pytorch-lightning

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# Copyright The Lightning AI team.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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#     http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import os
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from unittest import mock
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import pytest
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from lightning.fabric.plugins.environments import LightningEnvironment
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@mock.patch.dict(os.environ, {}, clear=True)
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def test_default_attributes():
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    """Test the default attributes when no environment variables are set."""
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    env = LightningEnvironment()
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    assert not env.creates_processes_externally
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    assert env.main_address == "127.0.0.1"
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    assert isinstance(env.main_port, int)
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    assert env.world_size() == 1
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    assert env.local_rank() == 0
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    assert env.node_rank() == 0
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@mock.patch.dict(os.environ, {"MASTER_ADDR": "1.2.3.4", "MASTER_PORT": "500", "LOCAL_RANK": "2", "NODE_RANK": "3"})
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def test_attributes_from_environment_variables():
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    """Test that the default cluster environment takes the attributes from the environment variables."""
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    env = LightningEnvironment()
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    assert env.main_address == "1.2.3.4"
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    assert env.main_port == 500
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    assert env.world_size() == 1
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    assert env.global_rank() == 0
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    assert env.local_rank() == 2
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    assert env.node_rank() == 3
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    env.set_global_rank(100)
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    assert env.global_rank() == 100
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    env.set_world_size(100)
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    assert env.world_size() == 100
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@pytest.mark.parametrize(
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    ("environ", "creates_processes_externally"), [({}, False), ({"LOCAL_RANK": "2"}, True), ({"NODE_RANK": "1"}, False)]
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)
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def test_manual_user_launch(environ, creates_processes_externally):
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    """Test that the environment switches to manual user mode when LOCAL_RANK env variable detected."""
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    with mock.patch.dict(os.environ, environ):
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        env = LightningEnvironment()
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        assert env.creates_processes_externally == creates_processes_externally
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@mock.patch.dict(os.environ, {"GROUP_RANK": "1"})
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def test_node_rank_from_group_rank():
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    """Test that the GROUP_RANK substitutes NODE_RANK."""
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    env = LightningEnvironment()
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    assert "NODE_RANK" not in os.environ
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    assert env.node_rank() == 1
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@mock.patch.dict(os.environ, {}, clear=True)
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def test_random_main_port():
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    """Test randomly chosen main port when no main port was given by user."""
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    env = LightningEnvironment()
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    port = env.main_port
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    assert isinstance(port, int)
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    # repeated calls do not generate a new port number
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    assert env.main_port == port
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@mock.patch.dict(os.environ, {"WORLD_SIZE": "1"})
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def test_teardown():
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    """Test that the GROUP_RANK substitutes NODE_RANK."""
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    env = LightningEnvironment()
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    assert "WORLD_SIZE" in os.environ
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    env.teardown()
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    assert "WORLD_SIZE" not in os.environ
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def test_detect():
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    assert LightningEnvironment.detect()
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