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Author-------Dansen-----xzd2734@163.com
wait_queue_head_t wait_q;
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typedef struct
__wait_queue_head wait_queue_head_t;
struct __wait_queue_head {
 wq_lock_t
lock;
 struct list_head task_list;
};
# define wq_lock_t
spinlock_t
typedef struct {
 volatile unsigned int lock;
}
spinlock_t;
struct list_head {
 struct list_head *next, *prev;
};
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wait_q.lock.lock  volatile unsigned int
wait_q.task_list.next  struct
list_head *
wait_q.task_list.prev  struct list_head *
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init_waitqueue_head(&wait_q);
static inline void
init_waitqueue_head(wait_queue_head_t *q)
{
 q->lock =
WAITQUEUE_RW_LOCK_UNLOCKED;
 INIT_LIST_HEAD(&q->task_list);
}
#define
WAITQUEUE_RW_LOCK_UNLOCKED SPIN_LOCK_UNLOCKED
#define
SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
#define INIT_LIST_HEAD(ptr) do {
\
 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)
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wait_q.lock.lock=0;
wait_q.task_list.next=&(wait_q.task_list)
wait_q.task_list.prev=&(wait_q.task_list)
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#define DECLARE_WAIT_QUEUE_HEAD(name) \
 wait_queue_head_t
name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
#define
__WAIT_QUEUE_HEAD_INITIALIZER(name) {    \
 lock:  WAITQUEUE_RW_LOCK_UNLOCKED,   \
 task_list: {
&(name).task_list, &(name).task_list }
 }
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DECLARE_WAITQUEUE(wait, current);
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#define DECLARE_WAITQUEUE(name, tsk)     \
 wait_queue_t
name = __WAITQUEUE_INITIALIZER(name, tsk)
#define
__WAITQUEUE_INITIALIZER(name, tsk) {    \
 task: