUN CCONV InitSpec(int, _TCHAR*, int, PcmsObjStruct*);

from distutils.core import setup
from Cython.Build import cythonize

METADATA = {'name': 'mymodule', 
            'ext_modules': cythonize("mymodule.pyx"),}

if __name__ == '__main__':
    metadata = METADATA.copy()
    setup(**metadata)

h文件与一组静态库（.lib文件）一起驻留在为distutils

C:\Program Files（x86）\App\api

指定的目录中。这些库似乎可以访问

C:\ProgramFiles（x86）\App\prog

文件夹中的dll文件。这是导致访问冲突的dll

apiclient10m.dll

所在位置

distutils setup.py:

# distutils: language = c++
# distutils: extra_compile_args = ["/EHsc"]
# distutils: sources = [connection.cpp, object.cpp]
# distutils: include_dirs=['C:\\Program Files (x86)\\App\\api']
# distutils: library_dirs=['C:\\Program Files (x86)\\App\\api']

from libcpp.string cimport string
from cython.operator cimport dereference as deref

cdef extern from "connection.h" namespace "pvcs":

    cdef cppclass connection:
        connection() except +
        ...

cdef class PyConnection:

    cdef connection *_cpp_connection_instance    # Pointer to wrapped connection instance

    def __cinit__(self):
        self._cpp_connection_instance = new connection()

    def __dealloc__(self):
        del self._cpp_connection_instance

cdef extern from "object.h" namespace "pvcs":

    cdef int get_baseline_uid(connection c, string spec)

def get_uid(PyConnection connection, bytes specification):
    return get_baseline_uid(
        deref(connection._cpp_connection_instance), specification)

namespace pvcs {
  class connection {
    public:
      connection();
      ~connection();

  int get_baseline_uid(connection & c, std::string & spec) {
    ObjStruct os = { 0 };

    //Fills the struct os with the information
    if(InitSpec(c.uid(), const_cast<char *>(spec.c_str()), BASELINE, &os) == 1) {
      int uid = os.uid;
      ObjFree(&os);
      return uid;  // Somewhere after this point the error occurs.
    }
    return -1;
  }

typedef struct ObjStruct
{
    int         uid;
    int         objType;
    int         typeUid;
    _TCHAR      typeName[(L_TYPE_NAME + 1)*CHARSIZEMAX];
    _TCHAR      productId[(L_PRODUCT_ID + 1)*CHARSIZEMAX];
    _TCHAR      objId[(MAX_L_ID + 1)*CHARSIZEMAX];
    _TCHAR      variant[(L_VARIANT + 1)*CHARSIZEMAX];
    _TCHAR      revision[(L_REVISION + 1)*CHARSIZEMAX];
    _TCHAR      description[(L_DESCRIPTION + 1)*CHARSIZEMAX];
    _TCHAR      userName[(L_USER + 1)*CHARSIZEMAX];
    _TCHAR      status[(L_STATUS + 1)*CHARSIZEMAX];
    _TCHAR      dateTime[(L_DATE_TIME + 1)*CHARSIZEMAX];
    _TCHAR      isExtracted;
    int         noAttrs;        /* The number of attributes for this object. */
    ObjAttrStruct *attrs;   /* Pointer to the array of attributes. */
    int         specUid;
}   ObjStruct;

extern int APIFUN CCONV InitSpec(int, _TCHAR*, int, PcmsObjStruct*);

from distutils.core import setup
from Cython.Build import cythonize

METADATA = {'name': 'mymodule', 
            'ext_modules': cythonize("mymodule.pyx"),}

if __name__ == '__main__':
    metadata = METADATA.copy()
    setup(**metadata)

一切编译和链接都很好，但在运行时，例如，根据我上面的解释，它在最后一行失败：

import mymodule
con = mymodule.PyConnection()
uid = mymodule.get_uid(con, "item specification")

---

const\u cast（spec.c\u str（））

看起来很恐怖。如果该函数正在以任何方式修改它所指向的内容，那么程序行为是未定义的。@Bathsheba将其替换为

itemid

，根据以下构造，它并没有解决访问冲突：

char itemid[PCMS\u L\u ID+1]={'\0'}；strncpy（itemid，spec.c_str（），PCMS_L_ID）