timer.c

EGui是一个开源的图形系统软件,类似于QT/Embedded、GTK-FB、MicroWindow。目标是嵌入式平台整合解 决方案。基于Linux Framebuffer 设备驱动上实现。有完

/********************************************************
 * Egui code,LGPL
 * Function : Timer for EGui 
 * Author: [e-mail]
 * Data : 2006-03-15
 * $Id: timer.c,v 1.7 2006/04/13 22:52:54 baozheng Exp $
 ********************************************************/
/*
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                          _ )_( _
                        /`_) H (_`\
                      .' (  { }  ) '.
                    _/ /` '-'='-' `\ \_
                   [_.'   _,...,_   '._]
                    |   .:"`````":.   |
                    |__//_________\\__|
                     | .-----------. |
                     | |  .-"""-.  | |
                     | | /    /  \ | |
                     | ||-   <   -|| |
                     | | \    \  / | |
                     | |[`'-...-'`]| |
                     | | ;-.___.-; | |
                     | | |  |||  | | |
                     | | |  |||  | | |
                     | | |  |||  | | |
                     | | |  |||  | | |
                     | | |  |||  | | |
                     | | | _|||_ | | |
                     | | | >===< | | |
                     | | | |___| | | |
                     | | |  |||  | | |
                     | | |  ;-;  | | |
                     | | | (   ) | | |
                     | | |  '-'  | | |
                     | | '-------' | |
                    _| '-----------' |_
                   [= === === ==== == =]
                   [__--__--___--__--__]
                  /__-___-___-___-___-__\
                 `"""""""""""""""""""""""`
 */


#include <stdio.h>
#include <stdlib.h>

#include <Egui.h>

#define GET_MS(sec)  (1*(sec))

egui_timer_list_t    egui_timer_list_table={(egui_timer_t*)&egui_timer_list_table,
					    (egui_timer_t*)&egui_timer_list_table};
egui_timer_list_t    *egui_timer_list=&egui_timer_list_table;

void
Egui_timer_init()
{
    gettimeofday (&(egui_timer_list->start_msec), NULL);
    gettimeofday (&(egui_timer_list->last_msec), NULL);
   
}


/* allocate and initialize a new timer node */
egui_timer_t *Egui_timer_new()
{
    egui_timer_t  *new_timer;

    new_timer = (egui_timer_t *)malloc (sizeof(egui_timer_t));

    new_timer -> prev		= NULL;
    new_timer -> next		= NULL;
    new_timer -> delta_interval	= 0;
    new_timer -> function	= NULL;
    new_timer -> parameter	= NULL;

    return new_timer;
}

void Egui_timer_free(egui_timer_t *p_timer)
{
    free(p_timer);
}

/*
  insert interval=3:        3
  insert interval=4:        3 -> 1
  insert interval=4:        3 -> 1 -> 0
  insert interval=8:        3 -> 1 -> 0 -> 4
  insert interval=10:       3 -> 1 -> 0 -> 4 -> 2
  insert interval=2:        2 -> 1 -> 1 -> 0 -> 4 -> 2
  
 */
void Egui_timer_insert(unsigned int interval,
		       timer_callback_t function,
		       unsigned int *para)
{
    egui_timer_t  *new_timer, *index;
    unsigned int  delta_interval;

    new_timer		= Egui_timer_new();
    
    new_timer ->function	= function;
    new_timer ->parameter	= para; 
    /* search the whole list, insert the whole list at a proper position */
    for(index = ((egui_timer_t *)egui_timer_list)->next, delta_interval = GET_MS(interval);
	;
	index = index->next)
    {
	if (delta_interval == 0 || /* we have got it, it is "<0" probably */
	    (index==(egui_timer_t *)egui_timer_list))	/* end of whole list */
	    break;
	if ( delta_interval < index->delta_interval ) /* we've got it */
	{
	    index->delta_interval -= delta_interval;
	    break;
	}
	delta_interval -= index->delta_interval;
    }
    /* got it, didnt we? */
    new_timer ->delta_interval	= delta_interval;
    /* insert before index */
    new_timer ->prev	= index->prev;
    new_timer ->next	= index;
    index->prev->next	= new_timer;
    index->prev		= new_timer;
}

static unsigned int
get_elapse()
{
    struct timeval	current;
    struct timeval	elapsed;

    gettimeofday (&current, NULL);
    if (egui_timer_list->last_msec.tv_usec >
	current.tv_usec)
    {
	current.tv_usec += 1000000;
	current.tv_sec--;
    }
    elapsed.tv_sec = current.tv_sec - egui_timer_list->last_msec.tv_sec;
    elapsed.tv_usec = current.tv_usec - egui_timer_list->last_msec.tv_usec;
    /* update the timer */
    egui_timer_list->last_msec = current;

    return (elapsed.tv_sec * 1000) + (elapsed.tv_usec / 1000);
}

/*
 
 */
void Egui_timer_handler()
{
    egui_timer_t	*index, *tmp;
    signed int		elapsed_time;

    /* if the whole list is empty, return */
    elapsed_time = 0 - get_elapse();

    for(index = ((egui_timer_t *)egui_timer_list)->next;
	index!=(egui_timer_t *)egui_timer_list;
	tmp = index,  index = index->next, Egui_timer_free(tmp))
    {
	elapsed_time += index->delta_interval;

	if (elapsed_time > 0)
	{
	    index->delta_interval = elapsed_time;
	    break;		/* we still have to wait. */
	}
	/* got one, delete it from the queue. */
	egui_timer_list->first	= index->next;
	index->next->prev		= (egui_timer_t *)egui_timer_list;
	if (index->function)
	    index->function (index->parameter);

    }
}