001: /*
002: *
003: *
004: * Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
005: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
006: *
007: * This program is free software; you can redistribute it and/or
008: * modify it under the terms of the GNU General Public License version
009: * 2 only, as published by the Free Software Foundation.
010: *
011: * This program is distributed in the hope that it will be useful, but
012: * WITHOUT ANY WARRANTY; without even the implied warranty of
013: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014: * General Public License version 2 for more details (a copy is
015: * included at /legal/license.txt).
016: *
017: * You should have received a copy of the GNU General Public License
018: * version 2 along with this work; if not, write to the Free Software
019: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020: * 02110-1301 USA
021: *
022: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
023: * Clara, CA 95054 or visit www.sun.com if you need additional
024: * information or have any questions.
025: */
026:
027: package com.sun.midp.links;
028:
029: /**
030: * A thread that receives a message on a given link.
031: */
032: class Receiver extends Thread {
033: public static final long TIMEOUT = 1000L;
034:
035: Link link;
036: LinkMessage msg;
037: boolean done;
038: Throwable exception;
039:
040: /**
041: * Constructs a new Receiver that starts a thread that calls receive() on
042: * newlink. After starting the thread, sleeps the indicated number of
043: * milliseconds to give the new thread a chance to run and call receive()
044: * before letting the caller's thread continue.
045: */
046: Receiver(Link newlink, long sleeptime) {
047: link = newlink;
048: done = false;
049: exception = null;
050: start();
051:
052: if (sleeptime > 0) {
053: Utils.sleep(sleeptime);
054: }
055: }
056:
057: /**
058: * Constructs a new Receiver, providing a default sleep time.
059: */
060: Receiver(Link newlink) {
061: this (newlink, 50L);
062: }
063:
064: /**
065: * Waits until the thread finishes or until a timeout has expired.
066: */
067: public void await() {
068: long timeout = System.currentTimeMillis() + TIMEOUT;
069: synchronized (this ) {
070: try {
071: while (System.currentTimeMillis() < timeout && !done) {
072: wait(TIMEOUT);
073: }
074: } catch (InterruptedException ignore) {
075: }
076: }
077: }
078:
079: /**
080: * Receives a message and notifies when done, capturing any exceptions.
081: */
082: public void run() {
083: LinkMessage lm;
084: try {
085: msg = link.receive();
086: } catch (Throwable t) {
087: exception = t;
088: } finally {
089: synchronized (this ) {
090: done = true;
091: notifyAll();
092: }
093: }
094:
095: completed(msg, exception);
096: }
097:
098: /**
099: * A completion callback. Called after the thread returns from the
100: * receive() call. The msg parameter contains the received message, or
101: * null if there was an exception was thrown. The thr parameter contains
102: * any Throwable caught, or null there was none. This is intended to be
103: * overridden by a subclass. The default implementation does nothing.
104: */
105: public void completed(LinkMessage msg, Throwable thr) {
106: }
107:
108: }
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