udapl_tavor/common/dapl_evd_wait.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2002-2003, Network Appliance, Inc. All rights reserved.
 */

/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 *
 * MODULE: dapl_evd_wait.c
 *
 * PURPOSE: EVENT management
 *
 * Description: Interfaces in this file are completely defined in
 *              the uDAPL 1.1 API specification
 *
 * $Id: dapl_evd_wait.c,v 1.22 2003/08/20 13:18:36 sjs2 Exp $
 */

#include "dapl.h"
#include "dapl_evd_util.h"
#include "dapl_ring_buffer_util.h"
#include "dapl_adapter_util.h"

/*
 * dapl_evd_wait
 *
 * UDAPL Requirements Version xxx,
 *
 * Wait, up to specified timeout, for notification event on EVD.
 * Then return first available event.
 *
 * Input:
 *  evd_handle
 *  timeout
 *
 * Output:
 *  event
 *
 * Returns:
 *  DAT_SUCCESS
 *  DAT_INVALID_PARAMETER
 *  DAT_INVALID_STATE
 */
DAT_RETURN dapl_evd_wait(
    IN  DAT_EVD_HANDLE  evd_handle,
    IN  DAT_TIMEOUT time_out,
    IN  DAT_COUNT   threshold,
    OUT DAT_EVENT   *event,
    OUT DAT_COUNT   *nmore)

{
    DAPL_EVD        *evd_ptr;
    DAT_RETURN      dat_status;
    DAT_EVENT       *local_event;
    DAT_BOOLEAN     waitable;
    DAPL_EVD_STATE      evd_state;

    dapl_dbg_log(DAPL_DBG_TYPE_API,
        "dapl_evd_wait (%p, %d, %d, %p, %p)\n",
        evd_handle,
        time_out,
        threshold,
        event,
        nmore);

    evd_ptr = (DAPL_EVD *)evd_handle;
    dat_status = DAT_SUCCESS;

    if (DAPL_BAD_HANDLE(evd_ptr, DAPL_MAGIC_EVD)) {
        /*
         * We return directly rather than bailing because
         * bailing attempts to update the evd, and we don't have
         * one.
         */
        dat_status = DAT_ERROR(DAT_INVALID_HANDLE, 0);
        goto bail;
    }
    if (!event) {
        dat_status = DAT_ERROR(DAT_INVALID_PARAMETER, DAT_INVALID_ARG4);
        goto bail;
    }
    if (!nmore) {
        dat_status = DAT_ERROR(DAT_INVALID_PARAMETER, DAT_INVALID_ARG5);
        goto bail;
    }
    if (threshold <= 0 ||
        (threshold > 1 &&
        evd_ptr->completion_type != DAPL_EVD_STATE_THRESHOLD)) {
        dat_status = DAT_ERROR(DAT_INVALID_PARAMETER, DAT_INVALID_ARG3);
        goto bail;
    }
    if (evd_ptr->catastrophic_overflow) {
        dat_status = DAT_ERROR(DAT_INVALID_STATE, 0);
        goto bail;
    }

    dapl_dbg_log(DAPL_DBG_TYPE_EVD,
        "dapl_evd_wait: EVD %p, CQ %p\n",
        evd_ptr,
        (void *)evd_ptr->ib_cq_handle);

    /*
     * Make sure there are no other waiters and the evd is active.
     * Currently this means only the OPEN state is allowed.
     * We need to take a lock to synchronize with dapl_evd_dequeue().
     */

    dapl_os_lock(&evd_ptr->header.lock);
    waitable = evd_ptr->evd_waitable;
    evd_state = evd_ptr->evd_state;
    if (evd_state != DAPL_EVD_STATE_OPEN || !waitable) {
        dapl_os_unlock(&evd_ptr->header.lock);
        dat_status = DAT_ERROR(DAT_INVALID_STATE, 0);
        goto bail;
    }
    evd_ptr->evd_state = DAPL_EVD_STATE_WAITED;
    dapl_os_unlock(&evd_ptr->header.lock);

    /*
     * We now own the EVD, we don't have the lock anymore,
     * because we're in the WAITED state.
     */

    evd_ptr->threshold = threshold;

    /* return pending events immediately without further polling */
    if (dapls_rbuf_count(&evd_ptr->pending_event_queue) > 0) {
        evd_ptr->evd_state = DAPL_EVD_STATE_OPEN;
        dat_status = DAT_SUCCESS;
    } else {
        dat_status = dapls_evd_copy_events(evd_ptr, time_out);
        evd_ptr->evd_state = DAPL_EVD_STATE_OPEN;
        if (DAT_GET_TYPE(dat_status) == DAT_INTERRUPTED_CALL) {
            goto bail;
        }
        if (!evd_ptr->evd_waitable) {
            /* See if we were awakened by evd_set_unwaitable */
            dat_status = DAT_ERROR(DAT_INVALID_STATE, 0);
            goto bail;
        }
        if (dapls_rbuf_count(&evd_ptr->pending_event_queue) == 0) {
            dat_status = DAT_ERROR(DAT_TIMEOUT_EXPIRED, 0);
        }
    }

    if (dat_status == DAT_SUCCESS) {
        local_event = dapls_rbuf_remove(&evd_ptr->pending_event_queue);
        *event = *local_event;
        dat_status = dapls_rbuf_add(&evd_ptr->free_event_queue,
            local_event);
        dapl_os_assert(dat_status == DAT_SUCCESS);
    }

    /*
     * Valid if dat_status == DAT_SUCCESS || dat_status == DAT_TIMEOUT
     * Undefined otherwise, so ok to set it.
     */
    *nmore = dapls_rbuf_count(&evd_ptr->pending_event_queue);

bail:
    dapl_dbg_log(DAPL_DBG_TYPE_RTN,
        "dapl_evd_wait () returns 0x%x\n",
        dat_status);

    return (dat_status);
}