COMPMID-485: Offset-based memory manager support.

Adds support for offset-based memory mappings used from CPU system
memory and SVM based allocations.

Change-Id: Ibee6a3c02a61df9b11fe8878cfe40dc6fd9a4be0
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/88307
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/arm_compute/runtime/OffsetMemoryPool.h b/arm_compute/runtime/OffsetMemoryPool.h
new file mode 100644
index 0000000..9685fd1
--- /dev/null
+++ b/arm_compute/runtime/OffsetMemoryPool.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2017 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_OFFSETMEMORYPOOL_H__
+#define __ARM_COMPUTE_OFFSETMEMORYPOOL_H__
+
+#include "arm_compute/runtime/IMemoryPool.h"
+
+#include "arm_compute/runtime/Types.h"
+
+#include <cstddef>
+
+namespace arm_compute
+{
+class IAllocator;
+
+/** Offset based memory pool */
+class OffsetMemoryPool : public IMemoryPool
+{
+public:
+    /** Default Constructor
+     *
+     * @note allocator should outlive the memory pool
+     *
+     * @param[in] allocator Backing memory allocator
+     * @param[in] blob_size Size of the memory be allocated
+     */
+    OffsetMemoryPool(IAllocator *allocator, size_t blob_size);
+    /** Default Destructor */
+    ~OffsetMemoryPool();
+    /** Prevent instances of this class to be copy constructed */
+    OffsetMemoryPool(const OffsetMemoryPool &) = delete;
+    /** Prevent instances of this class to be copy assigned */
+    OffsetMemoryPool &operator=(const OffsetMemoryPool &) = delete;
+    /** Allow instances of this class to be move constructed */
+    OffsetMemoryPool(OffsetMemoryPool &&) = default;
+    /** Allow instances of this class to be move assigned */
+    OffsetMemoryPool &operator=(OffsetMemoryPool &&) = default;
+
+    // Inherited methods overridden:
+    void acquire(MemoryMappings &handles) override;
+    void release(MemoryMappings &handles) override;
+    MappingType                  mapping_type() const override;
+    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 */
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_OFFSETMEMORYPOOL_H__ */