On Sat, Jun 29, 2019 at 11:25 PM Benjamin Morel <benjamin.mo...@gmail.com> wrote:
> > The problem here is that OP is *creating* many classes (the fact that > they are anonymous ultimately doesn't matter) by eval'ing code. That is > what causes the leak. > > I still don't understand why there is no leak when *not* using eval(), > though. > > Ben > Without eval you are creating many objects of the same anonymous class. With eval you are creating a single object each for many anonymous classes. In the first case there is only a single class, in the second there are as many classes as there are eval()s. That's the theory. In practice we have a long-standing bug with RTD key collisions -- this means that the names generated for anonymous classes (and closures for that matter) are not actually unique. For anonymous classes the current workaround is to reuse the existing class definition if an RTD key collision occurs. For your original code (and I should say that this is very specific to the code because it is susceptible to memory layout details) it happens that the RTD key for all those anonymous classes is the same, so in the end you end up with just one class definition also in the eval() case. The leaked memory is an allocated but unused class entry. We could plug that particular leak -- but I should emphasize that the current behavior is incorrect and once the key collision issue is resolved this will create a new class for each eval. Nikita
