fsm_misc.c

一个有限状态机的实现源代码。C语言实现。

/*
  The oSIP library implements the Session Initiation Protocol (SIP -rfc2543-)
  Copyright (C) 2001  Aymeric MOIZARD [e-mail]
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library 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
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <stdio.h>

#include <osip/fifo.h>
#include <osip/osip.h>
#include <osip/port.h>
#include "fsm.h"


/* find the transition for state and type in statemachine */
/* return NULL; if transition is not found.               */
transition_t *
fsm_findmethod(type_t type,state_t state,statemachine_t *statemachine)
{
  int pos;
  pos = 0;
  while (!list_eol(statemachine->transitions,pos))
    {
      transition_t *transition;
      transition = (transition_t *)list_get(statemachine->transitions,pos);
      if (transition->type == type
	  && transition->state == state)
	return transition;
      pos++;
    }
  return NULL;
}


/* call the right execution method.          */
/*   return -1 when event must be discarded  */
int
fsm_callmethod(type_t type,state_t state,statemachine_t *statemachine,
	       void *sipevent,void *transaction)
{
  transition_t *transition;
  transition   = fsm_findmethod(type,state,statemachine);
  if (transition==NULL)
    {
      /* No transition found for this event */
      return -1; /* error */
    }
  transition->method(sipevent,transaction); 
  return 0; /* ok */
}