COMPMID-1088: Use IMemoryRegion in interfaces where possible

-Simplifies import memory interface
-Changes the used of void** handles with appropriate interfaces.

Change-Id: I5918c855c11f46352058864623336b352162a4b7

17 files changed, 387 insertions, 115 deletions

diff --git a/arm_compute/runtime/BlobMemoryPool.h b/arm_compute/runtime/BlobMemoryPool.h
index 25bfd539f6..c9c4da0f54 100644
--- a/arm_compute/runtime/BlobMemoryPool.h
+++ b/arm_compute/runtime/BlobMemoryPool.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -26,6 +26,7 @@
 
 #include "arm_compute/runtime/IMemoryPool.h"
 
+#include "arm_compute/runtime/IMemoryRegion.h"
 #include "arm_compute/runtime/Types.h"
 
 #include <cstddef>
@@ -75,9 +76,9 @@ private:
     void free_blobs();
 
 private:
-    IAllocator         *_allocator;  /**< Allocator to use for internal allocation */
-    std::vector<void *> _blobs;      /**< Vector holding all the memory blobs */
-    std::vector<size_t> _blob_sizes; /**< Sizes of each blob */
+    IAllocator                                 *_allocator;  /**< Allocator to use for internal allocation */
+    std::vector<std::unique_ptr<IMemoryRegion>> _blobs;      /**< Vector holding all the memory blobs */
+    std::vector<size_t>                         _blob_sizes; /**< Sizes of each blob */
 };
 } // namespace arm_compute
 #endif /* __ARM_COMPUTE_BLOBMEMORYPOOL_H__ */
diff --git a/arm_compute/runtime/CL/CLMemory.h b/arm_compute/runtime/CL/CLMemory.h
index edd9de8097..02d36614ae 100644
--- a/arm_compute/runtime/CL/CLMemory.h
+++ b/arm_compute/runtime/CL/CLMemory.h
@@ -24,6 +24,8 @@
 #ifndef __ARM_COMPUTE_RUNTIME_CL_CLMEMORY_H__
 #define __ARM_COMPUTE_RUNTIME_CL_CLMEMORY_H__
 
+#include "arm_compute/runtime/IMemory.h"
+
 #include "arm_compute/core/CL/OpenCL.h"
 #include "arm_compute/runtime/CL/CLMemoryRegion.h"
 
@@ -33,7 +35,7 @@
 namespace arm_compute
 {
 /** OpenCL implementation of memory object */
-class CLMemory
+class CLMemory : public IMemory
 {
 public:
     /** Default Constructor */
@@ -59,20 +61,22 @@ public:
     CLMemory(CLMemory &&) noexcept = default;
     /** Allow instances of this class to be move assigned */
     CLMemory &operator=(CLMemory &&) noexcept = default;
-    /** Region accessor
+    /** OpenCL Region accessor
      *
      * @return Memory region
      */
-    ICLMemoryRegion *region();
-    /** Region accessor
+    ICLMemoryRegion *cl_region();
+    /** OpenCL Region accessor
      *
      * @return Memory region
      */
-    ICLMemoryRegion *region() const;
+    ICLMemoryRegion *cl_region() const;
 
-private:
-    /** Creates empty region */
-    void create_empty_region();
+    // Inherited methods overridden:
+    IMemoryRegion *region() final;
+    IMemoryRegion *region() const final;
+    void set_region(IMemoryRegion *region) final;
+    void set_owned_region(std::unique_ptr<IMemoryRegion> region) final;
 
 private:
     ICLMemoryRegion                 *_region;
diff --git a/arm_compute/runtime/CL/CLMemoryRegion.h b/arm_compute/runtime/CL/CLMemoryRegion.h
index 01dd54e391..dbfd8225ca 100644
--- a/arm_compute/runtime/CL/CLMemoryRegion.h
+++ b/arm_compute/runtime/CL/CLMemoryRegion.h
@@ -81,9 +81,9 @@ public:
     virtual void unmap(cl::CommandQueue &q) = 0;
 
