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/*
* Copyright (C) 2013-2014 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors:
* José Bollo <jose.bollo@open.eurogiciel.org>
* Stéphane Desneux <stephane.desneux@open.eurogiciel.org>
* Jean-Benoit Martin <jean-benoit.martin@open.eurogiciel.org>
*
*/
#define _GNU_SOURCE
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <sys/mman.h>
#include "heap.h"
/* align to a size_t size */
inline static size_t align(size_t size)
{
/* we assume that sizeof(size_t) is a power of 2 */
assert( (sizeof(size_t) & (sizeof(size_t)-1)) == 0 );
return (size + (sizeof(size_t)-1)) & ~(sizeof(size_t)-1);
}
/* align to a page size */
inline static size_t pagealign( size_t size)
{
static size_t pagemask = 0;
/* we assume that pagesize is a power of 2 */
if (!pagemask) {
pagemask = (size_t)sysconf(_SC_PAGE_SIZE) - 1;
assert( pagemask );
assert( (pagemask & (pagemask+1)) == 0 );
}
return (size + pagemask) & ~pagemask;
}
int heap_create( struct heap *heap, size_t capacity)
{
char *data;
/* allocation of the heap */
capacity = pagealign(capacity ? capacity : 1);
data = mmap(NULL, capacity, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
/* success of the allocation? */
if (data == MAP_FAILED)
return -1;
/* yes. initialisae the heap */
heap->data = data;
heap->capacity = capacity;
heap->size = 0;
return 0;
}
int heap_destroy( struct heap *heap)
{
return munmap( heap->data, heap->capacity);
}
int heap_resize( struct heap *heap, size_t size)
{
/* has heap enought data? */
if (size > heap->capacity) {
/* no. resizing of the heap. */
/* compute the sizes and realloc */
size_t capa = pagealign(size);
char *data = mremap(heap->data, heap->capacity, capa, MREMAP_MAYMOVE);
/* error if failure */
if (data == MAP_FAILED)
return -1;
/* record new parameters. */
heap->data = data;
heap->capacity = capa;
}
heap->size = size;
return 0;
}
size_t heap_alloc( struct heap *heap, size_t count)
{
size_t result = heap->size;
if( heap_resize( heap, align( result + count)) != 0)
result = HNULL;
return result;
}
size_t heap_strndup( struct heap *heap, const char *value, size_t length)
{
size_t offset;
char *string;
offset = heap_alloc( heap, length+1);
if (offset != HNULL) {
string = heap_address( heap, offset);
memcpy( string, value, length);
string[length] = 0;
}
return offset;
}
size_t heap_strdup( struct heap *heap, const char *string)
{
return heap_strndup( heap, string, strlen(string));
}
int heap_read_write( struct heap *heap)
{
return mprotect(heap->data, heap->capacity, PROT_READ|PROT_WRITE);
}
int heap_read_only( struct heap *heap)
{
return mprotect(heap->data, heap->capacity, PROT_READ);
}
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