Fix graph copy memory spike

 * Change layer storage of ConstTensors to std::shared_ptr<ConstCpuTensorHandle>
 * Change clone to share ConstTensor rather than copy
 * Remove uses of non-const GetTensor() call
 * Reduce scope of non-optimized network in ExeNet, so memory can be released after use

Signed-off-by: Finn Williams <Finn.Williams@arm.com>

Change-Id: Ibb2c7309d12411d21405bd6024c76bcdf5404545

1 files changed, 21 insertions, 21 deletions

diff --git a/src/armnn/layers/QLstmLayer.hpp b/src/armnn/layers/QLstmLayer.hpp
index 70cc4f2b15..09a020dc1d 100644
--- a/src/armnn/layers/QLstmLayer.hpp
+++ b/src/armnn/layers/QLstmLayer.hpp
@@ -14,65 +14,65 @@ class ScopedCpuTensorHandle;
 struct QLstmBasicParameters
 {
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, inputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputToForgetWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputToForgetWeights;
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, inputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputToCellWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputToCellWeights;
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, inputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputToOutputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputToOutputWeights;
 
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, outputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToForgetWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_RecurrentToForgetWeights;
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, outputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToCellWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_RecurrentToCellWeights;
     /// A unique pointer to represent 2D weights tensor with dimensions [num_units, outputSize] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToOutputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_RecurrentToOutputWeights;
 
     /// A unique pointer to represent 1D bias tensor with dimensions [num_units] (int32).
-    std::unique_ptr<ScopedCpuTensorHandle> m_ForgetGateBias;
+    std::shared_ptr<ConstCpuTensorHandle> m_ForgetGateBias;
     /// A unique pointer to represent 1D bias tensor with dimensions [num_units] (int32).
-    std::unique_ptr<ScopedCpuTensorHandle> m_CellBias;
+    std::shared_ptr<ConstCpuTensorHandle> m_CellBias;
     /// A unique pointer to represent 1D bias tensor with dimensions [num_units] (int32).
-    std::unique_ptr<ScopedCpuTensorHandle> m_OutputGateBias;
+    std::shared_ptr<ConstCpuTensorHandle> m_OutputGateBias;
 };
 
 struct QLstmOptProjectionParameters
 {
     /// A unique pointer to represent 2D weights tensor with dimensions [output_size, num_units] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_ProjectionWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_ProjectionWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [output_size] (int32).
-    std::unique_ptr<ScopedCpuTensorHandle> m_ProjectionBias;
+    std::shared_ptr<ConstCpuTensorHandle> m_ProjectionBias;
 };
 
 struct QLstmOptPeepholeParameters
 {
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_CellToInputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_CellToInputWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_CellToForgetWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_CellToForgetWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_CellToOutputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_CellToOutputWeights;
 };
 
 struct QLstmOptCifgParameters
 {
     /// A unique pointer to represent 2D weights tensor with dimensions [input_size, num_units] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputToInputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputToInputWeights;
     /// A unique pointer to represent 2D weights tensor with dimensions [input_size, num_units] (QSymmS8).
-    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToInputWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_RecurrentToInputWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (int32).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputGateBias;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputGateBias;
 };
 
 struct QLstmOptLayerNormParameters
 {
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_InputLayerNormWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_InputLayerNormWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_ForgetLayerNormWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_ForgetLayerNormWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_CellLayerNormWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_CellLayerNormWeights;
     /// A unique pointer to represent 1D weights tensor with dimensions [num_units] (QSymmS16).
-    std::unique_ptr<ScopedCpuTensorHandle> m_OutputLayerNormWeights;
+    std::shared_ptr<ConstCpuTensorHandle> m_OutputLayerNormWeights;
 };
 
 /// This layer represents a QLstm operation.