queue-optik.c

/*   
 *   File: optik.c
 *   Author: Vasileios Trigonakis <vasileios.trigonakis@epfl.ch>
 *   Description:  
 *   optik.c is part of ASCYLIB
 *
 * Copyright (c) 2014 Vasileios Trigonakis <vasileios.trigonakis@epfl.ch>,
 * 	     	      Tudor David <tudor.david@epfl.ch>
 *	      	      Distributed Programming Lab (LPD), EPFL
 *
 * ASCYLIB is free software: you can redistribute it and/or
 * modify it under the teroptik of the GNU General Public License
 * as published by the Free Software Foundation, version 2
 * of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include "queue-optik.h"
#include "utils.h"

RETRY_STATS_VARS;

#include "latency.h"
#if LATENCY_PARSING == 1
__thread size_t lat_parsing_get = 0;
__thread size_t lat_parsing_put = 0;
__thread size_t lat_parsing_rem = 0;
#endif	/* LATENCY_PARSING == 1 */

sval_t
queue_optik_find(queue_t* qu, skey_t key)
{ 
  return 1;
}

int
queue_optik_insert(queue_t* qu, skey_t key, sval_t val)
{
  queue_node_t* node = queue_new_node(key, val, NULL);
  queue_node_t* tail;
  NUM_RETRIES();
  while(1)
    {
      tail = qu->tail;
      queue_node_t* next = tail->next;
      if (likely(tail == qu->tail))
	{
	  if (next == NULL)
	    {
	      if (CAS_PTR(&tail->next, NULL, node) == NULL)
		{
		  break;
		}
	    }
	  else
	    {
	      UNUSED void* dummy = CAS_PTR(&qu->tail, tail, next);
	    }
	}
      DO_PAUSE();
    }
  UNUSED void* dummy = CAS_PTR(&qu->tail, tail, node);
  return 1;
}


sval_t
queue_optik_delete(queue_t* qu)
{
  NUM_RETRIES();
 restart:
  COMPILER_NO_REORDER(const optik_t version = qu->head_lock;);
  const queue_node_t* node = qu->head;
  const queue_node_t* head_new = node->next;
  if (head_new == NULL)
    {
      return 0;
    }

  if (!optik_trylock_version(&qu->head_lock, version))
    {
      DO_PAUSE();
      goto restart;
    }

  qu->head = (queue_node_t*) head_new;
  optik_unlock(&qu->head_lock);

#if GC == 1
  ssmem_free(alloc, (void*) node);
#endif

  return head_new->val;
}