(Note: PEP 554 is not accepted and the implementation in the code base is a private one for use in the test suite.)
If code running in a subinterpreter raises an uncaught exception then the "run" call in the calling interpreter fails. A RunFailedError is raised there that summarizes the original exception as a string. The actual exception type, __cause__, __context__, state, etc. are all discarded. This turned out to be functionally insufficient in practice. There is a more helpful solution (and PEP 554 has been updated appropriately).
This change adds the exception propagation behavior described in PEP 554 to the _xxsubinterpreters module. With this change a copy of the original exception is set to __cause__ on the RunFailedError. For now we are using "pickle", which preserves the exception's state. We also preserve the original __cause__, __context__, and __traceback__ (since "pickle" does not preserve those).
https://bugs.python.org/issue32604
An isolated subinterpreter cannot spawn threads, spawn a child
process or call os.fork().
* Add private _Py_NewInterpreter(isolated_subinterpreter) function.
* Add isolated=True keyword-only parameter to
_xxsubinterpreters.create().
* Allow again os.fork() in "non-isolated" subinterpreters.
This allows the caller to avoid creation of an exception when the channel is empty (just like `dict.get()` works). `ChannelEmptyError` is still raised if no default is provided.
Automerge-Triggered-By: @ericsnowcurrently
Adds an additional assertion check based on a race condition for `test__xxsubinterpreters.DestroyTests.test_still_running` discovered in the bpo issue.
https://bugs.python.org/issue37224
* Fix a crash in comparing with float (and maybe other crashes).
* They are now never equal to strings and non-integer numbers.
* Comparison with a large number no longer raises OverflowError.
* Arbitrary exceptions no longer silenced in constructors and comparisons.
* TypeError raised in the constructor contains now the name of the type.
* Accept only ChannelID and int-like objects in channel functions.
* Accept only InterpreterId, int-like objects and str in the InterpreterId constructor.
* Accept int-like objects, not just int in interpreter related functions.
When os.fork() is called (on platforms that support it) all threads but the current one are destroyed in the child process. Consequently we must ensure that all but the associated interpreter are likewise destroyed. The main interpreter is critical for runtime operation, so we must ensure that fork only happens in the main interpreter.
https://bugs.python.org/issue34651
All the subinterpreter tests were disabled in gh-7513. This commit re-enables them, but leaves one bad test disabled. The test is partly causing problems because it makes assumptions about the availability of a high-level interpreters module (see PEP 554). So I'm disabling the test until such a high-level module is available.
For bpo-32604 I added extra subinterpreter-related tests (see #6914), which caused a few buildbots to crash. This patch fixes the crash by ensuring that refcounts in channels are handled properly.
For bpo-32604 I added some subinterpreter-related tests (see #6914) that are causing crashes on a few buildbots. I'm working on fixing the crashes (see #7251). This change temporarily disables the triggering test.
The CPython runtime assumes that there is a one-to-one relationship (for a given interpreter) between PyThreadState and OS threads. Sending and receiving on a channel in the same interpreter was causing crashes because of this (specifically due to a check in PyThreadState_Swap()). The solution is to not switch threads if the interpreter is the same.
An Long
Victor Stinner
Eric Snow
Lewis Gaul
Kyle Stanley
Serhiy Storchaka
Victor Stinner
Alexey Izbyshev
Ville Skyttä