lightning/tests/tests_fabric/strategies/launchers/test_subprocess_script.py

184 lines
8.2 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 signal
import sys
from unittest import mock
from unittest.mock import ANY, Mock
import lightning.fabric
import pytest
from lightning.fabric.strategies.launchers.subprocess_script import (
_HYDRA_AVAILABLE,
_ChildProcessObserver,
_SubprocessScriptLauncher,
)
def test_subprocess_script_launcher_interactive_compatible():
launcher = _SubprocessScriptLauncher(Mock(), num_processes=2, num_nodes=1)
assert not launcher.is_interactive_compatible
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.subprocess.Popen")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script._ChildProcessObserver")
def test_subprocess_script_launcher_can_launch(*_):
cluster_env = Mock()
cluster_env.creates_processes_externally = False
cluster_env.local_rank.return_value = 1
launcher = _SubprocessScriptLauncher(cluster_env, num_processes=2, num_nodes=1)
with pytest.raises(RuntimeError, match="attempted to launch new distributed processes with `local_rank > 0`"):
launcher.launch(Mock())
launcher.procs = [Mock()] # there are already processes running
with pytest.raises(RuntimeError, match="The launcher can only create subprocesses once"):
launcher.launch(Mock())
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.subprocess.Popen")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script._ChildProcessObserver")
def test_subprocess_script_launcher_external_processes(_, popen_mock):
cluster_env = Mock()
cluster_env.creates_processes_externally = True
function = Mock()
launcher = _SubprocessScriptLauncher(cluster_env, num_processes=4, num_nodes=2)
launcher.launch(function, "positional-arg", keyword_arg=0)
function.assert_called_with("positional-arg", keyword_arg=0)
popen_mock.assert_not_called()
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.subprocess.Popen")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script._ChildProcessObserver")
def test_subprocess_script_launcher_launch_processes(_, popen_mock):
cluster_env = Mock()
cluster_env.creates_processes_externally = False
cluster_env.local_rank.return_value = 0
cluster_env.main_address = "address"
cluster_env.main_port = 1234
function = Mock()
launcher = _SubprocessScriptLauncher(cluster_env, num_processes=4, num_nodes=2)
num_new_processes = launcher.num_processes - 1
# launches n-1 new processes, the current one will participate too
launcher.launch(function, "positional-arg", keyword_arg=0)
calls = popen_mock.call_args_list
assert len(calls) == num_new_processes
# world size in child processes
world_sizes = [int(calls[i][1]["env"]["WORLD_SIZE"]) for i in range(num_new_processes)]
assert world_sizes == [launcher.num_processes * launcher.num_nodes] * num_new_processes
# local rank in child processes
local_ranks = [int(calls[i][1]["env"]["LOCAL_RANK"]) for i in range(num_new_processes)]
assert local_ranks == list(range(1, num_new_processes + 1))
# the current process
assert int(os.environ["WORLD_SIZE"]) == launcher.num_processes * launcher.num_nodes
assert int(os.environ["LOCAL_RANK"]) == 0
@pytest.mark.skipif(not _HYDRA_AVAILABLE, reason="hydra-core is required")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.subprocess.Popen")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script._ChildProcessObserver")
def test_subprocess_script_launcher_hydra_in_use(_, popen_mock, monkeypatch):
basic_command = Mock(return_value="basic_command")
hydra_command = Mock(return_value=("hydra_command", "hydra_cwd"))
monkeypatch.setattr(lightning.fabric.strategies.launchers.subprocess_script, "_basic_subprocess_cmd", basic_command)
monkeypatch.setattr(lightning.fabric.strategies.launchers.subprocess_script, "_hydra_subprocess_cmd", hydra_command)
def simulate_launch():
cluster_env = Mock()
cluster_env.creates_processes_externally = False
cluster_env.local_rank.return_value = 0
cluster_env.main_address = "address"
cluster_env.main_port = 1234
function = Mock()
launcher = _SubprocessScriptLauncher(cluster_env, num_processes=4, num_nodes=2)
launcher.launch(function)
# when hydra not available
monkeypatch.setattr(lightning.fabric.strategies.launchers.subprocess_script, "_HYDRA_AVAILABLE", False)
simulate_launch()
popen_mock.assert_called_with("basic_command", env=ANY, cwd=None)
popen_mock.reset_mock()
import hydra
# when hydra available but not initialized
monkeypatch.setattr(lightning.fabric.strategies.launchers.subprocess_script, "_HYDRA_AVAILABLE", True)
HydraConfigMock = Mock()
HydraConfigMock.initialized.return_value = False
monkeypatch.setattr(hydra.core.hydra_config, "HydraConfig", HydraConfigMock)
simulate_launch()
popen_mock.assert_called_with("basic_command", env=ANY, cwd=None)
popen_mock.reset_mock()
# when hydra available and initialized
monkeypatch.setattr(lightning.fabric.strategies.launchers.subprocess_script, "_HYDRA_AVAILABLE", True)
HydraConfigMock = Mock()
HydraConfigMock.initialized.return_value = True
monkeypatch.setattr(hydra.core.hydra_config, "HydraConfig", HydraConfigMock)
simulate_launch()
popen_mock.assert_called_with("hydra_command", env=ANY, cwd="hydra_cwd")
popen_mock.reset_mock()
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.os.kill")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.time.sleep")
def test_child_process_observer(sleep_mock, os_kill_mock):
# Case 1: All processes are running and did not exit yet
processes = [Mock(returncode=None), Mock(returncode=None)]
observer = _ChildProcessObserver(main_pid=1234, child_processes=processes)
finished = observer._run() # call _run() directly to simulate while loop
assert not finished
# Case 2: All processes have finished with exit code 0 (success)
processes = [Mock(returncode=0), Mock(returncode=0)]
observer = _ChildProcessObserver(main_pid=1234, child_processes=processes)
finished = observer._run() # call _run() directly to simulate while loop
assert finished
# Case 3: One process has finished with exit code 1 (failure)
processes = [Mock(returncode=0), Mock(returncode=1)]
observer = _ChildProcessObserver(main_pid=1234, child_processes=processes)
finished = observer._run() # call _run() directly to simulate while loop
assert finished
expected_signal = signal.SIGTERM if sys.platform == "win32" else signal.SIGKILL
processes[0].send_signal.assert_called_once_with(expected_signal)
processes[1].send_signal.assert_called_once_with(expected_signal)
os_kill_mock.assert_called_once_with(1234, expected_signal)
# The main routine stops
observer = _ChildProcessObserver(main_pid=1234, child_processes=[Mock(), Mock()])
observer._run = Mock()
assert not observer._finished
observer.run()
assert observer._finished
sleep_mock.assert_called_once_with(5)
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script.subprocess.Popen")
@mock.patch("lightning.fabric.strategies.launchers.subprocess_script._ChildProcessObserver")
def test_validate_cluster_environment_user_settings(*_):
"""Test that the launcher calls into the cluster environment to validate the user settings."""
cluster_env = Mock(validate_settings=Mock(side_effect=RuntimeError("test")))
cluster_env.creates_processes_externally = True
launcher = _SubprocessScriptLauncher(cluster_env, num_processes=2, num_nodes=1)
with pytest.raises(RuntimeError, match="test"):
launcher.launch(Mock())