88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
#
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/*
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*/
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/*
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* Structure of the coremap and swapmap
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* arrays. Consists of non-zero count
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* and base address of that many
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* contiguous units.
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* (The coremap unit is 64 bytes,
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* the swapmap unit is 512 bytes)
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* The addresses are increasing and
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* the list is terminated with the
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* first zero count.
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*/
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struct map
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{
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char *m_size;
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char *m_addr;
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};
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/*
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* Allocate size units from the given
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* map. Return the base of the allocated
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* space.
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* Algorithm is first fit.
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*/
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malloc(mp, size)
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struct map *mp;
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{
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register int a;
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register struct map *bp;
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for (bp = mp; bp->m_size; bp++) {
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if (bp->m_size >= size) {
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a = bp->m_addr;
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bp->m_addr =+ size;
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if ((bp->m_size =- size) == 0)
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do {
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bp++;
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(bp-1)->m_addr = bp->m_addr;
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} while ((bp-1)->m_size = bp->m_size);
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return(a);
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}
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}
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return(0);
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}
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/*
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* Free the previously allocated space aa
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* of size units into the specified map.
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* Sort aa into map and combine on
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* one or both ends if possible.
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*/
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mfree(mp, size, aa)
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struct map *mp;
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{
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register struct map *bp;
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register int t;
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register int a;
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a = aa;
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for (bp = mp; bp->m_addr<=a && bp->m_size!=0; bp++);
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if (bp>mp && (bp-1)->m_addr+(bp-1)->m_size == a) {
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(bp-1)->m_size =+ size;
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if (a+size == bp->m_addr) {
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(bp-1)->m_size =+ bp->m_size;
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while (bp->m_size) {
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bp++;
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(bp-1)->m_addr = bp->m_addr;
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(bp-1)->m_size = bp->m_size;
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}
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}
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} else {
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if (a+size == bp->m_addr && bp->m_size) {
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bp->m_addr =- size;
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bp->m_size =+ size;
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} else if (size) do {
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t = bp->m_addr;
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bp->m_addr = a;
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a = t;
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t = bp->m_size;
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bp->m_size = size;
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bp++;
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} while (size = t);
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}
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}
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