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32 lines
837 B
32 lines
837 B
#include "alloc.h"
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#include "error.h"
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//extern char *malloc();
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//extern void free();
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#define ALIGNMENT 16 /* XXX: assuming that this alignment is enough */
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#define SPACE 4096 /* must be multiple of ALIGNMENT */
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typedef union { char irrelevant[ALIGNMENT]; double d; } aligned;
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static aligned realspace[SPACE / ALIGNMENT];
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#define space ((char *) realspace)
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static unsigned int avail = SPACE; /* multiple of ALIGNMENT; 0<=avail<=SPACE */
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/*@null@*//*@out@*/char *alloc(n)
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unsigned int n;
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{
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char *x;
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n = ALIGNMENT + n - (n & (ALIGNMENT - 1)); /* XXX: could overflow */
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if (n <= avail) { avail -= n; return space + avail; }
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x = malloc(n);
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if (!x) errno = error_nomem;
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return x;
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}
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void alloc_free(x)
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char *x;
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{
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if (x >= space)
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if (x < space + SPACE)
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return; /* XXX: assuming that pointers are flat */
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free(x);
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}
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