util/concurrent/TimeUnit.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

package java.util.concurrent;

import java.time.temporal.ChronoUnit;
import java.util.Objects;

/**
 * A {@code TimeUnit} represents time durations at a given unit of
 * granularity and provides utility methods to convert across units,
 * and to perform timing and delay operations in these units.  A
 * {@code TimeUnit} does not maintain time information, but only
 * helps organize and use time representations that may be maintained
 * separately across various contexts.  A nanosecond is defined as one
 * thousandth of a microsecond, a microsecond as one thousandth of a
 * millisecond, a millisecond as one thousandth of a second, a minute
 * as sixty seconds, an hour as sixty minutes, and a day as twenty four
 * hours.
 *
 * <p>A {@code TimeUnit} is mainly used to inform time-based methods
 * how a given timing parameter should be interpreted. For example,
 * the following code will timeout in 50 milliseconds if the {@link
 * java.util.concurrent.locks.Lock lock} is not available:
 *
 * <pre> {@code
 * Lock lock = ...;
 * if (lock.tryLock(50L, TimeUnit.MILLISECONDS)) ...}</pre>
 *
 * while this code will timeout in 50 seconds:
 * <pre> {@code
 * Lock lock = ...;
 * if (lock.tryLock(50L, TimeUnit.SECONDS)) ...}</pre>
 *
 * Note however, that there is no guarantee that a particular timeout
 * implementation will be able to notice the passage of time at the
 * same granularity as the given {@code TimeUnit}.
 *
 * @since 1.5
 * @author Doug Lea
 */
public enum TimeUnit {
    /**
     * Time unit representing one thousandth of a microsecond.
     */
    NANOSECONDS(1L), // (cannot use symbolic scale names here)
    /**
     * Time unit representing one thousandth of a millisecond.
     */
    MICROSECONDS(1000L),
    /**
     * Time unit representing one thousandth of a second.
     */
    MILLISECONDS(1000L * 1000L),
    /**
     * Time unit representing one second.
     */
    SECONDS(1000L * 1000L * 1000L),
    /**
     * Time unit representing sixty seconds.
     * @since 1.6
     */
    MINUTES(1000L * 1000L * 1000L * 60L),
    /**
     * Time unit representing sixty minutes.
     * @since 1.6
     */
    HOURS(1000L * 1000L * 1000L * 60L * 60L),
    /**
     * Time unit representing twenty four hours.
     * @since 1.6
     */
    DAYS(1000L * 1000L * 1000L * 60L * 60L * 24L);

    // Scales as constants
    private static final long NANO_SCALE   = 1L;
    private static final long MICRO_SCALE  = 1000L * NANO_SCALE;
    private static final long MILLI_SCALE  = 1000L * MICRO_SCALE;
    private static final long SECOND_SCALE = 1000L * MILLI_SCALE;
    private static final long MINUTE_SCALE = 60L * SECOND_SCALE;
    private static final long HOUR_SCALE   = 60L * MINUTE_SCALE;
    private static final long DAY_SCALE    = 24L * HOUR_SCALE;

    /*
     * Instances cache conversion ratios and saturation cutoffs for
     * the units most commonly used in conversion results, in methods
     * toNanos, toMillis and toSeconds. Other cases compute them, in
     * method cvt.
     */

    private final long scale;
    private final long maxNanos;
    private final long maxMillis;
    private final long maxSecs;
    private final int milliRatio;
    private final int secRatio;

    TimeUnit(long scale) {
        this.scale = scale;
        this.maxNanos = Long.MAX_VALUE / scale;
        long mr = (scale >= MILLI_SCALE)
            ? (scale / MILLI_SCALE)
            : (MILLI_SCALE / scale);
        this.milliRatio = (int)mr;
        this.maxMillis = Long.MAX_VALUE / mr;
        long sr = (scale >= SECOND_SCALE)
            ? (scale / SECOND_SCALE)
            : (SECOND_SCALE / scale);
        this.secRatio = (int)sr;
        this.maxSecs = Long.MAX_VALUE / sr;
    }

    /**
     * General conversion utility.
     *
     * @param d duration
     * @param dst result scale unit
     * @param src source scale unit
     */
    private static long cvt(long d, long dst, long src) {
        long r, m;
        if (src == dst)
            return d;
        else if (src < dst)
            return d / (dst / src);
        else if (d > (m = Long.MAX_VALUE / (r = src / dst)))
            return Long.MAX_VALUE;
        else if (d < -m)
            return Long.MIN_VALUE;
        else
            return d * r;
    }

