如何解决带有带参数的回调函数的 Python ctypes - 抛出错误“分段错误核心转储”
我正在制作一个 python 应用程序,它使用 ctypes 库与第三方提供的 c++ 共享库进行通信。
我得到了一个演示 C++ 程序来演示共享库的用法,所以我基本上是将 C++ 代码重写为 python/ctypes。
分段错误(核心转储)
在下面的代码上(特别是在应该回调python函数的那一行):
from ctypes import *
LIB_PATH = 'libxxyy.so'
DEFINE1 = 8
DEFINE1_A = (DEFINE1 + 1 + 3) & 0xfffffffc
DEFINE2 = 255
DEFINE2_A = (DEFINE2 + 1 + 3) & 0xfffffffc
class VAR_ENTRY(Structure):
_fields_ = [
('Name',c_char * (DEFINE1_A + DEFINE2_A)),('Format',c_uint16),('Len',c_uint16)
]
ListvariablesCallBack = CFUNCTYPE(c_uint8,POINTER(VAR_ENTRY),c_void_p) #see Update 1 below
@CFUNCTYPE(c_uint8,c_void_p)
def ListvariablesCallBack_func(pvEntry,userParam):
print("hello from callback")
# Then read data from pvEntry,add 1 to userParam
return 0
def MODULE_Listvariables(moduleHandle: c_void_p,cb,userParam: c_void_p) -> c_int32:
'''
cb – Callback function to be called for every variable.
userParam – Parameter,that is passed to callback function.
'''
x1lib.MODULE_Listvariables.argtypes = (c_void_p,ListvariablesCallBack,c_void_p) # See Update 1 below
x1lib.MODULE_Listvariables.ABCtype = c_int32
return x1lib.MODULE_Listvariables(moduleHandle,userParam) # ERROR OCCURS HERE
def browseVariables(targetHandle: c_void_p,moduleName: c_char_p) -> c_int32:
modHandle = # calculated
countModules = c_uint32(0)
ret = MODULE_Listvariables(modHandle,ListvariablesCallBack_func,byref(countModules))
return
def main():
targetHandle = # calculated
browseVariables(targetHandle,c_char_p(b"ABC"))
if __name__ == "__main__":
x1lib = CDLL(LIB_PATH)
main()
我正在翻译的 cpp 演示如下所示:
/*
* <demo.h>
*/
#define CALLBACK
typedef struct
{
CHAR8 Name[DEFINE1_A + DEFINE2_A];
UINT16 Format;
UINT16 Len;
} VAR_ENTRY;
typedef BOOL8 (CALLBACK *ListvariablesCallBack) (const VAR_ENTRY * varEntry,const VOID* userParam);
X1LIB SINT32 MODULE_Listvariables(M1C_H_MODULE moduleHandle,const ListvariablesCallBack cb,const VOID * userParam);
/*
* <demo.cpp>
*/
static BOOL8 CALLBACK listvariablesCallback(const VAR_ENTRY *pvEntry,const VOID *userParam)
{
UINT32 *countElements = (UINT32 *)userParam;
(*countElements)++;
printf("%s\n",pvEntry->Name);
return true;
}
SINT32 browseVariables(M1C_H_TARGET targetHandle,CHAR8* moduleName)
{
/* modHandle calculated*/
UINT32 countModules=0;
ret = MODULE_Listvariables(modHandle,listvariablesCallback,&countModules);
return;
}
int main(int argc,char* argv[])
{
browseVariables(targetHandle,(CHAR8 *)"ABC");
}
我做错了什么? (见更新 1)
使用的来源(到目前为止): https://docs.python.org/3.3/library/ctypes.html?highlight=ctypes#callback-functions https://stackoverflow.com/a/33485103
更新 1:
因此,我设法使脚本运行,方法是在 ListvariablesCallBack = CFUNCTYPE(c_uint8,c_void_p)
正上方添加行 @CFUNCTYPE(c_uint8,c_void_p)
并将 MODULE_Listvariables 函数中的 argTypes 设置为:x1lib.MODULE_Listvariables.argtypes = (c_void_p,c_void_p)
(我已经在上面的脚本中添加了更改)
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。