1 |
dl |
1.1 |
/* |
2 |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
dl |
1.11 |
* Expert Group and released to the public domain, as explained at |
4 |
jsr166 |
1.58 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
dl |
1.1 |
*/ |
6 |
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package java.util.concurrent; |
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jsr166 |
1.82 |
|
9 |
jsr166 |
1.83 |
import static java.util.concurrent.TimeUnit.MILLISECONDS; |
10 |
jsr166 |
1.62 |
import static java.util.concurrent.TimeUnit.NANOSECONDS; |
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jsr166 |
1.83 |
|
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jsr166 |
1.82 |
import java.util.AbstractQueue; |
13 |
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import java.util.Arrays; |
14 |
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import java.util.Collection; |
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import java.util.Iterator; |
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import java.util.List; |
17 |
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import java.util.NoSuchElementException; |
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jsr166 |
1.106 |
import java.util.Objects; |
19 |
jsr166 |
1.83 |
import java.util.concurrent.atomic.AtomicLong; |
20 |
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import java.util.concurrent.locks.Condition; |
21 |
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import java.util.concurrent.locks.ReentrantLock; |
22 |
dl |
1.1 |
|
23 |
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/** |
24 |
dl |
1.7 |
* A {@link ThreadPoolExecutor} that can additionally schedule |
25 |
jsr166 |
1.75 |
* commands to run after a given delay, or to execute periodically. |
26 |
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* This class is preferable to {@link java.util.Timer} when multiple |
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* worker threads are needed, or when the additional flexibility or |
28 |
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* capabilities of {@link ThreadPoolExecutor} (which this class |
29 |
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* extends) are required. |
30 |
dl |
1.1 |
* |
31 |
jsr166 |
1.46 |
* <p>Delayed tasks execute no sooner than they are enabled, but |
32 |
dl |
1.18 |
* without any real-time guarantees about when, after they are |
33 |
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* enabled, they will commence. Tasks scheduled for exactly the same |
34 |
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* execution time are enabled in first-in-first-out (FIFO) order of |
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jsr166 |
1.46 |
* submission. |
36 |
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* |
37 |
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* <p>When a submitted task is cancelled before it is run, execution |
38 |
jsr166 |
1.75 |
* is suppressed. By default, such a cancelled task is not |
39 |
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* automatically removed from the work queue until its delay elapses. |
40 |
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* While this enables further inspection and monitoring, it may also |
41 |
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* cause unbounded retention of cancelled tasks. To avoid this, use |
42 |
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* {@link #setRemoveOnCancelPolicy} to cause tasks to be immediately |
43 |
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* removed from the work queue at time of cancellation. |
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dl |
1.1 |
* |
45 |
jsr166 |
1.75 |
* <p>Successive executions of a periodic task scheduled via |
46 |
jsr166 |
1.84 |
* {@link #scheduleAtFixedRate scheduleAtFixedRate} or |
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* {@link #scheduleWithFixedDelay scheduleWithFixedDelay} |
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* do not overlap. While different executions may be performed by |
49 |
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* different threads, the effects of prior executions |
50 |
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* <a href="package-summary.html#MemoryVisibility"><i>happen-before</i></a> |
51 |
dl |
1.51 |
* those of subsequent ones. |
52 |
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* |
53 |
dl |
1.1 |
* <p>While this class inherits from {@link ThreadPoolExecutor}, a few |
54 |
dl |
1.8 |
* of the inherited tuning methods are not useful for it. In |
55 |
jsr166 |
1.53 |
* particular, because it acts as a fixed-sized pool using |
56 |
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* {@code corePoolSize} threads and an unbounded queue, adjustments |
57 |
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* to {@code maximumPoolSize} have no useful effect. Additionally, it |
58 |
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* is almost never a good idea to set {@code corePoolSize} to zero or |
59 |
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* use {@code allowCoreThreadTimeOut} because this may leave the pool |
60 |
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* without threads to handle tasks once they become eligible to run. |
61 |
dl |
1.1 |
* |
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jsr166 |
1.103 |
* <p>As with {@code ThreadPoolExecutor}, if not otherwise specified, |
63 |
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* this class uses {@link Executors#defaultThreadFactory} as the |
64 |
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* default thread factory, and {@link ThreadPoolExecutor.AbortPolicy} |
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* as the default rejected execution handler. |
66 |
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* |
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jsr166 |
1.39 |
* <p><b>Extension notes:</b> This class overrides the |
68 |
jsr166 |
1.69 |
* {@link ThreadPoolExecutor#execute(Runnable) execute} and |
69 |
jsr166 |
1.39 |
* {@link AbstractExecutorService#submit(Runnable) submit} |
70 |
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* methods to generate internal {@link ScheduledFuture} objects to |
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* control per-task delays and scheduling. To preserve |
72 |
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* functionality, any further overrides of these methods in |
73 |
dl |
1.32 |
* subclasses must invoke superclass versions, which effectively |
74 |
jsr166 |
1.39 |
* disables additional task customization. However, this class |
75 |
dl |
1.32 |
* provides alternative protected extension method |
76 |
jsr166 |
1.39 |
* {@code decorateTask} (one version each for {@code Runnable} and |
77 |
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* {@code Callable}) that can be used to customize the concrete task |
78 |
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* types used to execute commands entered via {@code execute}, |
79 |
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* {@code submit}, {@code schedule}, {@code scheduleAtFixedRate}, |
80 |
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* and {@code scheduleWithFixedDelay}. By default, a |
81 |
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* {@code ScheduledThreadPoolExecutor} uses a task type extending |
82 |
dl |
1.32 |
* {@link FutureTask}. However, this may be modified or replaced using |
83 |
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* subclasses of the form: |
84 |
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* |
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jsr166 |
1.85 |
* <pre> {@code |
86 |
dl |
1.23 |
* public class CustomScheduledExecutor extends ScheduledThreadPoolExecutor { |
87 |
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* |
88 |
jsr166 |
1.39 |
* static class CustomTask<V> implements RunnableScheduledFuture<V> { ... } |
89 |
dl |
1.23 |
* |
90 |
jsr166 |
1.39 |
* protected <V> RunnableScheduledFuture<V> decorateTask( |
91 |
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* Runnable r, RunnableScheduledFuture<V> task) { |
92 |
