text: /*
   * Copyright 2010-2016, Tarantool AUTHORS, please see AUTHORS file.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * 1. Redistributions of source code must retain the above
   *    copyright notice, this list of conditions and the
   *    following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above
   *    copyright notice, this list of conditions and the following
   *    disclaimer in the documentation and/or other materials
   *    provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
   * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
   * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #include "lsregion.h"
  
  void *
  lsregion_alloc_slow(struct lsregion *lsregion, size_t size, int64_t id)
  {
  	struct lslab *slab = NULL;
  	size_t slab_size = lsregion->arena->slab_size;
  
  	/* If there is an existing slab then try to use it. */
  	if (! rlist_empty(&lsregion->slabs.slabs)) {
  		slab = rlist_last_entry(&lsregion->slabs.slabs, struct lslab,
  					next_in_list);
  		assert(slab != NULL);
  	}
  	if ((slab != NULL && size > lslab_unused(slab)) ||
  	    slab == NULL) {
  		if (size + lslab_sizeof() >= slab_size) {
  			/* Large allocation, use malloc() */
  			slab_size = size + lslab_sizeof();
  			struct quota *quota = lsregion->arena->quota;
  			if (quota_use(quota, slab_size) < 0)
  				return NULL;
  			slab = malloc(slab_size);
  			if (slab == NULL) {
  				quota_release(quota, slab_size);
  				return NULL;
  			}
  			lslab_create(slab, slab_size);
  			rlist_add_tail_entry(&lsregion->slabs.slabs, slab,
  					     next_in_list);
  			lsregion->slabs.stats.total += slab_size;
  		} else if (lsregion->cached != NULL) {
  			/* If there is the cached slab then use it. */
  			slab = lsregion->cached;
  			lsregion->cached = NULL;
  			rlist_add_tail_entry(&lsregion->slabs.slabs, slab,
  					     next_in_list);
  		} else {
  			slab = (struct lslab *) slab_map(lsregion->arena);
  			if (slab == NULL)
  				return NULL;
  			lslab_create(slab, slab_size);
  			rlist_add_tail_entry(&lsregion->slabs.slabs, slab,
  					     next_in_list);
  			lsregion->slabs.stats.total += slab_size;
  		}
  	}
  	assert(slab != NULL);
  	assert(slab->max_id <= id);
  	assert(size <= lslab_unused(slab));
  	void *res = lslab_pos(slab);
  	slab->slab_used += size;
  
  	/* Update the memory block meta info. */
  	assert(slab->max_id <= id);
  	slab->max_id = id;
  	lsregion->slabs.stats.used += size;
  	return res;
  }
  