#!/usr/bin/env python3
# Copyright (c) Facebook, Inc. and its affiliates. (http://www.facebook.com)
import unittest
from threading import Condition, Event, Lock

from test_support import pyro_only


class LockTests(unittest.TestCase):
    def test_lock_acquire_and_release_locks_and_releases(self):
        lock = Lock()
        self.assertFalse(lock.locked())
        self.assertTrue(lock.acquire())
        self.assertTrue(lock.locked())
        lock.release()
        self.assertFalse(lock.locked())

    def test_lock_as_context_manager_locks_and_releases(self):
        lock = Lock()
        self.assertFalse(lock.locked())
        with lock:
            self.assertTrue(lock.locked())
        self.assertFalse(lock.locked())

    def test_lock_acquire_nonblocking_locks(self):
        lock = Lock()
        self.assertFalse(lock.locked())
        self.assertTrue(lock.acquire(False))
        self.assertTrue(lock.locked())
        lock.release()

    def test_lock_acquire_nonblocking_does_not_lock(self):
        lock = Lock()
        self.assertTrue(lock.acquire())
        self.assertTrue(lock.locked())
        self.assertFalse(lock.acquire(False))
        self.assertTrue(lock.locked())
        lock.release()

        self.assertTrue(lock.acquire(False))
        self.assertTrue(lock.locked())
        self.assertFalse(lock.acquire(False))
        self.assertTrue(lock.locked())
        lock.release()


class ConditionTests(unittest.TestCase):
    def test_dunder_init_creates_lock(self):
        c = Condition()
        self.assertIsNotNone(c._lock)

    @pyro_only
    def test_enter_exit_functionality(self):
        c = Condition()
        lock_count = c._lock._count
        with c:
            self.assertEqual(lock_count + 1, c._lock._count)
        self.assertEqual(lock_count, c._lock._count)


class EventTests(unittest.TestCase):
    def test_dunder_init_clears_flag(self):
        e = Event()
        self.assertFalse(e.is_set())

    def test_clear_clears_flag(self):
        e = Event()
        e.set()
        self.assertTrue(e.is_set())
        e.clear()
        self.assertFalse(e.is_set())

    def test_set_sets_flag(self):
        e = Event()
        self.assertFalse(e.is_set())
        e.set()
        self.assertTrue(e.is_set())

    def test_wait_on_set_flag_returns(self):
        e = Event()
        e.set()
        e.wait()
        val = e.wait(5)
        self.assertTrue(val)


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