     // Inherited methods overridden :
-    void *buffer() override;
-    void *buffer() const override;
-    void **handle() override;
+    void                          *buffer() override;
+    void                          *buffer() const override;
+    std::unique_ptr<IMemoryRegion> extract_subregion(size_t offset, size_t size) override;
 
 protected:
     cl::Context _ctx;
@@ -102,11 +102,16 @@ public:
      * @param[in] size  Region size
      */
     CLBufferMemoryRegion(cl::Context ctx, cl_mem_flags flags, size_t size);
+    /** Constructor
+     *
+     * @param[in] buffer Buffer to be used as a memory region
+     */
+    CLBufferMemoryRegion(const cl::Buffer &buffer);
 
     // Inherited methods overridden :
-    void *ptr() override;
-    void *map(cl::CommandQueue &q, bool blocking) override;
-    void unmap(cl::CommandQueue &q) override;
+    void *ptr() final;
+    void *map(cl::CommandQueue &q, bool blocking) final;
+    void unmap(cl::CommandQueue &q) final;
 };
 
 /** OpenCL SVM memory region interface */
@@ -153,8 +158,8 @@ public:
     CLCoarseSVMMemoryRegion(cl::Context ctx, cl_mem_flags flags, size_t size, size_t alignment);
 
     // Inherited methods overridden :
-    void *map(cl::CommandQueue &q, bool blocking) override;
-    void unmap(cl::CommandQueue &q) override;
+    void *map(cl::CommandQueue &q, bool blocking) final;
+    void unmap(cl::CommandQueue &q) final;
 };
 
 /** OpenCL fine-grain SVM memory region implementation */
@@ -171,8 +176,8 @@ public:
     CLFineSVMMemoryRegion(cl::Context ctx, cl_mem_flags flags, size_t size, size_t alignment);
 
     // Inherited methods overridden :
-    void *map(cl::CommandQueue &q, bool blocking) override;
-    void unmap(cl::CommandQueue &q) override;
+    void *map(cl::CommandQueue &q, bool blocking) final;
+    void unmap(cl::CommandQueue &q) final;
 };
 } // namespace arm_compute
 #endif /* __ARM_COMPUTE_RUNTIME_CL_CL_MEMORY_REGION_H__ */
diff --git a/arm_compute/runtime/CL/CLTensorAllocator.h b/arm_compute/runtime/CL/CLTensorAllocator.h
index a372195555..de5f482d05 100644
--- a/arm_compute/runtime/CL/CLTensorAllocator.h
+++ b/arm_compute/runtime/CL/CLTensorAllocator.h
@@ -103,17 +103,13 @@ public:
     void free() override;
     /** Import an existing memory as a tensor's backing memory
      *
-     * @warning If the tensor is flagged to be managed by a memory manager,
-     *          this call will lead to an error.
-     * @warning Ownership of memory depends on the way the @ref CLMemory object was constructed
-     * @note    Calling free on a tensor with imported memory will just clear
-     *          the internal pointer value.
+     * @warning ownership of memory is not transferred
      *
-     * @param[in] memory Memory to import
+     * @param[in] buffer Buffer to import
      *
      * @return error status
      */
-    arm_compute::Status import_memory(CLMemory memory);
+    arm_compute::Status import_memory(cl::Buffer buffer);
     /** Associates the tensor with a memory group
      *
      * @param[in] associated_memory_group Memory group to associate the tensor with
@@ -130,8 +126,12 @@ protected:
     void unlock() override;
 
