+/*
+ * "Copyright (c) 2005 Washington University in St. Louis.
+ * 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 WASHINGTON UNIVERSITY IN ST. LOUIS 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 WASHINGTON
+ * UNIVERSITY IN ST. LOUIS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * WASHINGTON UNIVERSITY IN ST. LOUIS 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 WASHINGTON UNIVERSITY IN ST. LOUIS HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
+ * MODIFICATIONS."
+ */
+
+/*
+ * Copyright (c) 2004, Technische Universitat Berlin
+ * 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 Technische Universitat Berlin 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 COPYRIGHT
+ * OWNER OR 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.
+ *
+ */
+
+ /**
+ * This interface is the same as the standard <tt>Resource</tt>
+ * interface, except that it has one new command <tt>transferTo()</tt>
+ * and one new event <tt>transferred()</tt>, which allow to pass
+ * the resource from one component to another.
+ *
+ * @author Jan Hauer <hauer@tkn.tu-berlin.de>
+ */
+
+interface TransferableResource
+{
+ /**
+ * Request access to a shared resource. You must call release()
+ * when you are done with it.
+ *
+ * @return SUCCESS When a request has been accepted. The granted()
+ * event will be signaled once you have control of the
+ * resource.<br>
+ * EBUSY You have already requested this resource and a
+ * granted event is pending
+ */
+ async command error_t request();
+
+ /**
+ * Request immediate access to a shared resource. You must call release()
+ * when you are done with it.
+ *
+ * @return SUCCESS When a request has been accepted. <br>
+ * FAIL The request cannot be fulfilled
+ */
+ async command error_t immediateRequest();
+
+ /**
+ * You are now in control of the resource.
+ */
+ event void granted();
+
+ /**
+ * Transfers ownership of a resource to another client, which will in turn
+ * be signalled the <tt>transferred()</tt> event. This command may override
+ * the default queueing policy.
+ *
+ * @param dstClient The identifier of the client to transfer the resource to.
+ *
+ * @return SUCCESS If ownership has been transferred; FAIL if ownership has
+ * not been transferred, because the caller is not owner of the resource or
+ * a client with the identifer <tt>dstClient</tt> is not present.
+ */
+ async command error_t transferTo(uint8_t dstClient);
+
+ /**
+ * Another client transferred ownership of the resource to you by calling
+ * the <tt>transfer()</tt> command, i.e. you are now in control of the resource.
+ *
+ * @param srcClient The identifier of the client that transferred the resource to you.
+ */
+ async event void transferredFrom(uint8_t srcClient);
+
+ /**
+ * Release a shared resource you previously acquired.
+ *
+ * @return SUCCESS The resource has been released <br>
+ * FAIL You tried to release but you are not the
+ * owner of the resource
+ *
+ * @note This command should never be called between putting in a request
+ * and waiting for a granted event. Doing so will result in a
+ * potential race condition. There are ways to guarantee that no
+ * race will occur, but they are clumsy and overly complicated.
+ * Since it doesn't logically make since to be calling
+ * <code>release</code> before receiving a <code>granted</code> event,
+ * we have opted to keep thing simple and warn you about the potential
+ * race.
+ */
+ async command error_t release();
+
+ /**
+ * Check if the user of this interface is the current
+ * owner of the Resource
+ * @return TRUE It is the owner <br>
+ * FALSE It is not the owner
+ */
+ async command bool isOwner();
+}