Why needs double check in ncclIbIsend and ncclIbIrecv?

[jiangxiaobin96]

Some codes not understand when studying source code.
comm->ready only set in connect and accept when init connecting . why here needs double check?

// ncclIbIsend
if (comm->ready == 0) { WARN("NET/IB: ncclIbIsend() called when comm->ready == 0"); return ncclInternalError; }
if (comm->ready == 0) { *request = NULL; return ncclSuccess; }
// ncclIbIrecv
if (comm->ready == 0) { WARN("NET/IB: ncclIbIrecv() called when comm->ready == 0"); return ncclInternalError; }
if (comm->ready == 0) { *request = NULL; return ncclSuccess; }