    /**
     * Converts the given time duration in the given unit to this unit.
     * Conversions from finer to coarser granularities truncate, so
     * lose precision. For example, converting {@code 999} milliseconds
     * to seconds results in {@code 0}. Conversions from coarser to
     * finer granularities with arguments that would numerically
     * overflow saturate to {@code Long.MIN_VALUE} if negative or
     * {@code Long.MAX_VALUE} if positive.
     *
     * <p>For example, to convert 10 minutes to milliseconds, use:
     * {@code TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)}
     *
     * @param sourceDuration the time duration in the given {@code sourceUnit}
     * @param sourceUnit the unit of the {@code sourceDuration} argument
     * @return the converted duration in this unit,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     */
    public long convert(long sourceDuration, TimeUnit sourceUnit) {
        return cvt(sourceDuration, scale, sourceUnit.scale);
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) NANOSECONDS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     */
    public long toNanos(long duration) {
        long s, m;
        if ((s = scale) == NANO_SCALE)
            return duration;
        else if (duration > (m = maxNanos))
            return Long.MAX_VALUE;
        else if (duration < -m)
            return Long.MIN_VALUE;
        else
            return duration * s;
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) MICROSECONDS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     */
    public long toMicros(long duration) {
        return cvt(duration, MICRO_SCALE, scale);
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) MILLISECONDS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     */
    public long toMillis(long duration) {
        long s, m;
        if ((s = scale) == MILLI_SCALE)
            return duration;
        else if (s < MILLI_SCALE)
            return duration / milliRatio;
        else if (duration > (m = maxMillis))
            return Long.MAX_VALUE;
        else if (duration < -m)
            return Long.MIN_VALUE;
        else
            return duration * milliRatio;
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) SECONDS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     */
    public long toSeconds(long duration) {
        long s, m;
        if ((s = scale) == SECOND_SCALE)
            return duration;
        else if (s < SECOND_SCALE)
            return duration / secRatio;
        else if (duration > (m = maxSecs))
            return Long.MAX_VALUE;
        else if (duration < -m)
            return Long.MIN_VALUE;
        else
            return duration * secRatio;
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) MINUTES.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     * @since 1.6
     */
    public long toMinutes(long duration) {
        return cvt(duration, MINUTE_SCALE, scale);
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) HOURS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration,
     * or {@code Long.MIN_VALUE} if conversion would negatively
     * overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
     * @since 1.6
     */
    public long toHours(long duration) {
        return cvt(duration, HOUR_SCALE, scale);
    }

    /**
     * Equivalent to
     * {@link #convert(long, TimeUnit) DAYS.convert(duration, this)}.
     * @param duration the duration
     * @return the converted duration
     * @since 1.6
     */
    public long toDays(long duration) {
        return cvt(duration, DAY_SCALE, scale);
    }

    /**
     * Utility to compute the excess-nanosecond argument to wait,
     * sleep, join.
     * @param d the duration
     * @param m the number of milliseconds
     * @return the number of nanoseconds
     */
    private int excessNanos(long d, long m) {
        long s;
        if ((s = scale) == NANO_SCALE)
            return (int)(d - (m * MILLI_SCALE));
        else if (s == MICRO_SCALE)
            return (int)((d * 1000L) - (m * MILLI_SCALE));
        else
            return 0;
    }

    /**
     * Performs a timed {@link Object#wait(long, int) Object.wait}
     * using this time unit.
     * This is a convenience method that converts timeout arguments
     * into the form required by the {@code Object.wait} method.
     *
     * <p>For example, you could implement a blocking {@code poll}
     * method (see {@link BlockingQueue#poll BlockingQueue.poll})
     * using:
     *
     * <pre> {@code
     * public synchronized Object poll(long timeout, TimeUnit unit)
     *     throws InterruptedException {
     *   while (empty) {
     *     unit.timedWait(this, timeout);
     *     ...
     *   }
     * }}</pre>
     *
     * @param obj the object to wait on
     * @param timeout the maximum time to wait. If less than
     * or equal to zero, do not wait at all.
     * @throws InterruptedException if interrupted while waiting
     */
    public void timedWait(Object obj, long timeout)
            throws InterruptedException {
        if (timeout > 0) {
            long ms = toMillis(timeout);
            int ns = excessNanos(timeout, ms);
            obj.wait(ms, ns);
        }
    }

