https://bugs.gentoo.org/show_bug.cgi?id=912709 https://github.com/adamchainz/time-machine/pull/400 From b489a478193982c17cf7847d32cae2b53a904222 Mon Sep 17 00:00:00 2001 From: matoro Date: Thu, 9 Nov 2023 13:03:49 -0500 Subject: [PATCH 1/2] Fix tests on platforms with low clock resolution On platforms without a high-resolution clock, such as Alpha and PA-RISC is is likely that two sequential calls to time.time() will return the same value if the execution time is not sufficient to allow one full clock resolution cycle to pass. This adds sleeps of one cycle to enforce that the minimum amount of time to guarantee a clock change has passed. On systems with high-resolution clocks, clock_getres() will return 1ns; in reality the sleep will take longer than 1ns to execute but should still be a negligible amount of time. --- tests/test_time_machine.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tests/test_time_machine.py b/tests/test_time_machine.py index fe98fb7..7b5abbe 100644 --- a/tests/test_time_machine.py +++ b/tests/test_time_machine.py @@ -155,8 +155,10 @@ def test_time_clock_gettime_realtime(): @py_have_clock_gettime def test_time_clock_gettime_monotonic_unaffected(): start = time.clock_gettime(time.CLOCK_MONOTONIC) + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) with time_machine.travel(EPOCH + 180.0): frozen = time.clock_gettime(time.CLOCK_MONOTONIC) + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert isinstance(frozen, float) assert frozen > start @@ -169,6 +171,7 @@ def test_time_clock_gettime_monotonic_unaffected(): def test_time_clock_gettime_ns_realtime(): with time_machine.travel(EPOCH + 190.0): first = time.clock_gettime_ns(time.CLOCK_REALTIME) + time.sleep(time.clock_getres(time.CLOCK_REALTIME)) assert isinstance(first, int) assert first == int((EPOCH + 190.0) * NANOSECONDS_PER_SECOND) second = time.clock_gettime_ns(time.CLOCK_REALTIME) @@ -182,8 +185,10 @@ def test_time_clock_gettime_ns_realtime(): @py_have_clock_gettime def test_time_clock_gettime_ns_monotonic_unaffected(): start = time.clock_gettime_ns(time.CLOCK_MONOTONIC) + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) with time_machine.travel(EPOCH + 190.0): frozen = time.clock_gettime_ns(time.CLOCK_MONOTONIC) + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert isinstance(frozen, int) assert frozen > start @@ -279,6 +284,7 @@ def test_time_strftime_format_t(): def test_time_time(): with time_machine.travel(EPOCH): first = time.time() + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert isinstance(first, float) assert first == EPOCH second = time.time() @@ -300,6 +306,7 @@ def test_time_time(): def test_time_time_windows(): with time_machine.travel(EPOCH): first = time.time() + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert isinstance(first, float) assert first == windows_epoch_in_posix @@ -316,6 +323,7 @@ def test_time_time_no_tick(): def test_time_time_ns(): with time_machine.travel(EPOCH + 150.0): first = time.time_ns() + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert isinstance(first, int) assert first == int((EPOCH + 150.0) * NANOSECONDS_PER_SECOND) second = time.time_ns() @@ -561,6 +569,7 @@ def test_method_decorator(self): @time_machine.travel(EPOCH + 95.0) class UnitTestClassTests(TestCase): def test_class_decorator(self): + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert EPOCH + 95.0 < time.time() < EPOCH + 96.0 @time_machine.travel(EPOCH + 25.0) @@ -578,6 +587,7 @@ def setUpClass(cls): cls.custom_setupclass_ran = True def test_class_decorator(self): + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert EPOCH + 95.0 < time.time() < EPOCH + 96.0 assert self.custom_setupclass_ran @@ -639,6 +649,7 @@ def test_move_to_datetime(): traveller.move_to(EPOCH_PLUS_ONE_YEAR_DATETIME) first = time.time() + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert first == EPOCH_PLUS_ONE_YEAR second = time.time() @@ -706,6 +717,7 @@ def test_move_to_datetime_change_tick_on(): with time_machine.travel(EPOCH, tick=False) as traveller: traveller.move_to(EPOCH_PLUS_ONE_YEAR_DATETIME, tick=True) assert time.time() == EPOCH_PLUS_ONE_YEAR + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert time.time() > EPOCH_PLUS_ONE_YEAR @@ -756,6 +768,7 @@ def test_fixture_used_tick_false(time_machine): def test_fixture_used_tick_true(time_machine): time_machine.move_to(EPOCH, tick=True) original = time.time() + time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) assert original == EPOCH assert original < time.time() < EPOCH + 10.0 From 9e84584325ec06eb997716b6a0f42e9ca6540994 Mon Sep 17 00:00:00 2001 From: matoro Date: Fri, 10 Nov 2023 11:06:23 -0500 Subject: [PATCH 2/2] Wrap sleep calls in "sleep_one_cycle" function --- tests/test_time_machine.py | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/tests/test_time_machine.py b/tests/test_time_machine.py index 7b5abbe..163ec2b 100644 --- a/tests/test_time_machine.py +++ b/tests/test_time_machine.py @@ -38,6 +38,10 @@ ) +def sleep_one_cycle(clock: int) -> None: + time.sleep(time.clock_getres(clock)) + + @contextmanager def change_local_timezone(local_tz: str | None) -> typing.Iterator[None]: orig_tz = os.environ["TZ"] @@ -155,10 +159,10 @@ def test_time_clock_gettime_realtime(): @py_have_clock_gettime def test_time_clock_gettime_monotonic_unaffected(): start = time.clock_gettime(time.CLOCK_MONOTONIC) - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) with time_machine.travel(EPOCH + 180.0): frozen = time.clock_gettime(time.CLOCK_MONOTONIC) - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert isinstance(frozen, float) assert frozen > start @@ -171,7 +175,7 @@ def test_time_clock_gettime_monotonic_unaffected(): def test_time_clock_gettime_ns_realtime(): with time_machine.travel(EPOCH + 190.0): first = time.clock_gettime_ns(time.CLOCK_REALTIME) - time.sleep(time.clock_getres(time.CLOCK_REALTIME)) + sleep_one_cycle(time.CLOCK_REALTIME) assert isinstance(first, int) assert first == int((EPOCH + 190.0) * NANOSECONDS_PER_SECOND) second = time.clock_gettime_ns(time.CLOCK_REALTIME) @@ -185,10 +189,10 @@ def test_time_clock_gettime_ns_realtime(): @py_have_clock_gettime def test_time_clock_gettime_ns_monotonic_unaffected(): start = time.clock_gettime_ns(time.CLOCK_MONOTONIC) - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) with time_machine.travel(EPOCH + 190.0): frozen = time.clock_gettime_ns(time.CLOCK_MONOTONIC) - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert isinstance(frozen, int) assert frozen > start @@ -284,7 +288,7 @@ def test_time_strftime_format_t(): def test_time_time(): with time_machine.travel(EPOCH): first = time.time() - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert isinstance(first, float) assert first == EPOCH second = time.time() @@ -306,7 +310,7 @@ def test_time_time(): def test_time_time_windows(): with time_machine.travel(EPOCH): first = time.time() - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert isinstance(first, float) assert first == windows_epoch_in_posix @@ -323,7 +327,7 @@ def test_time_time_no_tick(): def test_time_time_ns(): with time_machine.travel(EPOCH + 150.0): first = time.time_ns() - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert isinstance(first, int) assert first == int((EPOCH + 150.0) * NANOSECONDS_PER_SECOND) second = time.time_ns() @@ -569,7 +573,7 @@ def test_method_decorator(self): @time_machine.travel(EPOCH + 95.0) class UnitTestClassTests(TestCase): def test_class_decorator(self): - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert EPOCH + 95.0 < time.time() < EPOCH + 96.0 @time_machine.travel(EPOCH + 25.0) @@ -587,7 +591,7 @@ def setUpClass(cls): cls.custom_setupclass_ran = True def test_class_decorator(self): - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert EPOCH + 95.0 < time.time() < EPOCH + 96.0 assert self.custom_setupclass_ran @@ -649,7 +653,7 @@ def test_move_to_datetime(): traveller.move_to(EPOCH_PLUS_ONE_YEAR_DATETIME) first = time.time() - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert first == EPOCH_PLUS_ONE_YEAR second = time.time() @@ -717,7 +721,7 @@ def test_move_to_datetime_change_tick_on(): with time_machine.travel(EPOCH, tick=False) as traveller: traveller.move_to(EPOCH_PLUS_ONE_YEAR_DATETIME, tick=True) assert time.time() == EPOCH_PLUS_ONE_YEAR - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert time.time() > EPOCH_PLUS_ONE_YEAR @@ -768,7 +772,7 @@ def test_fixture_used_tick_false(time_machine): def test_fixture_used_tick_true(time_machine): time_machine.move_to(EPOCH, tick=True) original = time.time() - time.sleep(time.clock_getres(time.CLOCK_MONOTONIC)) + sleep_one_cycle(time.CLOCK_MONOTONIC) assert original == EPOCH assert original < time.time() < EPOCH + 10.0