tos/interfaces/ArbiterInfo.nc

   1 /*
   2  * "Copyright (c) 2005 Washington University in St. Louis.
   3  * All rights reserved.
   4  *
   5  * Permission to use, copy, modify, and distribute this software and its
   6  * documentation for any purpose, without fee, and without written agreement is
   7  * hereby granted, provided that the above copyright notice, the following
   8  * two paragraphs and the author appear in all copies of this software.
   9  *
  10  * IN NO EVENT SHALL WASHINGTON UNIVERSITY IN ST. LOUIS BE LIABLE TO ANY PARTY
  11  * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
  12  * OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF WASHINGTON
  13  * UNIVERSITY IN ST. LOUIS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  14  *
  15  * WASHINGTON UNIVERSITY IN ST. LOUIS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  16  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  17  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  18  * ON AN "AS IS" BASIS, AND WASHINGTON UNIVERSITY IN ST. LOUIS HAS NO
  19  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
  20  * MODIFICATIONS."
  21  */
  22
  23 /*
  24  * Copyright (c) 2004, Technische Universitat Berlin
  25  * All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * - Redistributions of source code must retain the above copyright notice,
  31  *   this list of conditions and the following disclaimer.
  32  * - Redistributions in binary form must reproduce the above copyright
  33  *   notice, this list of conditions and the following disclaimer in the
  34  *   documentation and/or other materials provided with the distribution.
  35  * - Neither the name of the Technische Universitat Berlin nor the names
  36  *   of its contributors may be used to endorse or promote products derived
  37  *   from this software without specific prior written permission.
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  40  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  41  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  42  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  43  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  45  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
  46  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  47  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  48  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  49  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  50 */
  51
  52 /*
  53  * - Revision -------------------------------------------------------------
  54  * $Revision$
  55  * $Date$
  56  * ========================================================================
  57  */
  58
  59 /**
  60  * Please refer to TEP 108 for more information about this interface and its
  61  * intended use.<br><br>
  62  *
  63  * The ArbiterInfo interface allows a component to query the current
  64  * status of an arbiter.  It must be provided by ALL arbiter implementations,
  65  * and can be used for a variety of different purposes.  Normally it will be
  66  * used in conjunction with the Resource interface for performing run time
  67  * checks on access rights to a particular shared resource.
  68  *
  69  * @author Kevin Klues (klueska@cs.wustl.edu)
  70  */
  71
  72 interface ArbiterInfo {
  73   /**
  74    * Check whether a resource is currently allocated.
  75    *
  76    * @return TRUE If the resource being arbitrated is currently allocated
  77    *              to any of its users<br>
  78    *         FALSE Otherwise.
  79    */
  80   async command bool inUse();
  81
  82   /**
  83    * Get the id of the client currently using a resource.
  84    *
  85    * @return Id of the current owner of the resource<br>
  86    *         0xFF if no one currently owns the resource
  87    */
  88   async command uint8_t userId();
  89 }