r3/src/list.c

/*
 * list.c
 * Copyright (C) 2014 c9s <c9s@c9smba.local>
 *
 * Distributed under terms of the MIT license.
 */
#include <stdlib.h>
#include "r3_list.h"
#include "zmalloc.h"

/* Naive linked list implementation */

list *
list_create()
{
  list *l = (list *) zmalloc(sizeof(list));
  l->count = 0;
  l->head = NULL;
  l->tail = NULL;
  pthread_mutex_init(&(l->mutex), NULL);
  return l;
}

void
list_free(l)
  list *l;
{
  if (l) {
    list_item *li, *tmp;

    pthread_mutex_lock(&(l->mutex));

    if (l != NULL) {
      li = l->head;
      while (li != NULL) {
        tmp = li->next;
        li = tmp;
      }
    }

    pthread_mutex_unlock(&(l->mutex));
    pthread_mutex_destroy(&(l->mutex));
    zfree(l);
  }
}

list_item *
list_add_element(l, ptr)
  list *l;
  void *ptr;
{
  list_item *li;

  pthread_mutex_lock(&(l->mutex));

  li = (list_item *) zmalloc(sizeof(list_item));
  li->value = ptr;
  li->next = NULL;
  li->prev = l->tail;

  if (l->tail == NULL) {
    l->head = l->tail = li;
  }
  else {
    l->tail = li;
  }
  l->count++;

  pthread_mutex_unlock(&(l->mutex));

  return li;
}

int
list_remove_element(l, ptr)
  list *l;
  void *ptr;
{
  int result = 0;
  list_item *li = l->head;

  pthread_mutex_lock(&(l->mutex));

  while (li != NULL) {
    if (li->value == ptr) {
      if (li->prev == NULL) {
        l->head = li->next;
      }
      else {
        li->prev->next = li->next;
      }

      if (li->next == NULL) {
        l->tail = li->prev;
      }
      else {
        li->next->prev = li->prev;
      }
      l->count--;
      zfree(li);
      result = 1;
      break;
    }
    li = li->next;
  }

  pthread_mutex_unlock(&(l->mutex));

  return result;
}

void
list_each_element(l, func)
  list *l;
  int (*func)(list_item *);
{
  list_item *li;

  pthread_mutex_lock(&(l->mutex));

  li = l->head;
  while (li != NULL) {
    if (func(li) == 1) {
      break;
    }
    li = li->next;
  }

  pthread_mutex_unlock(&(l->mutex));
}