C DLL中的Python对象

Python Objects in C++ DLL

本文关键字:对象 Python 中的 DLL      更新时间:2023-10-16

i编码C++ DLL用于MQL4。我必须使用一些python模块。

dll代码:

#define WIN32_LEAN_AND_MEAN  // Exclude rarely-used stuff from Windows headers
//#define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
#include <windows.h>
#include <string>
#include <stdlib.h>
#include <stdio.h>
#include "Python.h"
#include "numpy/arrayobject.h"
//----
#define MT4_EXPFUNC __declspec(dllexport)
PyObject *Amanda;
PyObject *AmandaZones;

#pragma pack(push,1)
#pragma pack(pop)

BOOL APIENTRY DllMain(HANDLE hModule,DWORD ul_reason_for_call,LPVOID lpReserved)
  {
//----
   switch(ul_reason_for_call)
     {
      case DLL_PROCESS_ATTACH:
          Py_Initialize();
          import_array1(-1);
          PyObject *pName;
          pName = PyString_FromString("Amanda");
          Amanda = PyImport_Import(pName);
          Py_DECREF(pName);
          if (Amanda != NULL){
              AmandaZones = PyObject_GetAttrString(Amanda, "CalculateZones");
          }
          break;
      case DLL_THREAD_ATTACH:
          break;
      case DLL_THREAD_DETACH:

          break;
      case DLL_PROCESS_DETACH:
              Py_DECREF(Amanda);
              Py_DECREF(AmandaZones);
              Py_Finalize();
          break;
     }
//----
   return(TRUE);
  }
MT4_EXPFUNC int __stdcall CalculateZones(double *data, double quantile,const int arraySize)
  {
    if (arraySize < 1 || data == NULL) return 2;
    if (AmandaZones == NULL) return 0;
   return 1;
  }

它运行良好,直到我将其从Metatrader删除并再次附加。它返回0,这仅表示AmandaZonesNULL

简单地说,如果第二次附加了DLL文件,则不会加载PyObjects并返回null指针。代码有什么问题?我认为这是一个内存泄漏问题,因为如果我删除if (AmandaZones == NULL) return 0;,它将抛出Access Violation Read error

谢谢

numpy在使用C 时不应两次初始化。Py_finilize()无法正常工作,也不会删除numpy模块对象。我从这里https://github.com/numpy/numpy/issues/8097