COMPMID-3391: Implement Async interfaces

Change-Id: I8168cea5056ff48a0253ebb8c88ea549a3ea69a2
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/3335
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/arm_compute/runtime/IOperator.h b/arm_compute/runtime/IOperator.h
new file mode 100644
index 0000000..110c935
--- /dev/null
+++ b/arm_compute/runtime/IOperator.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2020 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_IOPERATOR_H
+#define ARM_COMPUTE_IOPERATOR_H
+
+#include "arm_compute/runtime/IOperator.h"
+#include "arm_compute/runtime/IRuntimeContext.h"
+#include "arm_compute/runtime/Types.h"
+
+namespace arm_compute
+{
+namespace experimental
+{
+/** Base class for all async functions */
+class IOperator
+{
+public:
+    /** Destructor */
+    virtual ~IOperator() = default;
+    /** Run the kernels contained in the function
+     *
+     *
+     * @param[in] inputs    Vector that contains the input tensors.
+     * @param[in] outputs   Vector that contains the output tensors.
+     * @param[in] workspace Vector that contains the workspace tensors.
+     *
+     */
+    virtual void run(std::vector<InputOperatorTensors *> &inputs, std::vector<OutputOperatorTensors *> &outputs, std::vector<OperatorTensors *> &workspace) = 0;
+    /** Prepare the function for executing
+     *
+     * Any one off pre-processing step required by the function is handled here
+     *
+     * @param[in] constants Vector that contains the constants tensors.
+     *
+     * @note Prepare stage might not need all the function's buffers' backing memory to be available in order to execute
+     */
+    virtual void prepare(std::vector<OperatorTensors *> constants) = 0;
+
+    /** Return the memory requirements required by the workspace
+     */
+    virtual MemoryRequirements workspace() const = 0;
+};
+} // namespace experimental
+} // namespace arm_compute
+#endif /*ARM_COMPUTE_IOPERATOR_H */