| /* |
| * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| package sun.jvm.hotspot.utilities; |
| |
| /** <p> A two-way unbounded-length message queue useful for |
| communication between threads. Messages written on one side become |
| readable on the other in first-in, first-out order. This is an |
| interface to one of two "sides" of an underlying backend, for |
| example, the MessageQueueBackend. </p> */ |
| |
| public interface MessageQueue { |
| /** This blocks until a message is available. Even if the thread is |
| interrupted while it is waiting, this will not return until a |
| message is written by the entity on the other side of the |
| queue. */ |
| public Object readMessage(); |
| |
| /** This blocks for up to <code>millis</code> milliseconds until a |
| message is available. If no message becomes available within |
| this time period, or the thread is interrupted during the wait, |
| returns null. (This implies that passing the value null back and |
| forth is not distinguishable with this method.) Passing a value |
| of 0 for the <code>millis</code> argument causes this method to |
| return without blocking. The millis argument must be greater |
| than or equal to zero. */ |
| public Object readMessageWithTimeout(long millis); |
| |
| /** Write a message to the queue */ |
| public void writeMessage(Object obj); |
| } |