.\" Extracted by src2man from /build/rpma-11eW7Q/rpma-1.3.0/src/include/librpma.h
.\" Text automatically generated by txt2man
.TH rpma_cq_get_fd 3 "29 May 2023" "RPMA" "RPMA Programmer's Manual"
.SH NAME
\fBrpma_cq_get_fd \fP- get the completion queue's file descriptor
.SH SYNOPSIS
.nf
.fam C
      #include <librpma.h>

      struct rpma_cq;
      int \fBrpma_cq_get_fd\fP(const struct rpma_cq *cq, int *fd);

.fam T
.fi
.fam T
.fi
.SH DESCRIPTION
\fBrpma_cq_get_fd\fP() gets the file descriptor of the completion queue (CQ in short). When a next
completion in the CQ is ready to be consumed by \fBrpma_cq_get_wc\fP(3), the notification is delivered
via the file descriptor. The default mode of the file descriptor is blocking but it can be
changed to non-blocking mode using \fBfcntl\fP(2). The CQ is either the connection's main CQ or
the receive CQ or CQ of shared RQ, please see \fBrpma_conn_get_cq\fP(3), \fBrpma_conn_get_rcq\fP(3) or
\fBrpma_srq_get_rcq\fP() for details.
.PP
Note after spotting the notification using the provided file descriptor you do not have to call
\fBrpma_cq_wait\fP(3) before consuming the completion but it may cause that the next call to
\fBrpma_cq_wait\fP(3) will notify you of already consumed completion.
.SH RETURN VALUE
The \fBrpma_cq_get_fd\fP() function returns 0 on success or a negative error code on failure.
\fBrpma_cq_get_fd\fP() does not set *fd value on failure.
.SH ERRORS
\fBrpma_cq_get_fd\fP() can fail with the following error:
.IP \(bu 3
RPMA_E_INVAL - cq or fd is NULL
.SH SEE ALSO
\fBfcntl\fP(2), \fBrpma_conn_get_cq\fP(3), \fBrpma_conn_get_rcq\fP(3), \fBrpma_srq_get_rcq\fP(3), \fBrpma_cq_wait\fP(3),
\fBrpma_cq_get_wc\fP(3), \fBlibrpma\fP(7) and https://pmem.io/rpma/