completion

在Linux kernel  中我們可以使用completion來等待某樣事情完成
ex.

#include linux/completion.h
struct completion comp;
void module_init{

         //初始化my_completion, set comp.done=0
         init_completion(&comp);
}


ssiz​​e_t complete_read (struct file *filp, char __user *buf, size_t count, loff_t *pos)
{
    //等待所有的comp 都被complete. 
    wait_for_completion(&comp);
    printk(KERN_DEBUG "awoken %i (%s)\n", current->pid, current->comm);
    return 0; /* EOF */
}

ssiz​​e_t complete_write (struct file *filp, const char __user *buf, size_t count, loff_t *pos)
{
 
    complete(&comp);
    return count; /* succeed, to avoid retrial */
}