poll_wait - wait for selectable event to be ready

SYNOPSIS

       #include <linux/poll.h>

       void poll_wait(structwait_queue**sync, poll_table*pt)

DESCRIPTION

       This function is used in support of the poll device driver
       entry point. The intent is for a device driver to put sync
       into  the  poll table immediately entering the device poll
       routine, then returning a bit mask of events that are cur­
       rently  ready.  The  kernel looks at the mask of events to
       see if something it needs is ready, and suspends the  pro­
       cess if not.

       static unsigned int xxpoll(struct file*file, poll_table*pt)
       {
           poll_wait(&data_in_sync, pt);
           if (data_in.cnt > 0) return POLLIN | POLLRDNORM;
           else return 0;
       }

       This  example  shows  the  basic  use of poll_wait(9) in a
       device driver poll function.

AVAILABILITY

       Linux kernel 2.1.34+

SEE ALSO

       intro(9)

AUTHOR

       Stephen Williams <steve@icarus.com>

BUGS

       To early to say.