struct semaphore

头文件:

#include 

定义:

/* Please don't access any members of this structure directly */
struct semaphore {
	spinlock_t		lock;
	unsigned int		count;
	struct list_head	wait_list;
};

初始化:

 void sema_init(struct semaphore *sem,int val);

P函数:

void down(struct seamphore *sem)
int down_interruptible(struct seamphore *sem)
int down_trylock(struct seamphore *sem)

V函数:

void up(struct seamphore *sem)