Convert voidPtrPtr to voidPtr for clib

Question

vadim onuchin 2021-8-11

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/896357-convert-voidptrptr-to-voidptr-for-clib

回答： vadim onuchin 2021-8-12

采纳的回答： vadim onuchin

在 MATLAB Online 中打开

Hello. I can't find the resolve of my problem.

I want to convert voidPtrPtr in MATLAB which I use in method on C in MyLibExport.dll:

int32_t CreateInstance(void **instance) {
    *instance = (void *)malloc(sizeof(MyStruct));
    return 1;
}

in voidPtr which I use in next method on C in MyLibExport.dll:

int32_t DeleteInstance(void *instance) {
    free(instance);
    return 2;
}

MATLAB code of using MyLibExport.dll and methods CreateInstance and DeleteInstance:

loadlibrary('MyLibExport', 'MyLibExport.h'); % load my DLL
pv = libpointer('voidPtrPtr', 0); % Create 'void **variable = NULL;'
resultInt32 = calllib('MyLibExport','CreateInstance',pv); % Create 
resultInt32 = calllib('MyLibExport','DeleteInstance', ???); % what can I use here?

OS Windows. DLL build in VS2019.

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Answer 1

vadim onuchin 2021-8-12

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/896357-convert-voidptrptr-to-voidptr-for-clib#answer_765512

在 MATLAB Online 中打开

It was not difficult as it turned out.

loadlibrary('MyLibExport', 'MyLibExport.h'); % load my DLL
pv = libpointer('voidPtr', 0); % Create 'void *variable = NULL;'
pvPtr = libpointer('voidPtrPtr', pv); % Create 'void **variablePtr = &variable;'
resultInt32 = calllib('MyLibExport','CreateInstance',pvPtr); % Create 
resultInt32 = calllib('MyLibExport','DeleteInstance', pv); % Free