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(TimeUnit.NANO_SCALE),
    /**
     * Time unit representing one thousandth of a millisecond.
     */
    MICROSECONDS(TimeUnit.MICRO_SCALE),
    /**
     * Time unit representing one thousandth of a second.
     */
    MILLISECONDS(TimeUnit.MILLI_SCALE),
    /**
     * Time unit representing one second.
     */
    SECONDS(TimeUnit.SECOND_SCALE),
    /**
     * Time unit representing sixty seconds.
     * @since 1.6
     */
    MINUTES(TimeUnit.MINUTE_SCALE),
    /**
     * Time unit representing sixty minutes.
     * @since 1.6
     */
    HOURS(TimeUnit.HOUR_SCALE),
    /**
     * Time unit representing twenty four hours.
     * @since 1.6
     */
    DAYS(TimeUnit.DAY_SCALE);

    // 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 up through SECONDS. Other cases compute them, in
     * method cvt.
     */

    private final long scale;
    private final long maxNanos;
    private final long maxMicros;
    private final long maxMillis;
    private final long maxSecs;
    private final long microRatio;
    private final int milliRatio;   // fits in 32 bits
    private final int secRatio;     // fits in 32 bits

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

    /**
     * General conversion utility.
     *
     * @param d duration
     * @param dst result unit scale
     * @param src source unit scale
     */
    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) {
        switch (this) {
        case NANOSECONDS:  return sourceUnit.toNanos(sourceDuration);
        case MICROSECONDS: return sourceUnit.toMicros(sourceDuration);
        case MILLISECONDS: return sourceUnit.toMillis(sourceDuration);
        case SECONDS:      return sourceUnit.toSeconds(sourceDuration);
        default: 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) {
        long s, m;
        if ((s = scale) == MICRO_SCALE)
            return duration;
        else if (s < MICRO_SCALE)
            return duration / microRatio;
        else if (duration > (m = maxMicros))
            return Long.MAX_VALUE;
        else if (duration < -m)
            return Long.MIN_VALUE;
        else
            return duration * microRatio;
    }

    /**
     * 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:	1.58
Committed:	Sat Mar 26 17:05:48 2016 UTC (8 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.57:	+14 -14 lines
Log Message:	very small readability improvement
#	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	jsr166	1.56	NANOSECONDS(TimeUnit.NANO_SCALE),
50	jsr166	1.43	/**
51	jsr166	1.47	* Time unit representing one thousandth of a millisecond.
52	jsr166	1.43	*/
53	jsr166	1.56	MICROSECONDS(TimeUnit.MICRO_SCALE),
54	jsr166	1.43	/**
55	jsr166	1.47	* Time unit representing one thousandth of a second.
56	jsr166	1.43	*/
57	jsr166	1.56	MILLISECONDS(TimeUnit.MILLI_SCALE),
58	jsr166	1.43	/**
59	jsr166	1.47	* Time unit representing one second.
60	jsr166	1.43	*/
61	jsr166	1.56	SECONDS(TimeUnit.SECOND_SCALE),
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	jsr166	1.56	MINUTES(TimeUnit.MINUTE_SCALE),
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	jsr166	1.56	HOURS(TimeUnit.HOUR_SCALE),
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	jsr166	1.56	DAYS(TimeUnit.DAY_SCALE);
77	dl	1.49
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	1.53	* the units up through SECONDS. Other cases compute them, in
90	dl	1.52	* method cvt.