    /**
     * Performs a timed {@link Thread#join(long, int) Thread.join}
     * using this time unit.
     * This is a convenience method that converts time arguments into the
     * form required by the {@code Thread.join} method.
     *
     * @param thread the thread to wait for
     * @param timeout the maximum time to wait. If less than
     * or equal to zero, do not wait at all.
     * @throws InterruptedException if interrupted while waiting
     */
    public void timedJoin(Thread thread, long timeout)
            throws InterruptedException {
        if (timeout > 0) {
            long ms = toMillis(timeout);
            int ns = excessNanos(timeout, ms);
            thread.join(ms, ns);
        }
    }

    /**
     * Performs a {@link Thread#sleep(long, int) Thread.sleep} using
     * this time unit.
     * This is a convenience method that converts time arguments into the
     * form required by the {@code Thread.sleep} method.
     *
     * @param timeout the minimum time to sleep. If less than
     * or equal to zero, do not sleep at all.
     * @throws InterruptedException if interrupted while sleeping
     */
    public void sleep(long timeout) throws InterruptedException {
        if (timeout > 0) {
            long ms = toMillis(timeout);
            int ns = excessNanos(timeout, ms);
            Thread.sleep(ms, ns);
        }
    }

    /**
     * Converts this {@code TimeUnit} to the equivalent {@code ChronoUnit}.
     *
     * @return the converted equivalent ChronoUnit
     * @since 9
     */
    public ChronoUnit toChronoUnit() {
        switch (this) {
        case NANOSECONDS:  return ChronoUnit.NANOS;
        case MICROSECONDS: return ChronoUnit.MICROS;
        case MILLISECONDS: return ChronoUnit.MILLIS;
        case SECONDS:      return ChronoUnit.SECONDS;
        case MINUTES:      return ChronoUnit.MINUTES;
        case HOURS:        return ChronoUnit.HOURS;
        case DAYS:         return ChronoUnit.DAYS;
        default: throw new AssertionError();
        }
    }

    /**
     * Converts a {@code ChronoUnit} to the equivalent {@code TimeUnit}.
     *
     * @param chronoUnit the ChronoUnit to convert
     * @return the converted equivalent TimeUnit
     * @throws IllegalArgumentException if {@code chronoUnit} has no
     *         equivalent TimeUnit
     * @throws NullPointerException if {@code chronoUnit} is null
     * @since 9
     */
    public static TimeUnit of(ChronoUnit chronoUnit) {
        switch (Objects.requireNonNull(chronoUnit, "chronoUnit")) {
        case NANOS:   return TimeUnit.NANOSECONDS;
        case MICROS:  return TimeUnit.MICROSECONDS;
        case MILLIS:  return TimeUnit.MILLISECONDS;
        case SECONDS: return TimeUnit.SECONDS;
        case MINUTES: return TimeUnit.MINUTES;
        case HOURS:   return TimeUnit.HOURS;
        case DAYS:    return TimeUnit.DAYS;
        default:
            throw new IllegalArgumentException(
                "No TimeUnit equivalent for " + chronoUnit);
        }
    }

