_test_multiprocessing.py 文件源码

def test_context(self):
        for method in ('fork', 'spawn', 'forkserver'):
            try:
                ctx = multiprocessing.get_context(method)
            except ValueError:
                continue
            self.assertEqual(ctx.get_start_method(), method)
            self.assertIs(ctx.get_context(), ctx)
            self.assertRaises(ValueError, ctx.set_start_method, 'spawn')
            self.assertRaises(ValueError, ctx.set_start_method, None)
            self.check_context(ctx)