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/* Copyright (c) 1991 Regents of the University of California */
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#ifndef lint
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static char SCCSid[] = "$SunId$ LBL";
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#endif
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/*
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* Bmalloc provides basic memory allocation without overhead (no free lists).
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* Use only to take the load off of malloc for all those
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* piddling little requests that you never expect to free.
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* Bmalloc defers to malloc for big requests.
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* Bfree should hand memory to bmalloc, but it usually fails here.
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*/
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#define NULL 0
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#ifndef MBLKSIZ
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#define MBLKSIZ 16376 /* size of memory allocation block */
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#endif
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#define WASTEFRAC 12 /* don't waste more than a fraction */
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#ifndef ALIGN
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#define ALIGN int /* type for alignment */
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#endif
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#define BYTES_WORD sizeof(ALIGN)
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extern char *malloc();
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static char *bposition = NULL;
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static unsigned nremain = 0;
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char *
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bmalloc(n) /* allocate a block of n bytes, no refunds */
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register unsigned n;
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{
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if (n > nremain && (n > MBLKSIZ || nremain > MBLKSIZ/WASTEFRAC))
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return(malloc(n)); /* too big */
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n = (n+(BYTES_WORD-1))&~(BYTES_WORD-1); /* word align */
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if (n > nremain) {
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if ((bposition = malloc((unsigned)MBLKSIZ)) == NULL) {
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nremain = 0;
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return(NULL);
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}
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nremain = MBLKSIZ;
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}
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bposition += n;
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nremain -= n;
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return(bposition - n);
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}
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bfree(p, n) /* free random memory */
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register char *p;
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register unsigned n;
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{
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register unsigned bsiz;
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/* check alignment */
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bsiz = BYTES_WORD - ((unsigned)p&(BYTES_WORD-1));
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if (bsiz < BYTES_WORD) {
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p += bsiz;
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n -= bsiz;
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}
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if (p + n == bposition) { /* just allocated? */
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bposition = p;
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nremain += n;
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return;
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}
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if (n > nremain) { /* better than what we've got? */
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bposition = p;
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nremain = n;
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return;
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}
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/* just throw it away, then */
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}
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