}
Revision:	1.52
Committed:	Fri Mar 25 16:16:02 2016 UTC (8 years, 2 months ago) by dl
Branch:	MAIN
Changes since 1.51:	+29 -11 lines
Log Message:	Cache toSeconds conversion constants
#	User	Rev	Content
1	dl	1.2	/*
2	jsr166	1.35	* Written by Doug Lea with assistance from members of JCP JSR-166
3			* Expert Group and released to the public domain, as explained at
4	jsr166	1.38	* http://creativecommons.org/publicdomain/zero/1.0/
5	jsr166	1.35	*/
6	dl	1.2
7	tim	1.1	package java.util.concurrent;
8
9	jsr166	1.48	import java.time.temporal.ChronoUnit;
10			import java.util.Objects;
11
12	tim	1.1	/**
13	jsr166	1.40	* A {@code TimeUnit} represents time durations at a given unit of
14	dl	1.27	* granularity and provides utility methods to convert across units,
15			* and to perform timing and delay operations in these units. A
16	jsr166	1.40	* {@code TimeUnit} does not maintain time information, but only
17	dl	1.27	* helps organize and use time representations that may be maintained
18			* separately across various contexts. A nanosecond is defined as one
19			* thousandth of a microsecond, a microsecond as one thousandth of a
20			* millisecond, a millisecond as one thousandth of a second, a minute
21			* as sixty seconds, an hour as sixty minutes, and a day as twenty four
22			* hours.
23			*
24	jsr166	1.40	* <p>A {@code TimeUnit} is mainly used to inform time-based methods
25	dl	1.27	* how a given timing parameter should be interpreted. For example,
26			* the following code will timeout in 50 milliseconds if the {@link
27			* java.util.concurrent.locks.Lock lock} is not available:
28			*
29	jsr166	1.45	* <pre> {@code
30	jsr166	1.39	* Lock lock = ...;
31			* if (lock.tryLock(50L, TimeUnit.MILLISECONDS)) ...}</pre>
32			*
33	dl	1.27	* while this code will timeout in 50 seconds:
34	jsr166	1.45	* <pre> {@code
35	jsr166	1.39	* Lock lock = ...;
36			* if (lock.tryLock(50L, TimeUnit.SECONDS)) ...}</pre>
37	dl	1.27	*
38			* Note however, that there is no guarantee that a particular timeout
39			* implementation will be able to notice the passage of time at the
40	jsr166	1.40	* same granularity as the given {@code TimeUnit}.
41	dl	1.27	*
42			* @since 1.5
43			* @author Doug Lea
44			*/
45	dl	1.20	public enum TimeUnit {
46	jsr166	1.43	/**
47	jsr166	1.47	* Time unit representing one thousandth of a microsecond.
48	jsr166	1.43	*/
49	dl	1.49	NANOSECONDS(1L), // (cannot use symbolic scale names here)
50	jsr166	1.43	/**
51	jsr166	1.47	* Time unit representing one thousandth of a millisecond.
52	jsr166	1.43	*/
53	dl	1.49	MICROSECONDS(1000L),
54	jsr166	1.43	/**
55	jsr166	1.47	* Time unit representing one thousandth of a second.
56	jsr166	1.43	*/
57	dl	1.49	MILLISECONDS(1000L * 1000L),
58	jsr166	1.43	/**
59	jsr166	1.47	* Time unit representing one second.
60	jsr166	1.43	*/
61	dl	1.49	SECONDS(1000L * 1000L * 1000L),
62	jsr166	1.43	/**
63	jsr166	1.47	* Time unit representing sixty seconds.
64	jsr166	1.44	* @since 1.6
65	jsr166	1.43	*/
66	dl	1.49	MINUTES(1000L * 1000L * 1000L * 60L),
67	jsr166	1.43	/**
68	jsr166	1.47	* Time unit representing sixty minutes.
69	jsr166	1.44	* @since 1.6
70	jsr166	1.43	*/
71	dl	1.49	HOURS(1000L * 1000L * 1000L * 60L * 60L),
72	jsr166	1.43	/**
73	jsr166	1.47	* Time unit representing twenty four hours.
74	jsr166	1.44	* @since 1.6
75	jsr166	1.43	*/
76	dl	1.49	DAYS(1000L * 1000L * 1000L * 60L * 60L * 24L);
77
78			// Scales as constants
79			private static final long NANO_SCALE = 1L;
80			private static final long MICRO_SCALE = 1000L * NANO_SCALE;
81			private static final long MILLI_SCALE = 1000L * MICRO_SCALE;
82			private static final long SECOND_SCALE = 1000L * MILLI_SCALE;
83			private static final long MINUTE_SCALE = 60L * SECOND_SCALE;
84			private static final long HOUR_SCALE = 60L * MINUTE_SCALE;
85			private static final long DAY_SCALE = 24L * HOUR_SCALE;
86
87			/*
