/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

#include <isc/os.h>

#include <isc/urcu.h>

STATIC_ASSERT(sizeof(struct __cds_wfcq_head) <= ISC_OS_CACHELINE_SIZE,

        "size of struct __cds_wfcq_head must be smaller than "

        "ISC_OS_CACHELINE_SIZE");

typedef struct isc_queue {

  struct __cds_wfcq_head head;

  uint8_t          __padding_head[ISC_OS_CACHELINE_SIZE -

              sizeof(struct __cds_wfcq_head)];

  struct cds_wfcq_tail   tail;

  uint8_t          __padding_tail[ISC_OS_CACHELINE_SIZE -

              sizeof(struct __cds_wfcq_head)];

} isc_queue_t;

typedef struct cds_wfcq_node isc_queue_node_t;

static inline void

isc_queue_node_init(isc_queue_node_t *node) {

  cds_wfcq_node_init(node);

}

static inline void

isc_queue_init(isc_queue_t *queue) {

  __cds_wfcq_init(&(queue)->head, &(queue)->tail);

}

static inline void

isc_queue_destroy(isc_queue_t *queue) {

  UNUSED(queue);

}

static inline bool

isc_queue_empty(isc_queue_t *queue) {

  return cds_wfcq_empty(&(queue)->head, &(queue)->tail);

}

static inline bool

isc_queue_enqueue(isc_queue_t *queue, isc_queue_node_t *node) {

  return cds_wfcq_enqueue(&(queue)->head, &(queue)->tail, node);

}

#define isc_queue_enqueue_entry(queue, entry, member) \

  cds_wfcq_enqueue(&(queue)->head, &(queue)->tail, &((entry)->member))

static inline isc_queue_node_t *

isc_queue_dequeue(isc_queue_t *queue) {

  return __cds_wfcq_dequeue_nonblocking(&(queue)->head, &(queue)->tail);

}

#define isc_queue_entry(ptr, type, member) \

  caa_container_of_check_null(ptr, type, member)

#define isc_queue_dequeue_entry(queue, type, member) \

  isc_queue_entry(isc_queue_dequeue(queue), type, member)

static inline bool

isc_queue_splice(isc_queue_t *dest, isc_queue_t *src) {

  enum cds_wfcq_ret ret = __cds_wfcq_splice_blocking(

    &dest->head, &dest->tail, &src->head, &src->tail);

  INSIST(ret != CDS_WFCQ_RET_WOULDBLOCK &&

         ret != CDS_WFCQ_RET_DEST_NON_EMPTY);

  return ret != CDS_WFCQ_RET_SRC_EMPTY;

}

#define isc_queue_first_entry(queue, type, member)                         \

  isc_queue_entry(                                                   \

    __cds_wfcq_first_blocking(&(queue)->head, &(queue)->tail), \

    type, member)

#define isc_queue_next_entry(queue, node, type, member)                 \

  isc_queue_entry(__cds_wfcq_next_blocking(&(queue)->head,        \

             &(queue)->tail, node), \

      type, member)

#define isc_queue_for_each_entry(queue, pos, member)                       \

  for (pos = isc_queue_first_entry(queue, __typeof__(*pos), member); \

       pos != NULL;                                                  \

       pos = isc_queue_next_entry(queue, &(pos)->member,             \

          __typeof__(*pos), member))

#define isc_queue_for_each_entry_safe(queue, pos, next, member)            \

  for (pos = isc_queue_first_entry(queue, __typeof__(*pos), member), \

      next = (pos ? isc_queue_next_entry(queue, &(pos)->member,      \

                 __typeof__(*pos), member)   \

      : NULL);                                           \

       pos != NULL; pos = next,                                      \

      next = (pos ? isc_queue_next_entry(queue, &(pos)->member,      \

                 __typeof__(*pos), member)   \

      : NULL))