the issue was (I think), that I was calling createThread without actually
checking whether the previous thread spawned with that same thread object had
finished execution, so I added a call to joinThread before spawning a new one
and the issues disappeared. In my defense, this kind of bug was really hard to
track down because due to how the code was structured logically, a new worker
wouldn't be spawned until the previous one was done, the problem was that my
definition of done is "it printed the result on the console" (which is the last
operation in the thread proc), while of course the thread could've been doing
some cleanup before fully exiting (probably arc stuff)