ioctl_pipe(2) — Linux manual page


ioctl_pipe(2)              System Calls Manual             ioctl_pipe(2)

NAME         top

       ioctl_pipe - ioctl() operations for General notification

SYNOPSIS         top

       #include <linux/watch_queue.h>  /* Definition of IOC_WATCH_QUEUE_* */
       #include <sys/ioctl.h>

       int ioctl(int pipefd[1], IOC_WATCH_QUEUE_SET_SIZE, int size);
       int ioctl(int pipefd[1], IOC_WATCH_QUEUE_SET_FILTER,
                 struct watch_notification_filter *filter);

DESCRIPTION         top

       The following ioctl(2) operations are provided to set up general
       notification queue parameters.  The notification queue is built
       on the top of a pipe(2) opened with the O_NOTIFICATION_PIPE flag.

       IOC_WATCH_QUEUE_SET_SIZE (since Linux 5.8)
              Preallocates the pipe buffer memory so that it can fit
              size notification messages.  Currently, size must be
              between 1 and 512.

       IOC_WATCH_QUEUE_SET_FILTER (since Linux 5.8)
              Watch queue filter can limit events that are received.
              Filters are passed in a struct watch_notification_filter
              and each filter is described by a struct
              watch_notification_type_filter structure.

                  struct watch_notification_filter {
                          __u32   nr_filters;
                          __u32   __reserved;
                          struct watch_notification_type_filter filters[];

                  struct watch_notification_type_filter {
                          __u32   type;
                          __u32   info_filter;
                          __u32   info_mask;
                          __u32   subtype_filter[8];

SEE ALSO         top

       pipe(2), ioctl(2)

Linux man-pages (unreleased)     (date)                    ioctl_pipe(2)