104 lines
2 KiB
C++
104 lines
2 KiB
C++
// Copyright (c) 1994 James Clark
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// See the file COPYING for copying permission.
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#include "splib.h"
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#include "Allocator.h"
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#include "macros.h"
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#ifdef SP_NAMESPACE
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namespace SP_NAMESPACE {
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#endif
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Allocator::Allocator(size_t maxSize, unsigned blocksPerSegment)
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: objectSize_(maxSize),
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blocksPerSegment_(blocksPerSegment),
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freeList_(0),
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segments_(0)
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{
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}
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Allocator::~Allocator()
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{
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SegmentHeader *p = segments_;
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while (p) {
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SegmentHeader *tem = p->next;
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if (p->liveCount == 0)
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::operator delete(p);
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else
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p->freeList = 0;
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p = tem;
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}
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}
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void *Allocator::alloc(size_t sz)
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{
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if (sz > objectSize_)
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tooBig(sz);
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Block *tem = freeList_;
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if (tem) {
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tem->header.seg->liveCount += 1;
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freeList_ = tem->next;
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return &(tem->next);
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}
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else
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return alloc1();
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}
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void *Allocator::allocSimple(size_t sz)
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{
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BlockHeader *p = (BlockHeader *)::operator new(sz + sizeof(BlockHeader));
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p->seg = 0;
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return p + 1;
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}
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void Allocator::free(void *p)
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{
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BlockHeader *b = ((BlockHeader *)p) - 1;
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SegmentHeader *seg = b->seg;
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if (seg == 0)
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::operator delete(b);
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else {
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Block **freeList = seg->freeList;
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if (freeList == 0) {
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seg->liveCount -= 1;
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if (seg->liveCount == 0)
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::operator delete(seg);
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}
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else {
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((Block *)b)->next = *freeList;
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*freeList = (Block *)b;
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seg->liveCount -= 1;
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}
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}
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}
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void *Allocator::alloc1()
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{
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SegmentHeader *seg
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= (SegmentHeader *)::operator new(sizeof(SegmentHeader)
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+ ((objectSize_ + sizeof(BlockHeader))
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* blocksPerSegment_));
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seg->next = segments_;
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segments_ = seg;
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seg->liveCount = 1;
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seg->freeList = &freeList_;
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char *p = (char *)(seg + 1);
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Block *head = 0;
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for (size_t n = blocksPerSegment_; n > 0; n--) {
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((Block *)p)->next = head;
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((Block *)p)->header.seg = seg;
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head = (Block *)p;
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p += sizeof(BlockHeader) + objectSize_;
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}
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freeList_ = head->next;
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return &(head->next);
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}
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void Allocator::tooBig(size_t sz)
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{
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ASSERT(sz <= objectSize_);
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}
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#ifdef SP_NAMESPACE
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}
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#endif
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