lightning/tests/tests_fabric/conftest.py

254 lines
10 KiB
Python

# Copyright The Lightning AI team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import sys
import threading
from concurrent.futures.process import _ExecutorManagerThread
from pathlib import Path
from unittest.mock import Mock
import lightning.fabric
import pytest
import torch.distributed
from lightning.fabric.accelerators import XLAAccelerator
from lightning.fabric.strategies.launchers.subprocess_script import _ChildProcessObserver
from lightning.fabric.utilities.distributed import _destroy_dist_connection
@pytest.fixture(autouse=True)
def preserve_global_rank_variable():
"""Ensures that the rank_zero_only.rank global variable gets reset in each test."""
from lightning.fabric.utilities.rank_zero import rank_zero_only as rank_zero_only_fabric
from lightning_utilities.core.rank_zero import rank_zero_only as rank_zero_only_utilities
functions = (rank_zero_only_fabric, rank_zero_only_utilities)
ranks = [getattr(fn, "rank", None) for fn in functions]
yield
for fn, rank in zip(functions, ranks):
if rank is not None:
setattr(fn, "rank", rank)
@pytest.fixture(autouse=True)
def restore_env_variables():
"""Ensures that environment variables set during the test do not leak out."""
env_backup = os.environ.copy()
yield
leaked_vars = os.environ.keys() - env_backup.keys()
# restore environment as it was before running the test
os.environ.clear()
os.environ.update(env_backup)
# these are currently known leakers - ideally these would not be allowed
# TODO(fabric): this list can be trimmed, maybe PL's too after moving tests
allowlist = {
"CUDA_DEVICE_ORDER",
"LOCAL_RANK",
"NODE_RANK",
"WORLD_SIZE",
"MASTER_ADDR",
"MASTER_PORT",
"PL_GLOBAL_SEED",
"PL_SEED_WORKERS",
"RANK", # set by DeepSpeed
"CUDA_MODULE_LOADING", # leaked by PyTorch
"CRC32C_SW_MODE", # set by tensorboardX
"OMP_NUM_THREADS", # set by our launchers
# set by torchdynamo
"TRITON_CACHE_DIR",
"TORCHINDUCTOR_CACHE_DIR",
}
leaked_vars.difference_update(allowlist)
assert not leaked_vars, f"test is leaking environment variable(s): {set(leaked_vars)}"
@pytest.fixture(autouse=True)
def teardown_process_group():
"""Ensures that the distributed process group gets closed before the next test runs."""
yield
_destroy_dist_connection()
@pytest.fixture(autouse=True)
def thread_police_duuu_daaa_duuu_daaa():
"""Attempts to stop left-over threads to avoid test interactions."""
active_threads_before = set(threading.enumerate())
yield
active_threads_after = set(threading.enumerate())
if XLAAccelerator.is_available():
# Ignore the check when running XLA tests for now
return
for thread in active_threads_after - active_threads_before:
stop = getattr(thread, "stop", None) or getattr(thread, "exit", None)
if thread.daemon and callable(stop):
# A daemon thread would anyway be stopped at the end of a program
# We do it preemptively here to reduce the risk of interactions with other tests that run after
stop()
assert not thread.is_alive()
elif isinstance(thread, _ChildProcessObserver):
thread.join(timeout=10)
elif (
thread.name == "QueueFeederThread" # tensorboardX
or thread.name == "QueueManagerThread" # torch.compile
or "(_read_thread)" in thread.name # torch.compile
):
thread.join(timeout=20)
elif (
sys.version_info >= (3, 9)
and isinstance(thread, _ExecutorManagerThread)
or "ThreadPoolExecutor-" in thread.name
):
# probably `torch.compile`, can't narrow it down further
continue
else:
raise AssertionError(f"Test left zombie thread: {thread}")
@pytest.fixture(autouse=True)
def reset_in_fabric_backward():
"""Ensures that the wrappers.in_fabric_backward global variable gets reset after each test."""
import lightning.fabric.wrappers as wrappers
assert hasattr(wrappers, "_in_fabric_backward")
yield
wrappers._in_fabric_backward = False
@pytest.fixture()
def reset_deterministic_algorithm():
"""Ensures that torch determinism settings are reset before the next test runs."""
yield
os.environ.pop("CUBLAS_WORKSPACE_CONFIG", None)
torch.use_deterministic_algorithms(False)
@pytest.fixture()
def reset_cudnn_benchmark():
"""Ensures that the `torch.backends.cudnn.benchmark` setting gets reset before the next test runs."""
