add_backend_ops_unittest.md

How to add test units for backend ops

This tutorial introduces how to add unit test for backend ops. When you add a custom op under backend_ops, you need to add the corresponding test unit. Test units of ops are included in tests/test_ops/test_ops.py.

Prerequisite

• Compile new ops: After adding a new custom op, needs to recompile the relevant backend, referring to build.md.

1. Add the test program test_XXXX()

You can put unit test for ops in tests/test_ops/. Usually, the following program template can be used for your custom op.

example of ops unit test

@pytest.mark.parametrize('backend', [TEST_TENSORRT, TEST_ONNXRT])        # 1.1 backend test class
@pytest.mark.parametrize('pool_h,pool_w,spatial_scale,sampling_ratio',   # 1.2 set parameters of op
                         [(2, 2, 1.0, 2), (4, 4, 2.0, 4)])               # [(# Examples of op test parameters),...]
def test_roi_align(backend,
                   pool_h,                                               # set parameters of op
                   pool_w,
                   spatial_scale,
                   sampling_ratio,
                   input_list=None,
                   save_dir=None):
    backend.check_env()

    if input_list is None:
        input = torch.rand(1, 1, 16, 16, dtype=torch.float32)            # 1.3 op input data initialization
        single_roi = torch.tensor([[0, 0, 0, 4, 4]], dtype=torch.float32)
    else:
        input = torch.tensor(input_list[0], dtype=torch.float32)
        single_roi = torch.tensor(input_list[1], dtype=torch.float32)

    from mmcv.ops import roi_align

    def wrapped_function(torch_input, torch_rois):                       # 1.4 initialize op model to be tested
        return roi_align(torch_input, torch_rois, (pool_w, pool_h),
                         spatial_scale, sampling_ratio, 'avg', True)

    wrapped_model = WrapFunction(wrapped_function).eval()

    with RewriterContext(cfg={}, backend=backend.backend_name, opset=11): # 1.5 call the backend test class interface
        backend.run_and_validate(
            wrapped_model, [input, single_roi],
            'roi_align',
            input_names=['input', 'rois'],
            output_names=['roi_feat'],
            save_dir=save_dir)

1.1 backend test class

We provide some functions and classes for difference backends, such as TestOnnxRTExporter, TestTensorRTExporter, TestNCNNExporter.

1.2 set parameters of op

Set some parameters of op, such as ’pool_h‘, ’pool_w‘, ’spatial_scale‘, ’sampling_ratio‘ in roi_align. You can set multiple parameters to test op.

1.3 op input data initialization

Initialization required input data.

1.4 initialize op model to be tested

The model containing custom op usually has two forms.

• torch model: Torch model with custom operators. Python code related to op is required, refer to roi_align unit test.
• onnx model: Onnx model with custom operators. Need to call onnx api to build, refer to multi_level_roi_align unit test.

1.5 call the backend test class interface

Call the backend test class run_and_validate to run and verify the result output by the op on the backend.

    def run_and_validate(self,
                         model,
                         input_list,
                         model_name='tmp',
                         tolerate_small_mismatch=False,
                         do_constant_folding=True,
                         dynamic_axes=None,
                         output_names=None,
                         input_names=None,
                         expected_result=None,
                         save_dir=None):

Parameter Description

• model: Input model to be tested and it can be torch model or any other backend model.
• input_list: List of test data, which is mapped to the order of input_names.
• model_name: The name of the model.
• tolerate_small_mismatch: Whether to allow small errors in the verification of results.
• do_constant_folding: Whether to use constant light folding to optimize the model.
• dynamic_axes: If you need to use dynamic dimensions, enter the dimension information.
• output_names: The node name of the output node.
• input_names: The node name of the input node.
• expected_result: Expected ground truth values for verification.
• save_dir: The folder used to save the output files.

2. Test Methods

Use pytest to call the test function to test ops.

pytest tests/test_ops/test_ops.py::test_XXXX