klish/lub/heap/heap_graft_to_top.c

#include <assert.h>

#include "private.h"

/*--------------------------------------------------------- */
void
lub_heap_graft_to_top(lub_heap_t * this,
		      lub_heap_block_t * free_block,
		      void *ptr,
		      words_t words, bool_t seg_end, bool_t other_free_block)
{
	lub_heap_tag_t *tail;

	assert(1 == free_block->free.tag.free);

	/* remove the previous block from the free tree */
	lub_bintree_remove(&this->free_tree, free_block);

	if (BOOL_FALSE == other_free_block) {
		tail = lub_heap_block__get_tail(free_block);
		/* 
		 * taint the memory being given back 
		 * NB. we don't bother to taint all the memory if we are
		 * combining two free blocks; they'll already be tainted.
		 */
		lub_heap_taint_memory((char *)tail,
				      LUB_HEAP_TAINT_FREE,
				      (words << 2) + sizeof(lub_heap_tag_t));
	} else {
		char *tmp = ptr;
		/* clear out the freeblock details */
		lub_heap_taint_memory(tmp - sizeof(lub_heap_tag_t),
				      LUB_HEAP_TAINT_FREE,
				      sizeof(lub_heap_tag_t) +
				      sizeof(lub_heap_free_block_t));
	}
	/* update the size of the previous block */
	free_block->free.tag.words += words;
	this->stats.free_bytes += (words << 2);

	/* make sure we retain the segment details */
	tail = lub_heap_block__get_tail(free_block);
	tail->segment = seg_end;
	tail->free = 1;

	/* update the size of the tail */
	tail->words = free_block->free.tag.words;

	/* insert back into the tree */
	lub_bintree_insert(&this->free_tree, free_block);
}

/*--------------------------------------------------------- */