1# Copyright 2017 The TensorFlow Authors. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14# ============================================================================== 15"""Experimental API for TensorFlow's "Eager" mode of execution.""" 16 17from tensorflow.python import pywrap_tfe 18from tensorflow.python.framework import errors 19 20# Trace of execution and memory usage. 21_active_trace = None 22 23 24def _status_to_exception(status): 25 try: 26 error_class = errors.exception_type_from_error_code(status.code) 27 return error_class(None, None, status.message, status.payloads) 28 except KeyError: 29 return errors.UnknownError(None, None, status.message, status.code, 30 status.payloads) 31 32 33class _NotOkStatusException(Exception): 34 """Exception class to handle not ok Status.""" 35 36 def __init__(self, message, code, payloads): 37 super(_NotOkStatusException, self).__init__() 38 self.message = message 39 self.code = code 40 self.payloads = payloads 41 42 def __str__(self): 43 e = _status_to_exception(self) 44 return "%s: %s" % (e.__class__.__name__, e) 45 46 47pywrap_tfe.TFE_Py_RegisterExceptionClass(_NotOkStatusException) 48 49 50class _FallbackException(Exception): 51 """Exception class to handle fallback from the fastpath. 52 53 The fastpath that we refer to here is the one implemented to reduce per-op 54 overheads (TFE_Py_FastPathExecute_C). If the conditions for executing the op 55 on the fastpath are not met, we fallback to a safer (and more complete) 56 slowpath, and this Exception is raised to signal that transition. 57 """ 58 pass 59 60 61class _SymbolicException(Exception): 62 """Exception class to handle use of symbolic tensors when executing eagerly. 63 64 `keras.Input()` creates symbolic tensors (in a FuncGraph managed by the 65 Keras backend) while in eager execution. This exception is used to 66 identify this case (raised in `convert_to_tensor` cause generated functions 67 for ops to construct graphs instead of executing the kernel). 68 """ 69 pass 70 71 72pywrap_tfe.TFE_Py_RegisterFallbackExceptionClass(_FallbackException) 73