rstplib/statmch.c

   1 /************************************************************************
   2  * RSTP library - Rapid Spanning Tree (802.1t, 802.1w)
   3  * Copyright (C) 2001-2003 Optical Access
   4  * Author: Alex Rozin
   5  *
   6  * This file is part of RSTP library.
   7  *
   8  * RSTP library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by the
  10  * Free Software Foundation; version 2.1
  11  *
  12  * RSTP library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with RSTP library; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  **********************************************************************/
  22
  23 /* Generic (abstract) state machine : 17.13, 17.14 */
  24
  25 #include "base.h"
  26 #include "statmch.h"
  27
  28 #if STP_DBG
  29 #  include "stpm.h"
  30 #endif
  31
  32 STATE_MACH_T *
  33 STP_state_mach_create (void (*concreteEnterState) (STATE_MACH_T*),
  34                        Bool (*concreteCheckCondition) (STATE_MACH_T*),
  35                        char *(*concreteGetStatName) (int),
  36                        void *owner, char *name)
  37 {
  38   STATE_MACH_T *this;
  39
  40   STP_MALLOC(this, STATE_MACH_T, "state machine");
  41
  42   this->State = BEGIN;
  43   this->name = (char*) strdup (name);
  44   this->changeState = False;
  45 #if STP_DBG
  46   this->debug = False;
  47   this->ignoreHop2State = BEGIN;
  48 #endif
  49   this->concreteEnterState = concreteEnterState;
  50   this->concreteCheckCondition = concreteCheckCondition;
  51   this->concreteGetStatName = concreteGetStatName;
  52   this->owner.owner = owner;
  53
  54   return this;
  55 }
  56
  57 void
  58 STP_state_mach_delete (STATE_MACH_T *this)
  59 {
  60   free (this->name);
  61   STP_FREE(this, "state machine");
  62 }
  63
  64 Bool
  65 STP_check_condition (STATE_MACH_T* this)
  66 {
  67   Bool bret;
  68
  69   bret = (*(this->concreteCheckCondition)) (this);
  70   if (bret) {
  71     this->changeState = True;
  72   }
  73
  74   return bret;
  75 }
  76
  77 Bool
  78 STP_change_state (STATE_MACH_T* this)
  79 {
  80   register int number_of_loops;
  81
  82   for (number_of_loops = 0; ; number_of_loops++) {
  83     if (! this->changeState) return number_of_loops;
  84     (*(this->concreteEnterState)) (this);
  85     this->changeState = False;
  86     STP_check_condition (this);
  87   }
  88
  89   return number_of_loops;
  90 }
  91
  92 Bool
  93 STP_hop_2_state (STATE_MACH_T* this, unsigned int new_state)
  94 {
  95 #ifdef STP_DBG
  96   switch (this->debug) {
  97     case 0: break;
  98     case 1:
  99       if (new_state == this->State || new_state == this->ignoreHop2State) break;
 100       stp_trace ("%-8s(%s-%s): %s=>%s",
 101         this->name,
 102         *this->owner.port->owner->name ? this->owner.port->owner->name : "Glbl",
 103         this->owner.port->port_name,
 104         (*(this->concreteGetStatName)) (this->State),
 105         (*(this->concreteGetStatName)) (new_state));
 106       break;
 107     case 2:
 108       if (new_state == this->State) break;
 109       stp_trace ("%s(%s): %s=>%s",
 110         this->name,
 111         *this->owner.stpm->name ? this->owner.stpm->name : "Glbl",
 112         (*(this->concreteGetStatName)) (this->State),
 113         (*(this->concreteGetStatName)) (new_state));
 114       break;
 115   }
 116 #endif
 117
 118   this->State = new_state;
 119   this->changeState = True;
 120   return True;
 121 }
 122