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* return new CustomTask<V>(r, task); |
93 |
jsr166 |
1.29 |
* } |
94 |
dl |
1.23 |
* |
95 |
jsr166 |
1.39 |
* protected <V> RunnableScheduledFuture<V> decorateTask( |
96 |
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* Callable<V> c, RunnableScheduledFuture<V> task) { |
97 |
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* return new CustomTask<V>(c, task); |
98 |
jsr166 |
1.29 |
* } |
99 |
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* // ... add constructors, etc. |
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jsr166 |
1.39 |
* }}</pre> |
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* |
102 |
dl |
1.1 |
* @since 1.5 |
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* @author Doug Lea |
104 |
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*/ |
105 |
jsr166 |
1.21 |
public class ScheduledThreadPoolExecutor |
106 |
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extends ThreadPoolExecutor |
107 |
tim |
1.3 |
implements ScheduledExecutorService { |
108 |
dl |
1.1 |
|
109 |
dl |
1.37 |
/* |
110 |
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* This class specializes ThreadPoolExecutor implementation by |
111 |
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* |
112 |
jsr166 |
1.99 |
* 1. Using a custom task type ScheduledFutureTask, even for tasks |
113 |
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* that don't require scheduling because they are submitted |
114 |
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* using ExecutorService rather than ScheduledExecutorService |
115 |
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* methods, which are treated as tasks with a delay of zero. |
116 |
dl |
1.37 |
* |
117 |
jsr166 |
1.46 |
* 2. Using a custom queue (DelayedWorkQueue), a variant of |
118 |
dl |
1.37 |
* unbounded DelayQueue. The lack of capacity constraint and |
119 |
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* the fact that corePoolSize and maximumPoolSize are |
120 |
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* effectively identical simplifies some execution mechanics |
121 |
jsr166 |
1.46 |
* (see delayedExecute) compared to ThreadPoolExecutor. |
122 |
dl |
1.37 |
* |
123 |
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* 3. Supporting optional run-after-shutdown parameters, which |
124 |
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* leads to overrides of shutdown methods to remove and cancel |
125 |
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* tasks that should NOT be run after shutdown, as well as |
126 |
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* different recheck logic when task (re)submission overlaps |
127 |
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* with a shutdown. |
128 |
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* |
129 |
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* 4. Task decoration methods to allow interception and |
130 |
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* instrumentation, which are needed because subclasses cannot |
131 |
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* otherwise override submit methods to get this effect. These |
132 |
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* don't have any impact on pool control logic though. |
133 |
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*/ |
134 |
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|
135 |
dl |
1.1 |
/** |
136 |
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* False if should cancel/suppress periodic tasks on shutdown. |
137 |
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*/ |
138 |
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private volatile boolean continueExistingPeriodicTasksAfterShutdown; |
139 |
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140 |
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/** |
141 |
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* False if should cancel non-periodic tasks on shutdown. |
142 |
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*/ |
143 |
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private volatile boolean executeExistingDelayedTasksAfterShutdown = true; |
144 |
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145 |
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/** |
146 |
jsr166 |
1.75 |
* True if ScheduledFutureTask.cancel should remove from queue. |
147 |
dl |
1.41 |
*/ |
148 |
jsr166 |
1.90 |
volatile boolean removeOnCancel; |
149 |
dl |
1.41 |
|
150 |
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/** |
151 |
dl |
1.1 |
* Sequence number to break scheduling ties, and in turn to |
152 |
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* guarantee FIFO order among tied entries. |
153 |
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*/ |
154 |
jsr166 |
1.60 |
private static final AtomicLong sequencer = new AtomicLong(); |
155 |
dl |
1.14 |
|
156 |
jsr166 |
1.21 |
private class ScheduledFutureTask<V> |
157 |
peierls |
1.22 |
extends FutureTask<V> implements RunnableScheduledFuture<V> { |
158 |
jsr166 |
1.21 |
|
159 |
dl |
1.1 |
/** Sequence number to break ties FIFO */ |
160 |
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private final long sequenceNumber; |
161 |
jsr166 |
1.44 |
|
162 |
jsr166 |
1.99 |
/** The nanoTime-based time when the task is enabled to execute. */ |
163 |
dl |
1.88 |
private volatile long time; |
164 |
jsr166 |
1.44 |
|
165 |
dl |
1.16 |
/** |
166 |
jsr166 |
1.99 |
* Period for repeating tasks, in nanoseconds. |
167 |
jsr166 |
1.75 |
* A positive value indicates fixed-rate execution. |
168 |
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* A negative value indicates fixed-delay execution. |
169 |
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* A value of 0 indicates a non-repeating (one-shot) task. |
170 |
dl |
1.16 |
*/ |
171 |
dl |
1.1 |
private final long period; |
172 |
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|
173 |
jsr166 |
1.48 |
/** The actual task to be re-enqueued by reExecutePeriodic */ |
174 |
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RunnableScheduledFuture<V> outerTask = this; |
175 |
jsr166 |
1.44 |
|
176 |
dl |
1.1 |
/** |
177 |
dl |
1.40 |
* Index into delay queue, to support faster cancellation. |
178 |
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*/ |
179 |
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int heapIndex; |
180 |
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181 |
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/** |
182 |
jsr166 |
1.30 |
* Creates a one-shot action with given nanoTime-based trigger time. |
183 |
dl |
1.1 |
*/ |
184 |
jsr166 |
1.89 |
ScheduledFutureTask(Runnable r, V result, long triggerTime, |
185 |
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long sequenceNumber) { |
186 |
dl |
1.1 |
super(r, result); |
187 |
jsr166 |
1.75 |
this.time = triggerTime; |
188 |
dl |
1.1 |
this.period = 0; |
189 |
jsr166 |
1.89 |
this.sequenceNumber = sequenceNumber; |
190 |
dl |
1.1 |
} |
191 |
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192 |
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/** |
193 |
jsr166 |
1.75 |
* Creates a periodic action with given nanoTime-based initial |
194 |
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* trigger time and period. |
195 |
dl |
1.1 |
*/ |
196 |
jsr166 |
1.75 |
ScheduledFutureTask(Runnable r, V result, long triggerTime, |
197 |
jsr166 |
1.89 |
long period, long sequenceNumber) { |
198 |
dl |
1.1 |
super(r, result); |
199 |
jsr166 |
1.75 |
this.time = triggerTime; |
200 |
dl |
1.1 |
this.period = period; |
201 |
jsr166 |
1.89 |
this.sequenceNumber = sequenceNumber; |
202 |
dl |
1.1 |
} |
203 |
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|
204 |
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/** |
205 |
jsr166 |
1.65 |
* Creates a one-shot action with given nanoTime-based trigger time. |
206 |
dl |
1.1 |
*/ |
207 |
jsr166 |
1.89 |
ScheduledFutureTask(Callable<V> callable, long triggerTime, |
208 |
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long sequenceNumber) { |
209 |
dl |
1.1 |
super(callable); |
210 |
jsr166 |
1.75 |
this.time = triggerTime; |
211 |
dl |
1.1 |
this.period = 0; |
212 |
jsr166 |
1.89 |