88			* Instances cache conversion ratios and saturation cutoffs for
89	dl	1.52	* the units most commonly used in conversion results, in methods
90			* toNanos, toMillis and toSeconds. Other cases compute them, in
91			* method cvt.
92	dl	1.49	*/
93
94			private final long scale;
95			private final long maxNanos;
96			private final long maxMillis;
97	dl	1.52	private final long maxSecs;
98			private final int milliRatio;
99			private final int secRatio;
100	dl	1.49
101			TimeUnit(long scale) {
102			this.scale = scale;
103			this.maxNanos = Long.MAX_VALUE / scale;
104	dl	1.52	long mr = (scale >= MILLI_SCALE)
105			? (scale / MILLI_SCALE)
106			: (MILLI_SCALE / scale);
107			this.milliRatio = (int)mr;
108			this.maxMillis = Long.MAX_VALUE / mr;
109			long sr = (scale >= SECOND_SCALE)
110			? (scale / SECOND_SCALE)
111			: (SECOND_SCALE / scale);
112			this.secRatio = (int)sr;
113			this.maxSecs = Long.MAX_VALUE / sr;
114	dl	1.49	}
115
116			/**
117			* General conversion utility.
118			*
119			* @param d duration
120			* @param dst result scale unit
121			* @param src source scale unit
122			*/
123			private static long cvt(long d, long dst, long src) {
124			long r, m;
125	dl	1.50	if (src == dst)
126			return d;
127			else if (src < dst)
128			return d / (dst / src);
129			else if (d > (m = Long.MAX_VALUE / (r = src / dst)))
130			return Long.MAX_VALUE;
131			else if (d < -m)
132			return Long.MIN_VALUE;
133			else
134			return d * r;
135	dl	1.49	}
136	dl	1.32
137	dl	1.27	/**
138	jsr166	1.42	* Converts the given time duration in the given unit to this unit.
139			* Conversions from finer to coarser granularities truncate, so
140			* lose precision. For example, converting {@code 999} milliseconds
141			* to seconds results in {@code 0}. Conversions from coarser to
142			* finer granularities with arguments that would numerically
143			* overflow saturate to {@code Long.MIN_VALUE} if negative or
144			* {@code Long.MAX_VALUE} if positive.
145	jsr166	1.33	*
146			* <p>For example, to convert 10 minutes to milliseconds, use:
147	jsr166	1.40	* {@code TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)}
148	dl	1.27	*
149	jsr166	1.40	* @param sourceDuration the time duration in the given {@code sourceUnit}
150			* @param sourceUnit the unit of the {@code sourceDuration} argument
151	dl	1.27	* @return the converted duration in this unit,
152	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
153			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
154	dl	1.27	*/
155	dl	1.32	public long convert(long sourceDuration, TimeUnit sourceUnit) {
156	dl	1.49	return cvt(sourceDuration, scale, sourceUnit.scale);
157	dl	1.32	}
158	jsr166	1.29
159	dl	1.27	/**
160	jsr166	1.41	* Equivalent to
161			* {@link #convert(long, TimeUnit) NANOSECONDS.convert(duration, this)}.
162	dl	1.27	* @param duration the duration
163			* @return the converted duration,
164	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
165			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
166	dl	1.27	*/
167	dl	1.32	public long toNanos(long duration) {
168	dl	1.49	long s, m;
169	dl	1.50	if ((s = scale) == NANO_SCALE)
170			return duration;
171			else if (duration > (m = maxNanos))
172			return Long.MAX_VALUE;
173			else if (duration < -m)
174			return Long.MIN_VALUE;
175			else
176			return duration * s;
177	dl	1.32	}
178	jsr166	1.29
179	dl	1.27	/**
180	jsr166	1.41	* Equivalent to
181			* {@link #convert(long, TimeUnit) MICROSECONDS.convert(duration, this)}.
182	dl	1.27	* @param duration the duration
183			* @return the converted duration,
184	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
185			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
186	dl	1.27	*/
187	dl	1.32	public long toMicros(long duration) {
188	dl	1.49	return cvt(duration, MICRO_SCALE, scale);
189	dl	1.32	}
190	jsr166	1.29
191	dl	1.27	/**
192	jsr166	1.41	* Equivalent to
