/*									tab:4 * * * "Copyright (c) 2000-2002 The Regents of the University  of California.   * All rights reserved. * * Permission to use, copy, modify, and distribute this software and its * documentation for any purpose, without fee, and without written agreement is * hereby granted, provided that the above copyright notice, the following * two paragraphs and the author appear in all copies of this software. *  * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *  * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS." * *//*									tab:4 *  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.  By *  downloading, copying, installing or using the software you agree to *  this license.  If you do not agree to this license, do not download, *  install, copy or use the software. * *  Intel Open Source License  * *  Copyright (c) 2002 Intel Corporation  *  All rights reserved.  *  Redistribution and use in source and binary forms, with or without *  modification, are permitted provided that the following conditions are *  met: *  *	Redistributions of source code must retain the above copyright *  notice, this list of conditions and the following disclaimer. *	Redistributions in binary form must reproduce the above copyright *  notice, this list of conditions and the following disclaimer in the *  documentation and/or other materials provided with the distribution. *      Neither the name of the Intel Corporation nor the names of its *  contributors may be used to endorse or promote products derived from *  this software without specific prior written permission. *   *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE INTEL OR ITS *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, *  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *  *  *//* * Authors:   Philip Levis * History:   July 21, 2002 *	      * *//** * @author Philip Levis */includes Bombilla;module BLocksSafe {  provides interface BombillaLocks as Locks;  provides command bool indexValid(uint8_t lockIndex);  uses interface BombillaError;}implementation {  BombillaLock locks[BOMB_HEAPSIZE];    command bool indexValid(uint8_t lockIndex) {    if (lockIndex >= BOMB_HEAPSIZE) {return FALSE;}    else {return TRUE;}  }  command void Locks.reboot() {    int i;    for (i = 0; i < BOMB_HEAPSIZE; i++) {      locks[i].holder = NULL;    }  }  command result_t Locks.lock(BombillaContext* context,                              uint8_t lockNum) {    if (!(call indexValid(lockNum))) {      call BombillaError.error(context, BOMB_ERROR_INVALID_LOCK);      return FAIL;    }    if (call Locks.isLocked(lockNum)) {      dbg(DBG_ERROR, "VM: Context %i failed locking lock %i; already held by context %i.\n", (int)context->which, (int)lockNum, (int)locks[lockNum].holder->which);      call BombillaError.error(context, BOMB_ERROR_LOCK_STEAL);      return FAIL;    }    locks[(int)lockNum].holder = context;    context->heldSet |= (1 << lockNum);    dbg(DBG_USR2, "VM: Context %i locking lock %i\n", (int)context->which, (int)lockNum);    return SUCCESS;  }  command result_t Locks.unlock(BombillaContext* context,								uint8_t lockNum) {    if (!(call indexValid(lockNum))) {      call BombillaError.error(context, BOMB_ERROR_INVALID_LOCK);      return FAIL;    }    if (!call Locks.isLocked(lockNum)) {      dbg(DBG_ERROR, "VM: Context %i failed unlocking lock %i: lock not held.\n", (int)context->which, (int)lockNum);      call BombillaError.error(context, BOMB_ERROR_UNLOCK_INVALID);      return FAIL;    }    if (!(context->heldSet & (1 << lockNum))) {      dbg(DBG_ERROR, "VM: Context %i failed unlocking lock %i: don't hold lock.\n", (int)context->which, (int)lockNum);      call BombillaError.error(context, BOMB_ERROR_UNLOCK_INVALID);      return FAIL;    }    context->heldSet &= ~(1 << lockNum);    locks[(int)lockNum].holder = 0;    dbg(DBG_USR2, "VM: Context %i unlocking lock %i\n", (int)context->which, (int)lockNum);    return SUCCESS;  }	  command bool Locks.isLocked(uint8_t lockNum) {    if (!(call indexValid(lockNum))) {      return TRUE;    }    return (locks[(int)lockNum].holder != 0);  }	  command bool Locks.isHeldBy(uint8_t lockNum,                              BombillaContext* context) {    if (!(call indexValid(lockNum))) {      return FALSE;    }    return (locks[(int)lockNum].holder == context);  }}