timer.c

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/*
This file is part of CanFestival, a library implementing CanOpen Stack. 

Copyright (C): Edouard TISSERANT and Francis DUPIN

See COPYING file for copyrights details.

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
*/
/* #define DEBUG_WAR_CONSOLE_ON */
/* #define DEBUG_ERR_CONSOLE_ON */

#include <applicfg.h>
#include "timer.h"

/*  ---------  The timer table --------- */
s_timer_entry timers[MAX_NB_TIMER] = {{TIMER_FREE, NULL, NULL, 0, 0, 0},};

TIMEVAL total_sleep_time = TIMEVAL_MAX;
TIMER_HANDLE last_timer_raw = -1;

#define min_val(a,b) ((a<b)?a:b)

TIMER_HANDLE SetAlarm(CO_Data* d, UNS32 id, TimerCallback_t callback, TIMEVAL value, TIMEVAL period)
{
        /*printf("SetAlarm(UNS32 id=%d, TimerCallback_t callback=%x, TIMEVAL value=%d, TIMEVAL period=%d)\n", id, callback, value, period); */
        TIMER_HANDLE i;
        TIMER_HANDLE row_number = TIMER_NONE;

        /* in order to decide new timer setting we have to run over all timer rows */
        for(i=0; i <= last_timer_raw + 1 && i < MAX_NB_TIMER; i++)
        {
                s_timer_entry *row = (timers+i);

                if (callback &&         /* if something to store */
                   row->state == TIMER_FREE) /* and empty row */
                {       /* just store */
                        row->callback = callback;
                        row->d = d;
                        row->id = id;
                        row->val = value;
                        row->interval = period;
                        row->state = TIMER_ARMED;
                        row_number = i;
                        break;
                }
        }
        
        if (row_number != TIMER_NONE) /* if successfull **/
        {
                TIMEVAL real_timer_value;
                TIMEVAL elapsed_time;
                
                if (row_number == last_timer_raw + 1) last_timer_raw++;
                
                /* set next wakeup alarm if new entry is sooner than others, or if it is alone */
                real_timer_value = min_val(value, TIMEVAL_MAX);
                elapsed_time = getElapsedTime();

                /*printf("elapsed_time=%d real_timer_value=%d total_sleep_time=%d\n", elapsed_time, real_timer_value, total_sleep_time); */
                if (total_sleep_time > elapsed_time && total_sleep_time - elapsed_time > real_timer_value)
                {
                        total_sleep_time = elapsed_time + real_timer_value;
                        setTimer(real_timer_value);
                }
                /*printf("SetAlarm() return %d\n", row_number); */
                return row_number;
        }
        return TIMER_NONE;
}

TIMER_HANDLE DelAlarm(TIMER_HANDLE handle)
{
        /* Quick and dirty. system timer will continue to be trigged, but no action will be preformed. */
        MSG_WAR(0x3320, "DelAlarm. handle = ", handle);
        if(handle != TIMER_NONE)
        {
                if(handle == last_timer_raw) 
                        last_timer_raw--;
                timers[handle].state = TIMER_FREE;              
        }
        else {
        }
        return TIMER_NONE;
}

void TimeDispatch()
{
        TIMER_HANDLE i;
        TIMEVAL next_wakeup = TIMEVAL_MAX; /* used to compute when should normaly occur next wakeup */
        /* First run : change timer state depending on time */
        /* Get time since timer signal */
        TIMEVAL overrun = getElapsedTime();
        
        TIMEVAL real_total_sleep_time = total_sleep_time + overrun;
        /*printf("total_sleep_time %d + overrun %d\n", total_sleep_time , overrun); */

        for(i=0; i <= last_timer_raw; i++)
        {
                s_timer_entry *row = (timers+i);

                if (row->state & TIMER_ARMED) /* if row is active */
                {
                        if (row->val <= real_total_sleep_time) /* to be trigged */
                        {
                                /*printf("row->val(%d) <= (%d)real_total_sleep_time\n", row->val, real_total_sleep_time); */
                                if (!row->interval) /* if simply outdated */
                                {
                                        row->state = TIMER_TRIG; /* ask for trig */
                                }
                                else /* or period have expired */
                                {
                                        /* set val as interval, with overrun correction */
                                        row->val = row->interval - (overrun % row->interval);
                                        row->state = TIMER_TRIG_PERIOD; /* ask for trig, periodic */
                                        /* Check if this new timer value is the soonest */
                                        next_wakeup = min_val(row->val,next_wakeup);
                                }
                        }
                        else
                        {
                                /* Each armed timer value in decremented. */
                                row->val -= real_total_sleep_time;

                                /* Check if this new timer value is the soonest */
                                next_wakeup = min_val(row->val,next_wakeup);
                        }
                }
        }
        
        /* Remember how much time we should sleep. */
        total_sleep_time = next_wakeup;

        /* Set timer to soonest occurence */
        setTimer(next_wakeup);

        /* Then trig them or not. */
        for(i=0; i<=last_timer_raw; i++)
        {
                s_timer_entry *row = (timers+i);

                if (row->state & TIMER_TRIG)
                {
                        row->state &= ~TIMER_TRIG; /* reset trig state (will be free if not periodic) */
                        if(row->callback)
                                (*row->callback)(row->d, row->id); /* trig ! */
                }
        }
}

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