text: /* ***** BEGIN LICENSE BLOCK *****
   * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   *
   * The contents of this file are subject to the Mozilla Public License Version
   * 1.1 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   * http://www.mozilla.org/MPL/
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is Mozilla IPC.
   *
   * The Initial Developer of the Original Code is
   * Netscape Communications Corporation.
   * Portions created by the Initial Developer are Copyright (C) 2002
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *   Darin Fisher <darin@netscape.com>
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  
  #ifndef ipcLockProtocol_h__
  #define ipcLockProtocol_h__
  
  #include "prtypes.h"
  
  //
  // ipc lock message format:
  //
  //   +----------------------------------+
  //   | opcode : 4 bits                  |
  //   +----------------------------------+
  //   | flags  : 4 bits                  |
  //   +----------------------------------+
  //   | key    : null terminated string  |
  //   +----------------------------------+
  //
  
  // lock opcodes
  #define IPC_LOCK_OP_ACQUIRE          1
  #define IPC_LOCK_OP_RELEASE          2
  #define IPC_LOCK_OP_STATUS_ACQUIRED  3
  #define IPC_LOCK_OP_STATUS_FAILED    4
  #define IPC_LOCK_OP_STATUS_BUSY      5
  
  // lock flags
  #define IPC_LOCK_FL_NONBLOCKING 1
  
  // data structure for representing lock request message
  struct ipcLockMsg
  {
      PRUint8      opcode;
      PRUint8      flags;
      const char * key;
  };
  
  //
  // flatten a lock message
  //
  // returns a malloc'd buffer containing the flattened message.  on return,
  // bufLen contains the length of the flattened message.
  //
  PRUint8 *IPC_FlattenLockMsg(const ipcLockMsg *msg, PRUint32 *bufLen);
  
  //
  // unflatten a lock message.  upon return, msg->key points into buf, so
  // buf must not be deallocated until after msg is no longer needed.
  //
  void IPC_UnflattenLockMsg(const PRUint8 *buf, PRUint32 bufLen, ipcLockMsg *msg);
  
  //
  // TargetID for message passing
  //
  #define IPC_LOCK_TARGETID \
  { /* 703ada8a-2d38-4d5d-9d39-03d1ccceb567 */         \
      0x703ada8a,                                      \
      0x2d38,                                          \
      0x4d5d,                                          \
      {0x9d, 0x39, 0x03, 0xd1, 0xcc, 0xce, 0xb5, 0x67} \
  }
  
  #endif // !ipcLockProtocol_h__
  