Permalink
Fetching contributors…
Cannot retrieve contributors at this time
33 lines (28 sloc) 827 Bytes
#include "alloc.h"
#include "error.h"
extern char *malloc();
extern void free();
#define ALIGNMENT 16 /* XXX: assuming that this alignment is enough */
#define SPACE 4096 /* must be multiple of ALIGNMENT */
typedef union { char irrelevant[ALIGNMENT]; double d; } aligned;
static aligned realspace[SPACE / ALIGNMENT];
#define space ((char *) realspace)
static unsigned int avail = SPACE; /* multiple of ALIGNMENT; 0<=avail<=SPACE */
/*@null@*//*@out@*/char *alloc(n)
unsigned int n;
{
char *x;
n = ALIGNMENT + n - (n & (ALIGNMENT - 1)); /* XXX: could overflow */
if (n <= avail) { avail -= n; return space + avail; }
x = malloc(n);
if (!x) errno = error_nomem;
return x;
}
void alloc_free(x)
char *x;
{
if (x >= space)
if (x < space + SPACE)
return; /* XXX: assuming that pointers are flat */
free(x);
}