ipc.c.svn-base

RT-Thread是发展中的下一代微内核嵌入式实时操作系统

/*
 * File      : ipc.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.fayfayspace.org/license/LICENSE.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-03-14     Bernard      the first version
 * 2006-04-25     Bernard      implement semaphore
 * 2006-05-03     Bernard      add IPC_DEBUG
 *                             modify the type of IPC waiting time to rt_int32
 * 2006-05-10     Bernard      fix the semaphore take bug and add IPC object
 * 2006-05-12     Bernard      implement mailbox and message queue
 * 2006-05-20     Bernard      implement mutex
 * 2006-05-23     Bernard      implement fast event
 * 2006-05-24     Bernard      implement event
 * 2006-06-03     Bernard      fix the thread timer init bug
 * 2006-06-05     Bernard      fix the mutex release bug
 * 2006-06-07     Bernard      fix the message queue send bug
 */

#include <rtthread.h>
#include <rthw.h>

#include "kservice.h"

/**
 * @addtogroup Kernel
 */
/*@{*/

// #define IPC_DEBUG

rt_inline rt_err_t rt_ipc_object_init(struct rt_ipc_object *ipc)
{
	/* init ipc object */
	rt_list_init(&(ipc->suspend_thread));
	ipc->suspend_thread_count = 0;

	return RT_EOK;
}

rt_inline rt_err_t rt_ipc_object_suspend(struct rt_ipc_object *ipc, struct rt_thread *thread)
{
	/* suspend thread */
	rt_thread_suspend(thread);
	ipc->suspend_thread_count ++;

	switch (ipc->parent.flag)
	{
	case RT_IPC_FLAG_FIFO:
		rt_list_insert_after(&(ipc->suspend_thread), &(thread->tlist));
		break;

	case RT_IPC_FLAG_PRIO:
		{
			struct rt_list_node* n;
			struct rt_thread* sthread;

			/* find a suitable position */
			for (n = ipc->suspend_thread.next; n != &(ipc->suspend_thread); n = n->next)
			{
				sthread = rt_list_entry(n, struct rt_thread, tlist);

				/* find out */
				if (thread->current_priority < sthread->current_priority) break;
			}

			rt_list_insert_before(&(ipc->suspend_thread), &(thread->tlist));
		}
		break;
	}

	return RT_EOK;
}

rt_inline rt_err_t rt_ipc_object_resume(struct rt_ipc_object* ipc)
{
	struct rt_thread *thread;

	/* get thread entry */
	thread = rt_list_entry(ipc->suspend_thread.next, struct rt_thread, tlist);

#ifdef IPC_DEBUG
	rt_kprintf("resume thread:%s\n", thread->name);
#endif

	/* resume it */
	rt_thread_resume(thread);

	/* decrease suspended thread count */
	ipc->suspend_thread_count --;

	return RT_EOK;
}

rt_inline rt_err_t rt_ipc_object_resume_all(struct rt_ipc_object* ipc)
{
	struct rt_thread* thread;
	register rt_ubase_t temp;

	/* wakeup all suspend threads */
	while (!rt_list_isempty(&(ipc->suspend_thread)))
	{
		/* disable interrupt */
		temp = rt_hw_interrupt_disable();

		/* get next suspend thread */
		thread = rt_list_entry(ipc->suspend_thread.next, struct rt_thread, tlist);
		/* set error code to RT_ERROR */
		thread->error = -RT_ERROR;

		/*
		 * resume thread
		 * In rt_thread_resume function, it will remove current thread from suspend
		 * list
		 */
		rt_thread_resume(thread);

		/* decrease suspended thread count */
		ipc->suspend_thread_count --;

		/* enable interrupt */
		rt_hw_interrupt_enable(temp);
	}

	return RT_EOK;
}

#ifdef RT_USING_SEMAPHORE

/**
 * @brief init a semaphore
 *
 * This function will init a semaphore
 *
 * @param sem the semaphore handler
 * @param name the name of semaphore
 * @param value the init value of semaphore
 * @param flag the flag of semaphore
 *
 * @return the created semaphore, RT_NULL on error hanpen
 *
 * @see rt_sem_init
 */
rt_err_t rt_sem_init (rt_sem_t sem, const char* name, rt_uint32 value, rt_uint8 flag)
{
	RT_ASSERT(sem != RT_NULL);

	/* init object */
	rt_object_init(&(sem->parent.parent), RT_Object_Class_Semaphore, name);

	/* init ipc object */
	rt_ipc_object_init(&(sem->parent));

	/* set init value */
	sem->value	= value;

