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, 381 insertions, 0 deletions

diff --git a/arm_compute/Acl.hpp b/arm_compute/Acl.hpp
new file mode 100644
index 0000000000..b74e65430c
--- /dev/null
+++ b/arm_compute/Acl.hpp
@@ -0,0 +1,381 @@
+/*
+ * 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 ARM_COMPUTE_ACL_HPP_
+#define ARM_COMPUTE_ACL_HPP_
+
+#include "arm_compute/Acl.h"
+
+#include <cstdlib>
+#include <memory>
+#include <string>
+
+#if defined(ARM_COMPUTE_EXCEPTIONS_ENABLED)
+#include <exception>
+#endif /* defined(ARM_COMPUTE_EXCEPTIONS_ENABLED) */
+
+// Helper Macros
+#define ARM_COMPUTE_IGNORE_UNUSED(x) (void)(x)
+
+namespace acl
+{
+// Forward declarations
+class Context;
+
+/**< Status code enum */
+enum class StatusCode
+{
+    Success            = AclSuccess,
+    RuntimeError       = AclRuntimeError,
+    OutOfMemory        = AclOutOfMemory,
+    Unimplemented      = AclUnimplemented,
+    UnsupportedTarget  = AclUnsupportedTarget,
+    InvalidArgument    = AclInvalidArgument,
+    InvalidTarget      = AclInvalidTarget,
+    UnsupportedConfig  = AclUnsupportedConfig,
+    InvalidObjectState = AclInvalidObjectState,
+};
+
+/**< Utility namespace containing helpers functions */
+namespace detail
+{
+/** Construct to handle destruction of objects
+ *
+ * @tparam T Object base type
+ */
+template <typename T>
+struct ObjectDeleter
+{
+};
+
+#define OBJECT_DELETER(obj, func)              \
+    template <>                                \
+    struct ObjectDeleter<obj>                  \
+        \
+    {                                          \
+        static inline AclStatus Destroy(obj v) \
+        {                                      \
+            return func(v);                    \
+        }                                      \
+    };
+
+OBJECT_DELETER(AclContext, AclDestroyContext)
+
+#undef OBJECT_DELETER
+
+/** Convert a strongly typed enum to an old plain c enum
+  *
+  * @tparam E  Plain old C enum
+  * @tparam SE Strongly typed resulting enum
+  *
+  * @param[in] v Value to convert
+  *
+  * @return A corresponding plain old C enumeration
+  */
+template <typename E, typename SE>
+constexpr E as_cenum(SE v) noexcept
+{
+    return static_cast<E>(static_cast<typename std::underlying_type<SE>::type>(v));
+}
+
+/** Convert plain old enumeration to a strongly typed enum
+  *
+  * @tparam SE Strongly typed resulting enum
+  * @tparam E  Plain old C enum
+  *
+  * @param[in] val Value to convert
+  *
+  * @return A corresponding strongly typed enumeration
+  */
+template <typename SE, typename E>
+constexpr SE as_enum(E val) noexcept
+{
+    return static_cast<SE>(val);
+}
+
+/** Object base class for library objects
+ *
+ * Class is defining basic common interface for all the library objects
+ *
+ * @tparam T Object type to be templated on
+ */
+template <typename T>
+class ObjectBase
+{
+public:
+    /** Destructor */
+    ~ObjectBase() = default;
+    /** Copy constructor */
+    ObjectBase(const ObjectBase<T> &) = default;
+    /** Move Constructor */
+    ObjectBase(ObjectBase<T> &&) = default;
+    /** Copy assignment operator */
+    ObjectBase<T> &operator=(const ObjectBase<T> &) = default;
+    /** Move assignment operator */
+    ObjectBase<T> &operator=(ObjectBase<T> &&) = default;
+    /** Reset object value
+     *
+     * @param [in] val Value to set
+     */
+    void reset(T *val)
+    {
+        _object.reset(val, detail::ObjectDeleter<T *>::Destroy);
+    }
+    /** Access uderlying object
+     *
+     * @return Underlying object
+     */
+    const T *get() const
+    {
+        return _object.get();
+    }
+    /** Access uderlying object
+     *
+     * @return Underlying object
+     */
+    T *get()
+    {
+        return _object.get();
+    }
+
+protected:
+    /** Constructor */
+    ObjectBase() = default;
+
+protected:
+    std::shared_ptr<T> _object{ nullptr }; /**< Library object */
+};
+
+/** Equality operator for library object
+ *
+ * @tparam T Parameter to template on
+ *
+ * @param[in] lhs Left hand-side argument
+ * @param[in] rhs Right hand-side argument
+ *
+ * @return True if objects are equal, else false
+ */
+template <typename T>
+bool operator==(const ObjectBase<T> &lhs, const ObjectBase<T> &rhs)
+{
+    return lhs.get() == rhs.get();
+}
+
+/** Inequality operator for library object
+ *
+ * @tparam T Parameter to template on
+ *
+ * @param[in] lhs Left hand-side argument
+ * @param[in] rhs Right hand-side argument
+ *
+ * @return True if objects are equal, else false
+ */
+template <typename T>
+bool operator!=(const ObjectBase<T> &lhs, const ObjectBase<T> &rhs)
+{
+    return !(lhs == rhs);
+}
+} // namespace detail
+
+#if defined(ARM_COMPUTE_EXCEPTIONS_ENABLED)
+/** Status class
+ *
+ * Class is an extension of std::exception and contains the underlying
+ * status construct and an error explanatory message to be reported.
