This is the implementation of PEP683
Motivation:
The PR introduces the ability to immortalize instances in CPython which bypasses reference counting. Tagging objects as immortal allows up to skip certain operations when we know that the object will be around for the entire execution of the runtime.
Note that this by itself will bring a performance regression to the runtime due to the extra reference count checks. However, this brings the ability of having truly immutable objects that are useful in other contexts such as immutable data sharing between sub-interpreters.
support.print_warning() now stores the original value of
sys.__stderr__ and uses it to log warnings. libregrtest uses the same
stream to log unraisable exceptions and uncaught threading
exceptions.
Partially revert commit dbe213de7ef28712bbfdb9d94a33abb9c33ef0c2:
libregrtest no longer replaces sys.__stdout__, sys.__stderr__, and
stdout and stderr file descriptors.
Remove also a few unused imports in libregrtest.
libregrtest now clears the type cache later to reduce the risk of
false alarm when checking for reference leaks. Previously, the type
cache was cleared too early and libregrtest raised a false alarm
about reference leaks under very specific conditions.
Move also support.gc_collect() outside clear/cleanup functions to
make the garbage collection more explicit.
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
* Add co_firstinstr field to code object.
* Implement barebones quickening.
* Use non-quickened bytecode when tracing.
* Add NEWS item
* Add new file to Windows build.
* Don't specialize instructions with EXTENDED_ARG.
Move clear_caches() from libregrtest.refleak to libregrtest.utils to
avoid importing libregrtest.refleak when it's not needed.
clear_caches() now only calls re.purge() if 're' is in sys.modules.
* Add TestResult and MultiprocessResult types to ensure that results
always have the same fields.
* runtest() now handles KeyboardInterrupt
* accumulate_result() and format_test_result() now takes a TestResult
* cleanup_test_droppings() is now called by runtest() and mark the
test as ENV_CHANGED if the test leaks support.TESTFN file.
* runtest() now includes code "around" the test in the test timing
* Add print_warning() in test.libregrtest.utils to standardize how
libregrtest logs warnings to ease parsing the test output.
* support.unload() is now called with abstest rather than test_name
* Rename 'test' variable/parameter to 'test_name'
* dash_R(): remove unused the_module parameter
* Remove unused imports
dash_R() function of libregrtest doesn't call support.gc_collect()
directly anymore: it's already called by dash_R_cleanup().
Call dash_R_cleanup() before starting the loop.
Fix reference leak hunting in regrtest: compute also deltas (of
reference count, allocated memory blocks, file descriptor count)
during warmup, to ensure that everything is initialized before
starting to hunt reference leaks.
Other changes:
* Replace gc.collect() with support.gc_collect()
* Move calls to read memory statistics from dash_R_cleanup() to
dash_R()
* Pass regrtest 'ns' to dash_R()
* dash_R() is now more quiet with --quiet option (don't display
progress).
* Precompute the full range for "for it in range(repcount):" to
ensure that the iteration doesn't allocate anything new.
* dash_R() now is responsible to call warm_caches().
Use a pool of integer objects toprevent false alarm when checking for
memory block leaks. Fill the pool with values in -1000..1000 which
are the most common (reference, memory block, file descriptor)
differences.
Co-Authored-By: Antoine Pitrou <pitrou@free.fr>
* bpo-26732: fix too many fds in processes started with the "forkserver" method
A child process would inherit as many fds as the number of still-running children.
* Add blurb and test comment
* Change the regrtest --huntrleaks checker to decide if a test file
leaks or not. Require that each run leaks at least 1 reference.
* Warmup runs are now completely ignored: ignored in the checker test
and not used anymore to compute the sum.
* Add an unit test for a reference leak.
Example of reference differences previously considered a failure
(leak) and now considered as success (success, no leak):
[3, 0, 0]
[0, 1, 0]
[8, -8, 1]
* Fix "-m test --forever": replace _test_forever() with self._test_forever()
* Add unit test for --forever
* Add unit test for a failing test
* Fix also some pyflakes warnings in libregrtest
Eddie Elizondo
Brandt Bucher
Inada Naoki
Victor Stinner
Christian Clauss
Mark Shannon
Hai Shi
Victor Stinner
Ivan Levkivskyi
Victor Stinner
Antoine Pitrou
Serhiy Storchaka