vipcqwait.c

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/********************************************************
 * Myricom VI-GM  networking software and documentation *
 * Copyright (c) 2001 by Myricom, Inc.                  *
 * All rights reserved.                                 *
 * See the file `COPYING' for copyright notice.         *
 ********************************************************/

#include <stdlib.h>

#include "vipl_priv.h"


VIP_ENTRY_POINT VIP_RETURN
VipCQWait (VIP_CQ_HANDLE CQHandle,
           VIP_ULONG Timeout,
           VIP_VI_HANDLE * ViHandle, VIP_BOOLEAN * RecvQueue)
{
  VIP_CQ *vip_cq_ptr;
  VIP_GM *vip_gm_ptr;
  VIP_NIC *vip_nic_ptr;
  VIP_RETURN vip_status;
  VIP_CQ_ENTRY *vip_cq_entry_ptr;
  VIP_DEBUG_LABEL (("VipCQWait"));

  /* check CQ handle */
  vip_cq_ptr = (VIP_CQ *) CQHandle;
  if (VIP_INVALID_CQ_HANDLE (vip_cq_ptr))
    {
      VIP_DEBUG (("Invalid CQ handle"));
      return VIP_INVALID_PARAMETER;
    }
  vip_nic_ptr = vip_cq_ptr->handle.vip_nic_ptr;
  vip_gm_ptr = vip_nic_ptr->vip_gm_ptr;
  VIP_MUTEX_LOCK (&(vip_gm_ptr->lock));
  VIP_PROGRESSION (vip_gm_ptr);
  VIP_MUTEX_LOCK (&(vip_nic_ptr->lock));

  /* check if first entry is complete */
  VIP_ASSERT (vip_cq_ptr->next_poll < vip_cq_ptr->count);
  vip_cq_entry_ptr = &(vip_cq_ptr->queue[vip_cq_ptr->next_poll]);
  if ((vip_cq_ptr->event_count > 0)
      || (vip_cq_entry_ptr->completed == VIP_FALSE))
    {
      VIP_DEBUG (("First Completion Queue entry is not complete, blocks..."));

      /* blocks */
      vip_cq_ptr->event_count++;
      VIP_MUTEX_UNLOCK (&(vip_nic_ptr->lock));
      vip_status =
        vip_wait_for_notification (Timeout,
                                   (VIP_HANDLE *) vip_cq_ptr,
                                   &(vip_cq_ptr->event),
                                   vip_is_first_cq_entry_notified,
                                   vip_cq_ptr);
      VIP_MUTEX_LOCK (&(vip_nic_ptr->lock));
      vip_cq_ptr->event_count--;

      /* check return code of blocking wait */
      switch (vip_status)
        {
        case VIP_SUCCESS:
          /* Completed by the entry may have changed */
          vip_cq_entry_ptr = &(vip_cq_ptr->queue[vip_cq_ptr->next_poll]);
          VIP_ASSERT (vip_cq_entry_ptr->completed == VIP_TRUE);
          break;

        case VIP_INVALID_PARAMETER:
          VIP_MUTEX_UNLOCK (&(vip_nic_ptr->lock));
          VIP_MUTEX_UNLOCK (&(vip_gm_ptr->lock));
          return VIP_INVALID_PARAMETER;

        case VIP_TIMEOUT:
          VIP_MUTEX_UNLOCK (&(vip_nic_ptr->lock));
          VIP_MUTEX_UNLOCK (&(vip_gm_ptr->lock));
          return VIP_TIMEOUT;

        default:
          VIP_ABORT (("Blocking wait return code is invalid"));
        }
    }

  /* dequeue the completion queue entry */
  if ((vip_cq_ptr->next_poll + 1) < vip_cq_ptr->count)
    {
      vip_cq_ptr->next_poll++;
    }
  else
    {
      vip_cq_ptr->next_poll = 0;
    }

  /* return usefull information */

  VIP_ASSERT (vip_cq_entry_ptr->vip_vi_ptr != NULL);
  *ViHandle = (VIP_VI_HANDLE) (vip_cq_entry_ptr->vip_vi_ptr);
  *RecvQueue = vip_cq_entry_ptr->recv_queue;

  /* invalid the cq entry */
  vip_cq_entry_ptr->vip_vi_ptr = NULL;
  vip_cq_entry_ptr->completed = VIP_FALSE;

  VIP_DEBUG (("Success"));
  VIP_MUTEX_UNLOCK (&(vip_nic_ptr->lock));
  VIP_MUTEX_UNLOCK (&(vip_gm_ptr->lock));
  return VIP_SUCCESS;
}