高手进阶 Linux系统中内核定时器的应用

[CODE]

            #include<linux/init.h>

            #include<linux/sched.h>

            #include<linux/module.h>

            #include<linux/jiffies.h>

            #include<asm/io.h>

            #include<linux/timer.h>

            #include<linux/wait.h>

            MODULE_LICENSE("GPL");

            static DECLARE_WAIT_QUEUE_HEAD(wq);

            static int flag = 0;

            struct timer_list my_timer;

            void timer_test(unsigned long data)

            {

            printk("this is a test\n");

            flag = 1;

            wake_up_interruptible(&wq);

            }

            static int __init hello_init(void)

            {

            init_timer(&my_timer);

            my_timer.expires = jiffies   5000;

            my_timer.data = 0;

            my_timer.function = timer_test;

            add_timer(&my_timer);

            wait_event_interruptible(wq, flag != 0);

            flag = 0;

            return 0;

            }

            static void __exit hello_exit(void)

            {

            del_timer(&my_timer);

            printk(KERN_ALERT "Goodbye\n");

            }

            module_init(hello_init);

            module_exit(hello_exit);

            [/CODE]