	/* set parent */
	sem->parent.parent.flag = flag;

	return RT_EOK;
}

/**
 * @brief detach a semaphore
 *
 * This function will detach a semaphore from resource management
 *
 * @param sem the semaphore handler
 *
 * @return the error code
 *
 * @see rt_sem_delete
 */
rt_err_t rt_sem_detach (rt_sem_t sem)
{
	RT_ASSERT(sem != RT_NULL);

	/* wakeup all suspend threads */
	rt_ipc_object_resume_all(&(sem->parent));

	/* detach semaphore object */
	rt_object_detach(&(sem->parent.parent));

	return RT_EOK;
}

/**
 * @brief create a semaphore
 *
 * This function will create a semaphore from system resource
 *
 * @param name the name of semaphore
 * @param value the init value of semaphore
 * @param flag the flag of semaphore
 *
 * @return the created semaphore, RT_NULL on error hanpen
 *
 * @see rt_sem_init
 */
rt_sem_t rt_sem_create (const char* name, rt_uint32 value, rt_uint8 flag)
{
	rt_sem_t sem;

	/* allocate object */
	sem = (rt_sem_t) rt_object_allocate(RT_Object_Class_Semaphore, name);
	if (sem == RT_NULL) return sem;

	/* init ipc object */
	rt_ipc_object_init(&(sem->parent));

	/* set init value */
	sem->value	= value;

	/* set parent */
	sem->parent.parent.flag = flag;

	return sem;
}

/**
 * @brief delete a semaphore
 *
 * This function will delete a semaphore and release the system resource
 *
 * @param sem the semaphore handler
 *
 * @return the error code
 *
 * @see rt_sem_detach
 */
rt_err_t rt_sem_delete (rt_sem_t sem)
{
	RT_ASSERT(sem != RT_NULL);

	/* wakeup all suspend threads */
	rt_ipc_object_resume_all(&(sem->parent));

	/* delete semaphore object */
	rt_object_delete(&(sem->parent.parent));

	return RT_EOK;
}

/**
 * @brief take a semaphore
 *
 * This function will take a semaphore, if the semaphore is
 * unavailable, the thread shall wait for a specify time.
 *
 * @param sem the semaphore handler
 * @param time the waiting time
 *
 * @return the error code
 */
rt_err_t rt_sem_take (rt_sem_t sem, rt_int32 time)
{
	register rt_base_t temp;
	struct rt_thread* thread;

	RT_ASSERT(sem != RT_NULL);

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

#ifdef IPC_DEBUG
	rt_kprintf("sem_take:sem value: %d\n", sem->value);
#endif
	if (sem->value > 0)
	{
		/* semaphore is available */
		sem->value --;

		/* enable interrupt */
		rt_hw_interrupt_enable(temp);
	}
	else
	{
		/* no waiting, return with timeout */
		if (time == 0 )
		{
			rt_hw_interrupt_enable(temp);
			return -RT_ETIMEOUT;
		}
		else
		{
			/* semaphore is unavailable, push to suspend list */
			sem->value --;

			/* get current thread */
			thread = rt_thread_self();

			/* reset thread error number */
			thread->error = RT_EOK;

#ifdef IPC_DEBUG
			rt_kprintf("sem take: suspend thread - %s\n", thread->name);
#endif

			/* suspend thread */
			rt_ipc_object_suspend(&(sem->parent), thread);

			/* has waiting time, start thread timer */
			if (time > 0)
			{
#ifdef IPC_DEBUG
				rt_kprintf("set thread:%s to timer list\n", thread->name);
#endif
				/* reset the timeout of thread timer and start it */
				rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &time);
				rt_timer_start(&(thread->thread_timer));
			}

			/* enable interrupt */
			rt_hw_interrupt_enable(temp);

			/* do schedule */
			rt_schedule();

			if (thread->error != RT_EOK)
			{
				return thread->error;
			}
		}
	}

	return RT_EOK;
}

/**
 * @brief try to take a semaphore
 *
 * This function will try to take a semaphore and immediately return
 *
 * @param sem the semaphore handler
 *
 * @return the error code
 */
rt_err_t rt_sem_trytake(rt_sem_t sem)
{
	return rt_sem_take(sem, 0);
}

/**
 * @brief release a semaphore
 *
 * This function will release a semaphore
 *
 * @param sem the semaphore handler
 *
 * @return the error code
 */
rt_err_t rt_sem_release(rt_sem_t sem)
{
	register rt_base_t temp;

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

#ifdef IPC_DEBUG
	rt_kprintf("sem_release:sem value(%d)\n", sem->value);
#endif
	if (sem->value <= 0 && sem->parent.suspend_thread_count > 0)
	{
		rt_ipc_object_resume(&(sem->parent));
	}

	/* increase value */
	sem->value ++;

