rt-thread-official/src/clock.c

123 lines
3.0 KiB
C

/*
* File : clock.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2006-03-12 Bernard first version
* 2006-05-27 Bernard add support for same priority thread schedule
* 2006-08-10 Bernard remove the last rt_schedule in rt_tick_increase
* 2010-03-08 Bernard remove rt_passed_second
* 2010-05-20 Bernard fix the tick exceeds the maximum limits
* 2010-07-13 Bernard fix rt_tick_from_millisecond issue found by kuronca
* 2011-06-26 Bernard add rt_tick_set function.
*/
#include <rthw.h>
#include <rtthread.h>
static rt_tick_t rt_tick = 0;
extern void rt_timer_check(void);
/**
* This function will init system tick and set it to zero.
* @ingroup SystemInit
*
* @deprecated since 1.1.0, this function does not need to be invoked
* in the system initialization.
*/
void rt_system_tick_init(void)
{
}
/**
* @addtogroup Clock
*/
/**@{*/
/**
* This function will return current tick from operating system startup
*
* @return current tick
*/
rt_tick_t rt_tick_get(void)
{
/* return the global tick */
return rt_tick;
}
RTM_EXPORT(rt_tick_get);
/**
* This function will set current tick
*/
void rt_tick_set(rt_tick_t tick)
{
rt_base_t level;
level = rt_hw_interrupt_disable();
rt_tick = tick;
rt_hw_interrupt_enable(level);
}
/**
* This function will notify kernel there is one tick passed. Normally,
* this function is invoked by clock ISR.
*/
void rt_tick_increase(void)
{
struct rt_thread *thread;
/* increase the global tick */
++ rt_tick;
/* check time slice */
thread = rt_thread_self();
-- thread->remaining_tick;
if (thread->remaining_tick == 0)
{
/* change to initialized tick */
thread->remaining_tick = thread->init_tick;
/* yield */
rt_thread_yield();
}
/* check timer */
rt_timer_check();
}
/**
* This function will calculate the tick from millisecond.
*
* @param ms the specified millisecond
*
* @return the calculated tick
*/
rt_tick_t rt_tick_from_millisecond(rt_uint32_t ms)
{
/* return the calculated tick */
return (RT_TICK_PER_SECOND * ms + 999) / 1000;
}
RTM_EXPORT(rt_tick_from_millisecond);
/**@}*/