Re: [pygame] memory leaks with Py_BuildValue

["Nirav Patel" <olpc@xxxxxxxxxxxxxx>]

Thanks!  Patch committed.

Nirav

On Wed, Sep 3, 2008 at 7:10 PM, Campbell Barton <ideasman42@xxxxxxxxx> wrote:
> Heres more fixes to mask.c - Py_BuildValue returns a variable with 1
> ref and PyList_Append adds another. checked all other cases of
> PyList_Append and they all seem correct.
>
> Index: src/mask.c
> ===================================================================
> --- src/mask.c  (revision 1646)
> +++ src/mask.c  (working copy)
> @@ -312,7 +312,7 @@
>  {
>     bitmask_t* c = PyMask_AsBitmap(self);
>     bitmask_t* m = bitmask_create(c->w + 2, c->h + 2);
> -    PyObject* plist;
> +    PyObject* plist, *value;
>     int x, y, every, e, firstx, firsty, secx, secy, currx, curry,
> nextx, nexty, n;
>     int a[14], b[14];
>     a[0] = a[1] = a[7] = a[8] = a[9] = b[1] = b[2] = b[3] = b[9] =
> b[10] = b[11]= 1;
> @@ -343,7 +343,9 @@
>             if (bitmask_getbit(m, x, y)) {
>                  firstx = x;
>                  firsty = y;
> -                 PyList_Append(plist, Py_BuildValue("(ii)", x-1, y-1));
> +                 value = Py_BuildValue("(ii)", x-1, y-1);
> +                 PyList_Append(plist, value);
> +                 Py_DECREF(value);
>                  break;
>             }
>         }
> @@ -367,7 +369,9 @@
>             e--;
>             if (!e) {
>                 e = every;
> -                PyList_Append(plist, Py_BuildValue("(ii)", secx-1, secy-1));
> +                value = Py_BuildValue("(ii)", secx-1, secy-1);
> +                PyList_Append(plist, value);
> +                Py_DECREF(value);
>             }
>             break;
>         }
> @@ -392,7 +396,9 @@
>                     if ((curry == firsty && currx == firstx) && (secx
> == nextx && secy == nexty)) {
>                         break;
>                     }
> -                    PyList_Append(plist, Py_BuildValue("(ii)",
> nextx-1, nexty-1));
> +                                       value = Py_BuildValue("(ii)", nextx-1, nexty-1);
> +                    PyList_Append(plist, value);
> +                                       Py_DECREF(value);
>                 }
>                 break;
>             }
> @@ -1170,6 +1176,7 @@
>         if(maskobj) {
>             maskobj->mask = components[i];
>             PyList_Append (ret, (PyObject *) maskobj);
> +                       Py_DECREF((PyObject *) maskobj);
>         }
>     }
>
>
>
>
> On Thu, Sep 4, 2008 at 1:51 AM, Nirav Patel <olpc@xxxxxxxxxxxxxx> wrote:
>> Thanks,
>>
>> I just committed a fix for it in mask.c.
>>
>> Nirav
>>
>> On Wed, Sep 3, 2008 at 11:13 AM, Campbell Barton <ideasman42@xxxxxxxxx> wrote:
>>> Hi, over a year ago I had a look at pygames py-c/api usage for memory
>>> leaks, and found a few, mainly with Py_BuildValue() using PyObjects
>>> which are incref'd,
>>> had another look at the recent SVN and found some more, not sure if
>>> they are new but they definitely cause memory leaks.
>>>
>>> For example - call pygame.mouse.get_cursor() in a loop of 10000 for
>>> every update in chimp.py and memory will go up 100's of meg fairly
>>> fast, patch below.
>>>
>>> you also might want to consider using PyTuple_Pack() which is faster
>>> but only in python 2.4 or later.
>>> http://docs.python.org/api/tupleObjects.html#l2h-583
>>>
>>>
>>> These leak too, much the same changes need to be made here also.
>>> ./src/mask.c:265:        return Py_BuildValue ("(OO)", PyInt_FromLong(m10/m00),
>>> ./src/mask.c:268:        return Py_BuildValue ("(OO)",
>>> PyInt_FromLong(0), PyInt_FromLong(0));
>>> ./src/mask.c:298:        return Py_BuildValue ("O", PyFloat_FromDouble(theta));
>>> ./src/mask.c:300:        return Py_BuildValue ("O", PyFloat_FromDouble(0));
>>>
>>>
>>> Index: src/mouse.c
>>> ===================================================================
>>> --- src/mouse.c (revision 1645)
>>> +++ src/mouse.c (working copy)
>>> @@ -171,7 +171,7 @@
>>>  mouse_get_cursor (PyObject* self)
>>>  {
>>>     SDL_Cursor *cursor = NULL;
>>> -    PyObject* xordata, *anddata;
>>> +    PyObject* xordata, *anddata, *ret;
>>>     int size, loop, w, h, spotx, spoty;
>>>
>>>     VIDEO_INIT_CHECK ();
>>> @@ -201,8 +201,10 @@
>>>         PyTuple_SET_ITEM (xordata, loop, PyInt_FromLong (cursor->data[loop]));
>>>         PyTuple_SET_ITEM (anddata, loop, PyInt_FromLong (cursor->mask[loop]));
>>>     }
>>> -
>>> -    return Py_BuildValue ("((ii)(ii)OO)", w, h, spotx, spoty,
>>> xordata, anddata);
>>> +       ret = Py_BuildValue ("((ii)(ii)OO)", w, h, spotx, spoty, xordata, anddata);
>>> +       Py_DECREF (xordata);
>>> +       Py_DECREF (anddata);
>>> +    return ret;
>>>  }
>>>
>>>  static PyMethodDef mouse_builtins[] =
>>>
>>
>