arm_compute v18.05
diff --git a/src/graph/detail/CrossLayerMemoryManagerHelpers.cpp b/src/graph/detail/CrossLayerMemoryManagerHelpers.cpp
new file mode 100644
index 0000000..6b2f68c
--- /dev/null
+++ b/src/graph/detail/CrossLayerMemoryManagerHelpers.cpp
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/graph/detail/CrossLayerMemoryManagerHelpers.h"
+
+#include "arm_compute/graph/Graph.h"
+#include "arm_compute/graph/GraphContext.h"
+#include "arm_compute/graph/GraphManager.h"
+#include "arm_compute/graph/INode.h"
+#include "arm_compute/graph/Tensor.h"
+#include "arm_compute/graph/Types.h"
+#include "arm_compute/graph/backends/BackendRegistry.h"
+
+#include "arm_compute/core/ITensor.h"
+#include "arm_compute/core/utils/misc/Cast.h"
+
+#include <algorithm>
+#include <map>
+
+namespace arm_compute
+{
+namespace graph
+{
+namespace detail
+{
+namespace
+{
+using HandleCountPair     = std::pair<ITensorHandle *, unsigned int>;
+using HandleCounter       = std::map<HandleCountPair::first_type, HandleCountPair::second_type>;
+using TargetHandleCounter = std::map<Target, HandleCounter>;
+
+/** Holds managed IO tensor handles if a task */
+struct TaskHandles
+{
+    std::vector<std::pair<ITensorHandle *, IMemoryGroup *>> input_handles  = {}; /**< Input handles to a task */
+    std::vector<std::pair<ITensorHandle *, IMemoryGroup *>> output_handles = {}; /**< Output handles of a task */
+};
+
+/** Returns memory group depending on handle backend type
+ *
+ * @param[in] ctx    Graph context
+ * @param[in] handle Tensor handle
+ *
+ * @return Memory groupb
+ */
+IMemoryGroup *get_memory_group_from_handle(GraphContext &ctx, ITensorHandle *handle)
+{
+    ARM_COMPUTE_ERROR_ON(handle == nullptr);
+    return ctx.memory_management_ctx(handle->target())->cross_group.get();
+}
+
+/** Get handles of const tensors of graph
+ *
+ * @param[in] g Graph
+ *
+ * @return Handles of const tensors of graph
+ */
+std::set<ITensorHandle *> get_const_handles(const Graph &g)
+{
+    std::set<NodeType> const_node_types = { NodeType::Input, NodeType::Output, NodeType::Const };
+
+    std::set<ITensorHandle *> const_tensors;
+
+    auto &nodes = g.nodes();
+    for(auto &node : nodes)
+    {
+        // If its a const node:
+        if(node != nullptr && const_node_types.find(node->type()) != std::end(const_node_types))
+        {
+            // Add all its inputs / outputs to the list of constant handles
+            for(unsigned int i = 0; i < node->num_inputs(); ++i)
+            {
+                if(node->input(i) != nullptr)
+                {
+                    const_tensors.insert(node->input(i)->handle()->parent_handle());
+                }
+            }
+            for(unsigned int i = 0; i < node->num_outputs(); ++i)
+            {
+                if(node->output(i) != nullptr)
+                {
+                    const_tensors.insert(node->output(i)->handle()->parent_handle());
+                }
+            }
+        }
+    }
+
+    return const_tensors;
+}
+
+/** Builds a list of all the transition handles (Handles that are used to link two nodes)
+ *
+ * @param[in] ctx           Graph context
+ * @param[in] task          Workload task
+ * @param[in] const_tensors Constant tensors
+ *
+ * @return List of transition handles
+ */
+TaskHandles get_transition_handles(GraphContext                    &ctx,
+                                   ExecutionTask                   &task,
+                                   const std::set<ITensorHandle *> &const_tensors)
+{
+    ARM_COMPUTE_ERROR_ON(task.node == nullptr || task.task == nullptr);
+    INode &node = *task.node;
+
+    TaskHandles transition_handles;
+
+    // Add input handles
+    for(unsigned int i = 0; i < node.input_edges().size(); ++i)
+    {
+        Edge *input_edge = node.input_edge(i);
+        // If this input is the output of another node
+        if(input_edge != nullptr && input_edge->tensor() != nullptr && const_tensors.find(input_edge->tensor()->handle()->parent_handle()) == std::end(const_tensors))
+        {
