Environment

• Your SuperCollider version: 3.9.3
• Your operating system and version: macOS High Sierra 10.13.6

Steps to reproduce (for bugs)

It is necessary to build two example UGens to reproduce the problem. Source for this:
UGenTests.zip. After building the two UGens and moving the relevant files to the Extensions folder try the following 3 cases:

1. This fails (see next section for error)

s.boot; s.scope;

{ Test.ar(WhiteNoise.ar(0.1) ! 2) }.play

2. This works

s.boot; s.scope;

{ Test2.ar(WhiteNoise.ar(0.1) ! 2) }.play

3. This also works (kind of...)

s.boot; s.scope;

{ Test2.ar(WhiteNoise.ar(0.1) ! 2) }.play

Now free the synth and try

{ Test.ar(WhiteNoise.ar(0.1) ! 2) }.play

Now this does work if you start the synth right away. If you wait for a minute or so it fails again (garbage collection of allocated memory???)

Error message (for bugs)

For the first case, the server quits unexpectedly posting this in the SC console:

RESULT = 0
server 'localhost' disconnected shared memory interface

Expected Behavior

I would expect, given that I've done the memory allocating and free'ing in the UGen code correctly, that the Test UGen should not crash the server when ran.

Current Behavior

Clearly something goes wrong with allocating memory using the C++ style wrapper. It could very well be that I am misunderstanding something and hence, the error is entirely my fault. However, I cannot figure out myself what I might have done wrong. As far as I can tell I have followed the appropriate steps translating the old C way of doing this to the new C++ way.