 private:
+    static const cl::Buffer _empty_buffer;
+
+private:
     CLMemoryGroup *_associated_memory_group; /**< Registered memory manager */
     CLMemory       _memory;                  /**< OpenCL memory */
+    uint8_t       *_mapping;                 /**< Pointer to the CPU mapping of the OpenCL buffer. */
     CLTensor      *_owner;                   /**< Owner of the allocator */
 };
 } // namespace arm_compute
diff --git a/arm_compute/runtime/GLES_COMPUTE/GCMemory.h b/arm_compute/runtime/GLES_COMPUTE/GCMemory.h
new file mode 100644
index 0000000000..bf0428a341
--- /dev/null
+++ b/arm_compute/runtime/GLES_COMPUTE/GCMemory.h
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+#ifndef __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GCMEMORY_H__
+#define __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GCMEMORY_H__
+
+#include "arm_compute/runtime/IMemory.h"
+
+#include "arm_compute/runtime/GLES_COMPUTE/GCMemoryRegion.h"
+
+#include <cstddef>
+#include <memory>
+
+namespace arm_compute
+{
+/** GLES implementation of memory object */
+class GCMemory : public IMemory
+{
+public:
+    /** Default Constructor */
+    GCMemory();
+    /** Default Constructor
+     *
+     * @param[in] memory Memory to be imported
+     */
+    GCMemory(std::shared_ptr<IGCMemoryRegion> memory);
+    /** Default Constructor
+     *
+     * @note Ownership of the memory is not transferred to this object.
+     *       Thus management (allocate/free) should be done by the client.
+     *
+     * @param[in] memory Memory to be imported
+     */
+    GCMemory(IGCMemoryRegion *memory);
+    /** Allow instances of this class to be copied */
+    GCMemory(const GCMemory &) = default;
+    /** Allow instances of this class to be copy assigned */
+    GCMemory &operator=(const GCMemory &) = default;
+    /** Allow instances of this class to be moved */
+    GCMemory(GCMemory &&) noexcept = default;
+    /** Allow instances of this class to be move assigned */
+    GCMemory &operator=(GCMemory &&) noexcept = default;
+    /** GLES Region accessor
+     *
+     * @return Memory region
+     */
+    IGCMemoryRegion *gc_region();
+    /** GLES Region accessor
+     *
+     * @return Memory region
+     */
+    IGCMemoryRegion *gc_region() const;
+
+    // Inherited methods overridden:
+    IMemoryRegion *region() final;
+    IMemoryRegion *region() const final;
+    void set_region(IMemoryRegion *region) final;
+    void set_owned_region(std::unique_ptr<IMemoryRegion> region) final;
+
+private:
+    IGCMemoryRegion                 *_region;
+    std::shared_ptr<IGCMemoryRegion> _region_owned;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GCMEMORY_H__ */
diff --git a/arm_compute/runtime/GLES_COMPUTE/GCMemoryRegion.h b/arm_compute/runtime/GLES_COMPUTE/GCMemoryRegion.h
new file mode 100644
index 0000000000..23e3cebe3f
--- /dev/null
+++ b/arm_compute/runtime/GLES_COMPUTE/GCMemoryRegion.h
@@ -0,0 +1,108 @@
+/*
+ * 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.
+ */
+#ifndef __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GC_MEMORY_REGION_H__
+#define __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GC_MEMORY_REGION_H__
+
+#include "arm_compute/core/GLES_COMPUTE/OpenGLES.h"
+#include "arm_compute/runtime/IMemoryRegion.h"
+
+#include <cstddef>
+
+namespace arm_compute
+{
+/** GLES memory region interface */
+class IGCMemoryRegion : public IMemoryRegion
+{
+public:
+    /** Constructor
+     *
+     * @param[in] size Region size
+     */
+    IGCMemoryRegion(size_t size);
+    /** Default Destructor */
+    virtual ~IGCMemoryRegion() = default;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    IGCMemoryRegion(const IGCMemoryRegion &) = delete;
+    /** Default move constructor */
+    IGCMemoryRegion(IGCMemoryRegion &&) = default;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    IGCMemoryRegion &operator=(const IGCMemoryRegion &) = delete;
+    /** Default move assignment operator */
+    IGCMemoryRegion &operator=(IGCMemoryRegion &&) = default;
+    /** Returns the underlying CL buffer
+     *
+     * @return CL memory buffer object
+     */
+    const GLuint &gc_ssbo_name() const;
+    /** Host/SVM pointer accessor
+     *
+     * @return Host/SVM pointer base
+     */
+    virtual void *ptr() = 0;
+    /** Enqueue a map operation of the allocated buffer on the given queue.
+     *
+     * @param[in] blocking If true, then the mapping will be ready to use by the time
+     *                     this method returns, else it is the caller's responsibility
+     *                     to flush the queue and wait for the mapping operation to have completed before using the returned mapping pointer.
+     *
+     * @return The mapping address.
+     */
+    virtual void *map(bool blocking) = 0;
+    /** Enqueue an unmap operation of the allocated buffer on the given queue.
+     *
+     * @note This method simply enqueue the unmap operation, it is the caller's responsibility to flush the queue and make sure the unmap is finished before
+     *       the memory is accessed by the device.
+     *
+     */
+    virtual void unmap() = 0;
+
+    // Inherited methods overridden :
+    void *buffer() override;
+    void *buffer() const override;
+
+protected:
+    void *_mapping;
+    GLuint _ssbo_name;
+};
+
+/** GLES buffer memory region implementation */
+class GCBufferMemoryRegion final : public IGCMemoryRegion
+{
+public:
+    /** Constructor
+     *
+     * @param[in] size Region size
+     */
+    GCBufferMemoryRegion(size_t size);
+    /** Destructor */
+    ~GCBufferMemoryRegion();
+
+    // Inherited methods overridden :
+    void *ptr() final;
+    void *map(bool blocking) final;
+    void                           unmap() final;
+    std::unique_ptr<IMemoryRegion> extract_subregion(size_t offset, size_t size) final;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_RUNTIME_GLES_COMPUTE_GC_MEMORY_REGION_H__ */
diff --git a/arm_compute/runtime/GLES_COMPUTE/GCTensorAllocator.h b/arm_compute/runtime/GLES_COMPUTE/GCTensorAllocator.h
index 1bd3582b6c..b7067664fc 100644
--- a/arm_compute/runtime/GLES_COMPUTE/GCTensorAllocator.h
+++ b/arm_compute/runtime/GLES_COMPUTE/GCTensorAllocator.h
@@ -26,6 +26,7 @@
 #define __ARM_COMPUTE_GCTENSORALLOCATOR_H__
 