91	dl	1.49	*/
92
93			private final long scale;
94			private final long maxNanos;
95	dl	1.53	private final long maxMicros;
96	dl	1.49	private final long maxMillis;
97	dl	1.52	private final long maxSecs;
98	dl	1.53	private final long microRatio;
99			private final int milliRatio; // fits in 32 bits
100			private final int secRatio; // fits in 32 bits
101
102			TimeUnit(long s) {
103			this.scale = s;
104			this.maxNanos = Long.MAX_VALUE / s;
105			long ur = (s >= MICRO_SCALE) ? (s / MICRO_SCALE) : (MICRO_SCALE / s);
106			this.microRatio = ur;
107			this.maxMicros = Long.MAX_VALUE / ur;
108	jsr166	1.55	long mr = (s >= MILLI_SCALE) ? (s / MILLI_SCALE) : (MILLI_SCALE / s);
109	dl	1.52	this.milliRatio = (int)mr;
110			this.maxMillis = Long.MAX_VALUE / mr;
111	dl	1.53	long sr = (s >= SECOND_SCALE) ? (s / SECOND_SCALE) : (SECOND_SCALE / s);
112	dl	1.52	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	jsr166	1.57	* @param dst result unit scale
121			* @param src source unit scale
122	dl	1.49	*/
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	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
153			* 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	1.53	switch (this) {
157	jsr166	1.54	case NANOSECONDS: return sourceUnit.toNanos(sourceDuration);
158	dl	1.53	case MICROSECONDS: return sourceUnit.toMicros(sourceDuration);
159			case MILLISECONDS: return sourceUnit.toMillis(sourceDuration);
160	jsr166	1.54	case SECONDS: return sourceUnit.toSeconds(sourceDuration);
161	dl	1.53	default: return cvt(sourceDuration, scale, sourceUnit.scale);
162			}
163	dl	1.32	}
164	jsr166	1.29
165	dl	1.27	/**
166	jsr166	1.41	* Equivalent to
167			* {@link #convert(long, TimeUnit) NANOSECONDS.convert(duration, this)}.
168	dl	1.27	* @param duration the duration
169			* @return the converted duration,
170	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
171			* or {@code Long.MAX_VALUE} if it would positively overflow.
172	dl	1.27	*/
173	dl	1.32	public long toNanos(long duration) {
174	dl	1.49	long s, m;
175	dl	1.50	if ((s = scale) == NANO_SCALE)
176			return duration;
177			else if (duration > (m = maxNanos))
178			return Long.MAX_VALUE;
179			else if (duration < -m)
180			return Long.MIN_VALUE;
181			else
182			return duration * s;
183	dl	1.32	}
184	jsr166	1.29
185	dl	1.27	/**
186	jsr166	1.41	* Equivalent to
187			* {@link #convert(long, TimeUnit) MICROSECONDS.convert(duration, this)}.
188	dl	1.27	* @param duration the duration
189			* @return the converted duration,
190	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
191			* or {@code Long.MAX_VALUE} if it would positively overflow.
192	dl	1.27	*/
193	dl	1.32	public long toMicros(long duration) {
194	dl	1.53	long s, m;
195			if ((s = scale) == MICRO_SCALE)
196			return duration;
197			else if (s < MICRO_SCALE)
198			return duration / microRatio;
199			else if (duration > (m = maxMicros))
200			return Long.MAX_VALUE;
201			else if (duration < -m)
202			return Long.MIN_VALUE;
203			else
204			return duration * microRatio;
205	dl	1.32	}
206	jsr166	1.29
207	dl	1.27	/**
208	jsr166	1.41	* Equivalent to
209			* {@link #convert(long, TimeUnit) MILLISECONDS.convert(duration, this)}.
210	dl	1.27	* @param duration the duration
211			* @return the converted duration,
212	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
213			* or {@code Long.MAX_VALUE} if it would positively overflow.
214	dl	1.27	*/
215	dl	1.32	public long toMillis(long duration) {
216	dl	1.49	long s, m;
217	dl	1.50	if ((s = scale) == MILLI_SCALE)
218			return duration;
219			else if (s < MILLI_SCALE)
220	dl	1.52	return duration / milliRatio;
221	dl	1.50	else if (duration > (m = maxMillis))
222			return Long.MAX_VALUE;
223			else if (duration < -m)
224			return Long.MIN_VALUE;
225			else
226	dl	1.52	return duration * milliRatio;
227	dl	1.32	}
228	jsr166	1.29
229	dl	1.27	/**
230	jsr166	1.41	* Equivalent to
231			* {@link #convert(long, TimeUnit) SECONDS.convert(duration, this)}.
232	dl	1.27	* @param duration the duration
233			* @return the converted duration,
234	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
235			* or {@code Long.MAX_VALUE} if it would positively overflow.
