要确认的完成事件数。(Number of Completion events to acknowledge)

struct ibv_context *context;
struct ibv_cq *cq;
void *ev_ctx = NULL; /* can be initialized with other values for the CQ context *//* Create a CQ, which is associated with a Completion Event Channel */
cq = ibv_create_cq(ctx, 1, ev_ctx, channel, 0);
if (!cq) {fprintf(stderr, "Failed to create CQ\n");return -1;
}/* Request notification before any completion can be created (to prevent races) */
ret = ibv_req_notify_cq(cq, 0);
if (ret) {fprintf(stderr, "Couldn't request CQ notification\n");return -1;
}.
. /* Perform an operation that will eventually end with Work Completion */
./* The following code will be called each time you need to read a Work Completion */
struct ibv_cq *ev_cq;
void *ev_ctx;
int ret;
int ne;/* Wait for the Completion event */
ret = ibv_get_cq_event(channel, &ev_cq, &ev_ctx);
if (ret) {fprintf(stderr, "Failed to get CQ event\n");return -1;
}/* Request notification upon the next completion event */
ret = ibv_req_notify_cq(ev_cq, 0);
if (ret) {fprintf(stderr, "Couldn't request CQ notification\n");return -1;
}/* Empty the CQ: poll all of the completions from the CQ (if any exist) */
do {ne = ibv_poll_cq(cq, 1, &wc);if (ne < 0) {fprintf(stderr, "Failed to poll completions from the CQ: ret = %d\n",ne);return -1;}/* there may be an extra event with no completion in the CQ */if (ne) {if (wc.status != IBV_WC_SUCCESS) {fprintf(stderr, "Completion with status 0x%x was found\n",
wc.status);return -1;}}
} while (ne);/* Ack the event */
ibv_ack_cq_events(ev_cq, 1);