Tristan

Another probable noob style question... I have built a relatively simple external to generate low-passed random numbers (ie - skewed to the low end of a range). Nothing complicated, it takes two arguments - the range and a 'Q' value and when it receives a bang it spits out a random integer much like the native random object does. The external is working properly as far as I can tell, but it seems to be causing some amount of crashes. I had some difficulty getting it to work in the first place which was down to memory allocation issues and I suspect that may still be the problem now, but I have no idea why. the full code is as follows:

void *lprand_new(t_symbol *s, long argc, t_atom *argv);

void lprand_assist(t_lprand *x, void *b, long m, long a, char *s);

long lopass(t_lprand *x, long range, long q);

c = class_new("lprand", (method)lprand_new, (method)lprand_free, (long)sizeof(t_lprand), 0L, A_GIMME, 0);

class_addmethod(c, (method)lprand_bang, "bang", 0);

void lprand_assist(t_lprand *x, void *b, long m, long a, char *s)

sprintf(s, "Inlet %ld accepts a bang", a);

sprintf(s, "Outlet %ld delivers a low-passed random number.", a);

// ---------- lopass (low passed random number)

long lopass(t_lprand *x, long range, long q)

for (counter = 0; counter < q; counter++) {

void *lprand_new(t_symbol *s, long argc, t_atom *argv)

post("Incorrect number of arguments for the lprand object.");

post("Range argument must be greater than 1.");

post("Q argument out of bounds. It must be between 1 and 10 (inclusive).");

if ((x = (t_lprand *)object_alloc(lprand_class))) {

x->rndarray = (long *)sysmem_newptrclear(q);

Can anyone see what might be causing this? I'm still (slowly) learning my way around the API. Originally I was attempting to just create the rndarray with malloc in the lopass function but after looking through the documentation and examples thought the sysmem_xxx stuff was a better way to ensure compatibility. Perhaps I have implemented it incorrectly?

Another probable noob style question...  I have built a relatively simple external to generate low-passed random numbers (ie - skewed to the low end of a range).  Nothing complicated, it takes two arguments - the range and a 'Q' value and when it receives a bang it spits out a random integer much like the native random object does.  The external is working properly as far as I can tell, but it seems to be causing some amount of crashes.  I had some difficulty getting it to work in the first place which was down to memory allocation issues and I suspect that may still be the problem now, but I have no idea why.  the full code is as follows:

#ifdef WIN_VERSION
#define _CRT_RAND_S
#endif

typedef struct _lprand
{
    t_object obj;
    long *rndarray;
    long range;
    long q;
    void *out;
} t_lprand;

// standard set
void *lprand_new(t_symbol *s, long argc, t_atom *argv);
void lprand_free(t_lprand *x);
void lprand_assist(t_lprand *x, void *b, long m, long a, char *s);

// additional
void lprand_bang(t_lprand *x);
long rnum(long range);
long lopass(t_lprand *x, long range, long q);

    c = class_new("lprand", (method)lprand_new, (method)lprand_free, (long)sizeof(t_lprand), 0L, A_GIMME, 0);

    class_addmethod(c, (method)lprand_bang, "bang", 0);

    class_register(CLASS_BOX, c);
    lprand_class = c;

    post("lprand object instantiated.");
}

void lprand_assist(t_lprand *x, void *b, long m, long a, char *s)
{
    if (m == ASSIST_INLET) {
        sprintf(s, "Inlet %ld accepts a bang", a);
    }
    else {
        sprintf(s, "Outlet %ld delivers a low-passed random number.", a);
    }
}

#ifdef WIN_VERSION
    rand_s(&rand);
#else
    rand = random();
#endif

// ----------     lopass (low passed random number)

long lopass(t_lprand *x, long range, long q)
{
    long counter;
    long minimum;

    for (counter = 0; counter < q; counter++) {
        x->rndarray[counter] = rnum(range);
    }

    for (counter = 0; counter < q; counter++) {
        if (x->rndarray[counter] < minimum) {
            minimum = x->rndarray[counter];
        }
    }

void lprand_bang(t_lprand *x)
{
    long rand = lopass(x, x->range, x->q);

void lprand_free(t_lprand *x)
{
    sysmem_freeptr(x->rndarray);
}

void *lprand_new(t_symbol *s, long argc, t_atom *argv)
{
    t_lprand *x = NULL;
    long range, q;

    if (argc != 2) {
        post("Incorrect number of arguments for the lprand object.");
        return NULL;
    }

    range = atom_getlong(argv);
    if (range < 1) {
        post("Range argument must be greater than 1.");
        return NULL;}

    q = atom_getlong(argv+1);
    if (q < 1 || q > 10) {
        post("Q argument out of bounds.  It must be between 1 and 10 (inclusive).");
        return NULL;
    }

    if ((x = (t_lprand *)object_alloc(lprand_class))) {
        x->rndarray = (long *)sysmem_newptrclear(q);

        x->range = range;
        x->q = q;

        x->out = intout((t_lprand *)x);
    }

Can anyone see what might be causing this?   I'm still (slowly) learning my way around the API.  Originally I was attempting to just create the rndarray with malloc in the lopass function but after looking through the documentation and examples thought the sysmem_xxx stuff was a better way to ensure compatibility.  Perhaps I have implemented it incorrectly?

external-works-but-causes-crashiness-in-max7

x->rndarray = (long *)sysmem_newptrclear(q 

x->rndarray = (long *)sysmem_newptrclear(q *sizeof(long));


Hey, thanks for the reply. I'll give that a go. I thought I might be missing something around that declaration. Thanks again.

Hey, thanks for the reply.  I'll give that a go.  I thought I might be missing something around that declaration.  Thanks again.


External works, but causes 'crashiness' in Max7.