236	dl	1.27	*/
237	dl	1.32	public long toSeconds(long duration) {
238	dl	1.52	long s, m;
239			if ((s = scale) == SECOND_SCALE)
240			return duration;
241			else if (s < SECOND_SCALE)
242			return duration / secRatio;
243			else if (duration > (m = maxSecs))
244			return Long.MAX_VALUE;
245			else if (duration < -m)
246			return Long.MIN_VALUE;
247			else
248			return duration * secRatio;
249	dl	1.32	}
250	jsr166	1.29
251	dl	1.27	/**
252	jsr166	1.41	* Equivalent to
253			* {@link #convert(long, TimeUnit) MINUTES.convert(duration, this)}.
254	dl	1.27	* @param duration the duration
255			* @return the converted duration,
256	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
257			* or {@code Long.MAX_VALUE} if it would positively overflow.
258	dl	1.31	* @since 1.6
259	dl	1.27	*/
260	dl	1.32	public long toMinutes(long duration) {
261	dl	1.49	return cvt(duration, MINUTE_SCALE, scale);
262	dl	1.32	}
263	jsr166	1.29
264	dl	1.27	/**
265	jsr166	1.41	* Equivalent to
266			* {@link #convert(long, TimeUnit) HOURS.convert(duration, this)}.
267	dl	1.27	* @param duration the duration
268			* @return the converted duration,
269	jsr166	1.58	* or {@code Long.MIN_VALUE} if conversion would negatively overflow,
270			* or {@code Long.MAX_VALUE} if it would positively overflow.
271	dl	1.31	* @since 1.6
272	dl	1.27	*/
273	dl	1.32	public long toHours(long duration) {
274	dl	1.49	return cvt(duration, HOUR_SCALE, scale);
275	dl	1.32	}
276	jsr166	1.29
277	dl	1.27	/**
278	jsr166	1.41	* Equivalent to
279			* {@link #convert(long, TimeUnit) DAYS.convert(duration, this)}.
280	dl	1.27	* @param duration the duration
281			* @return the converted duration
282	dl	1.31	* @since 1.6
283	dl	1.27	*/
284	dl	1.32	public long toDays(long duration) {
285	dl	1.49	return cvt(duration, DAY_SCALE, scale);
286	dl	1.32	}
287	jsr166	1.29
288	dl	1.27	/**
289			* Utility to compute the excess-nanosecond argument to wait,
290			* sleep, join.
291			* @param d the duration
292			* @param m the number of milliseconds
293			* @return the number of nanoseconds
294			*/
295	dl	1.49	private int excessNanos(long d, long m) {
296			long s;
297	dl	1.50	if ((s = scale) == NANO_SCALE)
298			return (int)(d - (m * MILLI_SCALE));
299			else if (s == MICRO_SCALE)
300			return (int)((d * 1000L) - (m * MILLI_SCALE));
301			else
302			return 0;
303	dl	1.49	}
304	jsr166	1.29
305	dl	1.27	/**
306	jsr166	1.37	* Performs a timed {@link Object#wait(long, int) Object.wait}
307			* using this time unit.
308	dl	1.27	* This is a convenience method that converts timeout arguments
309	jsr166	1.40	* into the form required by the {@code Object.wait} method.
310	dl	1.27	*
311	jsr166	1.40	* <p>For example, you could implement a blocking {@code poll}
312	dl	1.27	* method (see {@link BlockingQueue#poll BlockingQueue.poll})
313			* using:
314			*
315	jsr166	1.45	* <pre> {@code
316	jsr166	1.36	* public synchronized Object poll(long timeout, TimeUnit unit)
317			* throws InterruptedException {
318			* while (empty) {
319			* unit.timedWait(this, timeout);
320			* ...
321			* }
322			* }}</pre>
323	dl	1.27	*
324			* @param obj the object to wait on
325	dl	1.28	* @param timeout the maximum time to wait. If less than
326			* or equal to zero, do not wait at all.