+ *
+ * @note Class is visible only when exceptions are enabled during compilation
+ */
+class Status : public std::exception
+{
+public:
+    /** Constructor
+     *
+     * @param[in] status Status returned
+     * @param[in] msg    Error message to be bound with the exception
+     */
+    Status(StatusCode status, const std::string &msg)
+        : _status(status), _msg(msg)
+    {
+    }
+    /** Returns an explanatory exception message
+     *
+     * @return Status message
+     */
+    const char *what() const noexcept override
+    {
+        return _msg.c_str();
+    }
+    /** Underlying status accessor
+     *
+     * @return Status code
+     */
+    StatusCode status() const
+    {
+        return _status;
+    }
+    /** Explicit status converter
+     *
+     * @return Status code
+     */
+    explicit operator StatusCode() const
+    {
+        return _status;
+    }
+
+private:
+    StatusCode  _status; /**< Status code */
+    std::string _msg;    /**< Status message */
+};
+
+/** Reports an error status and throws an exception object in case of failure
+ *
+ * @note This implementation is used when exceptions are enabled during compilation
+ *
+ * @param[in] status Status to report
+ * @param[in] msg    Explanatory error messaged
+ *
+ * @return Status code
+ */
+static inline StatusCode report_status(StatusCode status, const std::string &msg)
+{
+    if(status != StatusCode::Success)
+    {
+        throw Status(status, msg);
+    }
+    return status;
+}
+#else  /* defined(ARM_COMPUTE_EXCEPTIONS_ENABLED) */
+/** Reports a status code
+ *
+ * @note This implementation is used when exceptions are disabled during compilation
+ * @note Message is surpressed and not reported in this case
+ *
+ * @param[in] status Status to report
+ * @param[in] msg    Explanatory error messaged
+ *
+ * @return Status code
+ */
+static inline StatusCode report_status(StatusCode status, const std::string &msg)
+{
+    ARM_COMPUTE_IGNORE_UNUSED(msg);
+    return status;
+}
+#endif /* defined(ARM_COMPUTE_EXCEPTIONS_ENABLED) */
+
+/**< Target enum */
+enum class Target
+{
+    Cpu    = AclCpu,   /**< Cpu target that leverages SIMD */
+    GpuOcl = AclGpuOcl /**< Gpu target that leverages OpenCL */
+};
+
+/**< Available execution modes */
+enum class ExecutionMode
+{
+    FastRerun = AclPreferFastRerun, /**< Prefer minimum latency in consecutive runs, might introduce higher startup times */
+    FastStart = AclPreferFastStart, /**< Prefer minimizing startup time */
+};
+
+/** Context class
+ *
+ * Context acts as a central aggregate service for further objects created from it.
+ * It provides, internally, common facilities in order to avoid the use of global
+ * statically initialized objects that can lead to important side-effect under
+ * specific execution contexts.
+ *
+ * For example context contains allocators for object creation, for further backing memory allocation,
+ * any serialization interfaces and other modules that affect the construction of objects,
+ * like program caches for OpenCL.
+ */
+class Context : public detail::ObjectBase<AclContext_>
+{
+public:
+    /**< Context options */
+    struct Options
+    {
+        /** Default Constructor
+         *
+         * @note By default no precision loss is enabled for operators
+         * @note By default the preferred execution mode is to favor multiple consecutive reruns of an operator
+         */
+        Options() = default;
+        /** Constructor
+         *
+         * @param[in] mode              Execution mode to be used
+         * @param[in] caps              Capabilities to be used
+         * @param[in] enable_fast_math  Allow precision loss in favor of performance
+         * @param[in] kernel_config     Kernel configuration file containing construction tuning meta-data
+         * @param[in] max_compute_units Max compute units that are expected to used
+         * @param[in] allocator         Allocator to be used for internal memory allocation
+         */
+        Options(ExecutionMode         mode,
+                AclTargetCapabilities caps,
+                bool                  enable_fast_math,
+                const char           *kernel_config,
+                int32_t               max_compute_units,
+                AclAllocator         *allocator)
+        {
+            opts.mode               = detail::as_cenum<AclExecutionMode>(mode);
+            opts.capabilities       = caps;
+            opts.enable_fast_math   = enable_fast_math;
+            opts.kernel_config_file = kernel_config;
+            opts.max_compute_units  = max_compute_units;
+            opts.allocator          = allocator;
+        }
+        AclContextOptions opts{ acl_default_ctx_options };
+    };
+
+public:
+    /** Constructor
+     *
+     * @note Serves as a simpler delegate constructor
+     * @note As context options, default conservative options will be used
+     *
+     * @param[in]  target Target to create context for
+     * @param[out] status Status information if requested
+     */
+    explicit Context(Target target, StatusCode *status = nullptr)
+        : Context(target, Options(), status)
+    {
+    }
+    /** Constructor
+     *
+     * @param[in]  target  Target to create context for
+     * @param[in]  options Context construction options
+     * @param[out] status  Status information if requested
+     */
+    Context(Target target, const Options &options, StatusCode *status = nullptr)
+    {
+        AclContext ctx;
+        const auto st = detail::as_enum<StatusCode>(AclCreateContext(&ctx, detail::as_cenum<AclTarget>(target), &options.opts));
+        reset(ctx);
+        report_status(st, "Failure during context creation");
+        if(status)
+        {
+            *status = st;
+        }
+    }
+};
+} // namespace acl
+#undef ARM_COMPUTE_IGNORE_UNUSED
+#endif /* ARM_COMPUTE_ACL_HPP_ */