llist

#include "linkedlist.h"

typedef struct netobj
{
    int id;
    int socket;
    int status;
    in_addr_t ip_addr;
}netobj;

typedef struct node
{
    netobj obj;
    struct node *next;
}node;

node *head;
node *tail;
pthread_mutex_t llist_mutex = PTHREAD_MUTEX_INITIALIZER;

void init_llist()
{
    head = (node*)malloc(sizeof(node));
    (head->obj).id = 0;
    (head->obj).socket = 0;
    (head->obj).status = 0;
    (head->obj).ip_addr = 0;
    tail = (node*)malloc(sizeof(node));
    (tail->obj).id = 0;
    (tail->obj).socket = 0;
    (tail->obj).status = 0;
    (tail->obj).ip_addr = 0;
    tail->next = 0;
    head->next = tail;
}

node *init_node(netobj obj)
{
    node *ptr;
    ptr = (node*)calloc(1, sizeof(node));
    if(ptr == 0)
    {
        return (node*)0;
    }
    else
    {
        (ptr->obj).id = obj.id;
        (ptr->obj).socket = obj.socket;
        (ptr->obj).status = obj.status;
        (ptr->obj).ip_addr = obj.ip_addr;
    }
    return ptr;
}

void add_llist(netobj obj)
{
    pthread_mutex_lock(&llist_mutex);
    node *new = init_node(obj);
    node *it = head;
    if(head == 0)
    {
        head = new;
    }
    else if(head->next == 0)
    {
        head->next = new;
    }
    else
    {
        while(1)
        {
            if(it->next == 0)
            {
                new->next = tail;
                it->next = new;
                break;
            }
            it = it->next;
        }
    }
    pthread_mutex_unlock(&llist_mutex);
}

node *find_node_llist(netobj obj)
{
    pthread_mutex_lock(&llist_mutex);
    node *it = head;
    while((it->obj).id != obj.id && (it->obj).ip_addr == obj.ip_addr)
    {
        it = it->next;
        if(it == 0)
        {
            break;
        }
    }
    pthread_mutex_unlock(&llist_mutex);
    return it;
}

int find_llist(netobj obj)
{
    pthread_mutex_lock(&llist_mutex);
    node *it = head;
    while(it != 0)
    {
        if((it->obj).id == obj.id && (it->obj).ip_addr == obj.ip_addr
                && (it->obj).socket == obj.socket)
        {
            pthread_mutex_unlock(&llist_mutex);
            return 1;
        }
        it = it->next;
    }
    pthread_mutex_unlock(&llist_mutex);
    return 0;
}

int rm_llist(netobj obj)
{
    pthread_mutex_lock(&llist_mutex);
    node *rmnode = find_node_llist(obj);
    if(rmnode == 0)
    {
        pthread_mutex_unlock(&llist_mutex);
        return -1;
    }
    else
    {
        node *tmp, *prev;
        tmp = rmnode;
        prev = head;

        if(tmp == prev)
        {
            head = head->next;
            if(tail == tmp)
            {
                tail = tail->next;
            }
            free(tmp);
        }
        else
        {
            while(prev->next != tmp)
            {
                prev = prev->next;
            }
            prev->next = tmp->next;
            if(tail == tmp)
            {
                tail = prev;
            }
        }
    }
    pthread_mutex_unlock(&llist_mutex);
    return 0;
}

int cnt_llist()
{
    pthread_mutex_lock(&llist_mutex);
    node *it = head;
    int i = 0;
    while(it != 0)
    {
        it =  it->next;
        i++;
    }
    //printf("list count: %d\n", i - 1);
    pthread_mutex_unlock(&llist_mutex);
    return i - 1;
}

void print_llist()
{
    pthread_mutex_lock(&llist_mutex);
    node *it = head;
    printf("printing list:\n");
    printf("----------\n");
    while(it != 0)
    {
        printf("%d\n", (it->obj).id);
        it = it->next;
    }
    printf("----------\n");
    pthread_mutex_unlock(&llist_mutex);
}