/*
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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/*
*
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* 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;
/**
* 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 {
public long
toNanos(long
d) { return
d; }
public long
toMicros(long
d) { return
d/(
C1/
C0); }
public long
toMillis(long
d) { return
d/(
C2/
C0); }
public long
toSeconds(long
d) { return
d/(
C3/
C0); }
public long
toMinutes(long
d) { return
d/(
C4/
C0); }
public long
toHours(long
d) { return
d/(
C5/
C0); }
public long
toDays(long
d) { return
d/(
C6/
C0); }
public long
convert(long
d,
TimeUnit u) { return
u.
toNanos(
d); }
int
excessNanos(long
d, long
m) { return (int)(
d - (
m*
C2)); }
},
/**
* Time unit representing one thousandth of a millisecond
*/
MICROSECONDS {
public long
toNanos(long
d) { return
x(
d,
C1/
C0,
MAX/(
C1/
C0)); }
public long
toMicros(long
d) { return
d; }
public long
toMillis(long
d) { return
d/(
C2/
C1); }
public long
toSeconds(long
d) { return
d/(
C3/
C1); }
public long
toMinutes(long
d) { return
d/(
C4/
C1); }
public long
toHours(long
d) { return
d/(
C5/
C1); }
public long
toDays(long
d) { return
d/(
C6/
C1); }
public long
convert(long
d,
TimeUnit u) { return
u.
toMicros(
d); }
int
excessNanos(long
d, long
m) { return (int)((
d*
C1) - (
m*
C2)); }
},
/**
* Time unit representing one thousandth of a second
*/
MILLISECONDS {
public long
toNanos(long
d) { return
x(
d,
C2/
C0,
MAX/(
C2/
C0)); }
public long
toMicros(long
d) { return
x(
d,
C2/
C1,
MAX/(
C2/
C1)); }
public long
toMillis(long
d) { return
d; }
public long
toSeconds(long
d) { return
d/(
C3/
C2); }
public long
toMinutes(long
d) { return
d/(
C4/
C2); }
public long
toHours(long
d) { return
d/(
C5/
C2); }
public long
toDays(long
d) { return
d/(
C6/
C2); }
public long
convert(long
d,
TimeUnit u) { return
u.
toMillis(
d); }
int
excessNanos(long
d, long
m) { return 0; }
},
/**
* Time unit representing one second
*/
SECONDS {
public long
toNanos(long
d) { return
x(
d,
C3/
C0,
MAX/(
C3/
C0)); }
public long
toMicros(long
d) { return
x(
d,
C3/
C1,
MAX/(
C3/
C1)); }
public long
toMillis(long
d) { return
x(
d,
C3/
C2,
MAX/(
C3/
C2)); }
public long
toSeconds(long
d) { return
d; }
public long
toMinutes(long
d) { return
d/(
C4/
C3); }
public long
toHours(long
d) { return
d/(
C5/
C3); }
public long
toDays(long
d) { return
d/(
C6/
C3); }
public long
convert(long
d,
TimeUnit u) { return
u.
toSeconds(
d); }
int
excessNanos(long
d, long
m) { return 0; }
},
/**
* Time unit representing sixty seconds
*/
MINUTES {
public long
toNanos(long
d) { return
x(
d,
C4/
C0,
MAX/(
C4/
C0)); }
public long
toMicros(long
d) { return
x(
d,
C4/
C1,
MAX/(
C4/
C1)); }
public long
toMillis(long
d) { return
x(
d,
C4/
C2,
MAX/(
C4/
C2)); }
public long
toSeconds(long
d) { return
x(
d,
C4/
C3,
MAX/(
C4/
C3)); }
public long
toMinutes(long
d) { return
d; }
public long
toHours(long
d) { return
d/(
C5/
C4); }
public long
toDays(long
d) { return
d/(
C6/
C4); }
public long
convert(long
d,
TimeUnit u) { return
u.
toMinutes(
d); }
int
excessNanos(long
d, long
m) { return 0; }
},
/**
* Time unit representing sixty minutes
*/
HOURS {
public long
toNanos(long
d) { return
x(
d,
C5/
C0,
MAX/(
C5/
C0)); }
public long
toMicros(long
d) { return
x(
d,
C5/
C1,
MAX/(
C5/
C1)); }
public long
toMillis(long
d) { return
x(
d,
C5/
C2,
MAX/(
C5/
C2)); }
public long
toSeconds(long
d) { return
x(
d,
C5/
C3,
MAX/(
C5/
C3)); }
public long
toMinutes(long
d) { return
x(
d,
C5/
C4,
MAX/(
C5/
C4)); }
public long
toHours(long
d) { return
d; }
public long
toDays(long
d) { return
d/(
C6/
C5); }
public long
convert(long
d,
TimeUnit u) { return
u.
toHours(
d); }
int
excessNanos(long
d, long
m) { return 0; }
},
/**
* Time unit representing twenty four hours
*/
DAYS {
public long
toNanos(long
d) { return
x(
d,
C6/
C0,
MAX/(
C6/
C0)); }
public long
toMicros(long
d) { return
x(
d,
C6/
C1,
MAX/(
C6/
C1)); }
public long
toMillis(long
d) { return
x(
d,
C6/
C2,
MAX/(
C6/
C2)); }
public long
toSeconds(long
d) { return
x(
d,
C6/
C3,
MAX/(
C6/
C3)); }
public long
toMinutes(long
d) { return
x(
d,
C6/
C4,
MAX/(
C6/
C4)); }
public long
toHours(long
d) { return
x(
d,
C6/
C5,
MAX/(
C6/
C5)); }
public long
toDays(long
d) { return
d; }
public long
convert(long
d,
TimeUnit u) { return
u.
toDays(
d); }
int
excessNanos(long
d, long
m) { return 0; }
};
// Handy constants for conversion methods
static final long
C0 = 1L;
static final long
C1 =
C0 * 1000L;
static final long
C2 =
C1 * 1000L;
static final long
C3 =
C2 * 1000L;
static final long
C4 =
C3 * 60L;
static final long
C5 =
C4 * 60L;
static final long
C6 =
C5 * 24L;
static final long
MAX =
Long.
MAX_VALUE;
/**
* Scale d by m, checking for overflow.
* This has a short name to make above code more readable.
*/
static long
x(long
d, long
m, long
over) {
if (
d >
over) return
Long.
MAX_VALUE;
if (
d < -
over) return
Long.
MIN_VALUE;
return
d *
m;
}
// To maintain full signature compatibility with 1.5, and to improve the
// clarity of the generated javadoc (see 6287639: Abstract methods in
// enum classes should not be listed as abstract), method convert
// etc. are not declared abstract but otherwise act as abstract methods.
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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) {
throw new
AbstractMethodError();
}
/**
* 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
*/
abstract int
excessNanos(long
d, long
m);
/**
* 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);
}
}
}