klish/lub/heap/heap_graft_to_bottom.c

#include <assert.h>

#include "private.h"

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

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

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

	/* update the size of the next block */
	this->stats.free_bytes += (words << 2);

	new_words = words + free_block->free.tag.words;

	tail = lub_heap_block__get_tail(free_block);
	seg_end = tail->segment;

	if (BOOL_FALSE == other_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 *)ptr, LUB_HEAP_TAINT_FREE,
				      (words << 2) +
				      sizeof(lub_heap_free_block_t));
	} else {
		/* clear the free block details */
		lub_heap_taint_memory((char *)free_block, LUB_HEAP_TAINT_FREE,
				      sizeof(lub_heap_free_block_t));
	}

	free_block = ptr;
	/* make sure we retain the segment details */
	free_block->free.tag.free = 1;
	free_block->free.tag.words = new_words;
	free_block->free.tag.segment = seg_start;
	lub_bintree_node_init(&free_block->free.bt_node);

	/* and update the tail */
	tail->free = 1;
	tail->words = free_block->free.tag.words;
	tail->segment = seg_end;

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

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