Matlab crashes when calling dll

We have created a dll for an application if we try to call that dll(run loader.m file)suddenly matlab crashes..Need suggestion in this regard

[Kaustubha Govind]

You probably also want to clarify that you are calling into a DLL generated by Simulink Coder, and paste the prototypes of the exports from the library from the header file.

[vinothkannan K]

Hi Kaustubha Govind, We generated header file from dll, even though matlab crashes, when running dll.

This is the command we used for generation of header file

         loadlibrary('TOLI_win32','TOLI.h','mfilename','TOLI_header');

Answer 1

[Craig Cowled]

Try using 'loadlibrary'.

[vinothkannan K]

we used loadlibrary command to load the dll..

Below is the code:

 libfile='TOLI_win32';
 loadlibrary(libfile,@TOLI_header);
 libfunctionsview TOLI_win32;
 a=uint16(1);
 calllib('TOLI_win32', 'TOLI_initialize',a);
 while (1)
 calllib('TOLI_win32', 'TOLI_step');
 pause(1);
 end
 unloadlibrary('TOLI_win32')

Here the dll is "TOLI_win32" 'a' is the variable

[Friedrich]

Which lines raises the crash? Does your DLL work in a plain C/C++ application? The functionsignature of the functions you call seem pretty simple so I would guess its a BUG in the DLL.

[vinothkannan K]

 libfile='TOLI_win32';
 loadlibrary(libfile,@TOLI_header);
 libfunctionsview TOLI_win32;
 firstTime = uint8(1);
 calllib('TOLI_win32', 'TOLI_initialize',firstTime);
 while (1)
 calllib('TOLI_win32', 'TOLI_step');
 pause(1);
 end

 unloadlibrary('TOLI_win32')

This is the M file we are using to call dll, The model is working fine, while running dll its raising error at 'TOLI_step' function....

[Friedrich]

Write some C code and test it outside of ML. I guess it crashes there too.

[vinothkannan K]

Hi its crashing because of ResumeThread function, this function is available from windows. Any idea about it?

[Friedrich]

I would need to see the actual code. For now its to vague to tell anything.

[vinothkannan K]

Its crashing at this lines

if ( ResumeThread( ArrayThreadHandles[i].ThreadHandle ) != - 1)
       {  
          // set the state of this thread to active
          ArrayThreadHandles[i].ThreadActive = 1;
       }

[Friedrich]

Is i in valid range? Is the ThreadHandle still valid?

[vinothkannan K]

Yes, Because it is working while running model.,

[Friedrich]

One would assume that the generated code behaves like the model, however it could be a bug in the code generation or maybe a design problem of your model which works in MATLAB/Simulink becauses MATLAB takes care of out of bounds accesses whereas C doesnt.

If everything is valid, then it wouldn't crash.

Compile that DLL in debug mode and attach a Debugger to it at runtime to step thorugh the code and to be able to inspect the values at runtime.

[vinothkannan K]

Ok i will check in debug mode, Thanks for your support.,

[vinothkannan K]

Hi Friedrich

1)Can you please explain about compiling dll in debug mode?

2) What are all the configuration parameter settings for debug mode dll compilation?

3) How to attach debugger to it at runtime?

Thanks in advance