import imp

import unittest

from test import test_support

class LockTests(unittest.TestCase):

    """Very basic test of import lock functions."""

    def verify_lock_state(self, expected):

        self.failUnlessEqual(imp.lock_held(), expected,

                             "expected imp.lock_held() to be %r" % expected)

    def testLock(self):

        LOOPS = 50

        # The import lock may already be held, e.g. if the test suite is run

        # via "import test.autotest".

        lock_held_at_start = imp.lock_held()

        self.verify_lock_state(lock_held_at_start)

        for i in range(LOOPS):

            imp.acquire_lock()

            self.verify_lock_state(True)

        for i in range(LOOPS):

            imp.release_lock()

        # The original state should be restored now.

        self.verify_lock_state(lock_held_at_start)

        if not lock_held_at_start:

            try:

                imp.release_lock()

            except RuntimeError:

                pass

            else:

                self.fail("release_lock() without lock should raise "

                            "RuntimeError")

class ReloadTests(unittest.TestCase):

    """Very basic tests to make sure that imp.reload() operates just like

    reload()."""

    def test_source(self):

        import os

        imp.reload(os)

    def test_extension(self):

        import time

        imp.reload(time)

    def test_builtin(self):

        import marshal

        imp.reload(marshal)

def test_main():

    tests = [

        ReloadTests,

    ]

    try:

        import thread

    except ImportError:

        pass

    else:

        tests.append(LockTests)

    test_support.run_unittest(*tests)

if __name__ == "__main__":

    test_main()