2 * Copyright (c) 2014 Brocade Communications Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.yangtools.util.concurrent;
11 import com.google.common.base.MoreObjects;
12 import com.google.common.base.MoreObjects.ToStringHelper;
13 import java.util.concurrent.ThreadPoolExecutor;
14 import java.util.concurrent.TimeUnit;
15 import org.slf4j.LoggerFactory;
18 * A ThreadPoolExecutor with a specified bounded queue capacity that favors creating new threads
19 * over queuing, as the former is faster.
21 * <p>See {@link SpecialExecutors#newBoundedFastThreadPool} for more details.
23 * @author Thomas Pantelis
25 public class FastThreadPoolExecutor extends ThreadPoolExecutor {
27 private static final long DEFAULT_IDLE_TIMEOUT_IN_SEC = 15L;
29 private final String threadPrefix;
30 private final int maximumQueueSize;
33 * Constructs a FastThreadPoolExecutor instance.
35 * @param maximumPoolSize
36 * the maximum number of threads to allow in the pool. Threads will terminate after
37 * being idle for 15 seconds.
38 * @param maximumQueueSize
39 * the capacity of the queue.
41 * the name prefix for threads created by this executor.
42 * @param loggerIdentity
43 * the class to use as logger name for logging uncaught exceptions from the threads.
45 public FastThreadPoolExecutor(final int maximumPoolSize, final int maximumQueueSize, final String threadPrefix,
46 final Class<?> loggerIdentity) {
47 this(maximumPoolSize, maximumQueueSize, DEFAULT_IDLE_TIMEOUT_IN_SEC, TimeUnit.SECONDS,
48 threadPrefix, loggerIdentity);
54 * @deprecated Please use
55 * {@link #FastThreadPoolExecutor(int, int, String, Class)}
59 public FastThreadPoolExecutor(final int maximumPoolSize, final int maximumQueueSize, final String threadPrefix) {
60 this(maximumPoolSize, maximumQueueSize, DEFAULT_IDLE_TIMEOUT_IN_SEC, TimeUnit.SECONDS,
67 * @deprecated Please use
68 * {@link #FastThreadPoolExecutor(int, int, long, TimeUnit, String, Class)}
72 public FastThreadPoolExecutor(final int maximumPoolSize, final int maximumQueueSize, final long keepAliveTime,
73 final TimeUnit unit, final String threadPrefix) {
74 this(maximumPoolSize, maximumQueueSize, keepAliveTime, unit, threadPrefix, FastThreadPoolExecutor.class);
78 * Constructs a FastThreadPoolExecutor instance.
80 * @param maximumPoolSize
81 * the maximum number of threads to allow in the pool.
82 * @param maximumQueueSize
83 * the capacity of the queue.
84 * @param keepAliveTime
85 * the maximum time that idle threads will wait for new tasks before terminating.
87 * the time unit for the keepAliveTime argument
89 * the name prefix for threads created by this executor.
90 * @param loggerIdentity
91 * the class to use as logger name for logging uncaught exceptions from the threads.
93 // due to loggerIdentity argument usage
94 @SuppressWarnings("checkstyle:LoggerFactoryClassParameter")
95 public FastThreadPoolExecutor(final int maximumPoolSize, final int maximumQueueSize, final long keepAliveTime,
96 final TimeUnit unit, final String threadPrefix, final Class<?> loggerIdentity) {
97 // We use all core threads (the first 2 parameters below equal) so, when a task is submitted,
98 // if the thread limit hasn't been reached, a new thread will be spawned to execute
99 // the task even if there is an existing idle thread in the pool. This is faster than
100 // handing the task to an existing idle thread via the queue. Once the thread limit is
101 // reached, subsequent tasks will be queued. If the queue is full, tasks will be rejected.
103 super(maximumPoolSize, maximumPoolSize, keepAliveTime, unit,
104 new TrackingLinkedBlockingQueue<>(maximumQueueSize));
106 this.threadPrefix = threadPrefix;
107 this.maximumQueueSize = maximumQueueSize;
109 setThreadFactory(ThreadFactoryProvider.builder().namePrefix(threadPrefix)
110 .logger(LoggerFactory.getLogger(loggerIdentity)).build().get());
112 if (keepAliveTime > 0) {
113 // Need to specifically configure core threads to timeout.
114 allowCoreThreadTimeOut(true);
117 setRejectedExecutionHandler(CountingRejectedExecutionHandler.newAbortPolicy());
120 public long getLargestQueueSize() {
121 return ((TrackingLinkedBlockingQueue<?>)getQueue()).getLargestQueueSize();
124 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
125 return toStringHelper;
129 public final String toString() {
130 return addToStringAttributes(MoreObjects.toStringHelper(this)
131 .add("Thread Prefix", threadPrefix)
132 .add("Current Thread Pool Size", getPoolSize())
133 .add("Largest Thread Pool Size", getLargestPoolSize())
134 .add("Max Thread Pool Size", getMaximumPoolSize())
135 .add("Current Queue Size", getQueue().size())
136 .add("Largest Queue Size", getLargestQueueSize())
137 .add("Max Queue Size", maximumQueueSize)
138 .add("Active Thread Count", getActiveCount())
139 .add("Completed Task Count", getCompletedTaskCount())
140 .add("Total Task Count", getTaskCount())).toString();