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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <sys/sysmacros.h>
#include "vmem_base.h"
#define ALLOC_PROT PROT_READ | PROT_WRITE | PROT_EXEC
#define FREE_PROT PROT_NONE
#define ALLOC_FLAGS MAP_PRIVATE | MAP_ANON
#define FREE_FLAGS MAP_PRIVATE | MAP_ANON | MAP_NORESERVE
#define CHUNKSIZE (64*1024) /* 64 kilobytes */
static vmem_t *mmap_heap;
static void *
vmem_mmap_alloc(vmem_t *src, size_t size, int vmflags)
{
void *ret;
int old_errno = errno;
ret = vmem_alloc(src, size, vmflags);
if (ret != NULL &&
mmap(ret, size, ALLOC_PROT, ALLOC_FLAGS | MAP_FIXED, -1, 0) ==
MAP_FAILED) {
vmem_free(src, ret, size);
vmem_reap();
ASSERT((vmflags & VM_NOSLEEP) == VM_NOSLEEP);
errno = old_errno;
return (NULL);
}
errno = old_errno;
return (ret);
}
static void
vmem_mmap_free(vmem_t *src, void *addr, size_t size)
{
int old_errno = errno;
(void) mmap(addr, size, FREE_PROT, FREE_FLAGS | MAP_FIXED, -1, 0);
vmem_free(src, addr, size);
errno = old_errno;
}
static void *
vmem_mmap_top_alloc(vmem_t *src, size_t size, int vmflags)
{
void *ret;
void *buf;
int old_errno = errno;
ret = vmem_alloc(src, size, VM_NOSLEEP);
if (ret) {
errno = old_errno;
return (ret);
}
/*
* Need to grow the heap
*/
buf = mmap((void *)CHUNKSIZE, size, FREE_PROT, FREE_FLAGS | MAP_ALIGN,
-1, 0);
if (buf != MAP_FAILED) {
ret = _vmem_extend_alloc(src, buf, size, size, vmflags);
if (ret != NULL)
return (ret);
else {
(void) munmap(buf, size);
errno = old_errno;
return (NULL);
}
} else {
/*
* Growing the heap failed. The allocation above will
* already have called umem_reap().
*/
ASSERT((vmflags & VM_NOSLEEP) == VM_NOSLEEP);
errno = old_errno;
return (NULL);
}
}
vmem_t *
vmem_mmap_arena(vmem_alloc_t **a_out, vmem_free_t **f_out)
{
size_t pagesize = sysconf(_SC_PAGESIZE);
if (mmap_heap == NULL) {
mmap_heap = vmem_init("mmap_top", CHUNKSIZE,
vmem_mmap_top_alloc, vmem_free,
"mmap_heap", NULL, 0, pagesize,
vmem_mmap_alloc, vmem_mmap_free);
}
if (a_out != NULL)
*a_out = vmem_mmap_alloc;
if (f_out != NULL)
*f_out = vmem_mmap_free;
return (mmap_heap);
}
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