[Help-glpk] Re: Application crash due to assert in GLPK - glp_error_hook

[Xypron]

Hello Andrew,

I have had a look at the definition of glp_error_hook() in the GLPK 4.43 
pre release.

The function is sufficient to safely catch an error situation. I guess 
it is a big step
forward for safely using GLPK inside C programs.

When providing language wrappers like GLPK-Java it will require to wrap 
every single
API function.

The typical use in a language wrapper would probably be something like:

JNIEXPORT int JNICALL wrap_some_function(JNIENV *env, some args) {
int ret = 0;
MYENV *info
info = (myenv) malloc(sizeof(myenv));
info->env = env;
info->jmp = jmp;
if (!setjmp(info->jmp)) {
glp_error_hook(myhook, info);
ret = glp_some_function(args)
}
free(info);
return ret;
}

void myhook(void *info) {
MYENV env = (MYENV) *info;
/* throw exception */
jclass newExcCls;
(*env)->ExceptionDescribe(env);
(*env)->ExceptionClear(env);
newExcCls = (*env)->FindClass(env, "java/lang/IllegalArgumentException");
if (newExcCls != NULL)
(*env)->ThrowNew(env, newExcCls, "thrown from C code");
/* unset hook */
glp_error_hook(NULL, NULL);
/* safely return */
longjmp(env->jmp, 1);
}

I am wondering how maintaining the wrapper functions can be done 
efficiently. I guess
SWIG cannot do it.

The next step should be writing example code in C demonstrating the 
function of
the hook. I will give it a try.

Best regards

Xypron