Subversion Repositories HelenOS

Compare Revisions

Regard whitespace Rev 4717 → Rev 4718

/branches/network/uspace/lib/libc/generic/as.c
38,11 → 38,10
#include <align.h>
#include <sys/types.h>
#include <bitops.h>
#include <malloc.h>
 
/**
* Either 4*256M on 32-bit architecures or 16*256M on 64-bit architectures.
*/
#define MAX_HEAP_SIZE (sizeof(uintptr_t)<<28)
/** Last position allocated by as_get_mappable_page */
static uintptr_t last_allocated = 0;
 
/** Create address space area.
*
51,6 → 50,7
* @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)
{
65,7 → 65,8
* @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.
* @return zero on success or a code from @ref errno.h on failure.
*
*/
int as_area_resize(void *address, size_t size, int flags)
{
78,7 → 79,8
* @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.
* @return zero on success or a code from @ref errno.h on failure.
*
*/
int as_area_destroy(void *address)
{
91,7 → 93,8
* modified.
* @param flags New flags describing type of the area.
*
* @return Zero on success or a code from @ref errno.h on failure.
* @return zero on success or a code from @ref errno.h on failure.
*
*/
int as_area_change_flags(void *address, int flags)
{
99,101 → 102,29
(sysarg_t) flags);
}
 
static size_t heapsize = 0;
static size_t maxheapsize = (size_t) (-1);
 
static void *last_allocated = 0;
 
/* Start of heap linker symbol */
extern char _heap;
 
/** Sbrk emulation
*
* @param incr 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) && (((size_t) -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;
/* Check for user limit */
if ((maxheapsize != (size_t) (-1)) && (heapsize + incr) > maxheapsize)
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;
}
 
/** Set maximum heap size and return pointer just after the heap */
void *set_maxheapsize(size_t mhs)
{
maxheapsize = mhs;
/* Return pointer to area not managed by sbrk */
return ((void *) &_heap + maxheapsize);
}
 
/** Return pointer to some unmapped area, where fits new as_area
*
* @param sz Requested size of the allocation.
* @param size Requested size of the allocation.
*
* @return Pointer to the beginning
* @return pointer to the beginning
*
* TODO: make some first_fit/... algorithm, we are now just incrementing
* the pointer to last area
*/
void *as_get_mappable_page(size_t sz)
void *as_get_mappable_page(size_t size)
{
void *res;
uint64_t asz;
int i;
if (!sz)
if (size == 0)
return NULL;
 
asz = 1 << (fnzb64(sz - 1) + 1);
size_t sz = 1 << (fnzb(size - 1) + 1);
if (last_allocated == 0)
last_allocated = get_max_heap_addr();
 
/* Set heapsize to some meaningful value */
if (maxheapsize == (size_t) -1)
set_maxheapsize(MAX_HEAP_SIZE);
/*
* Make sure we allocate from naturally aligned address.
*/
i = 0;
if (!last_allocated) {
last_allocated = (void *) ALIGN_UP((void *) &_heap +
maxheapsize, asz);
} else {
last_allocated = (void *) ALIGN_UP(((uintptr_t)
last_allocated) + (int) (i > 0), asz);
}
uintptr_t res = ALIGN_UP(last_allocated, sz);
last_allocated = res + ALIGN_UP(size, PAGE_SIZE);
 
res = last_allocated;
last_allocated += ALIGN_UP(sz, PAGE_SIZE);
 
return res;
return ((void *) res);
}
 
/** @}