prseg.c

Netscape NSPR库源码

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape Portable Runtime (NSPR).
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s):
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 */

#include "primpl.h"

#if defined(_PR_PTHREADS)

/*
** The pthreads version doesn't use these functions.
*/
void _PR_InitSegs(void)
{
}

#else /* _PR_PTHREADS */

void _PR_InitSegs(void)
{
	_PR_MD_INIT_SEGS();
}

/*
** Allocate a memory segment. The size value is rounded up to the native
** system page size and a page aligned portion of memory is returned.
** This memory is not part of the malloc heap. If "vaddr" is not NULL
** then PR tries to allocate the segment at the desired virtual address.
*/
PRSegment* _PR_NewSegment(PRUint32 size, void *vaddr)
{
    PRSegment *seg;

	/* calloc the data structure for the segment */
    seg = PR_NEWZAP(PRSegment);

    if (seg) {
	    size = ((size + _pr_pageSize - 1) >> _pr_pageShift) << _pr_pageShift;
		/*
		**	Now, allocate the actual segment memory (or map under some OS)
		**	The OS specific code decides from where or how to allocate memory.
		*/
	    if (_PR_MD_ALLOC_SEGMENT(seg, size, vaddr) != PR_SUCCESS) {
			PR_DELETE(seg);
			return NULL;
    	}
	}

    return seg;
}

/*
** Free a memory segment.
*/
void _PR_DestroySegment(PRSegment *seg)
{
	_PR_MD_FREE_SEGMENT(seg);
    PR_DELETE(seg);
}

#endif /* _PR_PTHREADS */