| /* Copyright 2016 The TensorFlow 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. |
| ==============================================================================*/ |
| |
| #include "tensorflow/core/kernels/immutable_constant_op.h" |
| |
| #include <unordered_set> |
| |
| namespace tensorflow { |
| |
| namespace { |
| class MemmappedTensorAllocator : public Allocator { |
| public: |
| MemmappedTensorAllocator() {} |
| |
| Status InitializeFromRegion(const string& name, Env* env) { |
| const auto status = |
| env->NewReadOnlyMemoryRegionFromFile(name, &memory_region_); |
| if (!status.ok()) { |
| return status; |
| } |
| return Status::OK(); |
| } |
| string Name() override { return "MemmappedTensorAllocator"; } |
| |
| void* AllocateRaw(size_t alignment, size_t num_bytes) override { |
| if ((reinterpret_cast<intptr_t>(memory_region_->data())) % alignment != 0) { |
| allocation_status_ = |
| errors::Internal("Readonly memory region has wrong alignment"); |
| return nullptr; |
| } |
| if (num_bytes > memory_region_->length()) { |
| allocation_status_ = errors::Internal( |
| "Readonly memory region has wrong length (", memory_region_->length(), |
| ") when allocating ", num_bytes); |
| return nullptr; |
| } |
| return const_cast<void*>(memory_region_->data()); |
| } |
| |
| void DeallocateRaw(void* ptr) override { |
| if (ptr != memory_region_->data()) { |
| LOG(ERROR) |
| << "Deallocating not allocated region for readonly memory region"; |
| } |
| if (delete_on_deallocate_) { |
| delete this; |
| } |
| } |
| const Status& allocation_status() const { return allocation_status_; } |
| |
| void set_delete_on_deallocate() { delete_on_deallocate_ = true; } |
| |
| private: |
| std::unique_ptr<ReadOnlyMemoryRegion> memory_region_; |
| // If there is an error during allocation we keep it in this status. |
| Status allocation_status_; |
| |
| // When the allocator is owned by TensorBuffer it will be deleted on |
| // de-allocation. |
| bool delete_on_deallocate_ = false; |
| |
| TF_DISALLOW_COPY_AND_ASSIGN(MemmappedTensorAllocator); |
| }; |
| } // namespace |
| |
| ImmutableConstantOp::ImmutableConstantOp(OpKernelConstruction* context) |
| : OpKernel(context) { |
| OP_REQUIRES_OK(context, |
| context->GetAttr(kMemoryRegionNameAttr, ®ion_name_)); |
| OP_REQUIRES_OK(context, context->GetAttr(kDTypeAttr, &dtype_)); |
| OP_REQUIRES_OK(context, context->GetAttr(kShapeAttr, &shape_)); |
| } |
| |
| void ImmutableConstantOp::Compute(OpKernelContext* ctx) { |
| std::unique_ptr<MemmappedTensorAllocator> allocator( |
| new MemmappedTensorAllocator()); |
| |
| OP_REQUIRES_OK(ctx, |
| allocator->InitializeFromRegion(region_name_, ctx->env())); |
| ctx->set_output(0, Tensor(allocator.get(), dtype_, shape_)); |
| OP_REQUIRES_OK(ctx, allocator->allocation_status()); |
| // Allocator is owned by the tensor from this point. |
| allocator.release()->set_delete_on_deallocate(); |
| } |
| |
| ImmutableConstantOp::~ImmutableConstantOp() {} |
| constexpr char const* ImmutableConstantOp::kDTypeAttr; |
| constexpr char const* ImmutableConstantOp::kShapeAttr; |
| constexpr char const* ImmutableConstantOp::kMemoryRegionNameAttr; |
| |
| REGISTER_KERNEL_BUILDER(Name("ImmutableConst").Device(DEVICE_CPU), |
| ImmutableConstantOp); |
| } // namespace tensorflow |