NAME

       io_uring_buf_ring_add - add buffers to a shared buffer ring

SYNOPSIS

       #include <liburing.h>

       void io_uring_buf_ring_add(struct io_uring_buf_ring *br,
                                  void *addr,
                                  unsigned int len,
                                  unsigned short bid,
                                  int mask,
                                  int buf_offset);

DESCRIPTION

       The  io_uring_buf_ring_add(3)  adds  a  new  buffer  to the shared buffer ring br.  The buffer address is
       indicated by addr and is of len bytes of length.  bid is the buffer ID, which will  be  returned  in  the
       CQE.   mask  is  the  size mask of the ring, available from io_uring_buf_ring_mask(3).  buf_offset is the
       offset to insert at from the current tail. If just one  buffer  is  provided  before  the  ring  tail  is
       committed with io_uring_buf_ring_advance(3) or io_uring_buf_ring_cq_advance(3), then buf_offset should be
       0.  If  buffers  are provided in a loop before being committed, the buf_offset must be incremented by one
       for each buffer added.

RETURN VALUE

       None

NOTES

       liburing (or the kernel, for that matter) doesn't care about what buffer ID maps to what buffer,  and  in
       fact  when  recycling  buffers after use, the application is free to add a different buffer into the same
       buffer ID location. All that matters is that the application  knows  what  a  given  buffer  ID  in  time
       corresponds  to  in terms of virtual memory. There's no liburing or kernel assumption that these mappings
       are persistent over time, they can very well be different every time a given buffer ID is  added  to  the
       provided buffer ring.

SEE ALSO

       io_uring_register_buf_ring(3),          io_uring_buf_ring_mask(3),          io_uring_buf_ring_advance(3),
       io_uring_buf_ring_cq_advance(3)

liburing-2.2                                      May 18, 2022                          io_uring_buf_ring_add(3)