	/* enable interrupt */
	rt_hw_interrupt_enable(temp);

	rt_schedule();

	return RT_EOK;
}

/**
 * @brief control a semaphore execution
 *
 * This function can get or set some extra attribute of a semaphore
 *
 * @param sem the semaphore handler
 * @param cmd the execution command
 * @param arg the execution argument
 *
 * @return the error code
 */
rt_err_t rt_sem_control(rt_sem_t sem, rt_uint8 cmd, void* arg)
{
	return RT_EOK;
}

#endif /* end of RT_USING_SEMAPHORE */

#ifdef RT_USING_MUTEX

rt_err_t rt_mutex_init (rt_mutex_t mutex, const char* name, rt_uint8 flag)
{
	RT_ASSERT(mutex != RT_NULL);

	/* init object */
	rt_object_init(&(mutex->parent.parent), RT_Object_Class_Mutex, name);

	/* init ipc object */
	rt_ipc_object_init(&(mutex->parent));

	mutex->value = 1;
	mutex->owner = RT_NULL;
	mutex->original_priority = 0xFF;
	mutex->hold  = 0;

	/* set flag */
	mutex->parent.parent.flag = flag;

	return RT_EOK;
}

rt_err_t rt_mutex_detach (rt_mutex_t mutex)
{
	RT_ASSERT(mutex != RT_NULL);

	/* wakeup all suspend threads */
	rt_ipc_object_resume_all(&(mutex->parent));

	/* detach semaphore object */
	rt_object_detach(&(mutex->parent.parent));

	return RT_EOK;
}

rt_mutex_t rt_mutex_create (const char* name, rt_uint8 flag)
{
	struct rt_mutex *mutex;

	/* allocate object */
	mutex = (rt_mutex_t) rt_object_allocate(RT_Object_Class_Mutex, name);
	if (mutex == RT_NULL) return mutex;

	/* init ipc object */
	rt_ipc_object_init(&(mutex->parent));

	mutex->value = 1;
	mutex->owner = RT_NULL;
	mutex->original_priority = 0xFF;
	mutex->hold  = 0;

	/* set flag */
	mutex->parent.parent.flag = flag;

	return mutex;
}

rt_err_t rt_mutex_delete (rt_mutex_t mutex)
{
	RT_ASSERT(mutex != RT_NULL);

	/* wakeup all suspend threads */
	rt_ipc_object_resume_all(&(mutex->parent));

	/* delete semaphore object */
	rt_object_delete(&(mutex->parent.parent));

	return RT_EOK;
}

rt_err_t rt_mutex_take (rt_mutex_t mutex, rt_int32 time)
{
	register rt_base_t temp;
	struct rt_thread* thread;

	RT_ASSERT(mutex != RT_NULL);

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

#ifdef IPC_DEBUG
	rt_kprintf("mutex_take:mutex value: %d, hold: %d\n", mutex->value, mutex->hold);
#endif

	/* get current thread */
	thread = rt_thread_self();

	/* reset thread error */
	thread->error = RT_EOK;

	if (mutex->owner == thread)
	{
		/* it's the same thread */
		mutex->hold ++;
	}
	else
	{
		if (mutex->value > 0)
		{
			/* mutex is available */
			mutex->value --;

			/* set mutex owner and original priority */
			mutex->owner = thread;
			mutex->original_priority = thread->current_priority;
			mutex->hold ++;
		}
		else
		{
			/* no waiting, return with timeout */
			if (time == 0 )
			{
				/* set error as timeout */
				thread->error = -RT_ETIMEOUT;

				/* enable interrupt */
				rt_hw_interrupt_enable(temp);

				return -RT_ETIMEOUT;
			}
			else
			{
				/* mutex is unavailable, push to suspend list */
				mutex->value --;

#ifdef IPC_DEBUG
				rt_kprintf("sem take: suspend thread: %s\n", thread->name);
#endif
				/* change the owner thread priority of mutex */
				if (thread->current_priority < mutex->owner->current_priority)
				{
					/* change the owner thread priority */
					rt_thread_control(mutex->owner, RT_THREAD_CTRL_CHANGE_PRIORITY,
						&thread->current_priority);
				}

				/* suspend current thread */
				rt_ipc_object_suspend(&(mutex->parent), thread);

				/* has waiting time, start thread timer */
				if (time > 0)
				{
#ifdef IPC_DEBUG
					rt_kprintf("set thread:%s to timer list\n", thread->name);
#endif
					/* reset the timeout of thread timer and start it */
					rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &time);
					rt_timer_start(&(thread->thread_timer));
				}

				/* enable interrupt */
				rt_hw_interrupt_enable(temp);

				/* do schedule */
				rt_schedule();

				if (thread->error != RT_EOK)
				{
					/* return error */
					return thread->error;
				}
				else
				{
					/* disable interrupt */
					temp = rt_hw_interrupt_disable();

					/* take mutex */