 #include "arm_compute/core/GLES_COMPUTE/OpenGLES.h"
+#include "arm_compute/runtime/GLES_COMPUTE/GCMemory.h"
 #include "arm_compute/runtime/ITensorAllocator.h"
 #include "arm_compute/runtime/MemoryGroupBase.h"
 
@@ -38,20 +39,6 @@ template <typename>
 class MemoryGroupBase;
 using GCMemoryGroup = MemoryGroupBase<GCTensor>;
 
-class GLBufferWrapper
-{
-public:
-    GLBufferWrapper()
-        : _ssbo_name(0)
-    {
-        ARM_COMPUTE_GL_CHECK(glGenBuffers(1, &_ssbo_name));
-    }
-    ~GLBufferWrapper()
-    {
-        ARM_COMPUTE_GL_CHECK(glDeleteBuffers(1, &_ssbo_name));
-    }
-    GLuint _ssbo_name;
-};
 /** Basic implementation of a GLES memory tensor allocator. */
 class GCTensorAllocator : public ITensorAllocator
 {
@@ -72,7 +59,7 @@ public:
     GCTensorAllocator &operator=(GCTensorAllocator &&) = default;
 
     /** Default destructor */
-    ~GCTensorAllocator();
+    ~GCTensorAllocator() = default;
 
     /** Interface to be implemented by the child class to return the pointer to the mapped data.
      *
@@ -135,11 +122,10 @@ protected:
     void unlock() override;
 
 private:
-    GCMemoryGroup                   *_associated_memory_group; /**< Registered memory group */
-    std::unique_ptr<GLBufferWrapper> _gl_buffer;               /**< OpenGL ES object containing the tensor data. */
-    uint8_t                         *_mapping;                 /**< Pointer to the CPU mapping of the OpenGL ES buffer. */
-    GCTensor                        *_owner;                   /**< Owner of the allocator */
+    GCMemoryGroup *_associated_memory_group; /**< Registered memory group */
+    GCMemory       _memory;                  /**< OpenGL ES memory */
+    uint8_t       *_mapping;                 /**< Pointer to the CPU mapping of the OpenGL ES buffer. */
+    GCTensor      *_owner;                   /**< Owner of the allocator */
 };
-}
-
+} // namespace arm_compute
 #endif /* __ARM_COMPUTE_GCTENSORALLOCATOR_H__ */
diff --git a/arm_compute/runtime/ILifetimeManager.h b/arm_compute/runtime/ILifetimeManager.h
index 36743ac404..f2e9b497c9 100644
--- a/arm_compute/runtime/ILifetimeManager.h
+++ b/arm_compute/runtime/ILifetimeManager.h
@@ -32,8 +32,10 @@
 
 namespace arm_compute
 {
-class IMemoryGroup;
+// Forward declarations
 class IAllocator;
+class IMemory;
+class IMemoryGroup;
 
