test_cuda.py 文件源码

def test_streams(self):
        default_stream = torch.cuda.current_stream()
        user_stream = torch.cuda.Stream()
        self.assertEqual(torch.cuda.current_stream(), default_stream)
        self.assertNotEqual(default_stream, user_stream)
        self.assertEqual(default_stream.cuda_stream, 0)
        self.assertNotEqual(user_stream.cuda_stream, 0)
        with torch.cuda.stream(user_stream):
            self.assertEqual(torch.cuda.current_stream(), user_stream)
        self.assertTrue(user_stream.query())
        # copy 10 MB tensor from CPU-GPU which should take some time
        tensor1 = torch.ByteTensor(10000000).pin_memory()
        tensor2 = tensor1.cuda(async=True)
        self.assertFalse(default_stream.query())
        default_stream.synchronize()
        self.assertTrue(default_stream.query())