# Copyright 2024 The JAX Authors
#
# 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 gc
import threading

from absl.testing import absltest

from jax.jaxlib import _jax

config = _jax.config


test_race_config = config.Config("test_race", 1)


class ConfigTest(absltest.TestCase):

  def testBasic(self):
    c = config.Config("test", 1)
    self.assertEqual(c.name, "test")
    self.assertEqual(c.value, 1)
    self.assertEqual(c.get_global(), 1)
    self.assertEqual(c.get_local(), config.unset)

    c.set_global(2)
    self.assertEqual(c.value, 2)
    self.assertEqual(c.get_global(), 2)
    self.assertEqual(c.get_local(), config.unset)

    c.set_local(3)
    self.assertEqual(c.value, 3)
    self.assertEqual(c.get_global(), 2)
    self.assertEqual(c.get_local(), 3)

    c.set_global(4)
    self.assertEqual(c.value, 3)
    self.assertEqual(c.get_global(), 4)
    self.assertEqual(c.get_local(), 3)

    c.set_local(config.unset)
    self.assertEqual(c.value, 4)
    self.assertEqual(c.get_global(), 4)
    self.assertEqual(c.get_local(), config.unset)

  def testThreading(self):
    c = config.Config("test", 1)

    def Body():
      for i in range(100):
        c.set_local(i)
        self.assertEqual(c.get_local(), i)
        self.assertEqual(c.get_global(), 1)
        self.assertEqual(c.value, i)

    threads = [threading.Thread(target=Body) for _ in range(4)]
    for t in threads:
      t.start()
    for t in threads:
      t.join()

  def testConcurrentGlobalStateRace(self):
    def writer():
      for _ in range(2000):
        test_race_config.set_global(2)
        test_race_config.set_global(1)

    def reader():
      for _ in range(2000):
        _ = test_race_config.value

    def collector():
      for _ in range(50):
        gc.collect()

    threads = [
        threading.Thread(target=writer),
        threading.Thread(target=reader),
        threading.Thread(target=reader),
        threading.Thread(target=collector),
    ]
    for t in threads:
      t.start()
    for t in threads:
      t.join()


if __name__ == "__main__":
  absltest.main()