this.sequenceNumber = sequenceNumber; |
213 |
dl |
1.1 |
} |
214 |
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|
215 |
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public long getDelay(TimeUnit unit) { |
216 |
jsr166 |
1.98 |
return unit.convert(time - System.nanoTime(), NANOSECONDS); |
217 |
dl |
1.1 |
} |
218 |
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|
219 |
dl |
1.20 |
public int compareTo(Delayed other) { |
220 |
dl |
1.59 |
if (other == this) // compare zero if same object |
221 |
dl |
1.1 |
return 0; |
222 |
dl |
1.34 |
if (other instanceof ScheduledFutureTask) { |
223 |
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ScheduledFutureTask<?> x = (ScheduledFutureTask<?>)other; |
224 |
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long diff = time - x.time; |
225 |
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if (diff < 0) |
226 |
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return -1; |
227 |
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else if (diff > 0) |
228 |
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return 1; |
229 |
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else if (sequenceNumber < x.sequenceNumber) |
230 |
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return -1; |
231 |
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else |
232 |
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return 1; |
233 |
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} |
234 |
jsr166 |
1.64 |
long diff = getDelay(NANOSECONDS) - other.getDelay(NANOSECONDS); |
235 |
jsr166 |
1.61 |
return (diff < 0) ? -1 : (diff > 0) ? 1 : 0; |
236 |
dl |
1.1 |
} |
237 |
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|
238 |
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/** |
239 |
jsr166 |
1.70 |
* Returns {@code true} if this is a periodic (not a one-shot) action. |
240 |
jsr166 |
1.30 |
* |
241 |
jsr166 |
1.70 |
* @return {@code true} if periodic |
242 |
dl |
1.1 |
*/ |
243 |
dl |
1.23 |
public boolean isPeriodic() { |
244 |
dl |
1.16 |
return period != 0; |
245 |
dl |
1.1 |
} |
246 |
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|
247 |
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/** |
248 |
jsr166 |
1.39 |
* Sets the next time to run for a periodic task. |
249 |
dl |
1.13 |
*/ |
250 |
dl |
1.37 |
private void setNextRunTime() { |
251 |
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long p = period; |
252 |
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if (p > 0) |
253 |
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time += p; |
254 |
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else |
255 |
jsr166 |
1.54 |
time = triggerTime(-p); |
256 |
dl |
1.13 |
} |
257 |
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|
258 |
dl |
1.40 |
public boolean cancel(boolean mayInterruptIfRunning) { |
259 |
jsr166 |
1.100 |
// The racy read of heapIndex below is benign: |
260 |
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// if heapIndex < 0, then OOTA guarantees that we have surely |
261 |
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// been removed; else we recheck under lock in remove() |
262 |
dl |
1.41 |
boolean cancelled = super.cancel(mayInterruptIfRunning); |
263 |
|
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if (cancelled && removeOnCancel && heapIndex >= 0) |
264 |
jsr166 |
1.42 |
remove(this); |
265 |
dl |
1.41 |
return cancelled; |
266 |
dl |
1.40 |
} |
267 |
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|
268 |
dl |
1.13 |
/** |
269 |
dl |
1.5 |
* Overrides FutureTask version so as to reset/requeue if periodic. |
270 |
jsr166 |
1.21 |
*/ |
271 |
dl |
1.1 |
public void run() { |
272 |
dl |
1.37 |
boolean periodic = isPeriodic(); |
273 |
|
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if (!canRunInCurrentRunState(periodic)) |
274 |
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cancel(false); |
275 |
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else if (!periodic) |
276 |
jsr166 |
1.91 |
super.run(); |
277 |
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else if (super.runAndReset()) { |
278 |
dl |
1.37 |
setNextRunTime(); |
279 |
jsr166 |
1.44 |
reExecutePeriodic(outerTask); |
280 |
dl |
1.37 |
} |
281 |
dl |
1.1 |
} |
282 |
|
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} |
283 |
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|
284 |
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/** |
285 |
dl |
1.37 |
* Returns true if can run a task given current run state |
286 |
jsr166 |
1.39 |
* and run-after-shutdown parameters. |
287 |
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* |
288 |
dl |
1.37 |
* @param periodic true if this task periodic, false if delayed |
289 |
|
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*/ |
290 |
|
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boolean canRunInCurrentRunState(boolean periodic) { |
291 |
jsr166 |
1.38 |
return isRunningOrShutdown(periodic ? |
292 |
dl |
1.37 |
continueExistingPeriodicTasksAfterShutdown : |
293 |
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executeExistingDelayedTasksAfterShutdown); |
294 |
|
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} |
295 |
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|
296 |
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/** |
297 |
|
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* Main execution method for delayed or periodic tasks. If pool |
298 |
|
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* is shut down, rejects the task. Otherwise adds task to queue |
299 |
|
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* and starts a thread, if necessary, to run it. (We cannot |
300 |
|
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* prestart the thread to run the task because the task (probably) |
301 |
jsr166 |
1.67 |
* shouldn't be run yet.) If the pool is shut down while the task |
302 |
dl |
1.37 |
* is being added, cancel and remove it if required by state and |
303 |
jsr166 |
1.39 |
* run-after-shutdown parameters. |
304 |
|
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* |
305 |
dl |
1.37 |
* @param task the task |
306 |
|
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*/ |
307 |
|
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private void delayedExecute(RunnableScheduledFuture<?> task) { |
308 |
|
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if (isShutdown()) |
309 |
|
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reject(task); |
310 |
|
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else { |
311 |
|
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super.getQueue().add(task); |
312 |
|
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if (isShutdown() && |
313 |
|
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!canRunInCurrentRunState(task.isPeriodic()) && |
314 |
|
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remove(task)) |
315 |
|
|
task.cancel(false); |
316 |
jsr166 |
1.48 |
else |
317 |
dl |
1.63 |
ensurePrestart(); |
318 |
dl |
1.37 |
} |
319 |
|
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} |
320 |
jsr166 |
1.21 |
|
321 |
dl |
1.37 |
/** |
322 |
jsr166 |
1.39 |
* Requeues a periodic task unless current run state precludes it. |
323 |
|
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* Same idea as delayedExecute except drops task rather than rejecting. |
324 |
|
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* |
325 |
dl |
1.37 |
* @param task the task |
326 |
|
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*/ |
327 |
|
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void reExecutePeriodic(RunnableScheduledFuture<?> task) { |
328 |
|
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if (canRunInCurrentRunState(true)) { |
329 |
|
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super.getQueue().add(task); |
330 |
|
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if (!canRunInCurrentRunState(true) && remove(task)) |
331 |
|
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task.cancel(false); |
332 |
jsr166 |
1.48 |
else |
333 |
dl |
1.63 |
ensurePrestart(); |
334 |
dl |
1.37 |
} |
335 |
dl |
1.13 |
} |
336 |
dl |
1.1 |
|
337 |
dl |
1.13 |
/** |
338 |
jsr166 |
1.21 |
* Cancels and clears the queue of all tasks that should not be run |