yield
torch.backends.cudnn.benchmark = False
def mock_xla_available(monkeypatch: pytest.MonkeyPatch, value: bool = True) -> None:
monkeypatch.setattr(lightning.fabric.accelerators.xla, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.plugins.environments.xla, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.plugins.precision.xla, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.plugins.io.xla, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.strategies.single_xla, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.strategies.xla_fsdp, "_XLA_AVAILABLE", value)
monkeypatch.setattr(lightning.fabric.strategies.launchers.xla, "_XLA_AVAILABLE", value)
monkeypatch.setitem(sys.modules, "torch_xla", Mock())
monkeypatch.setitem(sys.modules, "torch_xla.core.xla_model", Mock())
monkeypatch.setitem(sys.modules, "torch_xla.experimental", Mock())
monkeypatch.setitem(sys.modules, "torch_xla.distributed.fsdp.wrap", Mock())
@pytest.fixture()
def xla_available(monkeypatch: pytest.MonkeyPatch) -> None:
mock_xla_available(monkeypatch)
def mock_tpu_available(monkeypatch: pytest.MonkeyPatch, value: bool = True) -> None:
mock_xla_available(monkeypatch, value)
monkeypatch.setattr(lightning.fabric.accelerators.xla.XLAAccelerator, "is_available", lambda: value)
monkeypatch.setattr(lightning.fabric.accelerators.xla.XLAAccelerator, "auto_device_count", lambda *_: 8)
@pytest.fixture()
def tpu_available(monkeypatch: pytest.MonkeyPatch) -> None:
mock_tpu_available(monkeypatch)
@pytest.fixture()
def caplog(caplog):
"""Workaround for https://github.com/pytest-dev/pytest/issues/3697.
Setting ``filterwarnings`` with pytest breaks ``caplog`` when ``not logger.propagate``.
"""
import logging
lightning_logger = logging.getLogger("lightning.fabric")
propagate = lightning_logger.propagate
lightning_logger.propagate = True
yield caplog
lightning_logger.propagate = propagate
@pytest.fixture(autouse=True)
def leave_no_artifacts_behind():
tests_root = Path(__file__).parent.parent
files_before = {p for p in tests_root.rglob("*") if "__pycache__" not in p.parts}
yield
files_after = {p for p in tests_root.rglob("*") if "__pycache__" not in p.parts}
difference = files_after - files_before
difference = {str(f.relative_to(tests_root)) for f in difference}
assert not difference, f"Test left artifacts behind: {difference}"
def pytest_collection_modifyitems(items: list[pytest.Function], config: pytest.Config) -> None:
"""An adaptation of `tests/tests_pytorch/conftest.py::pytest_collection_modifyitems`"""
initial_size = len(items)
conditions = []
filtered, skipped = 0, 0
options = {
"standalone": "PL_RUN_STANDALONE_TESTS",
"min_cuda_gpus": "PL_RUN_CUDA_TESTS",
"tpu": "PL_RUN_TPU_TESTS",
}
if os.getenv(options["standalone"], "0") == "1" and os.getenv(options["min_cuda_gpus"], "0") == "1":
# special case: we don't have a CPU job for standalone tests, so we shouldn't run only cuda tests.
# by deleting the key, we avoid filtering out the CPU tests
del options["min_cuda_gpus"]
for kwarg, env_var in options.items():
# this will compute the intersection of all tests selected per environment variable
if os.getenv(env_var, "0") != "1":
continue
conditions.append(env_var)
for i, test in reversed(list(enumerate(items))): # loop in reverse, since we are going to pop items
already_skipped = any(marker.name == "skip" for marker in test.own_markers)
if already_skipped:
# the test was going to be skipped anyway, filter it out
items.pop(i)
skipped += 1
continue
has_runif_with_kwarg = any(
marker.name == "skipif" and marker.kwargs.get(kwarg) for marker in test.own_markers
)
if not has_runif_with_kwarg:
# the test has `@RunIf(kwarg=True)`, filter it out
items.pop(i)
filtered += 1
if config.option.verbose >= 0 and (filtered or skipped):
writer = config.get_terminal_writer()
writer.write(
f"\nThe number of tests has been filtered from {initial_size} to {initial_size - filtered} after the"
f" filters {conditions}.\n{skipped} tests are marked as unconditional skips.\nIn total, {len(items)} tests"
" will run.\n",
flush=True,
bold=True,
purple=True, # oh yeah, branded pytest messages
)
# error out on our deprecation warnings - ensures the code and tests are kept up-to-date
deprecation_error = pytest.mark.filterwarnings(
"error::lightning.fabric.utilities.rank_zero.LightningDeprecationWarning",
)
for item in items:
item.add_marker(deprecation_error)