使用Ctypes与Fortran DLL进行接口时发生访问冲突

Question

我有一组从Fortran创建的dll，这些dll是我从python运行的。我已经成功创建了一个包装器类，并且已经运行dll数周了。

今天，我发现输入错误并进行了更改，但令我惊讶的是，这导致了以下情况：

OSError: exception: access violation reading 0x705206C8

如果某些输入值似乎以某种方式导致我尝试访问非法数据。我创建了以下MCVE，但确实重复了该问题。具体来说，在338 < R_o < 361时会引发错误。不幸的是，我无法发布原始的Fortran代码，也无法创建一个MCVE来复制问题并对其进行充分抽象，以便我可以共享它。在Fortran代码中，所有变量都被声明为integer或real(8)类型。

import ctypes
import os
DLL_PATH = "C:\Repos\CASS_PFM\dlls"
class wrapper:
    def __init__(self,data):
        self.data = data
        self.DLL = ctypes.CDLL(os.path.join(DLL_PATH,"MyDLL.dll"))
        self.fortran_subroutine = getattr(self.DLL,"MyFunction_".lower())
        self.output = {}

    def run(self):
        out = (ctypes.c_longdouble * len(self.data))()
        in_data = []
        for item in self.data:
            item.convert_to_ctypes()
            in_data.append(ctypes.byref(item.c_val))
        self.fortran_subroutine(*in_data, out)
        for item in self.data:
            self.output[item.name] = item.convert_to_python()

class FortranData:
    def __init__(self,name,py_val,ctype,some_param=True):
        self.name = name
        self.py_val = py_val
        self.ctype = ctype
        self.some_param = some_param

    def convert_to_ctypes(self):
        ctype_converter = getattr(ctypes,self.ctype)
        self.c_val = ctype_converter(self.py_val)
        return self.c_val

    def convert_to_python(self):
        self.py_val = self.c_val.value
        return self.py_val


def main():
    R_o = 350
    data = [
            FortranData("R_o",R_o,'c_double',False),
            FortranData("thick",57.15,'c_double',False),
            FortranData("axial_c",100,'c_double',False),
            FortranData("sigy",235.81,'c_double',False),
            FortranData("sigu",619.17,'c_double',False),
            FortranData("RO_alpha",1.49707,'c_double',False),
            FortranData("RO_sigo",235.81,'c_double',False),
            FortranData("RO_epso",0.001336,'c_double',False),
            FortranData("RO_n",6.6,'c_double',False),
            FortranData("Resist_Jic",116,'c_double',False),
            FortranData("Resist_C",104.02,'c_double',False),
            FortranData("Resist_m",0.28,'c_double',False),
            FortranData("pressure",15.51375,'c_double',False),
            FortranData("i_write",0,'c_int',False),
            FortranData("if_flag_twc",0,'c_int',),
            FortranData("i_twc_ll",0,'c_int',),
            FortranData("i_twc_epfm",0,'c_int',),
            FortranData("i_err_code",0,'c_int',),
            FortranData("Axial_TWC_ratio",0,'c_double',),
            FortranData("Axial_TWC_fail",0,'c_int',),
            FortranData("c_max_ll",0,'c_double',),
            FortranData("c_max_epfm",0,'c_double',)
    ]
    obj = wrapper(data)
    obj.run()
    print(obj.output)


if __name__ == "__main__": main()

也不只是R_o值；有些值的组合会导致相同的错误（看似没有押韵或原因）。上面的Python中是否有任何东西可能取决于传递给DLL的值而导致访问冲突？

Python版本是3.7.2，32位