339 |
jsr166 |
1.39 |
* due to shutdown policy. Invoked within super.shutdown. |
340 |
dl |
1.13 |
*/ |
341 |
dl |
1.37 |
@Override void onShutdown() { |
342 |
|
|
BlockingQueue<Runnable> q = super.getQueue(); |
343 |
|
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boolean keepDelayed = |
344 |
|
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getExecuteExistingDelayedTasksAfterShutdownPolicy(); |
345 |
|
|
boolean keepPeriodic = |
346 |
|
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getContinueExistingPeriodicTasksAfterShutdownPolicy(); |
347 |
jsr166 |
1.57 |
if (!keepDelayed && !keepPeriodic) { |
348 |
|
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for (Object e : q.toArray()) |
349 |
|
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if (e instanceof RunnableScheduledFuture<?>) |
350 |
|
|
((RunnableScheduledFuture<?>) e).cancel(false); |
351 |
dl |
1.37 |
q.clear(); |
352 |
jsr166 |
1.57 |
} |
353 |
dl |
1.37 |
else { |
354 |
|
|
// Traverse snapshot to avoid iterator exceptions |
355 |
jsr166 |
1.39 |
for (Object e : q.toArray()) { |
356 |
dl |
1.23 |
if (e instanceof RunnableScheduledFuture) { |
357 |
dl |
1.37 |
RunnableScheduledFuture<?> t = |
358 |
|
|
(RunnableScheduledFuture<?>)e; |
359 |
dl |
1.41 |
if ((t.isPeriodic() ? !keepPeriodic : !keepDelayed) || |
360 |
|
|
t.isCancelled()) { // also remove if already cancelled |
361 |
|
|
if (q.remove(t)) |
362 |
|
|
t.cancel(false); |
363 |
|
|
} |
364 |
dl |
1.13 |
} |
365 |
|
|
} |
366 |
dl |
1.1 |
} |
367 |
jsr166 |
1.48 |
tryTerminate(); |
368 |
dl |
1.1 |
} |
369 |
|
|
|
370 |
dl |
1.23 |
/** |
371 |
jsr166 |
1.30 |
* Modifies or replaces the task used to execute a runnable. |
372 |
jsr166 |
1.28 |
* This method can be used to override the concrete |
373 |
dl |
1.23 |
* class used for managing internal tasks. |
374 |
jsr166 |
1.30 |
* The default implementation simply returns the given task. |
375 |
jsr166 |
1.28 |
* |
376 |
dl |
1.23 |
* @param runnable the submitted Runnable |
377 |
|
|
* @param task the task created to execute the runnable |
378 |
jsr166 |
1.72 |
* @param <V> the type of the task's result |
379 |
dl |
1.23 |
* @return a task that can execute the runnable |
380 |
|
|
* @since 1.6 |
381 |
|
|
*/ |
382 |
peierls |
1.22 |
protected <V> RunnableScheduledFuture<V> decorateTask( |
383 |
dl |
1.23 |
Runnable runnable, RunnableScheduledFuture<V> task) { |
384 |
|
|
return task; |
385 |
peierls |
1.22 |
} |
386 |
|
|
|
387 |
dl |
1.23 |
/** |
388 |
jsr166 |
1.30 |
* Modifies or replaces the task used to execute a callable. |
389 |
jsr166 |
1.28 |
* This method can be used to override the concrete |
390 |
dl |
1.23 |
* class used for managing internal tasks. |
391 |
jsr166 |
1.30 |
* The default implementation simply returns the given task. |
392 |
jsr166 |
1.28 |
* |
393 |
dl |
1.23 |
* @param callable the submitted Callable |
394 |
|
|
* @param task the task created to execute the callable |
395 |
jsr166 |
1.72 |
* @param <V> the type of the task's result |
396 |
dl |
1.23 |
* @return a task that can execute the callable |
397 |
|
|
* @since 1.6 |
398 |
|
|
*/ |
399 |
peierls |
1.22 |
protected <V> RunnableScheduledFuture<V> decorateTask( |
400 |
dl |
1.23 |
Callable<V> callable, RunnableScheduledFuture<V> task) { |
401 |
|
|
return task; |
402 |
dl |
1.19 |
} |
403 |
|
|
|
404 |
dl |
1.1 |
/** |
405 |
jsr166 |
1.78 |
* The default keep-alive time for pool threads. |
406 |
|
|
* |
407 |
|
|
* Normally, this value is unused because all pool threads will be |
408 |
|
|
* core threads, but if a user creates a pool with a corePoolSize |
409 |
|
|
* of zero (against our advice), we keep a thread alive as long as |
410 |
|
|
* there are queued tasks. If the keep alive time is zero (the |
411 |
|
|
* historic value), we end up hot-spinning in getTask, wasting a |
412 |
|
|
* CPU. But on the other hand, if we set the value too high, and |
413 |
|
|
* users create a one-shot pool which they don't cleanly shutdown, |
414 |
|
|
* the pool's non-daemon threads will prevent JVM termination. A |
415 |
|
|
* small but non-zero value (relative to a JVM's lifetime) seems |
416 |
|
|
* best. |
417 |
|
|
*/ |
418 |
|
|
private static final long DEFAULT_KEEPALIVE_MILLIS = 10L; |
419 |
|
|
|
420 |
|
|
/** |
421 |
jsr166 |
1.39 |
* Creates a new {@code ScheduledThreadPoolExecutor} with the |
422 |
|
|
* given core pool size. |
423 |
jsr166 |
1.21 |
* |
424 |
jsr166 |
1.39 |
* @param corePoolSize the number of threads to keep in the pool, even |
425 |
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set |
426 |
|
|
* @throws IllegalArgumentException if {@code corePoolSize < 0} |
427 |
dl |
1.1 |
*/ |
428 |
|
|
public ScheduledThreadPoolExecutor(int corePoolSize) { |
429 |
jsr166 |
1.78 |
super(corePoolSize, Integer.MAX_VALUE, |
430 |
|
|
DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS, |
431 |
dl |
1.1 |
new DelayedWorkQueue()); |
432 |
|
|
} |
433 |
|
|
|
434 |
|
|
/** |
435 |
jsr166 |
1.39 |
* Creates a new {@code ScheduledThreadPoolExecutor} with the |
436 |
|
|
* given initial parameters. |
437 |
jsr166 |
1.21 |
* |
438 |
jsr166 |
1.39 |
* @param corePoolSize the number of threads to keep in the pool, even |
439 |
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set |
440 |
dl |
1.1 |
* @param threadFactory the factory to use when the executor |
441 |
jsr166 |
1.39 |
* creates a new thread |
442 |
|
|
* @throws IllegalArgumentException if {@code corePoolSize < 0} |
443 |
|
|
* @throws NullPointerException if {@code threadFactory} is null |
444 |
dl |
1.1 |
*/ |
445 |
|
|
public ScheduledThreadPoolExecutor(int corePoolSize, |
446 |
jsr166 |
1.56 |
ThreadFactory threadFactory) { |
447 |
jsr166 |
1.78 |
super(corePoolSize, Integer.MAX_VALUE, |
448 |
|
|
DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS, |
449 |
dl |
1.1 |
new DelayedWorkQueue(), threadFactory); |
450 |
|
|
} |
451 |
|
|
|
452 |
|
|
/** |
453 |
jsr166 |
1.79 |
* Creates a new {@code ScheduledThreadPoolExecutor} with the |
454 |
|
|
* given initial parameters. |
455 |
jsr166 |
1.21 |
* |
456 |
jsr166 |
1.39 |
* @param corePoolSize the number of threads to keep in the pool, even |
457 |
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set |
458 |
dl |
1.1 |
* @param handler the handler to use when execution is blocked |
459 |
jsr166 |
1.39 |
* because the thread bounds and queue capacities are reached |
460 |
|
|
* @throws IllegalArgumentException if {@code corePoolSize < 0} |
461 |
|
|
* @throws NullPointerException if {@code handler} is null |
462 |
dl |
1.1 |
*/ |
463 |
|
|
public ScheduledThreadPoolExecutor(int corePoolSize, |
464 |
jsr166 |
1.56 |
RejectedExecutionHandler handler) { |
465 |
jsr166 |
1.78 |
super(corePoolSize, Integer.MAX_VALUE, |
466 |
|
|
DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS, |
467 |
dl |
1.1 |
new DelayedWorkQueue(), handler); |
468 |
|
|
} |
469 |
|
|
|
470 |
|
|
/** |
471 |
jsr166 |
1.79 |
* Creates a new {@code ScheduledThreadPoolExecutor} with the |
472 |
|
|
* given initial parameters. |
473 |
jsr166 |
1.21 |
* |
474 |
jsr166 |
1.39 |
* @param corePoolSize the number of threads to keep in the pool, even |
475 |
|
|
* if they are idle, unless {@code allowCoreThreadTimeOut} is set |
476 |
dl |
1.1 |
* @param threadFactory the factory to use when the executor |
477 |
jsr166 |
1.39 |
* creates a new thread |
478 |
dl |
1.1 |
* @param handler the handler to use when execution is blocked |
479 |
jsr166 |
1.39 |
* because the thread bounds and queue capacities are reached |
480 |
|
|
* @throws IllegalArgumentException if {@code corePoolSize < 0} |
481 |
|
|
* @throws NullPointerException if {@code threadFactory} or |
482 |
|
|
* {@code handler} is null |
483 |
dl |
1.1 |
*/ |
484 |
|
|
public ScheduledThreadPoolExecutor(int corePoolSize, |
485 |
jsr166 |
1.56 |
ThreadFactory threadFactory, |
486 |
|
|
RejectedExecutionHandler handler) { |
487 |
jsr166 |
1.78 |
super(corePoolSize, Integer.MAX_VALUE, |
488 |
|
|
DEFAULT_KEEPALIVE_MILLIS, MILLISECONDS, |
489 |
dl |
1.1 |
new DelayedWorkQueue(), threadFactory, handler); |
490 |
|
|
} |
491 |
|
|
|
492 |
dl |
1.37 |
/** |
493 |
jsr166 |
1.73 |
* Returns the nanoTime-based trigger time of a delayed action. |
494 |
jsr166 |
1.54 |
*/ |
495 |
|
|
private long triggerTime(long delay, TimeUnit unit) { |