 /** Interface for managing the lifetime of objects */
 class ILifetimeManager
@@ -53,11 +55,11 @@ public:
     virtual void start_lifetime(void *obj) = 0;
     /** Ends lifetime of an object
      *
-     * @param[in] obj    Object
-     * @param[in] handle Memory handle of the object
-     * @param[in] size   Size of the given object at given time
+     * @param[in] obj        Object
+     * @param[in] obj_memory Object memory
+     * @param[in] size       Size of the given object at given time
      */
-    virtual void end_lifetime(void *obj, void **handle, size_t size) = 0;
+    virtual void end_lifetime(void *obj, IMemory &obj_memory, size_t size) = 0;
     /** Checks if the lifetime of the registered object is complete
      *
      * @return True if all object lifetimes are finalized else false.
diff --git a/arm_compute/runtime/IMemory.h b/arm_compute/runtime/IMemory.h
new file mode 100644
index 0000000000..e6f5058d94
--- /dev/null
+++ b/arm_compute/runtime/IMemory.h
@@ -0,0 +1,63 @@
+/*
+ * 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.
+ */
+#ifndef __ARM_COMPUTE_IMEMORY_H__
+#define __ARM_COMPUTE_IMEMORY_H__
+
+#include "arm_compute/runtime/IMemoryRegion.h"
+
+namespace arm_compute
+{
+/** Memory interface*/
+class IMemory
+{
+public:
+    /** Virtual default destructor */
+    virtual ~IMemory() = default;
+    /** Region accessor
+     *
+     * @return Memory region
+     */
+    virtual IMemoryRegion *region() = 0;
+    /** Region accessor
+     *
+     * @return Memory region
+     */
+    virtual IMemoryRegion *region() const = 0;
+    /** Sets a memory region
+     *
+     * @warning Ownership of the memory region remains to the caller
+     *
+     * @param region Memory region
+     */
+    virtual void set_region(IMemoryRegion *region) = 0;
+    /** Sets a memory region
+     *
+     * @warning Ownership of the memory region is transfered along
+     *
+     * @param region Memory region
+     */
+    virtual void set_owned_region(std::unique_ptr<IMemoryRegion> region) = 0;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_IMEMORY_H__ */
diff --git a/arm_compute/runtime/IMemoryRegion.h b/arm_compute/runtime/IMemoryRegion.h
index 4c08b4ab09..aa8c07ef2a 100644
--- a/arm_compute/runtime/IMemoryRegion.h
+++ b/arm_compute/runtime/IMemoryRegion.h
@@ -25,6 +25,7 @@
 #define __ARM_COMPUTE_RUNTIME_IMEMORY_REGION_H__
 
 #include <cstddef>
+#include <memory>
 
 namespace arm_compute
 {
@@ -36,12 +37,25 @@ public:
      *
      * @param[in] size Region size
      */
-    IMemoryRegion(size_t size)
+    explicit IMemoryRegion(size_t size)
         : _size(size)
     {
     }
     /** Virtual Destructor */
     virtual ~IMemoryRegion() = default;
+    /** Extract a sub-region from the memory
+     *
+     * @warning Ownership is maintained by the parent memory,
+     *          while a wrapped raw memory region is returned by this function.
+     *          Thus parent memory should not be released before this.
+     *
+     *
+     * @param[in] offset Offset to the region
+     * @param[in] size   Size of the region
+     *
+     * @return A wrapped memory sub-region with no ownership of the underlying memory
+     */
+    virtual std::unique_ptr<IMemoryRegion> extract_subregion(size_t offset, size_t size) = 0;
     /** Returns the pointer to the allocated data.
      *
      * @return Pointer to the allocated data
@@ -52,16 +66,11 @@ public:
      * @return Pointer to the allocated data
      */
     virtual void *buffer() const = 0;
-    /** Handle of internal memory
-     *
-     * @return Handle of memory
-     */
-    virtual void **handle() = 0;
     /** Memory region size accessor
      *
      * @return Memory region size
      */
-    size_t size()
+    size_t size() const
     {
         return _size;
     }
diff --git a/arm_compute/runtime/ISimpleLifetimeManager.h b/arm_compute/runtime/ISimpleLifetimeManager.h
index 7942e40f7f..f2eb4f5904 100644
--- a/arm_compute/runtime/ISimpleLifetimeManager.h
+++ b/arm_compute/runtime/ISimpleLifetimeManager.h
@@ -58,7 +58,7 @@ public:
     // Inherited methods overridden:
     void register_group(IMemoryGroup *group) override;
     void start_lifetime(void *obj) override;
-    void end_lifetime(void *obj, void **handle, size_t size) override;
+    void end_lifetime(void *obj, IMemory &obj_memory, size_t size) override;
     bool are_all_finalized() const override;
 