193			* {@link #convert(long, TimeUnit) MILLISECONDS.convert(duration, this)}.
194	dl	1.27	* @param duration the duration
195			* @return the converted duration,
196	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
197			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
198	dl	1.27	*/
199	dl	1.32	public long toMillis(long duration) {
200	dl	1.49	long s, m;
201	dl	1.50	if ((s = scale) == MILLI_SCALE)
202			return duration;
203			else if (s < MILLI_SCALE)
204	dl	1.52	return duration / milliRatio;
205	dl	1.50	else if (duration > (m = maxMillis))
206			return Long.MAX_VALUE;
207			else if (duration < -m)
208			return Long.MIN_VALUE;
209			else
210	dl	1.52	return duration * milliRatio;
211	dl	1.32	}
212	jsr166	1.29
213	dl	1.27	/**
214	jsr166	1.41	* Equivalent to
215			* {@link #convert(long, TimeUnit) SECONDS.convert(duration, this)}.
216	dl	1.27	* @param duration the duration
217			* @return the converted duration,
218	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
219			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
220	dl	1.27	*/
221	dl	1.32	public long toSeconds(long duration) {
222	dl	1.52	long s, m;
223			if ((s = scale) == SECOND_SCALE)
224			return duration;
225			else if (s < SECOND_SCALE)
226			return duration / secRatio;
227			else if (duration > (m = maxSecs))
228			return Long.MAX_VALUE;
229			else if (duration < -m)
230			return Long.MIN_VALUE;
231			else
232			return duration * secRatio;
233	dl	1.32	}
234	jsr166	1.29
235	dl	1.27	/**
236	jsr166	1.41	* Equivalent to
237			* {@link #convert(long, TimeUnit) MINUTES.convert(duration, this)}.
238	dl	1.27	* @param duration the duration
239			* @return the converted duration,
240	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
241			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
242	dl	1.31	* @since 1.6
243	dl	1.27	*/
244	dl	1.32	public long toMinutes(long duration) {
245	dl	1.49	return cvt(duration, MINUTE_SCALE, scale);
246	dl	1.32	}
247	jsr166	1.29
248	dl	1.27	/**
249	jsr166	1.41	* Equivalent to
250			* {@link #convert(long, TimeUnit) HOURS.convert(duration, this)}.
251	dl	1.27	* @param duration the duration
252			* @return the converted duration,
253	jsr166	1.40	* or {@code Long.MIN_VALUE} if conversion would negatively
254			* overflow, or {@code Long.MAX_VALUE} if it would positively overflow.
255	dl	1.31	* @since 1.6
256	dl	1.27	*/
257	dl	1.32	public long toHours(long duration) {
258	dl	1.49	return cvt(duration, HOUR_SCALE, scale);
259	dl	1.32	}
260	jsr166	1.29
261	dl	1.27	/**
262	jsr166	1.41	* Equivalent to
263			* {@link #convert(long, TimeUnit) DAYS.convert(duration, this)}.
264	dl	1.27	* @param duration the duration
265			* @return the converted duration
266	dl	1.31	* @since 1.6
267	dl	1.27	*/
268	dl	1.32	public long toDays(long duration) {
269	dl	1.49	return cvt(duration, DAY_SCALE, scale);
270	dl	1.32	}
271	jsr166	1.29
272	dl	1.27	/**
273			* Utility to compute the excess-nanosecond argument to wait,
274			* sleep, join.
275			* @param d the duration
276			* @param m the number of milliseconds
277			* @return the number of nanoseconds
278			*/
279	dl	1.49	private int excessNanos(long d, long m) {
280			long s;
281	dl	1.50	if ((s = scale) == NANO_SCALE)
282			return (int)(d - (m * MILLI_SCALE));
283			else if (s == MICRO_SCALE)
284			return (int)((d * 1000L) - (m * MILLI_SCALE));
285			else
286			return 0;
287	dl	1.49	}
288	jsr166	1.29
289	dl	1.27	/**
290	jsr166	1.37	* Performs a timed {@link Object#wait(long, int) Object.wait}
291			* using this time unit.
292	dl	1.27	* This is a convenience method that converts timeout arguments
293	jsr166	1.40	* into the form required by the {@code Object.wait} method.
294	dl	1.27	*
295	jsr166	1.40	* <p>For example, you could implement a blocking {@code poll}
296	dl	1.27	* method (see {@link BlockingQueue#poll BlockingQueue.poll})
297			* using:
298			*
299	jsr166	1.45	* <pre> {@code
