poll_wait

Section: Kernel Functions (9)
Updated: $Date:$
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NAME

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 currently ready. The kernel looks at the mask of events to see if something it needs is ready, and suspends the process 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+

AUTHOR

Stephen Williams <steve@icarus.com>

BUGS

To early to say.