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[Attila Kelemen]

Attila Kelemen <attila.kelemen85 at gmail.com> ezt írta (időpont: 2023. júl.
3., H, 10:58):

> Robert Engels <rengels at ix.netcom.com> ezt írta (időpont: 2023. júl. 3.,
> H, 1:58):
>
>> When you have virtual threads there is no need for generators - it is
>> simply queues. The typical generator is simply implemented as a task that
>> puts values on a queue with blocking semantics. The rest is syntactic
>> sugar.
>>
>>
>>
> Though I never checked every detail on how virtual threads are
> implemented, but your claim looks to be false to me. Consider that you are
> implementing a normal `Iterator`, and then you don't read the iterator
> fully. In that case, your virtual thread will be sitting in the scheduler
> forever waiting to be unblocked, while this is not the case for reasonably
> implemented generators.
>

After actually checking the relevant parts of the implementation, I would
rephrase what I wrote above. While an unmounted thread in this case is not
in any queue, your "start a virtual thread" solution could still lead to a
memory leak. Also, I'm not sure if VT (and its stack) is considered to be a
GC root or not. At least, it looks like the `delete` would never be called
in `jvmtiEventController.cpp`. Also, creating an intermediate queue is
probably less efficient than what the JVM can provide. Regardless, it still
looks conceptually wrong to start a thread that might be alive forever.
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