지나간 삶

#include <stdio.h>

struct list_head
{
    struct list_head *next;
    struct list_head *prev;
};

typedef struct
{
    int count;
    int pid;
    struct list_head list;
} TASK;

void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
    next->prev = new;
    new->next = next;
    new->prev = prev;
    prev->next = new;
}

void list_add(struct list_head *new, struct list_head *head)
{
    __list_add(new, head, head->next);
}

#define  list_entry( temp, type, list ) \
    ((type *)( (char*)temp - (unsigned long)(&((type *)0)->list)))

#define list_for_each(pos, head) \
    for (pos = (head)->next; pos != (head); pos = pos->next )

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)

int main()
{
    struct list_head *temp;
    LIST_HEAD(head);

    TASK  t1 = { 1, 1000, 0, 0 };
    TASK  t2 = { 2, 2000, 0, 0 };
    TASK *p;

    list_add ( &t1.list, &head );
    list_add ( &t2.list, &head );

    printf("[head]");
    list_for_each( temp, &head )
    {
        p = list_entry( temp, TASK, list );
        printf("->[%4d, %4d]",p->count, p->pid);
    }
    printf("\n");
    return 0;
}