Introduce Context opaque object of the new interface

An AclContext is introduced as part of the new interface.
This object is responsible for any constructural services that the
operators and other objects might need.

Main options that can be passed to a context object are:
- a target: for which all the subsequent object should bind with
- capabilities: which are the isa/target features to enable
- a mode: for which different strategies can be selected in the backend

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I315549e55d4d064cbe94dfa29d070dc281b447de
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5088
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 127 insertions, 0 deletions

diff --git a/src/common/IContext.h b/src/common/IContext.h
new file mode 100644
index 0000000000..0d23abd2be
--- /dev/null
+++ b/src/common/IContext.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2021 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 SRC_COMMON_ICONTEXT_H
+#define SRC_COMMON_ICONTEXT_H
+
+#include "src/common/Types.h"
+#include "src/common/utils/Log.h"
+#include "src/common/utils/Object.h"
+
+#include <atomic>
+
+struct AclContext_
+{
+    arm_compute::detail::Header header{ arm_compute::detail::ObjectType::Context, nullptr };
+
+protected:
+    AclContext_()  = default;
+    ~AclContext_() = default;
+};
+
+namespace arm_compute
+{
+/**< Context interface */
+class IContext : public AclContext_
+{
+public:
+    IContext(Target target)
+        : AclContext_(), _target(target), _refcount(0)
+    {
+    }
+    /** Virtual Destructor */
+    virtual ~IContext()
+    {
+        header.type = detail::ObjectType::Invalid;
+    };
+    /** Target type accessor
+     *
+     * @return Target that the context is associated with
+     */
+    Target type() const
+    {
+        return _target;
+    }
+    /** Increment context refcount */
+    void inc_ref() const
+    {
+        ++_refcount;
+    }
+    /** Decrement context refcount */
+    void dec_ref() const
+    {
+        --_refcount;
+    }
+    /** Reference counter accessor
+     *
+     * @return The number of references pointing to this object
+     */
+    int refcount() const
+    {
+        return _refcount;
+    }
+    /** Checks if an object is valid
+     *
+     * @return True if sucessful otherwise false
+     */
+    bool is_valid() const
+    {
+        return header.type == detail::ObjectType::Context;
+    }
+
+private:
+    Target                   _target;   /**< Target type of context */
+    mutable std::atomic<int> _refcount; /**< Reference counter */
+};
+
+/** Extract internal representation of a Context
+ *
+ * @param[in] ctx Opaque context pointer
+ *
+ * @return The internal representation as an IContext
+ */
+inline IContext *get_internal(AclContext ctx)
+{
+    return static_cast<IContext *>(ctx);
+}
+
+namespace detail
+{
+/** Check if an internal context is valid
+ *
+ * @param[in] ctx Internal context to check
+ *
+ * @return A status code
+ */
+inline StatusCode validate_internal_context(const IContext *ctx)
+{
+    if(ctx == nullptr || !ctx->is_valid())
+    {
+        ARM_COMPUTE_LOG_ERROR_ACL("Invalid context object");
+        return StatusCode::InvalidArgument;
+    }
+    return StatusCode::Success;
+}
+} // namespace detail
+} // namespace arm_compute
+#endif /* SRC_COMMON_ICONTEXT_H */