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Ignore whitespace Rev 1967 → Rev 1968

/tags/0.1.1/uspace/libc/generic/as.c
0,0 → 1,106
/*
* Copyright (C) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
 
#include <as.h>
#include <libc.h>
#include <unistd.h>
#include <kernel/mm/as_arg.h>
#include <task.h>
 
/** Create address space area.
*
* @param address Virtual address where to place new address space area.
* @param size Size of the area.
* @param flags Flags describing type of the area.
*
* @return address on success, (void *) -1 otherwise.
*/
void *as_area_create(void *address, size_t size, int flags)
{
return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
 
/** Resize address space area.
*
* @param address Virtual address pointing into already existing address space area.
* @param size New requested size of the area.
* @param flags Currently unused.
*
* @return Zero on success or a code from @ref errno.h on failure.
*/
int as_area_resize(void *address, size_t size, int flags)
{
return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
 
/** Destroy address space area.
*
* @param address Virtual address pointing into the address space area being destroyed.
*
* @return Zero on success or a code from @ref errno.h on failure.
*/
int as_area_destroy(void *address)
{
return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t ) address);
}
 
static size_t heapsize = 0;
/* Start of heap linker symbol */
extern char _heap;
 
/** Sbrk emulation
*
* @param size New area that should be allocated or negative,
if it should be shrinked
* @return Pointer to newly allocated area
*/
void *sbrk(ssize_t incr)
{
int rc;
void *res;
/* Check for invalid values */
if (incr < 0 && -incr > heapsize)
return NULL;
/* Check for too large value */
if (incr > 0 && incr+heapsize < heapsize)
return NULL;
/* Check for too small values */
if (incr < 0 && incr+heapsize > heapsize)
return NULL;
 
rc = as_area_resize(&_heap, heapsize + incr,0);
if (rc != 0)
return NULL;
/* Compute start of new area */
res = (void *)&_heap + heapsize;
 
heapsize += incr;
 
return res;
}