WebSVN - shark - Blame - Rev 29 - /shark/branches/xen/include/kernel/iqueue.h

Rev	Author	Line No.	Line
29	pj	1	/*
		2	* Project: S.Ha.R.K.
		3	*
		4	* Coordinators:
		5	* Giorgio Buttazzo <giorgio@sssup.it>
		6	* Paolo Gai <pj@gandalf.sssup.it>
		7	*
		8	* Authors :
		9	* Paolo Gai <pj@gandalf.sssup.it>
		10	* (see the web pages for full authors list)
		11	*
		12	* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
		13	*
		14	* http://www.sssup.it
		15	* http://retis.sssup.it
		16	* http://shark.sssup.it
		17	*/
		18
		19	/*
		20	------------
		21	CVS : $Id: iqueue.h,v 1.1 2002-11-11 08:36:01 pj Exp $
		22
		23	File: $File$
		24	Revision: $Revision: 1.1 $
		25	Last update: $Date: 2002-11-11 08:36:01 $
		26	------------
		27
		28	*/
		29
		30	/*
		31	* Copyright (C) 2002 Paolo Gai
		32	*
		33	* This program is free software; you can redistribute it and/or modify
		34	* it under the terms of the GNU General Public License as published by
		35	* the Free Software Foundation; either version 2 of the License, or
		36	* (at your option) any later version.
		37	*
		38	* This program is distributed in the hope that it will be useful,
		39	* but WITHOUT ANY WARRANTY; without even the implied warranty of
		40	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		41	* GNU General Public License for more details.
		42	*
		43	* You should have received a copy of the GNU General Public License
		44	* along with this program; if not, write to the Free Software
		45	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		46	*
		47	*/
		48
		49
		50	/*
		51	IQUEUEs
		52
		53	This file contains functions that helps to manage task queues.
		54
		55	These functions are different from the functions that manages the
		56	QUEUE and QQUEUE types. In particular, these functions no more relies
		57	on the prev & next fields of the task descriptor. In that way, tasks
		58	can be inserted in more than one queue at a time.
		59
		60	Basically, an IQUEUE has an "I"nternal prev/next structure, that may
		61	be shared between one or more queue. Of course, the user MUST
		62	guarantee that the same task will not be inserted in two IQUEUEs that
		63	share the same prev/next buffer.
		64
		65	The queue insertion is made by the following functions:
		66	iq_insert -> insertion based on the priority field.
		67	iq_timespec_insert -> same as above but use the timespec_priority field
		68	iq_insertfirst -> insert in the first position of the queue
		69	*/
		70
		71	#include <ll/ll.h>
		72	#include <kernel/const.h>
		73	#include <kernel/types.h>
		74
		75	#ifndef __KERNEL_IQUEUE_H__
		76	#define __KERNEL_IQUEUE_H__
		77
		78	#define IQUEUE_NO_PRIORITY 1
		79	#define IQUEUE_NO_TIMESPEC 2
		80
		81	struct IQUEUE_shared {
		82	PID prev[MAX_PROC];
		83	PID next[MAX_PROC];
		84	struct timespec *timespec_priority;
		85	DWORD *priority;
		86	};
		87
		88	typedef struct {
		89	PID first;
		90	PID last;
		91	struct IQUEUE_shared *s;
		92	} IQUEUE;
		93
		94
		95
		96	/* Internal queue initialization:
		97
		98	share = &x -> the internal data structure of the IQUEUE x is used
		99	to enqueue the tasks.
		100
		101	share = NULL -> an internal data structure to handle prev/next
		102	pairs is dynamically allocated (The amount of
		103	memory that is allocated can be reduced using the
		104	flags).
		105
		106	flags can be used to reduce the memory usage of an IQUEUE when share=NULL:
		107	IQUEUE_NO_PRIORITY -> the iqueue do not provide internally a priority field
		108	IQUEUE_NO_TIMESPEC -> the iqueue do not provide internally a timespec field
		109
		110	- note that, if these flags are used, the corresponding insert
		111	functions will not work!
		112	- the default value for the flags is, of course, 0
		113	*/
		114	void iq_init (IQUEUE q, IQUEUE share, int flags);
		115
		116	/* Queue insert functions:
		117
		118	- inserts a p into the q. p must not be already inserted into q.
		119	- four versions of the function;
		120	- iq_priority_insert -> ordered insertion using the priority field
		121	- iq_timespec_insert -> ordered insertion using the timespec field
		122	- iq_insertfirst -> insert at the first position of the queue
		123	- iq_insertlast -> insert at the last position of the queue
		124	*/
		125	void iq_priority_insert (PID p, IQUEUE *q);
		126	void iq_timespec_insert (PID p, IQUEUE *q);
		127	void iq_insertfirst (PID p, IQUEUE *q);
		128	void iq_insertlast (PID p, IQUEUE *q);
		129
		130	/* Queue extract functions:
		131
		132	- extracts a task p from the queue q.
		133	- three versions of the function;
		134	- iq_extract -> extracts given a task p
		135	(that must be inserted in the queue)
		136
		137	- iq_getfirst -> extracts the first task in the queue,
		138	NIL if the queue is empty
		139
		140	- iq_getlast -> extracts the last task in the queue,
		141	NIL if the queue is empty
		142
		143	*/
		144	void iq_extract (PID p, IQUEUE *q);
		145	PID iq_getfirst ( IQUEUE *q);
		146	PID iq_getlast ( IQUEUE *q);
		147
		148
		149	/* Queue query functions:
		150
		151	The first two functions return the first and the last task in the queue,
		152	NIL if the queue is empty.
		153
		154	The second two functions can be used to get/set the priority or the
		155	timespec field used when queuing.
		156	*/
		157	static __inline__ PID iq_query_first(IQUEUE *q)
		158	{
		159	return q->first;
		160	}
		161
		162	static __inline__ PID iq_query_last(IQUEUE *q)
		163	{
		164	return q->last;
		165	}
		166
		167	static __inline__ struct timespec iq_query_timespec(PID p, IQUEUE q)
		168	{
		169	return &q->s->timespec_priority[p];
		170	}
		171
		172	static __inline__ DWORD iq_query_priority (PID p, IQUEUE q)
		173	{
		174	return &q->s->priority[p];
		175	}
		176
		177	/* Queue iterators */
		178
		179	/* sometimes it is useful to go through the list. For that reason
		180	You can use the following two functions... */
		181	static __inline__ PID iq_query_next (PID p, IQUEUE *q)
		182	{
		183	return q->s->next[p];
		184	}
		185
		186	static __inline__ PID iq_query_prev (PID p, IQUEUE *q)
		187	{
		188	return q->s->prev[p];
		189	}
		190
		191	/* Queue test functions */
		192	static __inline__ int iq_isempty (IQUEUE *q)
		193	{
		194	return q->first == NIL;
		195	}
		196
		197	#endif

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