/*
 * Copyright (c) 2007 Jan Hudecek
 * Copyright (c) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup genericddi
 * @{
 */
/** @file
 */

#ifndef KERN_TASKLET_H_
#define KERN_TASKLET_H_

#include <arch/types.h>
#include <proc/task.h>



/** Structure describing a tasklet*/
typedef struct tasklet_descriptor {
 /** callback to call */
 void (*func)(void* data);
 /** parameters to pass to func */
 void* data;
 /** state of the tasklet one of tasklet_state_enum */
 uint32_t state; 
 struct tasklet_descriptor *next;
} tasklet_descriptor_t;

/** Initializes tasklets - except for the tasklet thread */
void tasklet_init(void);

/** 
* Creates and runs the tasklet thread 
*
*  @param kernel_task Pointer to the kernel task - for create_thread 
*/
void tasklet_run_tasklet_thread(task_t * kernel_task);

/** Thread which keeps executing scheduled enabled tasklets 
* @param data not used
*/
void tasklet_thread(void* data);


/** Executes scheduled enabled tasklets */
void tasklet_do(void);

/** Initializes tasklet structure 
* @param func tasklet callback function to be called 
* @param data pointer to be passed to the tasklet function
*/
tasklet_descriptor_t* tasklet_register(void (*func)(void* data), void* data);

/** Schedules the tasklet for execution on current CPU 
* @param t tasklet to be scheduled
*/
void tasklet_schedule(tasklet_descriptor_t* t);

/** Tasklet will not be run, even if scheduled 
* @param t tasklet to be disabled
*/
void tasklet_disable(tasklet_descriptor_t* t);

/** Tasklet will be run if scheduled 
* @param t tasklet to be enabled
*/
void tasklet_enable(tasklet_descriptor_t* t);

/** Frees the tasklet structure when no longer needed. The function doesn't provide 
*   any synchronization, the caller must be sure, the tasklet is not scheduled.
*
* @param tasklet to be freed
*/
void tasklet_free(tasklet_descriptor_t* t);


#endif

/** @}
 */