src/core/common/context.hpp

/*
 *  Copyright (c) 2017, The OpenThread Authors.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file
 *   This file includes definitions for maintaining a pointer to arbitrary context information.
 */

#ifndef CONTEXT_HPP_
#define CONTEXT_HPP_

#include <openthread/config.h>
#include <openthread/platform/toolchain.h>

#include "openthread-core-config.h"

namespace ot {

/**
 * @addtogroup core-context
 *
 * @brief
 *   This module includes definitions for maintaining a pointer to arbitrary context information.
 *
 * @{
 *
 */

/**
 * This class implements definitions for maintaining a pointer to arbitrary context information.
 *
 * This is used as base class for objects that provide a callback or handler (e.g., Timer or Tasklet).
 *
 */
class Context
{
public:

#if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
    /**
     * This method returns the pointer to the arbitrary context information.
     *
     * @returns The pointer to the context information.
     *
     */
    void *GetContext(void) const { return mContext; }
#endif

protected:
    /**
     * This constructor initializes the context object.
     *
     * @param[in]  aContext    A pointer to arbitrary context information.
     *
     */
    Context(void *aContext)
#if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
        : mContext(aContext)
#endif
    {
        OT_UNUSED_VARIABLE(aContext);
    }

private:
#if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
    void *mContext;
#endif
};

/**
 * @}
 *
 */

}  // namespace ot

#endif  // CONTEXT_HPP_