int MPID_Cancel_send(MPID_Request * sreq)
{
MPIDI_VC_t * vc;
int proto;
int flag;
int mpi_errno = MPI_SUCCESS;
MPIDI_STATE_DECL(MPID_STATE_MPID_CANCEL_SEND);
MPIDI_FUNC_ENTER(MPID_STATE_MPID_CANCEL_SEND);
MPIU_Assert(sreq->kind == MPID_REQUEST_SEND);
MPIDI_Request_cancel_pending(sreq, &flag);
if (flag)
{
goto fn_exit;
}
/*
* FIXME: user requests returned by MPI_Ibsend() have a NULL comm pointer
* and no pointer to the underlying communication
* request. For now, we simply fail to cancel the request. In the future,
* we should add a new request kind to indicate that
* the request is a BSEND. Then we can properly cancel the request, much
* in the way we do persistent requests.
*/
if (sreq->comm == NULL)
{
goto fn_exit;
}
MPIDI_Comm_get_vc_set_active(sreq->comm, sreq->dev.match.parts.rank, &vc);
proto = MPIDI_Request_get_msg_type(sreq);
if (proto == MPIDI_REQUEST_SELF_MSG)
{
MPID_Request * rreq;
MPIU_DBG_MSG(CH3_OTHER,VERBOSE,
"attempting to cancel message sent to self");
MPIU_THREAD_CS_ENTER(MSGQUEUE,);
rreq = MPIDI_CH3U_Recvq_FDU(sreq->handle, &sreq->dev.match);
MPIU_THREAD_CS_EXIT(MSGQUEUE,);
if (rreq)
{
MPIU_Assert(rreq->partner_request == sreq);
MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
"send-to-self cancellation successful, sreq=0x%08x, rreq=0x%08x",
sreq->handle, rreq->handle));
MPIU_Object_set_ref(rreq, 0);
MPIDI_CH3_Request_destroy(rreq);
sreq->status.cancelled = TRUE;
/* no other thread should be waiting on sreq, so it is safe to
reset ref_count and cc */
MPID_cc_set(&sreq->cc, 0);
/* FIXME should be a decr and assert, not a set */
MPIU_Object_set_ref(sreq, 1);
}
else
{
sreq->status.cancelled = FALSE;
MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
"send-to-self cancellation failed, sreq=0x%08x, rreq=0x%08x",
sreq->handle, rreq->handle));
}
goto fn_exit;
}
int MPID_Cancel_send(MPIR_Request * sreq)
{
MPIDI_VC_t * vc;
int proto;
int flag;
int mpi_errno = MPI_SUCCESS;
MPIR_FUNC_VERBOSE_STATE_DECL(MPID_STATE_MPID_CANCEL_SEND);
MPIR_FUNC_VERBOSE_ENTER(MPID_STATE_MPID_CANCEL_SEND);
MPIR_Assert(sreq->kind == MPIR_REQUEST_KIND__SEND);
MPIDI_Request_cancel_pending(sreq, &flag);
if (flag)
{
goto fn_exit;
}
/*
* FIXME: user requests returned by MPI_Ibsend() have a NULL comm pointer
* and no pointer to the underlying communication
* request. For now, we simply fail to cancel the request. In the future,
* we should add a new request kind to indicate that
* the request is a BSEND. Then we can properly cancel the request, much
* in the way we do persistent requests.
*/
if (sreq->comm == NULL)
{
goto fn_exit;
}
MPIDI_Comm_get_vc_set_active(sreq->comm, sreq->dev.match.parts.rank, &vc);
proto = MPIDI_Request_get_msg_type(sreq);
if (proto == MPIDI_REQUEST_SELF_MSG)
{
MPIR_Request * rreq;
MPL_DBG_MSG(MPIDI_CH3_DBG_OTHER,VERBOSE,
"attempting to cancel message sent to self");
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_MSGQ_MUTEX);
rreq = MPIDI_CH3U_Recvq_FDU(sreq->handle, &sreq->dev.match);
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_MSGQ_MUTEX);
if (rreq)
{
MPIR_Assert(rreq->dev.partner_request == sreq);
MPL_DBG_MSG_FMT(MPIDI_CH3_DBG_OTHER,VERBOSE,(MPL_DBG_FDEST,
"send-to-self cancellation successful, sreq=0x%08x, rreq=0x%08x",
sreq->handle, rreq->handle));
/* Pull the message out of the unexpected queue since it's
* being cancelled. The below request release drops one
* reference. We explicitly drop a second reference,
* because the receive request will never be visible to
* the user. */
MPIR_Request_free(rreq);
MPIR_Request_free(rreq);
MPIR_STATUS_SET_CANCEL_BIT(sreq->status, TRUE);
mpi_errno = MPID_Request_complete(sreq);
if (mpi_errno != MPI_SUCCESS) {
MPIR_ERR_POP(mpi_errno);
}
}
else
{
MPIR_STATUS_SET_CANCEL_BIT(sreq->status, FALSE);
MPL_DBG_MSG_FMT(MPIDI_CH3_DBG_OTHER,VERBOSE,(MPL_DBG_FDEST,
"send-to-self cancellation failed, sreq=0x%08x, rreq=0x%08x",
sreq->handle, rreq->handle));
}
goto fn_exit;
}
/* If the message went over a netmod and it provides a cancel_send
function, call it here. */
#ifdef ENABLE_COMM_OVERRIDES
if (vc->comm_ops && vc->comm_ops->cancel_send)
{
mpi_errno = vc->comm_ops->cancel_send(vc, sreq);
goto fn_exit;
}
#endif
/* Check to see if the send is still in the send queue. If so, remove it,
mark the request and cancelled and complete, and
release the device's reference to the request object.
