9 void completion_init(struct completion *x)  in completion_init()  argument
11     x->done = 0;  in completion_init()
12     wait_queue_head_init(&x->wait_queue);  in completion_init()
20 void complete(struct completion *x)  in complete()  argument
23     spin_lock(&x->wait_queue.lock);  in complete()
25     if (x->done != COMPLETE_ALL)  in complete()
26         ++(x->done);  in complete()
27     wait_queue_wakeup_on_stack(&x->wait_queue, -1UL); // -1UL代表所有节点都满足条件,暂时这么写  in complete()
29     spin_unlock(&x->wait_queue.lock);  in complete()
37 void complete_all(struct completion *x)  in complete_all()  argument
39     spin_lock(&x->wait_queue.lock);  in complete_all()
41     x->done = COMPLETE_ALL; // 永久赋值  in complete_all()
42     while (!list_empty(&x->wait_queue.wait_list))  in complete_all()
43         wait_queue_wakeup_on_stack(&x->wait_queue, -1UL); // -1UL代表所有节点都满足条件,暂时这么写  in complete_all()
45     spin_unlock(&x->wait_queue.lock);  in complete_all()
57 static long __wait_for_common(struct completion *x, long (*action)(long), long timeout, int state)  in __wait_for_common()  argument
59     if (!x->done)  in __wait_for_common()
63         while (!x->done && timeout > 0)  in __wait_for_common()
67                 list_append(&x->wait_queue.wait_list, &wait.wait_list);  in __wait_for_common()
70             spin_unlock(&x->wait_queue.lock);  in __wait_for_common()
73             spin_lock(&x->wait_queue.lock);  in __wait_for_common()
75         if (!x->done)  in __wait_for_common()
82     if (x->done != COMPLETE_ALL)  in __wait_for_common()
83         --(x->done);  in __wait_for_common()
92 void wait_for_completion(struct completion *x)  in wait_for_completion()  argument
94     spin_lock(&x->wait_queue.lock);  in wait_for_completion()
95     __wait_for_common(x, &schedule_timeout_ms, MAX_TIMEOUT, PROC_UNINTERRUPTIBLE);  in wait_for_completion()
96     spin_unlock(&x->wait_queue.lock);  in wait_for_completion()
106 long wait_for_completion_timeout(struct completion *x, long timeout)  in wait_for_completion_timeout()  argument
109     spin_lock(&x->wait_queue.lock);  in wait_for_completion_timeout()
110     timeout = __wait_for_common(x, &schedule_timeout_ms, timeout, PROC_UNINTERRUPTIBLE);  in wait_for_completion_timeout()
111     spin_unlock(&x->wait_queue.lock);  in wait_for_completion_timeout()
120 void wait_for_completion_interruptible(struct completion *x)  in wait_for_completion_interruptible()  argument
122     spin_lock(&x->wait_queue.lock);  in wait_for_completion_interruptible()
123     __wait_for_common(x, &schedule_timeout_ms, MAX_TIMEOUT, PROC_INTERRUPTIBLE);  in wait_for_completion_interruptible()
124     spin_unlock(&x->wait_queue.lock);  in wait_for_completion_interruptible()
134 long wait_for_completion_interruptible_timeout(struct completion *x, long timeout)  in wait_for_completion_interruptible_timeout()  argument
138     spin_lock(&x->wait_queue.lock);  in wait_for_completion_interruptible_timeout()
139     timeout = __wait_for_common(x, &schedule_timeout_ms, timeout, PROC_INTERRUPTIBLE);  in wait_for_completion_interruptible_timeout()
140     spin_unlock(&x->wait_queue.lock);  in wait_for_completion_interruptible_timeout()
151 bool try_wait_for_completion(struct completion *x)  in try_wait_for_completion()  argument
153     if (!READ_ONCE(x->done))  in try_wait_for_completion()
157     spin_lock(&x->wait_queue.lock);  in try_wait_for_completion()
159     if (!x->done)  in try_wait_for_completion()
161     else if (x->done != COMPLETE_ALL)  in try_wait_for_completion()
162         --(x->done);  in try_wait_for_completion()
164     spin_unlock(&x->wait_queue.lock);  in try_wait_for_completion()
175 bool completion_done(struct completion *x)  in completion_done()  argument
178     if (!READ_ONCE(x->done))  in completion_done()
182     spin_lock(&x->wait_queue.lock);  in completion_done()
184     if (!READ_ONCE(x->done))  in completion_done()
186         spin_unlock(&x->wait_queue.lock);  in completion_done()
189     spin_unlock(&x->wait_queue.lock);  in completion_done()
199 void wait_for_multicompletion(struct completion x[], int n)  in wait_for_multicompletion()  argument
203         if (!completion_done(&x[i])) // 如果没有done，直接wait  in wait_for_multicompletion()
205             wait_for_completion(&x[i]);  in wait_for_multicompletion()
207         else if (!try_wait_for_completion(&x[i])) //上面测试过done>0，那么这里尝试去获取一个done，如果失败了，就继续wait  in wait_for_multicompletion()
209             wait_for_completion(&x[i]);  in wait_for_multicompletion()