isci/scil/sci_base_state_machine.c

/*-
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * 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.
 *
 * 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
 * OWNER 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 INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/**
 * @file
 *
 * @brief This file contains all of the functionality common to all state
 *        machine object implementations.
 */

#include <dev/isci/scil/sci_base_state_machine.h>

#define SCI_STATE_MACHINE_EXIT_STATE(state_machine) \
   if ( \
       ((state_machine)->state_table[(state_machine)->current_state_id].\
          exit_state != NULL) \
      ) \
   { \
      ((state_machine)->state_table[(state_machine)->current_state_id].\
      exit_state((state_machine)->state_machine_owner)); \
   }

#define SCI_STATE_MACHINE_ENTER_STATE(state_machine) \
      ((state_machine)->state_table[(state_machine)->current_state_id].\
      enter_state((state_machine)->state_machine_owner))

#define SCI_STATE_MACHINE_SET_STATE(state_machine, id) \
   ((state_machine)->current_state_id = (id))

//******************************************************************************
//* P R O T E C T E D    M E T H O D S
//******************************************************************************

/**
 * @brief This method will set the initial state and state table
 *        for the state machine. The caller should follow this
 *        request with the initialize request to cause the state
 *        machine to start.
 *
 * @param[in] this_state_machine This parameter provides the state machine
 *            object to be constructed.
 * @param[in] state_machine_owner This parameter indicates the object that
 *            is owns the state machine being constructed.
 * @param[in] state_table This parameter specifies the table of state objects
 *            that is managed by this state machine.
 * @param[in] initial_state This parameter specifies the value of the initial
 *            state for this state machine.
 *
 * @return none
 */
void sci_base_state_machine_construct(
   SCI_BASE_STATE_MACHINE_T * this_state_machine,
   SCI_BASE_OBJECT_T        * my_state_machine_owner,
   SCI_BASE_STATE_T         * state_table,
   U32                        initial_state
)
{
#if defined(SCI_LOGGING)
   sci_base_subject_construct(&this_state_machine->parent);
#endif // defined(SCI_LOGGING)

   this_state_machine->state_machine_owner = my_state_machine_owner;
   this_state_machine->initial_state_id  = initial_state;
   this_state_machine->previous_state_id = initial_state;
   this_state_machine->current_state_id  = initial_state;
   this_state_machine->state_table       = state_table;
}

/**
 * @brief This method will cause the state machine to enter the
 *        initial state.
 *
 * @see sci_base_state_machine_construct() for how to set the initial state
 *
 * @param[in] this_state_machine This parameter specifies the state machine
 *            that is to be started.
 *
 * @return none
 */
void sci_base_state_machine_start(
   SCI_BASE_STATE_MACHINE_T *this_state_machine
)
{
   SCI_STATE_MACHINE_SET_STATE(
      this_state_machine, this_state_machine->initial_state_id
   );

#if defined(SCI_BASE_ENABLE_SUBJECT_NOTIFICATION)
   sci_base_subject_notify(&this_state_machine->parent);
#endif

   SCI_STATE_MACHINE_ENTER_STATE(this_state_machine);
}

/**
 * @brief This method will cause the state machine to exit it's current
 *        state only.
 *
 * @param[in] this_state_machine This parameter specifies the state machine
 *            that is to be stopped.
 *
 * @return none
 */
void sci_base_state_machine_stop(
   SCI_BASE_STATE_MACHINE_T *this_state_machine
)
{
   SCI_STATE_MACHINE_EXIT_STATE(this_state_machine);

#if defined(SCI_BASE_ENABLE_SUBJECT_NOTIFICATION)
   sci_base_subject_notify(&this_state_machine->parent);
#endif
}

/**
 * @brief This method performs an update to the current state of
 *        the state machine.
 *
 * @param[in] this_state_machine This parameter specifies the state machine
 *            for which the caller wishes to perform a state change.
 * @param[in] next_state This parameter specifies the new state for the
 *            state machine.
 *
 * @return none
 */
void sci_base_state_machine_change_state(
   SCI_BASE_STATE_MACHINE_T *this_state_machine,
   U32   next_state
)
{
   SCI_STATE_MACHINE_EXIT_STATE(this_state_machine);

   this_state_machine->previous_state_id = this_state_machine->current_state_id;
   SCI_STATE_MACHINE_SET_STATE(this_state_machine, next_state);

#if defined(SCI_BASE_ENABLE_SUBJECT_NOTIFICATION)
   // Notify of the state change prior to entering the state.
   sci_base_subject_notify(&this_state_machine->parent);
#endif

   SCI_STATE_MACHINE_ENTER_STATE(this_state_machine);
}

/**
 * @brief This method simply returns the current state of the
 *         state machine to the caller.
 *
 * @param[in] this_state_machine  This parameter specifies the state
 *            machine for which to retrieve the current state.
 *
 * @return This method returns a U32 value indicating the current state for
 *         the supplied state machine.
 */
U32 sci_base_state_machine_get_state(
   SCI_BASE_STATE_MACHINE_T *this_state_machine
)
{
   return this_state_machine->current_state_id;
}