 protected:
@@ -69,14 +69,14 @@ protected:
     /** Element struct */
     struct Element
     {
-        Element(void *id_ = nullptr, void **handle_ = nullptr, size_t size_ = 0, bool status_ = false)
+        Element(void *id_ = nullptr, IMemory *handle_ = nullptr, size_t size_ = 0, bool status_ = false)
             : id(id_), handle(handle_), size(size_), status(status_)
         {
         }
-        void *id;      /**< Element id */
-        void **handle; /**< Element's memory handle */
-        size_t size;   /**< Element's size */
-        bool   status; /**< Lifetime status */
+        void    *id;     /**< Element id */
+        IMemory *handle; /**< Element's memory handle */
+        size_t   size;   /**< Element's size */
+        bool     status; /**< Lifetime status */
     };
 
     /** Blob struct */
diff --git a/arm_compute/runtime/Memory.h b/arm_compute/runtime/Memory.h
index 2dadccf254..6f5254a689 100644
--- a/arm_compute/runtime/Memory.h
+++ b/arm_compute/runtime/Memory.h
@@ -24,6 +24,8 @@
 #ifndef __ARM_COMPUTE_MEMORY_H__
 #define __ARM_COMPUTE_MEMORY_H__
 
+#include "arm_compute/runtime/IMemory.h"
+
 #include "arm_compute/runtime/IMemoryRegion.h"
 
 #include <cstddef>
@@ -32,7 +34,7 @@
 namespace arm_compute
 {
 /** CPU implementation of memory object */
-class Memory
+class Memory : public IMemory
 {
 public:
     /** Default Constructor */
@@ -58,24 +60,16 @@ public:
     Memory(Memory &&) noexcept = default;
     /** Allow instances of this class to be move assigned */
     Memory &operator=(Memory &&) noexcept = default;
-    /** Region accessor
-     *
-     * @return Memory region
-     */
-    IMemoryRegion *region();
-    /** Region accessor
-     *
-     * @return Memory region
-     */
-    IMemoryRegion *region() const;
 
-private:
-    /** Creates empty region */
-    void create_empty_region();
+    // Inherited methods overridden:
+    IMemoryRegion *region() final;
+    IMemoryRegion *region() const final;
+    void set_region(IMemoryRegion *region) final;
+    void set_owned_region(std::unique_ptr<IMemoryRegion> region) final;
 
 private:
     IMemoryRegion                 *_region;
     std::shared_ptr<IMemoryRegion> _region_owned;
 };
-}
+} // namespace arm_compute
 #endif /* __ARM_COMPUTE_MEMORY_H__ */
diff --git a/arm_compute/runtime/MemoryGroupBase.h b/arm_compute/runtime/MemoryGroupBase.h
index 06e4321410..0ceaa900c5 100644
--- a/arm_compute/runtime/MemoryGroupBase.h
+++ b/arm_compute/runtime/MemoryGroupBase.h
@@ -35,6 +35,9 @@
 
 namespace arm_compute
 {
+// Forward declarations
+class IMemory;
+
 /** Memory group */
 template <typename TensorType>
 class MemoryGroupBase : public IMemoryGroup
@@ -63,11 +66,12 @@ public:
      *
      * @note Manager must not be finalized
      *
-     * @param[in] obj    Object to request memory for
-     * @param[in] handle Handle to store the memory
-     * @param[in] size   Size of memory to allocate
+     * @param[in, out] obj        Object to request memory for
+     * @param[in, out] obj_memory Object's memory handling interface which can be used to alter the underlying memory
+     *                            that is used by the object.
+     * @param[in]      size       Size of memory to allocate
      */
-    void finalize_memory(TensorType *obj, void **handle, size_t size);
+    void finalize_memory(TensorType *obj, IMemory &obj_memory, size_t size);
 
