init_poll_funcptr(&epq.pt, ep_ptable_queue_proc); /* * Attach the item to the poll hooks and get current event bits. * We can safely use the file* here because its usage count has * been increased by the caller of this function. Note that after * this operation completes, the p...
poll notes this operation and returns the value to the client function. Then the time taken since parfeval was called is displayed. Note a delay of 3 s while the worker is computing something (in this case a long pause). Input Arguments collapse all pollablequeue— Pollable data queue ...
二、驱动程序：驱动程序里与poll相关的地方有两处：一是构造file_operation结构时，要定义自己的poll函数。二是通过poll_wait来调用上面说到的__pollwait函数，pollwait的代码如下：static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p){if (p && ...
There are no other nodes in cluster. When i do poll with timeout, I am getting below error { IQueue notifyQueue=... .. Integer segmentId = notifyQueue.poll(2, TimeUnit.MINUTES); return segmentId; } Error: PollOperation invocation failed to complete due to operation-heartbeat-timeout....
上层要能使用select()和poll()系统调用来监测某个设备文件描述符,那么就必须实现这个设备驱动程序中struct file_operation结构体的poll函数,为什么? 因为这两个系统调用最终都会调用驱动程序中的poll函数来初始化一个等待队列项, 然后将其加入到驱动程序中的等待队列头,这样就可以在硬件可读写的时候wake up这个等待队列...
* 1. 等待队列 waitqueue * 我们简单解释一下等待队列: * 队列头(wait_queue_head_t)往往是资源生产者, * 队列成员(wait_queue_t)往往是资源消费者, * 当头的资源ready后, 会逐个执行每个成员指定的回调函数, * 来通知它们资源已经ready了, 等待队列大致就这个意思. ...
这和"open" file operation callback一样,因为 inside * ep_getfd() we did what the kernel usually does before invoking * corresponding file "open" callback. */ error = open_eventpoll(inode, file); if (error) goto eexit_2; /* "private_data" 由open_eventpoll()设置 */ ep = ...
which is serialized, sent over the network back to the client and put on a data queue.pollnotes this operation and returns the value to the client function. Then the time taken sinceparfevalwas called is displayed. Note a delay of 3 s while the worker is computing something (in this case...
(&epi->ffd, tfile, fd); //3.2 设置 socket 等待队列 //定义并初始化 ep_pqueue 对象 struct ep_pqueue epq; epq.epi = epi; init_poll_funcptr(&epq.pt, ep_ptable_queue_proc); //调用 ep_ptable_queue_proc 注册回调函数 //实际注入的函数为 ep_poll_callback revents = ep_item_poll(...
For each member of the array(s) pointed to by listptr, poll() examines the given file descriptor or message queue for the event(s) specified in the member. The number of pollmsg structures and the number of pollfd structures in the arrays are specified by nmsgsfds. The poll() function...