Internal Change.

PiperOrigin-RevId: 175307445

1 files changed, 68 insertions, 0 deletions

diff --git a/tensorflow/contrib/lite/kernels/gemm_support.cc b/tensorflow/contrib/lite/kernels/gemm_support.cc
new file mode 100644
index 0000000000..eb2b0aacf7
--- /dev/null
+++ b/tensorflow/contrib/lite/kernels/gemm_support.cc
@@ -0,0 +1,68 @@
+/* Copyright 2017 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/contrib/lite/kernels/gemm_support.h"
+
+#include "tensorflow/contrib/lite/kernels/op_macros.h"
+
+namespace tflite {
+namespace gemm_support {
+
+struct RefCountedGemmContext {
+  gemmlowp::GemmContext* gemm_context_ = nullptr;
+  int num_references_ = 0;
+};
+
+void IncrementUsageCounter(TfLiteContext* context) {
+  auto* ptr = reinterpret_cast<RefCountedGemmContext*>(context->gemm_context);
+  if (ptr == nullptr) {
+    ptr = new RefCountedGemmContext;
+    ptr->gemm_context_ = new gemmlowp::GemmContext();
+    ptr->num_references_ = 0;
+    context->gemm_context = ptr;
+  }
+  ptr->num_references_++;
+}
+
+void DecrementUsageCounter(TfLiteContext* context) {
+  auto* ptr = reinterpret_cast<RefCountedGemmContext*>(context->gemm_context);
+  if (ptr == nullptr) {
+    TF_LITE_FATAL(
+        "Call to DecrementUsageCounter() not preceded by "
+        "IncrementUsageCounter()");
+  }
+  if (--ptr->num_references_ == 0) {
+    delete ptr->gemm_context_;
+    delete ptr;
+    context->gemm_context = nullptr;
+  }
+}
+
+gemmlowp::GemmContext* GetFromContext(TfLiteContext* context) {
+  auto* ptr = reinterpret_cast<RefCountedGemmContext*>(context->gemm_context);
+  if (ptr == nullptr) {
+    TF_LITE_FATAL(
+        "Call to GetFromContext() not preceded by IncrementUsageCounter()");
+  }
+  return ptr->gemm_context_;
+}
+
+void SetMaxNumThreads(TfLiteContext* context, int num_threads) {
+  IncrementUsageCounter(context);
+  GetFromContext(context)->set_max_num_threads(num_threads);
+  DecrementUsageCounter(context);
+}
+
+}  // namespace gemm_support
+}  // namespace tflite