+            // Then add it to the list of transition buffers
+            ITensorHandle *tensor_handle = input_edge->tensor()->handle()->parent_handle();
+            IMemoryGroup *mm_group      = get_memory_group_from_handle(ctx, tensor_handle);
+            transition_handles.input_handles.push_back(std::make_pair(tensor_handle, mm_group));
+        }
+    }
+
+    // Add output handles
+    for(unsigned int i = 0; i < node.num_outputs(); ++i)
+    {
+        Tensor *output_tensor = node.output(i);
+        // If this output is used as an input for another node
+        if(output_tensor != nullptr && const_tensors.find(output_tensor->handle()->parent_handle()) == std::end(const_tensors))
+        {
+            ITensorHandle *tensor_handle = output_tensor->handle()->parent_handle();
+            IMemoryGroup *mm_group      = get_memory_group_from_handle(ctx, tensor_handle);
+            transition_handles.output_handles.push_back(std::make_pair(tensor_handle, mm_group));
+        }
+    }
+
+    return transition_handles;
+}
+
+/** Counts handles refcount for each input handle of each target
+ *
+ * @param[in]     task           Execution task containing the managed handles
+ * @param[in,out] handle_counter Data structure that keeps the handles reference count
+ */
+void count_input_handles_per_target(const TaskHandles &task_handles, TargetHandleCounter &handle_counter)
+{
+    for(const auto &handle : task_handles.input_handles)
+    {
+        ITensorHandle *key            = handle.first;
+        HandleCounter &target_counter = handle_counter[key->target()];
+        if(target_counter.find(key) == std::end(target_counter))
+        {
+            target_counter.emplace(std::make_pair(key, 1));
+        }
+        else
+        {
+            ++target_counter[key];
+        }
+    }
+}
+
+/** Calculates the lifetime of each tensor handle
+ *
+ * @param[in, out] tasks_handles Tensor handles for each task
+ * @param[in]      hc            Data structure that keeps the handles reference count
+ */
+void configure_handle_lifetime(std::vector<TaskHandles> &tasks_handles, const HandleCounter &hc)
+{
+    // Identify max number of tensors in flight
+    HandleCounter tensors_in_flight;
+
+    // Acquires the given handles and sets them as in flight if they aren't already
+    auto acquire = [&](std::vector<std::pair<ITensorHandle *, IMemoryGroup *>> &handles)
+    {
+        for(auto &handle : handles)
+        {
+            ITensorHandle *parent_handle = handle.first;
+            ARM_COMPUTE_ERROR_ON(parent_handle == nullptr);
+            // If the tensor is not already in flight:
+            if(tensors_in_flight.find(parent_handle) == std::end(tensors_in_flight))
+            {
+                ARM_COMPUTE_ERROR_ON(hc.find(parent_handle) == std::end(hc));
+                // Then add it to the list of in flight tensors
+                tensors_in_flight.insert(std::make_pair(parent_handle, hc.at(parent_handle)));
+                // Start of allocation's lifetime
+                parent_handle->manage(handle.second);
+            }
+        }
+    };
+
+    for(auto &task_handle : tasks_handles)
+    {
+        // Marking all the input and output tensors of the task as in flight
+        acquire(task_handle.input_handles);
+        acquire(task_handle.output_handles);
+
+        // Releasing the input tensors
+        for(auto &input_handle : task_handle.input_handles)
+        {
+            ITensorHandle *ihandle = input_handle.first;
+            ARM_COMPUTE_ERROR_ON(ihandle == nullptr);
+            ARM_COMPUTE_ERROR_ON(tensors_in_flight.find(ihandle) == std::end(tensors_in_flight));
+            --tensors_in_flight[ihandle];
+            if(tensors_in_flight[ihandle] <= 0)
+            {
+                // Remove tensor for tensors in flight
+                tensors_in_flight.erase(ihandle);
+                // End of allocation's lifetime
+                ihandle->allocate();
+            }
+        }
+    }
+}
+} // namespace
+
