irqtimers.c

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/*
 * irqtimers.c
 *
 *  Created on: 05-03-2011
 *      Author: lucck
 */
/*-----------------------------------------------------------------------*/
#include <prv/irqtimers.h>
#include <isix/irqtimers.h>
#include <isix/memory.h>
#include <prv/list.h>
#include <prv/scheduler.h>
#include <string.h>

/*-----------------------------------------------------------------------*/
#ifdef ISIX_CONFIG_USE_TIMERS   //If timers are enabled
/*-----------------------------------------------------------------------*/
//List entry for the virtual timers
static list_entry_t vtimer_list[2];
//Overflowed and not overflowed list
static list_entry_t *p_vtimer_list;
static list_entry_t *pov_vtimer_list;
/*-----------------------------------------------------------------------*/
//Initialize vtimers infrastructure
void isixp_vtimer_init(void)
{
        list_init( &vtimer_list[0] );
        list_init( &vtimer_list[1] );
        //Initialize overflow waiting list
        p_vtimer_list = &vtimer_list[0];
        pov_vtimer_list = &vtimer_list[1];
}

/*-----------------------------------------------------------------------*/
//Move selected task to waiting list
static void add_vtimer_to_list(vtimer_t *timer)
{
    //Scheduler lock
    isixp_enter_critical();
    timer->jiffies = isix_get_jiffies() + timer->timeout;
    if(timer->jiffies < isix_get_jiffies())
    {
        //Insert on overflow waiting list in time order
        vtimer_t *waitl;
        list_for_each_entry(pov_vtimer_list,waitl,inode)
        {
           if(timer->jiffies<waitl->jiffies) break;
        }
        list_insert_before(&waitl->inode,&timer->inode);
    }
    else
    {
        //Insert on waiting list in time order no overflow
        vtimer_t *waitl;
        list_for_each_entry(p_vtimer_list,waitl,inode)
        {
            if(timer->jiffies<waitl->jiffies) break;
        }
        list_insert_before(&waitl->inode,&timer->inode);
    }
    //Scheduler unlock
    isixp_exit_critical();
}

/*-----------------------------------------------------------------------*/
//Call timer funcs in the interrupt context
void isixp_vtimer_handle_time(tick_t jiffies)
{
        if(jiffies == 0)
        {
           list_entry_t *tmp = p_vtimer_list;
           p_vtimer_list = pov_vtimer_list;
           pov_vtimer_list = tmp;
        }
        vtimer_t *vtimer;
        while( !list_isempty(p_vtimer_list) &&
                        jiffies>=(vtimer = list_get_first(p_vtimer_list,inode,vtimer_t))->jiffies
              )
        {
                vtimer->timer_handler( vtimer->arg );
                list_delete(&vtimer->inode);
                add_vtimer_to_list(vtimer);
        }
}

/*-----------------------------------------------------------------------*/
//Create the virtual timer
vtimer_t* isix_vtimer_create(void (*func)(void*),void *arg )
{
        vtimer_t * const timer = (vtimer_t*)isix_alloc(sizeof(vtimer_t));
        if( func == NULL )  return NULL;
    if( timer == NULL ) return NULL;
    memset( timer, 0, sizeof(*timer) );
    timer->arg = arg;
    timer->timer_handler = func;
    return timer;
}

/*-----------------------------------------------------------------------*/
//Start the virtual timer
int isix_vtimer_start(vtimer_t* timer, tick_t timeout)
{
        if( timer == NULL ) return ISIX_EINVARG;
        isixp_enter_critical();
        //Search on ov list
        if( list_is_elem_assigned( &timer->inode ) )
        {
                list_delete( &timer->inode );
        }
        //Add timer to waiting list
        if( timeout > 0 )
        {
                timer->timeout = timeout;
                add_vtimer_to_list( timer );
        }
        isixp_exit_critical();
        return ISIX_EOK;
}

/*-----------------------------------------------------------------------*/
//Destroy the virtual timer
int isix_vtimer_destroy(vtimer_t* timer)
{
        if( timer == NULL ) return ISIX_EINVARG;
        isixp_enter_critical();
        if( list_is_elem_assigned( &timer->inode ) )
        {
                isixp_exit_critical();
                return ISIX_EBUSY;
        }
        isix_free( timer );
        isixp_exit_critical();
        return ISIX_EOK;
}
/*-----------------------------------------------------------------------*/


#endif /* ISIX_CONFIG_USE_TIMERS */