heap.h

rtai-3.1-test3的源代码(Real-Time Application Interface )

/*
 * Copyright (C) 2001,2002,2003 Philippe Gerum <[e-mail]>.
 *
 * Xenomai 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.
 *
 * Xenomai 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 Xenomai; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * As a special exception, the RTAI project gives permission
 * for additional uses of the text contained in its release of
 * Xenomai.
 *
 * The exception is that, if you link the Xenomai libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Xenomai libraries code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public
 * License.
 *
 * This exception applies only to the code released by the
 * RTAI project under the name Xenomai.  If you copy code from other
 * RTAI project releases into a copy of Xenomai, as the General Public
 * License permits, the exception does not apply to the code that you
 * add in this way.  To avoid misleading anyone as to the status of
 * such modified files, you must delete this exception notice from
 * them.
 *
 * If you write modifications of your own for Xenomai, it is your
 * choice whether to permit this exception to apply to your
 * modifications. If you do not wish that, delete this exception
 * notice.
 */

#ifndef _xenomai_heap_h
#define _xenomai_heap_h

#include "xenomai/mutex.h"

/*
 * CONSTRAINTS:
 *
 * Minimum page size is 2 ** XNHEAP_MINLOG2 (must be large enough to
 * hold a pointer).
 *
 * Maximum page size is 2 ** XNHEAP_MAXLOG2.
 *
 * Minimum block size equals the minimum page size.
 *
 * Requested block size smaller than the minimum block size is
 * rounded to the minimum block size.
 *
 * Requested block size larger than 2 times the page size is rounded
 * to the next page boundary and obtained from the free page
 * list. So we need a bucket for each power of two between
 * XNHEAP_MINLOG2 and XNHEAP_MAXLOG2 inclusive, plus one to honor
 * requests ranging from the maximum page size to twice this size.
 */

#define	XNHEAP_MINLOG2    3
#define	XNHEAP_MAXLOG2    22
#define	XNHEAP_MINALLOCSZ (1 << XNHEAP_MINLOG2)
#define	XNHEAP_MINALIGNSZ (1 << (XNHEAP_MINLOG2 + 1))
#define	XNHEAP_NBUCKETS   (XNHEAP_MAXLOG2 - XNHEAP_MINLOG2 + 2)
#define	XNHEAP_MAXEXTSZ   (1 << 24) /* i.e. 16Mo */

#define XNHEAP_PFREE   0
#define XNHEAP_PCONT   1
#define XNHEAP_PLIST   2

typedef struct xnextent {

    xnholder_t link;

#define link2extent(laddr) \
((xnextent_t *)(((char *)laddr) - (int)(&((xnextent_t *)0)->link)))

    caddr_t membase,	/* Base address of the page array */
	    memlim,	/* Memory limit of page array */
	    freelist;	/* Head of the free page list */

    u_char pagemap[1];	/* Beginning of page map */

} xnextent_t;

/* Creation flag */
#define XNHEAP_EXTENDABLE 0x1

/* Allocation flags */
#define XNHEAP_WAIT       0x0
#define XNHEAP_NOWAIT     0x1

typedef struct xnheap {

    xnflags_t flags;

    xnmutex_t mutex;

    u_long extentsize,
           pagesize,
           pageshift,
	   hdrsize,
	   npages,	/* Number of pages per extent */
	   ubytes,
           maxcont;

    xnqueue_t extents;

    caddr_t buckets[XNHEAP_NBUCKETS];

    XNARCH_DECL_DISPLAY_CONTEXT();

} xnheap_t;

extern xnheap_t kheap;

#define xnheap_page_size(heap)      ((heap)->pagesize)
#define xnheap_page_count(heap)     ((heap)->npages)
#define xnheap_used_mem(heap)       ((heap)->ubytes)

#ifdef __cplusplus
extern "C" {
#endif

int xnheap_init(xnheap_t *heap,
		void *heapaddr,
		u_long heapsize,
		u_long pagesize);

void xnheap_destroy(xnheap_t *heap);

void *xnheap_alloc(xnheap_t *heap,
		   u_long size,
		   xnflags_t flags);

int xnheap_free(xnheap_t *heap,
		void *block);

#ifdef __cplusplus
}
#endif

#endif /* !_xenomai_heap_h */