dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Johan Hake wrote:
> On Saturday 13 February 2010 12:03:28 Garth N. Wells wrote:
>> Johan Hake wrote:
>>> On Saturday 13 February 2010 11:58:39 Garth N. Wells wrote:
>>>> Johan Hake wrote:
>>>>> On Saturday 13 February 2010 11:44:15 Garth N. Wells wrote:
>>>>>> Johan Hake wrote:
>>>>>>> Should be fixed now
>>>>>> Seems we may a leak in array_typemaps.i too. Can you take a look?
>>>>> Could you elaborate?
>>>> When I create an Expression with a eval function and use it in a form
>>>> inside a loop, I see the memory use increasing, just like for the
>>>> std::vector<Foo*> case. I can try to boil down an example. The example I
>>>> have now is full of commented code.
>>> Is it in a Python Expression?
>> Yes.
>>
>>   class MyExpression(Expression):
>>       def eval(self, values, x):
>>           values[0] = 1.0 - x[0]
>>
> 
> I just exchanged a Function for an experssion of this type in your previous 
> leak script and I cannot detect any leak.
>

After looking closer, it may not be in the SWIG interface. The problem
is when the Expression is declared inside the loop. The below code
leaks. It doesn't if I move 'f = MyExpression(degree=1)' outside of the
loop.

Garth


from dolfin import *
parameters["form_compiler"]["cpp_optimize"] = True
parameters["form_compiler"]["optimize"] = True

class MyExpression(Expression):
    def eval(self, values, x):
        if x[0] < DOLFIN_EPS:
            values[0] =  1.0

mesh = UnitSquare(32, 32)
for t in xrange(20000):
    for level in xrange(100):
        V  = FunctionSpace(mesh, "CG", 1)
        v  = TestFunction(V)
        u  = Function(V)
        u0 = Function(V)
        f  = MyExpression(degree=1)
        L = v*(u-u0)*dx + v*f*ds
        b = assemble(L)
    print "----"


> Johan
>