1 | /* Copyright 2016 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 | #include "tensorflow/core/kernels/immutable_constant_op.h" |
17 | |
18 | #include <unordered_set> |
19 | |
20 | #include "tensorflow/core/framework/types.pb.h" |
21 | |
22 | namespace tensorflow { |
23 | |
24 | namespace { |
25 | class MemmappedTensorAllocator : public Allocator { |
26 | public: |
27 | MemmappedTensorAllocator() {} |
28 | |
29 | Status InitializeFromRegion(const string& name, Env* env) { |
30 | const auto status = |
31 | env->NewReadOnlyMemoryRegionFromFile(name, &memory_region_); |
32 | if (!status.ok()) { |
33 | return status; |
34 | } |
35 | return OkStatus(); |
36 | } |
37 | string Name() override { return "MemmappedTensorAllocator" ; } |
38 | |
39 | void* AllocateRaw(size_t alignment, size_t num_bytes) override { |
40 | if ((reinterpret_cast<intptr_t>(memory_region_->data())) % alignment != 0) { |
41 | allocation_status_ = |
42 | errors::Internal("Readonly memory region has wrong alignment" ); |
43 | return nullptr; |
44 | } |
45 | if (num_bytes > memory_region_->length()) { |
46 | allocation_status_ = errors::Internal( |
47 | "Readonly memory region has wrong length (" , memory_region_->length(), |
48 | ") when allocating " , num_bytes); |
49 | return nullptr; |
50 | } |
51 | return const_cast<void*>(memory_region_->data()); |
52 | } |
53 | |
54 | void DeallocateRaw(void* ptr) override { |
55 | if (ptr != memory_region_->data()) { |
56 | LOG(ERROR) |
57 | << "Deallocating not allocated region for readonly memory region" ; |
58 | } |
59 | if (delete_on_deallocate_) { |
60 | delete this; |
61 | } |
62 | } |
63 | const Status& allocation_status() const { return allocation_status_; } |
64 | |
65 | void set_delete_on_deallocate() { delete_on_deallocate_ = true; } |
66 | |
67 | // Make sure tensors or complex types (strings, variants, resources) don't get |
68 | // their constructor called via a placement new since that would require |
69 | // writing to immutable data. |
70 | // See also: tensorflow/core/framework/typed_allocator.h |
71 | bool AllocatesOpaqueHandle() const override { return true; } |
72 | |
73 | private: |
74 | std::unique_ptr<ReadOnlyMemoryRegion> memory_region_; |
75 | // If there is an error during allocation we keep it in this status. |
76 | Status allocation_status_; |
77 | |
78 | // When the allocator is owned by TensorBuffer it will be deleted on |
79 | // de-allocation. |
80 | bool delete_on_deallocate_ = false; |
81 | |
82 | TF_DISALLOW_COPY_AND_ASSIGN(MemmappedTensorAllocator); |
83 | }; |
84 | } // namespace |
85 | |
86 | ImmutableConstantOp::ImmutableConstantOp(OpKernelConstruction* context) |
87 | : OpKernel(context) { |
88 | OP_REQUIRES_OK(context, |
89 | context->GetAttr(kMemoryRegionNameAttr, ®ion_name_)); |
90 | OP_REQUIRES_OK(context, context->GetAttr(kDTypeAttr, &dtype_)); |
91 | OP_REQUIRES(context, dtype_ != DT_RESOURCE && dtype_ != DT_VARIANT, |
92 | errors::InvalidArgument( |
93 | "Resource and variant dtypes are invalid for this op." )); |
94 | OP_REQUIRES_OK(context, context->GetAttr(kShapeAttr, &shape_)); |
95 | } |
96 | |
97 | void ImmutableConstantOp::Compute(OpKernelContext* ctx) { |
98 | std::unique_ptr<MemmappedTensorAllocator> allocator( |
99 | new MemmappedTensorAllocator()); |
100 | |
101 | OP_REQUIRES_OK(ctx, |
102 | allocator->InitializeFromRegion(region_name_, ctx->env())); |
103 | OP_REQUIRES(ctx, dtype_ != DT_STRING, |
104 | errors::Unimplemented("Sorry, DT_STRING is not currently " |
105 | "supported for ImmutableConstOp." )); |
106 | ctx->set_output(0, Tensor(allocator.get(), dtype_, shape_)); |
107 | OP_REQUIRES_OK(ctx, allocator->allocation_status()); |
108 | // Allocator is owned by the tensor from this point. |
109 | allocator.release()->set_delete_on_deallocate(); |
110 | } |
111 | |
112 | ImmutableConstantOp::~ImmutableConstantOp() {} |
113 | constexpr char const* ImmutableConstantOp::kDTypeAttr; |
114 | constexpr char const* ImmutableConstantOp::kShapeAttr; |
115 | constexpr char const* ImmutableConstantOp::kMemoryRegionNameAttr; |
116 | |
117 | REGISTER_KERNEL_BUILDER(Name("ImmutableConst" ).Device(DEVICE_CPU), |
118 | ImmutableConstantOp); |
119 | } // namespace tensorflow |
120 | |