jehanne/sys/src/libc/9sys/sbrk.c

45 lines
854 B
C

/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <libc.h>
extern char end[];
static char *bloc = { end };
extern int brk_(void*);
enum
{
Round = 7
};
int
brk(void *p)
{
uintptr bl;
bl = ((uintptr)p + Round) & ~Round;
if(brk_((void*)bl) < 0)
return -1;
bloc = (char*)bl;
return 0;
}
void*
sbrk(uint32_t n)
{
uintptr bl;
bl = ((uintptr)bloc + Round) & ~Round;
if(brk_((void*)(bl+n)) < 0)
return (void*)-1;
bloc = (char*)bl + n;
return (void*)bl;
}