+void configure_transition_manager(Graph &g, GraphContext &ctx, ExecutionWorkload &workload)
+{
+    // Get const tensors (un-managed)
+    std::set<ITensorHandle *> const_tensors = get_const_handles(g);
+
+    std::vector<TaskHandles> tasks_handles;
+    TargetHandleCounter      target_handle_count;
+
+    // Count handles
+    for(auto &task : workload.tasks)
+    {
+        // Populates IO handles
+        tasks_handles.push_back(get_transition_handles(ctx, task, const_tensors));
+
+        // Count handles
+        count_input_handles_per_target(tasks_handles.back(), target_handle_count);
+    }
+
+    // Setup memory managers
+    for(auto &hc : target_handle_count)
+    {
+        MemoryManagerContext *mm_ctx = ctx.memory_management_ctx(hc.first);
+        if(mm_ctx != nullptr)
+        {
+            if(mm_ctx->cross_mm != nullptr && mm_ctx->cross_group != nullptr)
+            {
+                // Manage and allocate tensors
+                configure_handle_lifetime(tasks_handles, hc.second);
+            }
+        }
+    }
+}
+} // namespace detail
+} // namespace graph
+} // namespace arm_compute
diff --git a/src/graph/detail/ExecutionHelpers.cpp b/src/graph/detail/ExecutionHelpers.cpp
new file mode 100644
index 0000000..c370fdf
--- /dev/null
+++ b/src/graph/detail/ExecutionHelpers.cpp
@@ -0,0 +1,279 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/graph/detail/ExecutionHelpers.h"
+
+#include "arm_compute/graph/Graph.h"
+#include "arm_compute/graph/GraphContext.h"
+#include "arm_compute/graph/GraphManager.h"
+#include "arm_compute/graph/Tensor.h"
+#include "arm_compute/graph/backends/BackendRegistry.h"
+
+namespace arm_compute
+{
+namespace graph
+{
+namespace detail
+{
+void default_initialize_backends()
+{
+    for(const auto &backend : backends::BackendRegistry::get().backends())
+    {
+        backend.second->initialize_backend();
+    }
+}
+
+void validate_all_nodes(Graph &g)
+{
+    auto &nodes = g.nodes();
+
+    // Create tasks
+    for(auto &node : nodes)
+    {
+        if(node != nullptr)
+        {
+            Target assigned_target = node->assigned_target();
+            auto   backend         = backends::BackendRegistry::get().find_backend(assigned_target);
+            ARM_COMPUTE_ERROR_ON_MSG(!backend, "Requested backend doesn't exist!");
+            Status status = backend->validate_node(*node);
+            ARM_COMPUTE_ERROR_ON_MSG(!bool(status), status.error_description().c_str());
+        }
+    }
+}
+
+void configure_all_tensors(Graph &g)
+{
+    auto &tensors = g.tensors();
+
+    for(auto &tensor : tensors)
+    {
+        if(tensor)
+        {
+            Target target  = tensor->desc().target;
+            auto   backend = backends::BackendRegistry::get().find_backend(target);
+            ARM_COMPUTE_ERROR_ON_MSG(!backend, "Requested backend doesn't exist!");
+            auto handle = backend->create_tensor(*tensor);
+            ARM_COMPUTE_ERROR_ON_MSG(!backend, "Couldn't create backend handle!");
+            tensor->set_handle(std::move(handle));
+        }
+    }
+}
+
+void allocate_all_input_tensors(INode &node)
+{
+    for(unsigned int i = 0; i < node.num_inputs(); ++i)
+    {
+        Tensor *tensor = node.input(i);
+        if(tensor != nullptr && !tensor->bound_edges().empty())
+        {
+            ARM_COMPUTE_ERROR_ON_MSG(!tensor->handle(), "Tensor handle is not configured!");
+            tensor->handle()->allocate();
+        }
+    }
+}
+
+void allocate_all_output_tensors(INode &node)
+{
+    for(unsigned int i = 0; i < node.num_outputs(); ++i)
+    {
+        Tensor *tensor = node.output(i);
+        if(tensor != nullptr && !tensor->bound_edges().empty())
+        {
+            ARM_COMPUTE_ERROR_ON_MSG(!tensor->handle(), "Tensor handle is not configured!");
+            tensor->handle()->allocate();
+        }
+    }
+}
+
+void allocate_const_tensors(Graph &g)
+{
+    for(auto &node : g.nodes())
+    {
+        if(node != nullptr)
+        {
+            switch(node->type())
+            {
+                case NodeType::Const:
