1 /* Copyright 2020 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 #include "tensorflow/lite/delegates/utils/simple_delegate.h"
16 
17 #include <limits>
18 #include <memory>
19 #include <vector>
20 
21 #include "tensorflow/lite/builtin_ops.h"
22 #include "tensorflow/lite/c/common.h"
23 #include "tensorflow/lite/context_util.h"
24 #include "tensorflow/lite/delegates/utils.h"
25 #include "tensorflow/lite/kernels/internal/compatibility.h"
26 #include "tensorflow/lite/minimal_logging.h"
27 
28 namespace tflite {
29 namespace {
GetDelegateKernelRegistration(SimpleDelegateInterface * delegate)30 TfLiteRegistration GetDelegateKernelRegistration(
31     SimpleDelegateInterface* delegate) {
32   TfLiteRegistration kernel_registration;
33   kernel_registration.profiling_string = nullptr;
34   kernel_registration.builtin_code = kTfLiteBuiltinDelegate;
35   kernel_registration.custom_name = delegate->Name();
36   kernel_registration.version = 1;
37   kernel_registration.free = [](TfLiteContext* context, void* buffer) -> void {
38     delete reinterpret_cast<SimpleDelegateKernelInterface*>(buffer);
39   };
40   kernel_registration.init = [](TfLiteContext* context, const char* buffer,
41                                 size_t length) -> void* {
42     const TfLiteDelegateParams* params =
43         reinterpret_cast<const TfLiteDelegateParams*>(buffer);
44     if (params == nullptr) {
45       TF_LITE_KERNEL_LOG(context, "NULL TfLiteDelegateParams passed.");
46       return nullptr;
47     }
48     auto* delegate =
49         reinterpret_cast<SimpleDelegateInterface*>(params->delegate->data_);
50     std::unique_ptr<SimpleDelegateKernelInterface> delegate_kernel(
51         delegate->CreateDelegateKernelInterface());
52     if (delegate_kernel->Init(context, params) != kTfLiteOk) {
53       return nullptr;
54     }
55     return delegate_kernel.release();
56   };
57   kernel_registration.prepare = [](TfLiteContext* context,
58                                    TfLiteNode* node) -> TfLiteStatus {
59     if (node->user_data == nullptr) {
60       TF_LITE_KERNEL_LOG(context, "Delegate kernel was not initialized");
61       return kTfLiteError;
62     }
63     SimpleDelegateKernelInterface* delegate_kernel =
64         reinterpret_cast<SimpleDelegateKernelInterface*>(node->user_data);
65     return delegate_kernel->Prepare(context, node);
66   };
67   kernel_registration.invoke = [](TfLiteContext* context,
68                                   TfLiteNode* node) -> TfLiteStatus {
69     SimpleDelegateKernelInterface* delegate_kernel =
70         reinterpret_cast<SimpleDelegateKernelInterface*>(node->user_data);
71     TFLITE_DCHECK(delegate_kernel != nullptr);
72     return delegate_kernel->Eval(context, node);
73   };
74 
75   return kernel_registration;
76 }
77 
DelegatePrepare(TfLiteContext * context,TfLiteDelegate * base_delegate)78 TfLiteStatus DelegatePrepare(TfLiteContext* context,
79                              TfLiteDelegate* base_delegate) {
80   auto* delegate =
81       reinterpret_cast<SimpleDelegateInterface*>(base_delegate->data_);
82   auto delegate_options = delegate->DelegateOptions();
83   if (delegate_options.max_delegated_partitions <= 0)
84     delegate_options.max_delegated_partitions = std::numeric_limits<int>::max();
85 
86   TF_LITE_ENSURE_STATUS(delegate->Initialize(context));
87   delegates::IsNodeSupportedFn node_supported_fn =
88       [=](TfLiteContext* context, TfLiteNode* node,
89           TfLiteRegistration* registration,
90           std::string* unsupported_details) -> bool {
91     return delegate->IsNodeSupportedByDelegate(registration, node, context);
92   };
93   // TODO(b/149484598): Update to have method that gets all supported nodes.
94   delegates::GraphPartitionHelper helper(context, node_supported_fn);
95   TF_LITE_ENSURE_STATUS(helper.Partition(nullptr));
96 
97   std::vector<int> supported_nodes = helper.GetNodesOfFirstNLargestPartitions(
98       delegate_options.max_delegated_partitions,
99       delegate_options.min_nodes_per_partition);
100 
101   TFLITE_LOG_PROD(tflite::TFLITE_LOG_INFO,
102                   "%s delegate: %d nodes delegated out of %d nodes with "
103                   "%d partitions.\n",
104                   delegate->Name(), supported_nodes.size(),
105                   helper.num_total_nodes(), helper.num_partitions());
106   TfLiteRegistration delegate_kernel_registration =
107       GetDelegateKernelRegistration(delegate);
108 
109   return context->ReplaceNodeSubsetsWithDelegateKernels(
110       context, delegate_kernel_registration,
111       BuildTfLiteIntArray(supported_nodes).get(), base_delegate);
112 }
113 }  // namespace
114 
CreateSimpleDelegate(std::unique_ptr<SimpleDelegateInterface> simple_delegate,int64_t flag)115 TfLiteDelegate* TfLiteDelegateFactory::CreateSimpleDelegate(
116     std::unique_ptr<SimpleDelegateInterface> simple_delegate, int64_t flag) {
117   if (simple_delegate == nullptr) {
118     return nullptr;
119   }
120   auto delegate = new TfLiteDelegate();
121   delegate->Prepare = &DelegatePrepare;
122   delegate->flags = flag;
123   delegate->CopyFromBufferHandle = nullptr;
124   delegate->CopyToBufferHandle = nullptr;
125   delegate->FreeBufferHandle = nullptr;
126   delegate->data_ = simple_delegate.release();
127   return delegate;
128 }
129 
DeleteSimpleDelegate(TfLiteDelegate * delegate)130 void TfLiteDelegateFactory::DeleteSimpleDelegate(TfLiteDelegate* delegate) {
131   if (!delegate) return;
132   SimpleDelegateInterface* simple_delegate =
133       reinterpret_cast<SimpleDelegateInterface*>(delegate->data_);
134   delete simple_delegate;
135   delete delegate;
136 }
137 }  // namespace tflite
138