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/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. 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 PX4 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 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.
*
****************************************************************************/
/**
* @file state_table.h
*
* Finite-State-Machine helper class for state table
*/
#ifndef __SYSTEMLIB_STATE_TABLE_H
#define __SYSTEMLIB_STATE_TABLE_H
class StateTable
{
public:
typedef void (StateTable::*Action)();
struct Tran {
Action action;
unsigned nextState;
};
StateTable(Tran const *table, unsigned nStates, unsigned nSignals)
: myTable(table), myNsignals(nSignals), myNstates(nStates) {}
#define NO_ACTION &StateTable::doNothing
#define ACTION(_target) static_cast<StateTable::Action>(_target)
virtual ~StateTable() {}
void dispatch(unsigned const sig) {
register Tran const *t = myTable + myState*myNsignals + sig;
(this->*(t->action))();
myState = t->nextState;
}
void doNothing() {}
protected:
unsigned myState;
private:
Tran const *myTable;
unsigned myNsignals;
unsigned myNstates;
};
#endif
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