+                case NodeType::Input:
+                    allocate_all_output_tensors(*node);
+                    break;
+                case NodeType::Output:
+                    allocate_all_input_tensors(*node);
+                default:
+                    break;
+            }
+        }
+    }
+}
+
+void allocate_all_tensors(Graph &g)
+{
+    auto &tensors = g.tensors();
+
+    for(auto &tensor : tensors)
+    {
+        if(tensor && !tensor->bound_edges().empty() && tensor->handle() != nullptr && tensor->handle()->tensor().info()->is_resizable() && tensor->handle()->tensor().is_used())
+        {
+            tensor->handle()->allocate();
+        }
+    }
+}
+
+ExecutionWorkload configure_all_nodes(Graph &g, GraphContext &ctx)
+{
+    ExecutionWorkload workload;
+    workload.graph = &g;
+    workload.ctx   = &ctx;
+
+    auto &nodes = g.nodes();
+
+    // Create tasks
+    for(auto &node : nodes)
+    {
+        if(node != nullptr)
+        {
+            Target assigned_target = node->assigned_target();
+            auto   backend         = backends::BackendRegistry::get().find_backend(assigned_target);
+            ARM_COMPUTE_ERROR_ON_MSG(!backend, "Requested backend doesn't exist!");
+            auto func = backend->configure_node(*node, ctx);
+            if(func != nullptr)
+            {
+                ExecutionTask task;
+                task.task = std::move(func);
+                task.node = node.get();
+                workload.tasks.push_back(std::move(task));
+            }
+        }
+    }
+
+    // Add inputs and outputs
+    for(auto &node : nodes)
+    {
+        if(node != nullptr && node->type() == NodeType::Input)
+        {
+            workload.inputs.push_back(node->output(0));
+        }
+
+        if(node != nullptr && node->type() == NodeType::Output)
+        {
+            workload.outputs.push_back(node->input(0));
+            continue;
+        }
+    }
+
+    return workload;
+}
+
+void release_unused_tensors(Graph &g)
+{
+    for(auto &tensor : g.tensors())
+    {
+        if(tensor != nullptr && tensor->handle() != nullptr)
+        {
+            tensor->handle()->release_if_unused();
+        }
+    }
+}
+
+void call_tensor_accessor(Tensor *tensor)
+{
+    ARM_COMPUTE_ERROR_ON(!tensor);
+    tensor->call_accessor();
+}
+
+void call_all_const_node_accessors(Graph &g)
+{
+    auto &nodes = g.nodes();
+
+    for(auto &node : nodes)
+    {
+        if(node != nullptr && node->type() == NodeType::Const)
+        {
+            call_tensor_accessor(node->output(0));
+        }
+    }
+}
+
+void call_all_input_node_accessors(ExecutionWorkload &workload)
+{
+    for(auto &input : workload.inputs)
+    {
+        if(input != nullptr)
+        {
+            input->call_accessor();
+        }
+    }
+}
+
+void prepare_all_tasks(ExecutionWorkload &workload)
+{
+    ARM_COMPUTE_ERROR_ON(workload.graph == nullptr);
+    for(auto &task : workload.tasks)
+    {
+        task.prepare();
+        release_unused_tensors(*workload.graph);
+    }
+}
+
+void call_all_tasks(ExecutionWorkload &workload)
+{
+    ARM_COMPUTE_ERROR_ON(workload.ctx == nullptr);
+
+    // Acquire memory for the transition buffers
+    for(auto &mm_ctx : workload.ctx->memory_managers())
+    {
+        if(mm_ctx.second.cross_group != nullptr)
+        {
+            mm_ctx.second.cross_group->acquire();
+        }
+    }
+
+    // Execute tasks
+    for(auto &task : workload.tasks)
+    {
+        task();
+    }
+
+    // Release memory for the transition buffers
+    for(auto &mm_ctx : workload.ctx->memory_managers())
+    {
+        if(mm_ctx.second.cross_group != nullptr)
+        {
+            mm_ctx.second.cross_group->release();
+        }
+    }
+}
+
+void call_all_output_node_accessors(ExecutionWorkload &workload)
+{
+    for(auto &output : workload.outputs)
+    {
+        if(output != nullptr)
+        {
+            output->call_accessor();
+        }
+    }
+}
+} // namespace detail
+} // namespace graph
+} // namespace arm_compute
\ No newline at end of file