| 1 | #include "alloc.h" |
| 2 | #include "error.h" |
| 3 | extern char *malloc(); |
| 4 | extern void free(); |
| 5 | |
| 6 | #define ALIGNMENT 16 /* XXX: assuming that this alignment is enough */ |
| 7 | #define SPACE 4096 /* must be multiple of ALIGNMENT */ |
| 8 | |
| 9 | typedef union { char irrelevant[ALIGNMENT]; double d; } aligned; |
| 10 | static aligned realspace[SPACE / ALIGNMENT]; |
| 11 | #define space ((char *) realspace) |
| 12 | static unsigned int avail = SPACE; /* multiple of ALIGNMENT; 0<=avail<=SPACE */ |
| 13 | |
| 14 | /*@null@*//*@out@*/char *alloc(n) |
| 15 | unsigned int n; |
| 16 | { |
| 17 | char *x; |
| 18 | n = ALIGNMENT + n - (n & (ALIGNMENT - 1)); /* XXX: could overflow */ |
| 19 | if (n <= avail) { avail -= n; return space + avail; } |
| 20 | x = malloc(n); |
| 21 | if (!x) errno = error_nomem; |
| 22 | return x; |
| 23 | } |
| 24 | |
| 25 | void alloc_free(x) |
| 26 | char *x; |
| 27 | { |
| 28 | if (x >= space) |
| 29 | if (x < space + SPACE) |
| 30 | return; /* XXX: assuming that pointers are flat */ |
| 31 | free(x); |
| 32 | } |