| Clover coverage report - PLT Utilities Test Coverage (plt-20120304-r5436) |
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| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| DelayedInterrupter.java | 50% | 100% | 100% | 94.1% |
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| 1 | /*BEGIN_COPYRIGHT_BLOCK* | |
| 2 | ||
| 3 | PLT Utilities BSD License | |
| 4 | ||
| 5 | Copyright (c) 2007-2010 JavaPLT group at Rice University | |
| 6 | All rights reserved. | |
| 7 | ||
| 8 | Developed by: Java Programming Languages Team | |
| 9 | Rice University | |
| 10 | http://www.cs.rice.edu/~javaplt/ | |
| 11 | ||
| 12 | Redistribution and use in source and binary forms, with or without modification, are permitted | |
| 13 | provided that the following conditions are met: | |
| 14 | ||
| 15 | - Redistributions of source code must retain the above copyright notice, this list of conditions | |
| 16 | and the following disclaimer. | |
| 17 | - Redistributions in binary form must reproduce the above copyright notice, this list of | |
| 18 | conditions and the following disclaimer in the documentation and/or other materials provided | |
| 19 | with the distribution. | |
| 20 | - Neither the name of the JavaPLT group, Rice University, nor the names of the library's | |
| 21 | contributors may be used to endorse or promote products derived from this software without | |
| 22 | specific prior written permission. | |
| 23 | ||
| 24 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR | |
| 25 | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND | |
| 26 | FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND | |
| 27 | CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 28 | DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 29 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER | |
| 30 | IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |
| 31 | OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 32 | ||
| 33 | *END_COPYRIGHT_BLOCK*/ | |
| 34 | ||
| 35 | package edu.rice.cs.plt.concurrent; | |
| 36 | ||
| 37 | import java.util.Timer; | |
| 38 | import java.util.TimerTask; | |
| 39 | ||
| 40 | import edu.rice.cs.plt.lambda.LazyThunk; | |
| 41 | import edu.rice.cs.plt.lambda.Thunk; | |
| 42 | ||
| 43 | /** | |
| 44 | * <p>Sets a "time bomb" on a specific thread: if the {@link #abort} method is not invoked within a specified | |
| 45 | * amount of time (in milliseconds), the thread will be interrupted. In contrast to {@link Object#wait(long)}, | |
| 46 | * implementing a timeout in this way clearly distinguishes between a timeout-triggered wake-up and a | |
| 47 | * {@link Object#notify()}-triggered or spurious wake-up. This alternative is also useful where the thread to | |
| 48 | * timeout performs multiple blocking operations, invokes blocking APIs that don't support timeouts | |
| 49 | * (like {@link java.io.InputStream#read}), or polls for an interrupted state.</p> | |
| 50 | * | |
| 51 | * <p>The timeout is implemented with a single {@link Timer} for all DelayedInterrupter instances. This | |
| 52 | * timer is a daemon: an outstanding DelayedInterrupter will not prevent the program from terminating.</p> | |
| 53 | */ | |
| 54 | public class DelayedInterrupter { | |
| 55 | ||
| 56 | /** | |
| 57 | * Delays instantiation of the timer thread until it's actually needed. (Code may reference this | |
| 58 | * class, for example, but never actually create a DelayedInterrupter object.) | |
| 59 | */ | |
| 60 | private static final LazyThunk<Timer> TIMER = new LazyThunk<Timer>(new Thunk<Timer>() { | |
| 61 | 4 | public Timer value() { return new Timer("DelayedInterrupter Timer", true); } |
| 62 | }); | |
| 63 | ||
| 64 | private final Thread _worker; | |
| 65 | private final TimerTask _task; | |
| 66 | ||
| 67 | /** | |
| 68 | * Create an interrupter for the current thread. | |
| 69 | * @param timeToInterrupt Number of milliseconds to allow an abort before the thread will be interrupted. | |
| 70 | */ | |
| 71 | 13 | public DelayedInterrupter(long timeToInterrupt) { this(Thread.currentThread(), timeToInterrupt); } |
| 72 | ||
| 73 | /** | |
| 74 | * Create an interrupter for the specified thread. | |
| 75 | * @param timeToInterrupt Number of milliseconds to allow an abort before the thread will be interrupted. | |
| 76 | */ | |
| 77 | 13 | public DelayedInterrupter(Thread worker, final long timeToInterrupt) { |
| 78 | 13 | _worker = worker; |
| 79 | 13 | _task = new TimerTask() { |
| 80 | 5 | public void run() { _worker.interrupt(); } |
| 81 | }; | |
| 82 | 13 | TIMER.value().schedule(_task, timeToInterrupt); |
| 83 | } | |
| 84 | ||
| 85 | /** | |
| 86 | * Abort the request to interrupt the thread. When called from the worker thread (this is the intended usage), | |
| 87 | * clears the interrupted status, in case the interrupt occurred but was not detected. | |
| 88 | */ | |
| 89 | 8 | public void abort() { |
| 90 | 8 | _task.cancel(); |
| 91 | 8 | TIMER.value().purge(); |
| 92 | 8 | if (Thread.currentThread() == _worker) { |
| 93 | 8 | Thread.interrupted(); // clear the interrupted status, in case it occurred but wasn't detected |
| 94 | } | |
| 95 | } | |
| 96 | ||
| 97 | } |
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