.\" -*- nroff -*-
.\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
.\"
.TH IBV_CREATE_CQ 3 2006-10-31 libibverbs "Libibverbs Programmer's Manual"
.SH "NAME"
ibv_create_cq, ibv_destroy_cq \- create or destroy a completion queue (CQ)
.SH "SYNOPSIS"
.nf
.B #include <infiniband/verbs.h>
.sp
.BI "struct ibv_cq *ibv_create_cq(struct ibv_context " "*context" ", int " "cqe" ,
.BI "                             void " "*cq_context" ,
.BI "                             struct ibv_comp_channel " "*channel" ,
.BI "                             int " "comp_vector" );
.sp
.BI "int ibv_destroy_cq(struct ibv_cq " "*cq" );
.fi
.SH "DESCRIPTION"
.B ibv_create_cq()
creates a completion queue (CQ) with at least
.I cqe
entries for the RDMA device context
.I context\fR.
The pointer
.I cq_context
will be used to set user context pointer of the CQ structure. The argument
.I channel
is optional; if not NULL, the completion channel
.I channel
will be used to return completion events.  The CQ will use the
completion vector
.I comp_vector
for signaling completion events; it must be at least zero and less than
.I context\fR->num_comp_vectors.
.PP
.B ibv_destroy_cq()
destroys the CQ
.I cq\fR.
.SH "RETURN VALUE"
.B ibv_create_cq()
returns a pointer to the CQ, or NULL if the request fails.
.PP
.B ibv_destroy_cq()
returns 0 on success, or the value of errno on failure (which indicates the failure reason).
.SH "NOTES"
.B ibv_create_cq()
may create a CQ with size greater than or equal to the requested
size. Check the cqe attribute in the returned CQ for the actual size.
.PP
.B ibv_destroy_cq()
fails if any queue pair is still associated with this CQ.
.SH "SEE ALSO"
.BR ibv_resize_cq (3),
.BR ibv_req_notify_cq (3),
.BR ibv_ack_cq_events (3),
.BR ibv_create_qp (3)
.SH "AUTHORS"
.TP
Dotan Barak <dotanba@gmail.com>