496 |
|
|
return triggerTime(unit.toNanos((delay < 0) ? 0 : delay)); |
497 |
|
|
} |
498 |
|
|
|
499 |
|
|
/** |
500 |
jsr166 |
1.73 |
* Returns the nanoTime-based trigger time of a delayed action. |
501 |
dl |
1.50 |
*/ |
502 |
jsr166 |
1.54 |
long triggerTime(long delay) { |
503 |
jsr166 |
1.98 |
return System.nanoTime() + |
504 |
jsr166 |
1.54 |
((delay < (Long.MAX_VALUE >> 1)) ? delay : overflowFree(delay)); |
505 |
|
|
} |
506 |
|
|
|
507 |
|
|
/** |
508 |
|
|
* Constrains the values of all delays in the queue to be within |
509 |
|
|
* Long.MAX_VALUE of each other, to avoid overflow in compareTo. |
510 |
|
|
* This may occur if a task is eligible to be dequeued, but has |
511 |
|
|
* not yet been, while some other task is added with a delay of |
512 |
|
|
* Long.MAX_VALUE. |
513 |
|
|
*/ |
514 |
|
|
private long overflowFree(long delay) { |
515 |
|
|
Delayed head = (Delayed) super.getQueue().peek(); |
516 |
|
|
if (head != null) { |
517 |
jsr166 |
1.62 |
long headDelay = head.getDelay(NANOSECONDS); |
518 |
jsr166 |
1.54 |
if (headDelay < 0 && (delay - headDelay < 0)) |
519 |
|
|
delay = Long.MAX_VALUE + headDelay; |
520 |
|
|
} |
521 |
|
|
return delay; |
522 |
dl |
1.50 |
} |
523 |
|
|
|
524 |
|
|
/** |
525 |
dl |
1.37 |
* @throws RejectedExecutionException {@inheritDoc} |
526 |
|
|
* @throws NullPointerException {@inheritDoc} |
527 |
|
|
*/ |
528 |
jsr166 |
1.21 |
public ScheduledFuture<?> schedule(Runnable command, |
529 |
|
|
long delay, |
530 |
dl |
1.13 |
TimeUnit unit) { |
531 |
dl |
1.9 |
if (command == null || unit == null) |
532 |
dl |
1.1 |
throw new NullPointerException(); |
533 |
jsr166 |
1.76 |
RunnableScheduledFuture<Void> t = decorateTask(command, |
534 |
jsr166 |
1.54 |
new ScheduledFutureTask<Void>(command, null, |
535 |
jsr166 |
1.89 |
triggerTime(delay, unit), |
536 |
|
|
sequencer.getAndIncrement())); |
537 |
dl |
1.1 |
delayedExecute(t); |
538 |
|
|
return t; |
539 |
|
|
} |
540 |
jsr166 |
1.52 |
|
541 |
dl |
1.37 |
/** |
542 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
543 |
|
|
* @throws NullPointerException {@inheritDoc} |
544 |
|
|
*/ |
545 |
jsr166 |
1.21 |
public <V> ScheduledFuture<V> schedule(Callable<V> callable, |
546 |
|
|
long delay, |
547 |
dl |
1.13 |
TimeUnit unit) { |
548 |
dl |
1.9 |
if (callable == null || unit == null) |
549 |
dl |
1.1 |
throw new NullPointerException(); |
550 |
peierls |
1.22 |
RunnableScheduledFuture<V> t = decorateTask(callable, |
551 |
jsr166 |
1.54 |
new ScheduledFutureTask<V>(callable, |
552 |
jsr166 |
1.89 |
triggerTime(delay, unit), |
553 |
|
|
sequencer.getAndIncrement())); |
554 |
dl |
1.1 |
delayedExecute(t); |
555 |
|
|
return t; |
556 |
|
|
} |
557 |
|
|
|
558 |
dl |
1.37 |
/** |
559 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
560 |
|
|
* @throws NullPointerException {@inheritDoc} |
561 |
|
|
* @throws IllegalArgumentException {@inheritDoc} |
562 |
|
|
*/ |
563 |
jsr166 |
1.21 |
public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, |
564 |
|
|
long initialDelay, |
565 |
|
|
long period, |
566 |
dl |
1.13 |
TimeUnit unit) { |
567 |
dl |
1.9 |
if (command == null || unit == null) |
568 |
dl |
1.1 |
throw new NullPointerException(); |
569 |
jsr166 |
1.96 |
if (period <= 0L) |
570 |
dl |
1.1 |
throw new IllegalArgumentException(); |
571 |
jsr166 |
1.48 |
ScheduledFutureTask<Void> sft = |
572 |
|
|
new ScheduledFutureTask<Void>(command, |
573 |
|
|
null, |
574 |
jsr166 |
1.54 |
triggerTime(initialDelay, unit), |
575 |
jsr166 |
1.89 |
unit.toNanos(period), |
576 |
|
|
sequencer.getAndIncrement()); |
577 |
jsr166 |
1.44 |
RunnableScheduledFuture<Void> t = decorateTask(command, sft); |
578 |
jsr166 |
1.48 |
sft.outerTask = t; |
579 |
dl |
1.1 |
delayedExecute(t); |
580 |
|
|
return t; |
581 |
|
|
} |
582 |
jsr166 |
1.21 |
|
583 |
dl |
1.37 |
/** |
584 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
585 |
|
|
* @throws NullPointerException {@inheritDoc} |
586 |
|
|
* @throws IllegalArgumentException {@inheritDoc} |
587 |
|
|
*/ |
588 |
jsr166 |
1.21 |
public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, |
589 |
|
|
long initialDelay, |
590 |
|
|
long delay, |
591 |
dl |
1.13 |
TimeUnit unit) { |
592 |
dl |
1.9 |
if (command == null || unit == null) |
593 |
dl |
1.1 |
throw new NullPointerException(); |
594 |
jsr166 |
1.96 |
if (delay <= 0L) |
595 |
dl |
1.1 |
throw new IllegalArgumentException(); |
596 |
jsr166 |
1.48 |
ScheduledFutureTask<Void> sft = |
597 |
|
|
new ScheduledFutureTask<Void>(command, |
598 |
|
|
null, |
599 |
jsr166 |
1.54 |
triggerTime(initialDelay, unit), |
600 |
jsr166 |
1.97 |
-unit.toNanos(delay), |
601 |
jsr166 |
1.89 |
sequencer.getAndIncrement()); |
602 |
jsr166 |
1.44 |
RunnableScheduledFuture<Void> t = decorateTask(command, sft); |
603 |
jsr166 |
1.48 |
sft.outerTask = t; |
604 |
dl |
1.1 |
delayedExecute(t); |
605 |
|
|
return t; |
606 |
|
|
} |
607 |
jsr166 |
1.21 |
|
608 |
dl |
1.1 |
/** |
609 |
jsr166 |
1.39 |
* Executes {@code command} with zero required delay. |
610 |
|
|
* This has effect equivalent to |
611 |
|
|
* {@link #schedule(Runnable,long,TimeUnit) schedule(command, 0, anyUnit)}. |
612 |
|
|
* Note that inspections of the queue and of the list returned by |
613 |
|
|
* {@code shutdownNow} will access the zero-delayed |
614 |
|
|
* {@link ScheduledFuture}, not the {@code command} itself. |
615 |
|
|
* |
616 |
|
|
* <p>A consequence of the use of {@code ScheduledFuture} objects is |
617 |
|
|
* that {@link ThreadPoolExecutor#afterExecute afterExecute} is always |
618 |
|
|
* called with a null second {@code Throwable} argument, even if the |
619 |
|
|
* {@code command} terminated abruptly. Instead, the {@code Throwable} |
620 |
|
|
* thrown by such a task can be obtained via {@link Future#get}. |
621 |
dl |
1.1 |
* |
622 |
|
|
* @throws RejectedExecutionException at discretion of |
623 |
jsr166 |
1.39 |
* {@code RejectedExecutionHandler}, if the task |
624 |
|
|
* cannot be accepted for execution because the |
625 |
|
|
* executor has been shut down |
626 |
|
|
* @throws NullPointerException {@inheritDoc} |
627 |
dl |
1.1 |
*/ |
628 |
|
|
public void execute(Runnable command) { |
629 |
jsr166 |
1.62 |
schedule(command, 0, NANOSECONDS); |
630 |
dl |
1.1 |
} |
631 |
|
|
|
632 |
dl |
1.13 |
// Override AbstractExecutorService methods |
633 |
|
|
|
634 |
dl |
1.37 |
/** |
635 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
636 |
|
|
* @throws NullPointerException {@inheritDoc} |
637 |
|
|
*/ |
638 |
dl |
1.7 |
public Future<?> submit(Runnable task) { |
639 |
jsr166 |
1.62 |
return schedule(task, 0, NANOSECONDS); |
640 |
dl |
1.7 |
} |
641 |
|
|
|
642 |
dl |
1.37 |
/** |
643 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
644 |
|
|
* @throws NullPointerException {@inheritDoc} |
645 |
|
|
*/ |
646 |
dl |
1.7 |
public <T> Future<T> submit(Runnable task, T result) { |
647 |
jsr166 |
1.62 |
return schedule(Executors.callable(task, result), 0, NANOSECONDS); |
648 |
dl |
1.7 |
} |
649 |
|
|
|
650 |
dl |
1.37 |
/** |
651 |
|
|
* @throws RejectedExecutionException {@inheritDoc} |
652 |
|
|
* @throws NullPointerException {@inheritDoc} |
653 |
|
|
*/ |
654 |
dl |
1.7 |
public <T> Future<T> submit(Callable<T> task) { |
655 |
jsr166 |
1.62 |
return schedule(task, 0, NANOSECONDS); |
656 |
dl |
1.7 |
} |
657 |
dl |
1.1 |
|
658 |
|
|
/** |
659 |
dl |
1.37 |
* Sets the policy on whether to continue executing existing |
660 |
jsr166 |
1.39 |
* periodic tasks even when this executor has been {@code shutdown}. |
661 |
|
|
* In this case, these tasks will only terminate upon |
662 |
|
|
* {@code shutdownNow} or after setting the policy to |
663 |
|
|
* {@code false} when already shutdown. |
664 |
|
|
* This value is by default {@code false}. |
665 |
jsr166 |
1.30 |
* |
666 |
jsr166 |
1.68 |
* @param value if {@code true}, continue after shutdown, else don't |
667 |
jsr166 |
1.25 |
* @see #getContinueExistingPeriodicTasksAfterShutdownPolicy |
668 |
dl |
1.1 |
*/ |
669 |
|
|
public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean value) { |
670 |
|
|
continueExistingPeriodicTasksAfterShutdown = value; |
671 |
jsr166 |
1.39 |
if (!value && isShutdown()) |
672 |
dl |
1.37 |
onShutdown(); |
673 |
dl |
1.1 |
} |
674 |
|
|
|
675 |
|
|
/** |
676 |
jsr166 |
1.21 |
* Gets the policy on whether to continue executing existing |
677 |
jsr166 |
1.39 |
