Generate Shared Library for Export to External Code Base - MATLAB & Simulink (original) (raw)

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About Generated Shared Libraries

If you have Embedded Coder® software, you can generate a shared library—Windows® dynamic link library (.dll), UNIX® shared object (.so), or Macintosh OS X dynamic library (.dylib)— from a model component. You or others can integrate the shared library into an application that runs on a Windows, UNIX, or Macintosh OS X development computer. Uses of shared libraries include:

When producing a shared library, the code generator exports:

Workflow

To generate a shared library from a model component and use the library, complete the tasks listed in this table.

Generate Shared Libraries

  1. When configuring the model for code generation, select the system target file ert_shrlib.tlc.
  2. Build the model. The code generator produces source code for the model and a shared library version of the code. The code generator places the source code and the shared library (.dll,.so, or .dylib file) in the code generation folder. The code generator also produces and retains a.lib file to support implicit linking.

Create Application Code That Uses Generated Shared Libraries

This example application code is generated for the example Interface to a Development Computer Simulator by Using a Shared Library.

  1. Create an application header file that contains type declarations for model external input and output. For example:

#ifndef APP_MAIN_HEADER
#define APP_MAIN_HEADER
typedef struct {
int32_T Input;
} ExternalInputs_SharedLibraryCode;
typedef struct {
int32_T Output;
} ExternalOutputs_SharedLibraryCode;
#endif /APP_MAIN_HEADER/ 2. In the application C source code, dynamically load the shared library. Use preprocessing conditional statements to invoke platform-specific commands. For example:
#if (defined(_WIN32)||defined(_WIN64)) /* WINDOWS /
#include <windows.h>
#define GETSYMBOLADDR GetProcAddress
#define LOADLIB LoadLibrary
#define CLOSELIB FreeLibrary
#else / UNIX /
#include <dlfcn.h>
#define GETSYMBOLADDR dlsym
#define LOADLIB dlopen
#define CLOSELIB dlclose
#endif
int main()
{
void handleLib;
...
#if defined(_WIN64)
handleLib = LOADLIB("./SharedLibraryCode_win64.dll");
#else #if defined(_WIN32)
handleLib = LOADLIB("./SharedLibraryCode_win32.dll");
#else /* UNIX */
handleLib = LOADLIB("./SharedLibraryCode.so", RTLD_LAZY);
#endif
#endif
...
return(CLOSELIB(handleLib));
} 3. From the application C source code, access exported data and functions generated from the model. The code uses hooks to add user-defined initialization, step, and termination code.
int32_T i;
...
void (*mdl_initialize)(boolean_T);
void (*mdl_step)(void);
void (*mdl_terminate)(void);
ExternalInputs_SharedLibraryCode (*mdl_Uptr);
ExternalOutputs_SharedLibraryCode (*mdl_Yptr); 

uint8_T (*sum_outptr);

...
#if (defined(BORLANDCDLL))
/* Exported symbols contain leading underscores
when DLL is linked with BORLANDC /
mdl_initialize =
(void()(boolean_T))GETSYMBOLADDR(handleLib ,
"_SharedLibraryCode_initialize");
mdl_step =
(void()(void))GETSYMBOLADDR(handleLib ,
"_SharedLibraryCode_step");
mdl_terminate =
(void()(void))GETSYMBOLADDR(handleLib ,
"_SharedLibraryCode_terminate");
mdl_Uptr =
(ExternalInputs_SharedLibraryCode*)GETSYMBOLADDR(handleLib ,
"_SharedLibraryCode_U");
mdl_Yptr =
(ExternalOutputs_SharedLibraryCode*)GETSYMBOLADDR(handleLib ,
"_SharedLibraryCode_Y");
sum_outptr =
(uint8_T*)GETSYMBOLADDR(handleLib , "_sum_out");
#else
mdl_initialize =
(void()(boolean_T))GETSYMBOLADDR(handleLib ,
"SharedLibraryCode_initialize");
mdl_step =
(void()(void))GETSYMBOLADDR(handleLib ,
"SharedLibraryCode_step");
mdl_terminate =
(void()(void))GETSYMBOLADDR(handleLib ,
"SharedLibraryCode_terminate");
mdl_Uptr =
(ExternalInputs_SharedLibraryCode)GETSYMBOLADDR(handleLib ,
"SharedLibraryCode_U");
mdl_Yptr =
(ExternalOutputs_SharedLibraryCode*)GETSYMBOLADDR(handleLib ,
"SharedLibraryCode_Y");
sum_outptr =
(uint8_T*)GETSYMBOLADDR(handleLib , "sum_out");
#endif 

if ((mdl_initialize &&  
     mdl_step &&  
     mdl_terminate &&  
     mdl_Uptr &&  
     mdl_Yptr &&  
     sum_outptr)) {  
    /* user application  
       initialization function */  
    mdl_initialize(1);  
    /* insert other user defined  
       application initialization code here */  
      
    /* user application  
       step function */  
    for(i=0;i<=12;i++){  
        mdl_Uptr->Input = i;  
        mdl_step();  
        printf("Counter out(sum_out):  
               %d\tAmplifier in(Input):  
               %d\tout(Output):  
               %d\n", *sum_outptr, i,  
               mdl_Yptr->Output);  
        /* insert other user defined  
           application step function  
           code here */  
    }  
      
    /* user application  
       terminate function */  
    mdl_terminate();  
    /* insert other user defined  
       application termination  
       code here */  
}  
else {  
    printf("Cannot locate the specified  
            reference(s) in the shared library.\n");  
    return(-1);  
}

Limitations

See Also

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