327	jsr166	1.37	* @throws InterruptedException if interrupted while waiting
328	dl	1.27	*/
329			public void timedWait(Object obj, long timeout)
330	jsr166	1.37	throws InterruptedException {
331	dl	1.27	if (timeout > 0) {
332			long ms = toMillis(timeout);
333			int ns = excessNanos(timeout, ms);
334			obj.wait(ms, ns);
335			}
336			}
337	jsr166	1.29
338	dl	1.27	/**
339	jsr166	1.37	* Performs a timed {@link Thread#join(long, int) Thread.join}
340			* using this time unit.
341	dl	1.27	* This is a convenience method that converts time arguments into the
342	jsr166	1.40	* form required by the {@code Thread.join} method.
343	jsr166	1.37	*
344	dl	1.27	* @param thread the thread to wait for
345	dl	1.28	* @param timeout the maximum time to wait. If less than
346			* or equal to zero, do not wait at all.
347	jsr166	1.37	* @throws InterruptedException if interrupted while waiting
348	dl	1.27	*/
349			public void timedJoin(Thread thread, long timeout)
350	jsr166	1.37	throws InterruptedException {
351	dl	1.27	if (timeout > 0) {
352			long ms = toMillis(timeout);
353			int ns = excessNanos(timeout, ms);
354			thread.join(ms, ns);
355			}
356			}
357	jsr166	1.29
358	dl	1.27	/**
359	jsr166	1.37	* Performs a {@link Thread#sleep(long, int) Thread.sleep} using
360			* this time unit.
361	dl	1.27	* This is a convenience method that converts time arguments into the
362	jsr166	1.40	* form required by the {@code Thread.sleep} method.
363	jsr166	1.37	*
364	dl	1.28	* @param timeout the minimum time to sleep. If less than
365			* or equal to zero, do not sleep at all.
366	jsr166	1.37	* @throws InterruptedException if interrupted while sleeping
367	dl	1.27	*/
368			public void sleep(long timeout) throws InterruptedException {
369			if (timeout > 0) {
370			long ms = toMillis(timeout);
371			int ns = excessNanos(timeout, ms);
372			Thread.sleep(ms, ns);
373			}
374			}
375	jsr166	1.29
376	jsr166	1.48	/**
377			* Converts this {@code TimeUnit} to the equivalent {@code ChronoUnit}.
378			*
379			* @return the converted equivalent ChronoUnit
380			* @since 9
381			*/
382			public ChronoUnit toChronoUnit() {
383			switch (this) {
384			case NANOSECONDS: return ChronoUnit.NANOS;
385			case MICROSECONDS: return ChronoUnit.MICROS;
386			case MILLISECONDS: return ChronoUnit.MILLIS;
387			case SECONDS: return ChronoUnit.SECONDS;
388			case MINUTES: return ChronoUnit.MINUTES;
389			case HOURS: return ChronoUnit.HOURS;
390			case DAYS: return ChronoUnit.DAYS;
391			default: throw new AssertionError();
392			}
393			}
394
395			/**
396			* Converts a {@code ChronoUnit} to the equivalent {@code TimeUnit}.
397			*
398			* @param chronoUnit the ChronoUnit to convert
399			* @return the converted equivalent TimeUnit
400			* @throws IllegalArgumentException if {@code chronoUnit} has no
401			* equivalent TimeUnit
402			* @throws NullPointerException if {@code chronoUnit} is null
403			* @since 9
404			*/
405			public static TimeUnit of(ChronoUnit chronoUnit) {
406			switch (Objects.requireNonNull(chronoUnit, "chronoUnit")) {
407			case NANOS: return TimeUnit.NANOSECONDS;
408			case MICROS: return TimeUnit.MICROSECONDS;
409			case MILLIS: return TimeUnit.MILLISECONDS;
410			case SECONDS: return TimeUnit.SECONDS;
411			case MINUTES: return TimeUnit.MINUTES;
412			case HOURS: return TimeUnit.HOURS;
413			case DAYS: return TimeUnit.DAYS;
414			default:
415			throw new IllegalArgumentException(
416			"No TimeUnit equivalent for " + chronoUnit);
417			}
418			}
419
420	tim	1.1	}