* periodic tasks even when this executor has been {@code shutdown}. |
678 |
|
|
* In this case, these tasks will only terminate upon |
679 |
|
|
* {@code shutdownNow} or after setting the policy to |
680 |
|
|
* {@code false} when already shutdown. |
681 |
|
|
* This value is by default {@code false}. |
682 |
jsr166 |
1.30 |
* |
683 |
jsr166 |
1.39 |
* @return {@code true} if will continue after shutdown |
684 |
dl |
1.16 |
* @see #setContinueExistingPeriodicTasksAfterShutdownPolicy |
685 |
dl |
1.1 |
*/ |
686 |
|
|
public boolean getContinueExistingPeriodicTasksAfterShutdownPolicy() { |
687 |
|
|
return continueExistingPeriodicTasksAfterShutdown; |
688 |
|
|
} |
689 |
|
|
|
690 |
|
|
/** |
691 |
jsr166 |
1.21 |
* Sets the policy on whether to execute existing delayed |
692 |
jsr166 |
1.39 |
* tasks even when this executor has been {@code shutdown}. |
693 |
|
|
* In this case, these tasks will only terminate upon |
694 |
|
|
* {@code shutdownNow}, or after setting the policy to |
695 |
|
|
* {@code false} when already shutdown. |
696 |
|
|
* This value is by default {@code true}. |
697 |
jsr166 |
1.30 |
* |
698 |
jsr166 |
1.68 |
* @param value if {@code true}, execute after shutdown, else don't |
699 |
dl |
1.16 |
* @see #getExecuteExistingDelayedTasksAfterShutdownPolicy |
700 |
dl |
1.1 |
*/ |
701 |
|
|
public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean value) { |
702 |
|
|
executeExistingDelayedTasksAfterShutdown = value; |
703 |
jsr166 |
1.39 |
if (!value && isShutdown()) |
704 |
dl |
1.37 |
onShutdown(); |
705 |
dl |
1.1 |
} |
706 |
|
|
|
707 |
|
|
/** |
708 |
jsr166 |
1.21 |
* Gets the policy on whether to execute existing delayed |
709 |
jsr166 |
1.39 |
* tasks even when this executor has been {@code shutdown}. |
710 |
|
|
* In this case, these tasks will only terminate upon |
711 |
|
|
* {@code shutdownNow}, or after setting the policy to |
712 |
|
|
* {@code false} when already shutdown. |
713 |
|
|
* This value is by default {@code true}. |
714 |
jsr166 |
1.30 |
* |
715 |
jsr166 |
1.39 |
* @return {@code true} if will execute after shutdown |
716 |
dl |
1.16 |
* @see #setExecuteExistingDelayedTasksAfterShutdownPolicy |
717 |
dl |
1.1 |
*/ |
718 |
|
|
public boolean getExecuteExistingDelayedTasksAfterShutdownPolicy() { |
719 |
|
|
return executeExistingDelayedTasksAfterShutdown; |
720 |
|
|
} |
721 |
|
|
|
722 |
|
|
/** |
723 |
jsr166 |
1.46 |
* Sets the policy on whether cancelled tasks should be immediately |
724 |
|
|
* removed from the work queue at time of cancellation. This value is |
725 |
|
|
* by default {@code false}. |
726 |
dl |
1.41 |
* |
727 |
jsr166 |
1.42 |
* @param value if {@code true}, remove on cancellation, else don't |
728 |
dl |
1.41 |
* @see #getRemoveOnCancelPolicy |
729 |
jsr166 |
1.43 |
* @since 1.7 |
730 |
dl |
1.41 |
*/ |
731 |
|
|
public void setRemoveOnCancelPolicy(boolean value) { |
732 |
|
|
removeOnCancel = value; |
733 |
|
|
} |
734 |
|
|
|
735 |
|
|
/** |
736 |
jsr166 |
1.46 |
* Gets the policy on whether cancelled tasks should be immediately |
737 |
|
|
* removed from the work queue at time of cancellation. This value is |
738 |
|
|
* by default {@code false}. |
739 |
dl |
1.41 |
* |
740 |
jsr166 |
1.46 |
* @return {@code true} if cancelled tasks are immediately removed |
741 |
|
|
* from the queue |
742 |
dl |
1.41 |
* @see #setRemoveOnCancelPolicy |
743 |
jsr166 |
1.43 |
* @since 1.7 |
744 |
dl |
1.41 |
*/ |
745 |
|
|
public boolean getRemoveOnCancelPolicy() { |
746 |
|
|
return removeOnCancel; |
747 |
|
|
} |
748 |
|
|
|
749 |
|
|
/** |
750 |
dl |
1.1 |
* Initiates an orderly shutdown in which previously submitted |
751 |
jsr166 |
1.49 |
* tasks are executed, but no new tasks will be accepted. |
752 |
|
|
* Invocation has no additional effect if already shut down. |
753 |
|
|
* |
754 |
|
|
* <p>This method does not wait for previously submitted tasks to |
755 |
|
|
* complete execution. Use {@link #awaitTermination awaitTermination} |
756 |
|
|
* to do that. |
757 |
|
|
* |
758 |
|
|
* <p>If the {@code ExecuteExistingDelayedTasksAfterShutdownPolicy} |
759 |
|
|
* has been set {@code false}, existing delayed tasks whose delays |
760 |
|
|
* have not yet elapsed are cancelled. And unless the {@code |
761 |
|
|
* ContinueExistingPeriodicTasksAfterShutdownPolicy} has been set |
762 |
|
|
* {@code true}, future executions of existing periodic tasks will |
763 |
|
|
* be cancelled. |
764 |
jsr166 |
1.39 |
* |
765 |
|
|
* @throws SecurityException {@inheritDoc} |
766 |
dl |
1.1 |
*/ |
767 |
|
|
public void shutdown() { |
768 |
|
|
super.shutdown(); |
769 |
|
|
} |
770 |
|
|
|
771 |
|
|
/** |
772 |
|
|
* Attempts to stop all actively executing tasks, halts the |
773 |
jsr166 |
1.30 |
* processing of waiting tasks, and returns a list of the tasks |
774 |
jsr166 |
1.92 |
* that were awaiting execution. These tasks are drained (removed) |
775 |
|
|
* from the task queue upon return from this method. |
776 |
jsr166 |
1.21 |
* |
777 |
jsr166 |
1.49 |
* <p>This method does not wait for actively executing tasks to |
778 |
|
|
* terminate. Use {@link #awaitTermination awaitTermination} to |
779 |
|
|
* do that. |
780 |
|
|
* |
781 |
dl |
1.1 |
* <p>There are no guarantees beyond best-effort attempts to stop |
782 |
dl |
1.18 |
* processing actively executing tasks. This implementation |
783 |
jsr166 |
1.93 |
* interrupts tasks via {@link Thread#interrupt}; any task that |
784 |
jsr166 |
1.31 |
* fails to respond to interrupts may never terminate. |
785 |
dl |
1.1 |
* |
786 |
jsr166 |
1.39 |
* @return list of tasks that never commenced execution. |
787 |
jsr166 |
1.77 |
* Each element of this list is a {@link ScheduledFuture}. |
788 |
|
|
* For tasks submitted via one of the {@code schedule} |
789 |
|
|
* methods, the element will be identical to the returned |
790 |
|
|
* {@code ScheduledFuture}. For tasks submitted using |
791 |
jsr166 |
1.84 |
* {@link #execute execute}, the element will be a |
792 |
|
|
* zero-delay {@code ScheduledFuture}. |
793 |
jsr166 |
1.31 |
* @throws SecurityException {@inheritDoc} |
794 |
dl |
1.1 |
*/ |
795 |
tim |
1.4 |
public List<Runnable> shutdownNow() { |
796 |
dl |
1.1 |
return super.shutdownNow(); |
797 |
|
|
} |
798 |
|
|
|
799 |
|
|
/** |
800 |
jsr166 |
1.95 |
* Returns the task queue used by this executor. Access to the |
801 |
|
|
* task queue is intended primarily for debugging and monitoring. |
802 |
|
|
* This queue may be in active use. Retrieving the task queue |
803 |
|
|
* does not prevent queued tasks from executing. |
804 |
|
|
* |
805 |
|
|
* <p>Each element of this queue is a {@link ScheduledFuture}. |
806 |
jsr166 |
1.77 |
* For tasks submitted via one of the {@code schedule} methods, the |
807 |
|
|
* element will be identical to the returned {@code ScheduledFuture}. |
808 |
jsr166 |
1.84 |
* For tasks submitted using {@link #execute execute}, the element |
809 |
|
|
* will be a zero-delay {@code ScheduledFuture}. |
810 |
jsr166 |
1.77 |
* |
811 |
|
|
* <p>Iteration over this queue is <em>not</em> guaranteed to traverse |
812 |
|
|
* tasks in the order in which they will execute. |
813 |
dl |
1.1 |
* |
814 |
|
|
* @return the task queue |
815 |
|
|
*/ |
816 |
|
|
public BlockingQueue<Runnable> getQueue() { |
817 |
|
|
return super.getQueue(); |
818 |
|
|
} |
819 |
|
|
|
820 |
dl |
1.13 |
/** |
821 |
dl |
1.40 |
* Specialized delay queue. To mesh with TPE declarations, this |
822 |
|
|
* class must be declared as a BlockingQueue<Runnable> even though |
823 |
jsr166 |
1.42 |
* it can only hold RunnableScheduledFutures. |
824 |
jsr166 |
1.21 |
*/ |
825 |
dl |
1.40 |
static class DelayedWorkQueue extends AbstractQueue<Runnable> |
826 |
dl |
1.13 |
implements BlockingQueue<Runnable> { |
827 |
jsr166 |
1.21 |
|
828 |
dl |
1.40 |
/* |
829 |
|
|
* A DelayedWorkQueue is based on a heap-based data structure |
830 |
|
|
* like those in DelayQueue and PriorityQueue, except that |
831 |
|
|
* every ScheduledFutureTask also records its index into the |
832 |
|
|
* heap array. This eliminates the need to find a task upon |
833 |
|
|
* cancellation, greatly speeding up removal (down from O(n) |
834 |
|
|
* to O(log n)), and reducing garbage retention that would |
835 |
|
|
* otherwise occur by waiting for the element to rise to top |
836 |
|
|
* before clearing. But because the queue may also hold |
837 |
|
|
