WebSVN - shark - Blame - Rev 1658 - /unsupported/trunk/first/iqueue.h

Rev	Author	Line No.	Line
1658	giacomo	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 2004-06-01 11:42:43 giacomo Exp $
		22
		23	File: $File$
		24	Revision: $Revision: 1.1 $
		25	Last update: $Date: 2004-06-01 11:42:43 $
		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 <kernel/const.h>
		72	#include <kernel/types.h>
		73	#include <sys/types.h>
		74
		75	#define IQUEUE_NO_PRIORITY 1
		76	#define IQUEUE_NO_TIMESPEC 2
		77
		78	struct IQUEUE_shared {
		79	PID prev[MAX_PROC];
		80	PID next[MAX_PROC];
		81	struct timespec *timespec_priority;
		82	DWORD *priority;
		83	};
		84
		85	typedef struct {
		86	PID first;
		87	PID last;
		88	struct IQUEUE_shared *s;
		89	} IQUEUE;
		90
		91
		92
		93	/* Internal queue initialization:
		94
		95	share = &x -> the internal data structure of the IQUEUE x is used
		96	to enqueue the tasks.
		97
		98	share = NULL -> an internal data structure to handle prev/next
		99	pairs is dynamically allocated (The amount of
		100	memory that is allocated can be reduced using the
		101	flags).
		102
		103	flags can be used to reduce the memory usage of an IQUEUE when share=NULL:
		104	IQUEUE_NO_PRIORITY -> the iqueue do not provide internally a priority field
		105	IQUEUE_NO_TIMESPEC -> the iqueue do not provide internally a timespec field
		106
		107	- note that, if these flags are used, the corresponding insert
		108	functions will not work!
		109	- the default value for the flags is, of course, 0
		110	*/
		111	void iq_init (IQUEUE q, IQUEUE share, int flags);
		112
		113	/* Queue insert functions:
		114
		115	- inserts a p into the q. p must not be already inserted into q.
		116	- four versions of the function;
		117	- iq_priority_insert -> ordered insertion using the priority field
		118	- iq_timespec_insert -> ordered insertion using the timespec field
		119	- iq_insertfirst -> insert at the first position of the queue
		120	- iq_insertlast -> insert at the last position of the queue
		121	*/
		122	void iq_priority_insert (PID p, IQUEUE *q);
		123	void iq_timespec_insert (PID p, IQUEUE *q);
		124	void iq_insertfirst (PID p, IQUEUE *q);
		125	void iq_insertlast (PID p, IQUEUE *q);
		126
		127	/* Queue extract functions:
		128
		129	- extracts a task p from the queue q.
		130	- three versions of the function;
		131	- iq_extract -> extracts given a task p
		132	(that must be inserted in the queue)
		133
		134	- iq_getfirst -> extracts the first task in the queue,
		135	NIL if the queue is empty
		136
		137	- iq_getlast -> extracts the last task in the queue,
		138	NIL if the queue is empty
		139
		140	*/
		141	void iq_extract (PID p, IQUEUE *q);
		142	PID iq_getfirst ( IQUEUE *q);
		143	PID iq_getlast ( IQUEUE *q);
		144
		145
		146	/* Queue query functions:
		147
		148	The first two functions return the first and the last task in the queue,
		149	NIL if the queue is empty.
		150
		151	The second two functions can be used to get/set the priority or the
		152	timespec field used when queuing.
		153	*/
		154	static __inline__ PID iq_queryfirst(IQUEUE *q)
		155	{
		156	return q->first;
		157	}
		158
		159	static __inline__ PID iq_querylast(IQUEUE *q)
		160	{
		161	return q->last;
		162	}
		163
		164	static __inline__ struct timespec iq_query_timespec(PID p, IQUEUE q)
		165	{
		166	return &q->s->timespec_priority[p];
		167	}
		168
		169	static __inline__ DWORD iq_query_priority (PID p, IQUEUE q)
		170	{
		171	return &q->s->priority[p];
		172	}

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