*/
{
int cancelled;
if (proto == MPIDI_REQUEST_RNDV_MSG)
{
MPIR_Request * rts_sreq;
/* The cancellation of the RTS request needs to be atomic through
the destruction of the RTS request to avoid
conflict with release of the RTS request if the CTS is received
(see handling of a rendezvous CTS packet in
MPIDI_CH3U_Handle_recv_pkt()).
MPID_Request_fetch_and_clear_rts_sreq() is used to gurantee
that atomicity. */
MPIDI_Request_fetch_and_clear_rts_sreq(sreq, &rts_sreq);
if (rts_sreq != NULL)
{
cancelled = FALSE;
/* since we attempted to cancel a RTS request, then we are
responsible for releasing that request */
MPIR_Request_free(rts_sreq);
/* --BEGIN ERROR HANDLING-- */
if (mpi_errno != MPI_SUCCESS)
{
mpi_errno = MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, __func__, __LINE__, MPI_ERR_OTHER,
"**ch3|cancelrndv", 0);
goto fn_exit;
}
/* --END ERROR HANDLING-- */
if (cancelled)
{
MPIR_STATUS_SET_CANCEL_BIT(sreq->status, TRUE);
/* no other thread should be waiting on sreq, so it is
safe to reset ref_count and cc */
MPIR_cc_set(&sreq->cc, 0);
/* FIXME should be a decr and assert, not a set */
MPIR_Object_set_ref(sreq, 1);
goto fn_exit;
}
}
}
else
{
cancelled = FALSE;
if (cancelled)
{
MPIR_STATUS_SET_CANCEL_BIT(sreq->status, TRUE);
/* no other thread should be waiting on sreq, so it is safe to
reset ref_count and cc */
MPIR_cc_set(&sreq->cc, 0);
/* FIXME should be a decr and assert, not a set */
MPIR_Object_set_ref(sreq, 1);
goto fn_exit;
}
}
}
/* Part or all of the message has already been sent, so we need to send a
cancellation request to the receiver in an attempt
to catch the message before it is matched. */
{
int was_incomplete;
MPIDI_CH3_Pkt_t upkt;
MPIDI_CH3_Pkt_cancel_send_req_t * const csr_pkt = &upkt.cancel_send_req;
MPIR_Request * csr_sreq;
MPL_DBG_MSG_FMT(MPIDI_CH3_DBG_OTHER,VERBOSE,(MPL_DBG_FDEST,
"sending cancel request to %d for 0x%08x",
sreq->dev.match.parts.rank, sreq->handle));
/* The completion counter and reference count are incremented to keep
the request around long enough to receive a
response regardless of what the user does (free the request before
waiting, etc.). */
MPIDI_CH3U_Request_increment_cc(sreq, &was_incomplete);
if (!was_incomplete)
{
/* The reference count is incremented only if the request was
complete before the increment. */
MPIR_Request_add_ref( sreq );
}
MPIDI_Pkt_init(csr_pkt, MPIDI_CH3_PKT_CANCEL_SEND_REQ);
csr_pkt->match.parts.rank = sreq->comm->rank;
csr_pkt->match.parts.tag = sreq->dev.match.parts.tag;
csr_pkt->match.parts.context_id = sreq->dev.match.parts.context_id;
csr_pkt->sender_req_id = sreq->handle;
MPID_THREAD_CS_ENTER(POBJ, vc->pobj_mutex);
mpi_errno = MPIDI_CH3_iStartMsg(vc, csr_pkt, sizeof(*csr_pkt), &csr_sreq);
MPID_THREAD_CS_EXIT(POBJ, vc->pobj_mutex);
if (mpi_errno != MPI_SUCCESS) {
MPIR_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,"**ch3|cancelreq");
}
if (csr_sreq != NULL)
{
MPIR_Request_free(csr_sreq);
}
}
/* FIXME: if send cancellation packets are allowed to arrive out-of-order
with respect to send packets, then we need to
timestamp send and cancel packets to insure that a cancellation request
does not bypass the send packet to be cancelled
and erroneously cancel a previously sent message with the same request
handle. */
/* FIXME: A timestamp is more than is necessary; a message sequence number
should be adequate. */
fn_fail:
fn_exit:
MPIR_FUNC_VERBOSE_EXIT(MPID_STATE_MPID_CANCEL_SEND);
return mpi_errno;
}