* RunnableScheduledFutures that are not ScheduledFutureTasks, |
838 |
|
|
* we are not guaranteed to have such indices available, in |
839 |
|
|
* which case we fall back to linear search. (We expect that |
840 |
|
|
* most tasks will not be decorated, and that the faster cases |
841 |
|
|
* will be much more common.) |
842 |
|
|
* |
843 |
|
|
* All heap operations must record index changes -- mainly |
844 |
|
|
* within siftUp and siftDown. Upon removal, a task's |
845 |
|
|
* heapIndex is set to -1. Note that ScheduledFutureTasks can |
846 |
|
|
* appear at most once in the queue (this need not be true for |
847 |
|
|
* other kinds of tasks or work queues), so are uniquely |
848 |
|
|
* identified by heapIndex. |
849 |
|
|
*/ |
850 |
|
|
|
851 |
jsr166 |
1.46 |
private static final int INITIAL_CAPACITY = 16; |
852 |
jsr166 |
1.61 |
private RunnableScheduledFuture<?>[] queue = |
853 |
|
|
new RunnableScheduledFuture<?>[INITIAL_CAPACITY]; |
854 |
jsr166 |
1.46 |
private final ReentrantLock lock = new ReentrantLock(); |
855 |
jsr166 |
1.80 |
private int size; |
856 |
dl |
1.40 |
|
857 |
jsr166 |
1.48 |
/** |
858 |
|
|
* Thread designated to wait for the task at the head of the |
859 |
|
|
* queue. This variant of the Leader-Follower pattern |
860 |
|
|
* (http://www.cs.wustl.edu/~schmidt/POSA/POSA2/) serves to |
861 |
|
|
* minimize unnecessary timed waiting. When a thread becomes |
862 |
|
|
* the leader, it waits only for the next delay to elapse, but |
863 |
|
|
* other threads await indefinitely. The leader thread must |
864 |
|
|
* signal some other thread before returning from take() or |
865 |
|
|
* poll(...), unless some other thread becomes leader in the |
866 |
|
|
* interim. Whenever the head of the queue is replaced with a |
867 |
|
|
* task with an earlier expiration time, the leader field is |
868 |
|
|
* invalidated by being reset to null, and some waiting |
869 |
|
|
* thread, but not necessarily the current leader, is |
870 |
|
|
* signalled. So waiting threads must be prepared to acquire |
871 |
|
|
* and lose leadership while waiting. |
872 |
|
|
*/ |
873 |
jsr166 |
1.80 |
private Thread leader; |
874 |
jsr166 |
1.48 |
|
875 |
|
|
/** |
876 |
|
|
* Condition signalled when a newer task becomes available at the |
877 |
|
|
* head of the queue or a new thread may need to become leader. |
878 |
|
|
*/ |
879 |
|
|
private final Condition available = lock.newCondition(); |
880 |
dl |
1.40 |
|
881 |
|
|
/** |
882 |
jsr166 |
1.66 |
* Sets f's heapIndex if it is a ScheduledFutureTask. |
883 |
dl |
1.40 |
*/ |
884 |
jsr166 |
1.102 |
private static void setIndex(RunnableScheduledFuture<?> f, int idx) { |
885 |
dl |
1.40 |
if (f instanceof ScheduledFutureTask) |
886 |
|
|
((ScheduledFutureTask)f).heapIndex = idx; |
887 |
|
|
} |
888 |
|
|
|
889 |
|
|
/** |
890 |
jsr166 |
1.66 |
* Sifts element added at bottom up to its heap-ordered spot. |
891 |
dl |
1.40 |
* Call only when holding lock. |
892 |
|
|
*/ |
893 |
jsr166 |
1.61 |
private void siftUp(int k, RunnableScheduledFuture<?> key) { |
894 |
dl |
1.40 |
while (k > 0) { |
895 |
|
|
int parent = (k - 1) >>> 1; |
896 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> e = queue[parent]; |
897 |
dl |
1.40 |
if (key.compareTo(e) >= 0) |
898 |
|
|
break; |
899 |
|
|
queue[k] = e; |
900 |
|
|
setIndex(e, k); |
901 |
|
|
k = parent; |
902 |
|
|
} |
903 |
|
|
queue[k] = key; |
904 |
|
|
setIndex(key, k); |
905 |
|
|
} |
906 |
|
|
|
907 |
|
|
/** |
908 |
jsr166 |
1.66 |
* Sifts element added at top down to its heap-ordered spot. |
909 |
dl |
1.40 |
* Call only when holding lock. |
910 |
|
|
*/ |
911 |
jsr166 |
1.61 |
private void siftDown(int k, RunnableScheduledFuture<?> key) { |
912 |
jsr166 |
1.42 |
int half = size >>> 1; |
913 |
dl |
1.40 |
while (k < half) { |
914 |
jsr166 |
1.42 |
int child = (k << 1) + 1; |
915 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> c = queue[child]; |
916 |
dl |
1.40 |
int right = child + 1; |
917 |
|
|
if (right < size && c.compareTo(queue[right]) > 0) |
918 |
|
|
c = queue[child = right]; |
919 |
|
|
if (key.compareTo(c) <= 0) |
920 |
|
|
break; |
921 |
|
|
queue[k] = c; |
922 |
|
|
setIndex(c, k); |
923 |
|
|
k = child; |
924 |
|
|
} |
925 |
|
|
queue[k] = key; |
926 |
|
|
setIndex(key, k); |
927 |
|
|
} |
928 |
|
|
|
929 |
|
|
/** |
930 |
jsr166 |
1.66 |
* Resizes the heap array. Call only when holding lock. |
931 |
dl |
1.40 |
*/ |
932 |
|
|
private void grow() { |
933 |
|
|
int oldCapacity = queue.length; |
934 |
|
|
int newCapacity = oldCapacity + (oldCapacity >> 1); // grow 50% |
935 |
|
|
if (newCapacity < 0) // overflow |
936 |
|
|
newCapacity = Integer.MAX_VALUE; |
937 |
|
|
queue = Arrays.copyOf(queue, newCapacity); |
938 |
|
|
} |
939 |
|
|
|
940 |
|
|
/** |
941 |
jsr166 |
1.66 |
* Finds index of given object, or -1 if absent. |
942 |
dl |
1.40 |
*/ |
943 |
|
|
private int indexOf(Object x) { |
944 |
|
|
if (x != null) { |
945 |
jsr166 |
1.48 |
if (x instanceof ScheduledFutureTask) { |
946 |
|
|
int i = ((ScheduledFutureTask) x).heapIndex; |
947 |
|
|
// Sanity check; x could conceivably be a |
948 |
|
|
// ScheduledFutureTask from some other pool. |
949 |
|
|
if (i >= 0 && i < size && queue[i] == x) |
950 |
|
|
return i; |
951 |
|
|
} else { |
952 |
|
|
for (int i = 0; i < size; i++) |
953 |
|
|
if (x.equals(queue[i])) |
954 |
|
|
return i; |
955 |
|
|
} |
956 |
dl |
1.40 |
} |
957 |
|
|
return -1; |
958 |
|
|
} |
959 |
|
|
|
960 |
jsr166 |
1.48 |
public boolean contains(Object x) { |
961 |
|
|
final ReentrantLock lock = this.lock; |
962 |
jsr166 |
1.45 |
lock.lock(); |
963 |
|
|
try { |
964 |
jsr166 |
1.48 |
return indexOf(x) != -1; |
965 |
jsr166 |
1.45 |
} finally { |
966 |
|
|
lock.unlock(); |
967 |
|
|
} |
968 |
jsr166 |
1.48 |
} |
969 |
jsr166 |
1.45 |
|
970 |
dl |
1.40 |
public boolean remove(Object x) { |
971 |
|
|
final ReentrantLock lock = this.lock; |
972 |
|
|
lock.lock(); |
973 |
|
|
try { |
974 |
jsr166 |
1.45 |
int i = indexOf(x); |
975 |
jsr166 |
1.48 |
if (i < 0) |
976 |
|
|
return false; |
977 |
jsr166 |
1.45 |
|
978 |
jsr166 |
1.48 |
setIndex(queue[i], -1); |
979 |
|
|
int s = --size; |
980 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> replacement = queue[s]; |
981 |
jsr166 |
1.48 |
queue[s] = null; |
982 |
|
|
if (s != i) { |
983 |
|
|
siftDown(i, replacement); |
984 |
|
|
if (queue[i] == replacement) |
985 |
|
|
siftUp(i, replacement); |
986 |
|
|
} |
987 |
|
|
return true; |
988 |
dl |
1.40 |
} finally { |
989 |
|
|
lock.unlock(); |
990 |
|
|
} |
991 |
|
|
} |
992 |
|
|
|
993 |
|
|
public int size() { |
994 |
|
|
final ReentrantLock lock = this.lock; |
995 |
|
|
lock.lock(); |
996 |
|
|
try { |
997 |
jsr166 |
1.45 |
return size; |
998 |
dl |
1.40 |
} finally { |
999 |
|
|
lock.unlock(); |
1000 |
|
|
} |
1001 |
|
|
} |
1002 |
|
|
|
1003 |
jsr166 |
1.42 |
public boolean isEmpty() { |
1004 |
|
|
return size() == 0; |
1005 |
dl |
1.40 |
} |
1006 |
|
|
|
1007 |
|
|
public int remainingCapacity() { |
1008 |
|
|
return Integer.MAX_VALUE; |
1009 |
|
|
} |
1010 |
|
|
|
1011 |
jsr166 |
1.61 |
public RunnableScheduledFuture<?> peek() { |
1012 |
dl |
1.40 |
final ReentrantLock lock = this.lock; |
1013 |
|
|
lock.lock(); |
1014 |
|
|
try { |
1015 |
|
|
return queue[0]; |
1016 |
|
|
} finally { |
1017 |
|
|
lock.unlock(); |
1018 |
|
|
} |
1019 |
dl |
1.13 |
} |
1020 |
|
|
|
1021 |
dl |
1.40 |
public boolean offer(Runnable x) { |
1022 |
|
|
if (x == null) |
1023 |
|
|
throw new NullPointerException(); |
1024 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> e = (RunnableScheduledFuture<?>)x; |
1025 |
dl |
1.40 |
final ReentrantLock lock = this.lock; |
1026 |
|
|
lock.lock(); |
1027 |
|
|
try { |
1028 |
|
|
int i = size; |
1029 |
|
|
if (i >= queue.length) |
1030 |
|
|
grow(); |
1031 |
|
|
size = i + 1; |
1032 |
|
|
if (i == 0) { |
1033 |
|
|
queue[0] = e; |
1034 |
|
|
setIndex(e, 0); |
1035 |
jsr166 |
1.45 |
} else { |
1036 |
dl |
1.40 |
siftUp(i, e); |
1037 |
|
|
} |
1038 |
jsr166 |
1.46 |
if (queue[0] == e) { |
1039 |
jsr166 |
1.48 |
leader = null; |
1040 |
jsr166 |
1.46 |
available.signal(); |
1041 |
jsr166 |
1.48 |
} |
1042 |
dl |
1.40 |
} finally { |
1043 |
|
|
lock.unlock(); |
1044 |
|
|
} |
1045 |
|
|
return true; |
1046 |
jsr166 |
1.48 |
} |
1047 |
dl |
1.40 |
|
1048 |
|
|
public void put(Runnable e) { |
1049 |
|
|
offer(e); |
1050 |
|
|
} |
1051 |
|
|
|
1052 |
|
|