     // Inherited methods overridden:
     void            acquire() override;
@@ -112,16 +116,16 @@ inline void MemoryGroupBase<TensorType>::manage(TensorType *obj)
 }
 
 template <typename TensorType>
-inline void MemoryGroupBase<TensorType>::finalize_memory(TensorType *obj, void **handle, size_t size)
+inline void MemoryGroupBase<TensorType>::finalize_memory(TensorType *obj, IMemory &obj_memory, size_t size)
 {
     // TODO (geopin01) : Check size (track size in MemoryMappings)
     // Check if existing mapping is valid
-    ARM_COMPUTE_ERROR_ON(!_mappings.empty() && (_mappings.find(handle) == std::end(_mappings)));
+    ARM_COMPUTE_ERROR_ON(!_mappings.empty() && (_mappings.find(&obj_memory) == std::end(_mappings)));
 
     if(_memory_manager && _mappings.empty())
     {
         ARM_COMPUTE_ERROR_ON(!_memory_manager->lifetime_manager());
-        _memory_manager->lifetime_manager()->end_lifetime(obj, handle, size);
+        _memory_manager->lifetime_manager()->end_lifetime(obj, obj_memory, size);
     }
 }
 
diff --git a/arm_compute/runtime/MemoryRegion.h b/arm_compute/runtime/MemoryRegion.h
index 481b20d375..335486ed9d 100644
--- a/arm_compute/runtime/MemoryRegion.h
+++ b/arm_compute/runtime/MemoryRegion.h
@@ -37,13 +37,13 @@ namespace arm_compute
 class MemoryRegion final : public IMemoryRegion
 {
 public:
-    /** Default constructor
+    /** Constructor
      *
      * @param[in] size      Region size
      * @param[in] alignment Alignment in bytes of the base pointer. Defaults to 0
      */
     MemoryRegion(size_t size, size_t alignment = 0)
-        : IMemoryRegion(size), _mem(nullptr), _alignment(alignment), _offset(0)
+        : IMemoryRegion(size), _mem(nullptr), _ptr(nullptr)
     {
         if(size != 0)
         {
@@ -53,16 +53,25 @@ public:
             {
                 delete[] ptr;
             });
+            _ptr = _mem.get();
 
             // Calculate alignment offset
             if(alignment != 0)
             {
                 void *aligned_ptr = _mem.get();
                 support::cpp11::align(alignment, size, aligned_ptr, space);
-                _offset = reinterpret_cast<uintptr_t>(aligned_ptr) - reinterpret_cast<uintptr_t>(_mem.get());
+                _ptr = aligned_ptr;
             }
         }
     }
+    MemoryRegion(void *ptr, size_t size)
+        : IMemoryRegion(size), _mem(nullptr), _ptr(nullptr)
+    {
+        if(size != 0)
+        {
+            _ptr = ptr;
+        }
+    }
     /** Prevent instances of this class from being copied (As this class contains pointers) */
     MemoryRegion(const MemoryRegion &) = delete;
     /** Default move constructor */
@@ -75,22 +84,27 @@ public:
     // Inherited methods overridden :
     void *buffer() final
     {
-        return reinterpret_cast<void *>(_mem.get() + _offset);
+        return _ptr;
     }
     void *buffer() const final
     {
-        // FIXME (COMPMID-1088) : Remove handle() and _offset when done
-        return reinterpret_cast<void *>(_mem.get() + _offset);
+        return _ptr;
     }
-    void **handle() final
+    std::unique_ptr<IMemoryRegion> extract_subregion(size_t offset, size_t size) final
     {
-        return reinterpret_cast<void **>(&_mem);
+        if(_ptr != nullptr && (offset < _size) && (_size - offset >= size))
+        {
+            return support::cpp14::make_unique<MemoryRegion>(static_cast<uint8_t *>(_ptr) + offset, size);
+        }
+        else
+        {
+            return nullptr;
+        }
     }
 
