`concurrent.futures.Executor.map` now supports limiting the number of submitted
tasks whose results have not yet been yielded via the new `buffersize` parameter.
---------
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
This is an implementation of InterpreterPoolExecutor that builds on ThreadPoolExecutor.
(Note that this is not tied to PEP 734, which is strictly about adding a new stdlib module.)
Possible future improvements:
* support passing a script for the initializer or to submit()
* support passing (most) arbitrary functions without pickling
* support passing closures
* optionally exec functions against __main__ instead of the their original module
Check `my_object_collected.wait()` in a loop to give the main thread a
chance to merge the reference count fields. Additionally, call
`my_object_collected.set()` in a background thread to avoid deadlocking
when the destructor is called asynchronously via the eval breaker
within the body of of `my_object_collected.wait()`.
Biased reference counting maintains two refcount fields in each object:
`ob_ref_local` and `ob_ref_shared`. The true refcount is the sum of these two
fields. In some cases, when refcounting operations are split across threads,
the ob_ref_shared field can be negative (although the total refcount must be
at least zero). In this case, the thread that decremented the refcount
requests that the owning thread give up ownership and merge the refcount
fields.