1 /* Copyright 2015 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 16 #ifndef TENSORFLOW_FRAMEWORK_TENSOR_REFERENCE_H_ 17 #define TENSORFLOW_FRAMEWORK_TENSOR_REFERENCE_H_ 18 19 #include "tensorflow/core/framework/tensor.h" 20 #include "tensorflow/core/lib/gtl/inlined_vector.h" 21 22 namespace tensorflow { 23 24 // An opaque class that holds a reference to an underlying TensorBuffer. 25 // Unlike Tensor, it does not have any shape or type information, so 26 // it is cheaper to construct/move, but the only thing you can really do 27 // with it is Unref it, which releases one of the references to the underlying 28 // TensorBuffer. 29 // IMPORTANT: If you do not call Unref(), you will likely leak tensor memory. 30 class TensorReference { 31 public: 32 // Take the reference of the root buffer so the size will be more accurate 33 explicit TensorReference(const Tensor& tensor); 34 ~TensorReference()35 ~TensorReference() {} 36 Unref()37 void Unref() const { 38 if (buf_) buf_->Unref(); 39 } 40 41 // Return an estimate of the total bytes being kept alive by this reference. TotalBytes()42 size_t TotalBytes() const { 43 // We add 128 as a baseline to account for per-Tensor metadata 44 return 128 + (buf_ ? buf_->size() : 0); 45 } 46 FillDescription(AllocationDescription * description)47 void FillDescription(AllocationDescription* description) const { 48 if (buf_) buf_->FillAllocationDescription(description); 49 } 50 51 // Convenience function for de-duplicating tensor references. SharesBufferWith(const TensorReference & t)52 bool SharesBufferWith(const TensorReference& t) const { 53 return buf_ == t.buf_; 54 } 55 56 // Convenience function for de-duplicating tensor references. SharesBufferWith(const Tensor & t)57 bool SharesBufferWith(const Tensor& t) const { 58 return buf_ == (t.buf_ ? t.buf_->root_buffer() : nullptr); 59 } 60 61 // Convenience function for de-duplicating tensor references. BufferHash()62 size_t BufferHash() const { return std::hash<TensorBuffer*>()(buf_); } 63 64 // A constructor used only for tests TensorReference(TensorBuffer * test_buffer)65 explicit TensorReference(TensorBuffer* test_buffer) : buf_(test_buffer) { 66 if (buf_) buf_->Ref(); 67 } 68 69 private: 70 TensorBuffer* buf_; 71 }; 72 73 typedef gtl::InlinedVector<TensorReference, 4> TensorReferenceVector; 74 75 } // namespace tensorflow 76 77 #endif // TENSORFLOW_FRAMEWORK_TENSOR_REFERENCE_H_ 78