 protected:
     std::shared_ptr<uint8_t> _mem;
-    size_t                   _alignment;
-    size_t                   _offset;
+    void                    *_ptr;
 };
 } // namespace arm_compute
 #endif /* __ARM_COMPUTE_RUNTIME_MEMORY_REGION_H__ */
diff --git a/arm_compute/runtime/OffsetMemoryPool.h b/arm_compute/runtime/OffsetMemoryPool.h
index 9685fd1319..480d424b5b 100644
--- a/arm_compute/runtime/OffsetMemoryPool.h
+++ b/arm_compute/runtime/OffsetMemoryPool.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -26,6 +26,7 @@
 
 #include "arm_compute/runtime/IMemoryPool.h"
 
+#include "arm_compute/runtime/IMemoryRegion.h"
 #include "arm_compute/runtime/Types.h"
 
 #include <cstddef>
@@ -47,7 +48,7 @@ public:
      */
     OffsetMemoryPool(IAllocator *allocator, size_t blob_size);
     /** Default Destructor */
-    ~OffsetMemoryPool();
+    ~OffsetMemoryPool() = default;
     /** Prevent instances of this class to be copy constructed */
     OffsetMemoryPool(const OffsetMemoryPool &) = delete;
     /** Prevent instances of this class to be copy assigned */
@@ -64,9 +65,9 @@ public:
     std::unique_ptr<IMemoryPool> duplicate() override;
 
 private:
-    IAllocator *_allocator; /**< Allocator to use for internal allocation */
-    void       *_blob;      /**< Memory blob */
-    size_t      _blob_size; /**< Sizes of the allocated memory blob */
+    IAllocator                    *_allocator; /**< Allocator to use for internal allocation */
+    std::unique_ptr<IMemoryRegion> _blob;      /**< Memory blob */
+    size_t                         _blob_size; /**< Sizes of the allocated memory blob */
 };
 } // namespace arm_compute
 #endif /* __ARM_COMPUTE_OFFSETMEMORYPOOL_H__ */
diff --git a/arm_compute/runtime/TensorAllocator.h b/arm_compute/runtime/TensorAllocator.h
index 2ad37d0576..ba9e5163ab 100644
--- a/arm_compute/runtime/TensorAllocator.h
+++ b/arm_compute/runtime/TensorAllocator.h
@@ -95,17 +95,11 @@ public:
     void free() override;
     /** Import an existing memory as a tensor's backing memory
      *
-     * @warning If the tensor is flagged to be managed by a memory manager,
-     *          this call will lead to an error.
-     * @warning Ownership of memory depends on the way the @ref Memory object was constructed
-     * @note    Calling free on a tensor with imported memory will just clear
-     *          the internal pointer value.
-     *
-     * @param[in] memory Memory to import
+     * @warning ownership of memory is not transferred
      *
      * @return error status
      */
-    arm_compute::Status import_memory(Memory memory);
+    arm_compute::Status import_memory(void *memory, size_t size);
     /** Associates the tensor with a memory group
      *
      * @param[in] associated_memory_group Memory group to associate the tensor with
diff --git a/arm_compute/runtime/Types.h b/arm_compute/runtime/Types.h
index 9916e6d47b..b962427ef8 100644
--- a/arm_compute/runtime/Types.h
+++ b/arm_compute/runtime/Types.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2017 ARM Limited.
+ * Copyright (c) 2016-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -24,6 +24,8 @@
 #ifndef __ARM_COMPUTE_RUNTIME_TYPES_H__
 #define __ARM_COMPUTE_RUNTIME_TYPES_H__
 
+#include "arm_compute/runtime/IMemory.h"
+
 #include <map>
 
 namespace arm_compute
@@ -40,7 +42,7 @@ enum class MappingType
  *
  * @note All objects are pre-pinned to specific buffers to avoid any relevant overheads
  */
-using MemoryMappings = std::map<void **, size_t>;
+using MemoryMappings = std::map<IMemory *, size_t>;
 
 /** A map of the groups and memory mappings */
 using GroupMappings = std::map<size_t, MemoryMappings>;