300	jsr166	1.36	* public synchronized Object poll(long timeout, TimeUnit unit)
301			* throws InterruptedException {
302			* while (empty) {
303			* unit.timedWait(this, timeout);
304			* ...
305			* }
306			* }}</pre>
307	dl	1.27	*
308			* @param obj the object to wait on
309	dl	1.28	* @param timeout the maximum time to wait. If less than
310			* or equal to zero, do not wait at all.
311	jsr166	1.37	* @throws InterruptedException if interrupted while waiting
312	dl	1.27	*/
313			public void timedWait(Object obj, long timeout)
314	jsr166	1.37	throws InterruptedException {
315	dl	1.27	if (timeout > 0) {
316			long ms = toMillis(timeout);
317			int ns = excessNanos(timeout, ms);
318			obj.wait(ms, ns);
319			}
320			}
321	jsr166	1.29
322	dl	1.27	/**
323	jsr166	1.37	* Performs a timed {@link Thread#join(long, int) Thread.join}
324			* using this time unit.
325	dl	1.27	* This is a convenience method that converts time arguments into the
326	jsr166	1.40	* form required by the {@code Thread.join} method.
327	jsr166	1.37	*
328	dl	1.27	* @param thread the thread to wait for
329	dl	1.28	* @param timeout the maximum time to wait. If less than
330			* or equal to zero, do not wait at all.
331	jsr166	1.37	* @throws InterruptedException if interrupted while waiting
332	dl	1.27	*/
333			public void timedJoin(Thread thread, long timeout)
334	jsr166	1.37	throws InterruptedException {
335	dl	1.27	if (timeout > 0) {
336			long ms = toMillis(timeout);
337			int ns = excessNanos(timeout, ms);
338			thread.join(ms, ns);
339			}
340			}
341	jsr166	1.29
342	dl	1.27	/**
343	jsr166	1.37	* Performs a {@link Thread#sleep(long, int) Thread.sleep} using
344			* this time unit.
345	dl	1.27	* This is a convenience method that converts time arguments into the
346	jsr166	1.40	* form required by the {@code Thread.sleep} method.
347	jsr166	1.37	*
348	dl	1.28	* @param timeout the minimum time to sleep. If less than
349			* or equal to zero, do not sleep at all.
350	jsr166	1.37	* @throws InterruptedException if interrupted while sleeping
351	dl	1.27	*/
352			public void sleep(long timeout) throws InterruptedException {
353			if (timeout > 0) {
354			long ms = toMillis(timeout);
355			int ns = excessNanos(timeout, ms);
356			Thread.sleep(ms, ns);
357			}
358			}
359	jsr166	1.29
360	jsr166	1.48	/**
361			* Converts this {@code TimeUnit} to the equivalent {@code ChronoUnit}.
362			*
363			* @return the converted equivalent ChronoUnit
364			* @since 9
365			*/
366			public ChronoUnit toChronoUnit() {
367			switch (this) {
368			case NANOSECONDS: return ChronoUnit.NANOS;
369			case MICROSECONDS: return ChronoUnit.MICROS;
370			case MILLISECONDS: return ChronoUnit.MILLIS;
371			case SECONDS: return ChronoUnit.SECONDS;
372			case MINUTES: return ChronoUnit.MINUTES;
373			case HOURS: return ChronoUnit.HOURS;
374			case DAYS: return ChronoUnit.DAYS;
375			default: throw new AssertionError();
376			}
377			}
378
379			/**
380			* Converts a {@code ChronoUnit} to the equivalent {@code TimeUnit}.
381			*
382			* @param chronoUnit the ChronoUnit to convert
383			* @return the converted equivalent TimeUnit
384			* @throws IllegalArgumentException if {@code chronoUnit} has no
385			* equivalent TimeUnit
386			* @throws NullPointerException if {@code chronoUnit} is null
387			* @since 9
388			*/
389			public static TimeUnit of(ChronoUnit chronoUnit) {
390			switch (Objects.requireNonNull(chronoUnit, "chronoUnit")) {
391			case NANOS: return TimeUnit.NANOSECONDS;
392			case MICROS: return TimeUnit.MICROSECONDS;
393			case MILLIS: return TimeUnit.MILLISECONDS;
394			case SECONDS: return TimeUnit.SECONDS;
395			case MINUTES: return TimeUnit.MINUTES;
396			case HOURS: return TimeUnit.HOURS;
397			case DAYS: return TimeUnit.DAYS;
398			default:
399			throw new IllegalArgumentException(
400			"No TimeUnit equivalent for " + chronoUnit);
401			}
402			}
403
404	tim	1.1	}