diff --git a/python/paddle/fluid/imperative/tracer.py b/python/paddle/fluid/imperative/tracer.py new file mode 100644 index 0000000000000000000000000000000000000000..7b6e15cc83cbe71b2d55b5cf1787c8e389a69f3f --- /dev/null +++ b/python/paddle/fluid/imperative/tracer.py @@ -0,0 +1,65 @@ +# Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from __future__ import print_function + +import six + +from collections import defaultdict +from paddle.fluid import core +from paddle.fluid import framework + +__all__ = ['Tracer'] + + +def release_op(op): + del framework._imperative_tracer()._ops[op._trace_id] + + +class Tracer(core.Tracer): + """ + Python wrapper of imperative tracer + """ + + def __init__(self, block): + super(Tracer, self).__init__(block) + + self._ops = defaultdict() + self._trace_id = 0 + + def trace_op(self, op, stop_gradient=False): + # record op's trace id + op.iop._trace_id = self._trace_id + self._trace_id += 1 + + # trace op and save it + backward_refs = self.trace(op.iop, op.inputs, op.outputs, op.block.desc, + framework._current_expected_place(), + stop_gradient) + + if not stop_gradient: + self._ops[op.iop._trace_id] = op + + # register backward hooks and variables if needed + if len(backward_refs) > 0: + op.iop.register_backward_hooks(release_op) + + op.backward_refs = defaultdict(list) + for k, v in six.iteritems(op.inputs): + if k in backward_refs: + op.backward_refs[k] = op.inputs[k] + + for k, v in six.iteritems(op.outputs): + if k in backward_refs: + op.backward_refs[k] = op.outputs[k]