public boolean add(Runnable e) { |
1053 |
jsr166 |
1.48 |
return offer(e); |
1054 |
|
|
} |
1055 |
dl |
1.40 |
|
1056 |
|
|
public boolean offer(Runnable e, long timeout, TimeUnit unit) { |
1057 |
|
|
return offer(e); |
1058 |
|
|
} |
1059 |
jsr166 |
1.42 |
|
1060 |
jsr166 |
1.46 |
/** |
1061 |
|
|
* Performs common bookkeeping for poll and take: Replaces |
1062 |
jsr166 |
1.47 |
* first element with last and sifts it down. Call only when |
1063 |
|
|
* holding lock. |
1064 |
jsr166 |
1.46 |
* @param f the task to remove and return |
1065 |
|
|
*/ |
1066 |
jsr166 |
1.61 |
private RunnableScheduledFuture<?> finishPoll(RunnableScheduledFuture<?> f) { |
1067 |
jsr166 |
1.46 |
int s = --size; |
1068 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> x = queue[s]; |
1069 |
jsr166 |
1.46 |
queue[s] = null; |
1070 |
|
|
if (s != 0) |
1071 |
|
|
siftDown(0, x); |
1072 |
|
|
setIndex(f, -1); |
1073 |
|
|
return f; |
1074 |
|
|
} |
1075 |
|
|
|
1076 |
jsr166 |
1.61 |
public RunnableScheduledFuture<?> poll() { |
1077 |
dl |
1.40 |
final ReentrantLock lock = this.lock; |
1078 |
|
|
lock.lock(); |
1079 |
|
|
try { |
1080 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> first = queue[0]; |
1081 |
jsr166 |
1.87 |
return (first == null || first.getDelay(NANOSECONDS) > 0) |
1082 |
|
|
? null |
1083 |
|
|
: finishPoll(first); |
1084 |
dl |
1.40 |
} finally { |
1085 |
|
|
lock.unlock(); |
1086 |
|
|
} |
1087 |
|
|
} |
1088 |
|
|
|
1089 |
jsr166 |
1.61 |
public RunnableScheduledFuture<?> take() throws InterruptedException { |
1090 |
dl |
1.40 |
final ReentrantLock lock = this.lock; |
1091 |
|
|
lock.lockInterruptibly(); |
1092 |
|
|
try { |
1093 |
|
|
for (;;) { |
1094 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> first = queue[0]; |
1095 |
jsr166 |
1.42 |
if (first == null) |
1096 |
dl |
1.40 |
available.await(); |
1097 |
|
|
else { |
1098 |
jsr166 |
1.62 |
long delay = first.getDelay(NANOSECONDS); |
1099 |
jsr166 |
1.96 |
if (delay <= 0L) |
1100 |
jsr166 |
1.48 |
return finishPoll(first); |
1101 |
jsr166 |
1.71 |
first = null; // don't retain ref while waiting |
1102 |
|
|
if (leader != null) |
1103 |
jsr166 |
1.48 |
available.await(); |
1104 |
|
|
else { |
1105 |
|
|
Thread thisThread = Thread.currentThread(); |
1106 |
|
|
leader = thisThread; |
1107 |
|
|
try { |
1108 |
|
|
available.awaitNanos(delay); |
1109 |
|
|
} finally { |
1110 |
|
|
if (leader == thisThread) |
1111 |
|
|
leader = null; |
1112 |
|
|
} |
1113 |
|
|
} |
1114 |
dl |
1.40 |
} |
1115 |
|
|
} |
1116 |
|
|
} finally { |
1117 |
jsr166 |
1.48 |
if (leader == null && queue[0] != null) |
1118 |
|
|
available.signal(); |
1119 |
dl |
1.40 |
lock.unlock(); |
1120 |
|
|
} |
1121 |
|
|
} |
1122 |
|
|
|
1123 |
jsr166 |
1.61 |
public RunnableScheduledFuture<?> poll(long timeout, TimeUnit unit) |
1124 |
dl |
1.40 |
throws InterruptedException { |
1125 |
|
|
long nanos = unit.toNanos(timeout); |
1126 |
|
|
final ReentrantLock lock = this.lock; |
1127 |
|
|
lock.lockInterruptibly(); |
1128 |
|
|
try { |
1129 |
|
|
for (;;) { |
1130 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> first = queue[0]; |
1131 |
dl |
1.40 |
if (first == null) { |
1132 |
jsr166 |
1.96 |
if (nanos <= 0L) |
1133 |
dl |
1.40 |
return null; |
1134 |
|
|
else |
1135 |
|
|
nanos = available.awaitNanos(nanos); |
1136 |
|
|
} else { |
1137 |
jsr166 |
1.62 |
long delay = first.getDelay(NANOSECONDS); |
1138 |
jsr166 |
1.96 |
if (delay <= 0L) |
1139 |
dl |
1.40 |
return finishPoll(first); |
1140 |
jsr166 |
1.96 |
if (nanos <= 0L) |
1141 |
jsr166 |
1.48 |
return null; |
1142 |
jsr166 |
1.71 |
first = null; // don't retain ref while waiting |
1143 |
jsr166 |
1.48 |
if (nanos < delay || leader != null) |
1144 |
|
|
nanos = available.awaitNanos(nanos); |
1145 |
|
|
else { |
1146 |
|
|
Thread thisThread = Thread.currentThread(); |
1147 |
|
|
leader = thisThread; |
1148 |
|
|
try { |
1149 |
|
|
long timeLeft = available.awaitNanos(delay); |
1150 |
|
|
nanos -= delay - timeLeft; |
1151 |
|
|
} finally { |
1152 |
|
|
if (leader == thisThread) |
1153 |
|
|
leader = null; |
1154 |
|
|
} |
1155 |
|
|
} |
1156 |
|
|
} |
1157 |
|
|
} |
1158 |
dl |
1.40 |
} finally { |
1159 |
jsr166 |
1.48 |
if (leader == null && queue[0] != null) |
1160 |
|
|
available.signal(); |
1161 |
dl |
1.40 |
lock.unlock(); |
1162 |
|
|
} |
1163 |
|
|
} |
1164 |
|
|
|
1165 |
|
|
public void clear() { |
1166 |
|
|
final ReentrantLock lock = this.lock; |
1167 |
|
|
lock.lock(); |
1168 |
|
|
try { |
1169 |
|
|
for (int i = 0; i < size; i++) { |
1170 |
jsr166 |
1.61 |
RunnableScheduledFuture<?> t = queue[i]; |
1171 |
dl |
1.40 |
if (t != null) { |
1172 |
|
|
queue[i] = null; |
1173 |
|
|
setIndex(t, -1); |
1174 |
|
|
} |
1175 |
|
|
} |
1176 |
|
|
size = 0; |
1177 |
|
|
} finally { |
1178 |
|
|
lock.unlock(); |
1179 |
|
|
} |
1180 |
dl |
1.13 |
} |
1181 |
dl |
1.40 |
|
1182 |
|
|
public int drainTo(Collection<? super Runnable> c) { |
1183 |
jsr166 |
1.104 |
return drainTo(c, Integer.MAX_VALUE); |
1184 |
dl |
1.13 |
} |
1185 |
|
|
|
1186 |
jsr166 |
1.21 |
public int drainTo(Collection<? super Runnable> c, int maxElements) { |
1187 |
jsr166 |
1.106 |
Objects.requireNonNull(c); |
1188 |
dl |
1.40 |
if (c == this) |
1189 |
|
|
throw new IllegalArgumentException(); |
1190 |
|
|
if (maxElements <= 0) |
1191 |
|
|
return 0; |
1192 |
|
|
final ReentrantLock lock = this.lock; |
1193 |
|
|
lock.lock(); |
1194 |
|
|
try { |
1195 |
|
|
int n = 0; |
1196 |
jsr166 |
1.106 |
for (RunnableScheduledFuture<?> first; |
1197 |
|
|
n < maxElements |
1198 |
|
|
&& (first = queue[0]) != null |
1199 |
|
|
&& first.getDelay(NANOSECONDS) <= 0;) { |
1200 |
jsr166 |
1.62 |
c.add(first); // In this order, in case add() throws. |
1201 |
|
|
finishPoll(first); |
1202 |
jsr166 |
1.48 |
++n; |
1203 |
|
|
} |
1204 |
dl |
1.40 |
return n; |
1205 |
|
|
} finally { |
1206 |
|
|
lock.unlock(); |
1207 |
|
|
} |
1208 |
|
|
} |
1209 |
|
|
|
1210 |
|
|
public Object[] toArray() { |
1211 |
|
|
final ReentrantLock lock = this.lock; |
1212 |
|
|
lock.lock(); |
1213 |
|
|
try { |
1214 |
jsr166 |
1.45 |
return Arrays.copyOf(queue, size, Object[].class); |
1215 |
dl |
1.40 |
} finally { |
1216 |
|
|
lock.unlock(); |
1217 |
|
|
} |
1218 |
|
|
} |
1219 |
|
|
|
1220 |
jsr166 |
1.48 |
@SuppressWarnings("unchecked") |
1221 |
dl |
1.40 |
public <T> T[] toArray(T[] a) { |
1222 |
|
|
final ReentrantLock lock = this.lock; |
1223 |
|
|
lock.lock(); |
1224 |
|
|
try { |
1225 |
|
|
if (a.length < size) |
1226 |
|
|
return (T[]) Arrays.copyOf(queue, size, a.getClass()); |
1227 |
|
|
System.arraycopy(queue, 0, a, 0, size); |
1228 |
|
|
if (a.length > size) |
1229 |
|
|
a[size] = null; |
1230 |
|
|
return a; |
1231 |
|
|
} finally { |
1232 |
|
|
lock.unlock(); |
1233 |
|
|
} |
1234 |
dl |
1.13 |
} |
1235 |
|
|
|
1236 |
jsr166 |
1.21 |
public Iterator<Runnable> iterator() { |
1237 |
jsr166 |
1.105 |
final ReentrantLock lock = this.lock; |
1238 |
|
|
lock.lock(); |
1239 |
|
|
try { |
1240 |
|
|
return new Itr(Arrays.copyOf(queue, size)); |
1241 |
|
|
} finally { |
1242 |
|
|
lock.unlock(); |
1243 |
|
|
} |
1244 |
dl |
1.40 |
} |
1245 |
jsr166 |
1.42 |
|
1246 |
dl |
1.40 |
/** |
1247 |
|
|
* Snapshot iterator that works off copy of underlying q array. |
1248 |
|
|
*/ |
1249 |
|
|
private class Itr implements Iterator<Runnable> { |
1250 |
jsr166 |
1.74 |
final RunnableScheduledFuture<?>[] array; |
1251 |
jsr166 |
1.86 |
int cursor; // index of next element to return; initially 0 |
1252 |
|
|
int lastRet = -1; // index of last element returned; -1 if no such |
1253 |
jsr166 |
1.42 |
|
1254 |
jsr166 |
1.74 |
Itr(RunnableScheduledFuture<?>[] array) { |
1255 |
dl |
1.40 |
this.array = array; |
1256 |
|
|
} |
1257 |
jsr166 |
1.42 |
|
1258 |
dl |
1.40 |
public boolean hasNext() { |
1259 |
|
|
return cursor < array.length; |
1260 |
|
|
} |
1261 |
jsr166 |
1.42 |
|
1262 |
dl |
1.40 |
public Runnable next() { |
1263 |
|
|
if (cursor >= array.length) |
1264 |
|
|
throw new NoSuchElementException(); |
1265 |
jsr166 |
1.101 |
return array[lastRet = cursor++]; |
1266 |
dl |
1.40 |
} |
1267 |
jsr166 |
1.42 |
|
1268 |
dl |
1.40 |
public void remove() { |
1269 |
|
|
if (lastRet < 0) |
1270 |
|
|
throw new IllegalStateException(); |
1271 |
|
|
DelayedWorkQueue.this.remove(array[lastRet]); |
1272 |
|
|
lastRet = -1; |
1273 |
|
|
} |
1274 |
dl |
1.13 |
} |
1275 |
|
|
} |
1276 |
dl |
1.1 |
} |