Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/nsgmls/Allocator.C

@@ -0,0 +1,105 @@
+/* $XConsortium: Allocator.C /main/1 1996/07/29 16:45:56 cde-hp $ */
+// Copyright (c) 1994 James Clark
+// See the file COPYING for copying permission.
+
+#include "splib.h"
+#include "Allocator.h"
+#include "macros.h"
+
+#ifdef SP_NAMESPACE
+namespace SP_NAMESPACE {
+#endif
+
+Allocator::Allocator(size_t maxSize, unsigned blocksPerSegment)
+: objectSize_(maxSize),
+  blocksPerSegment_(blocksPerSegment),
+  freeList_(0),
+  segments_(0)
+{
+}
+
+Allocator::~Allocator()
+{
+  SegmentHeader *p = segments_;
+  while (p) {
+    SegmentHeader *tem = p->next;
+    if (p->liveCount == 0)
+      ::operator delete(p);
+    else
+      p->freeList = 0;
+    p = tem;
+  }
+}
+
+void *Allocator::alloc(size_t sz)
+{
+  if (sz > objectSize_)
+    tooBig(sz);
+  Block *tem = freeList_;
+  if (tem) {
+    tem->header.seg->liveCount += 1;
+    freeList_ = tem->next;
+    return &(tem->next);
+  }
+  else
+    return alloc1();
+}
+
+void *Allocator::allocSimple(size_t sz)
+{
+  BlockHeader *p = (BlockHeader *)::operator new(sz + sizeof(BlockHeader));
+  p->seg = 0;
+  return p + 1;
+}
+
+void Allocator::free(void *p)
+{
+  BlockHeader *b = ((BlockHeader *)p) - 1;
+  SegmentHeader *seg = b->seg;
+  if (seg == 0)
+    ::operator delete(b);
+  else {
+    Block **freeList = seg->freeList;
+    if (freeList == 0) {
+      seg->liveCount -= 1;
+      if (seg->liveCount == 0)
+	::operator delete(seg);
+    }
+    else {
+      ((Block *)b)->next = *freeList;
+      *freeList = (Block *)b;
+      seg->liveCount -= 1;
+    }
+  }
+}
+
+void *Allocator::alloc1()
+{
+  SegmentHeader *seg
+    = (SegmentHeader *)::operator new(sizeof(SegmentHeader)
+				      + ((objectSize_ + sizeof(BlockHeader))
+					 * blocksPerSegment_));
+  seg->next = segments_;
+  segments_ = seg;
+  seg->liveCount = 1;
+  seg->freeList = &freeList_;
+  char *p = (char *)(seg + 1);
+  Block *head = 0;
+  for (size_t n = blocksPerSegment_; n > 0; n--) {
+    ((Block *)p)->next = head;
+    ((Block *)p)->header.seg = seg;
+    head = (Block *)p;
+    p += sizeof(BlockHeader) + objectSize_;
+  }
+  freeList_ = head->next;
+  return &(head->next);
+}
+
+void Allocator::tooBig(size_t sz)
+{
+  ASSERT(sz <= objectSize_);
+}
+
+#ifdef SP_NAMESPACE
+}
+#endif