scala.actors.threadpool.TimeUnit Maven / Gradle / Ivy
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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/licenses/publicdomain
*/
package scala.actors.threadpool;
import java.io.InvalidObjectException;
import java.io.ObjectStreamException;
/**
* A 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
* 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.
*
* A 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
* edu.emory.mathcs.backport.java.util.concurrent.locks.Lock lock} is not available:
*
*
Lock lock = ...;
* if ( lock.tryLock(50L, TimeUnit.MILLISECONDS) ) ...
*
* while this code will timeout in 50 seconds:
*
* Lock lock = ...;
* if ( lock.tryLock(50L, TimeUnit.SECONDS) ) ...
*
*
* 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 TimeUnit.
*
* @since 1.5
* @author Doug Lea
*/
public abstract class TimeUnit implements java.io.Serializable {
public static final TimeUnit NANOSECONDS = new TimeUnit(0, "NANOSECONDS") {
private final static long serialVersionUID = 535148490883208361L;
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)); }
};
public static final TimeUnit MICROSECONDS = new TimeUnit(1, "MICROSECONDS") {
private final static long serialVersionUID = 2185906575929579108L;
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)); }
};
public static final TimeUnit MILLISECONDS = new TimeUnit(2, "MILLISECONDS") {
private final static long serialVersionUID = 9032047794123325184L;
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; }
};
public static final TimeUnit SECONDS = new TimeUnit(3, "SECONDS") {
private final static long serialVersionUID = 227755028449378390L;
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; }
};
public static final TimeUnit MINUTES = new TimeUnit(4, "MINUTES") {
private final static long serialVersionUID = 1827351566402609187L;
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; }
};
public static final TimeUnit HOURS = new TimeUnit(5, "HOURS") {
private final static long serialVersionUID = -6438436134732089810L;
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; }
};
public static final TimeUnit DAYS = new TimeUnit(6, "DAYS") {
private final static long serialVersionUID = 567463171959674600L;
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; }
};
private static final TimeUnit[] values = new TimeUnit[]
{ NANOSECONDS, MICROSECONDS, MILLISECONDS, SECONDS, MINUTES, HOURS, DAYS };
public static TimeUnit[] values() {
return (TimeUnit[])values.clone();
}
/**
* Returns the enum constant of this type with the specified name. The
* string must match exactly an identifier used to declare an
* enum constant in this type. (Extraneous whitespace characters are not
* permitted.)
*
* @param name the name of the enum constant to be returned
* @return the enum constant with the specified name
* @throws IllegalArgumentException
* if this enum type has no constant with the specified name
*/
public static TimeUnit valueOf(String name) {
for (int i = 0; i < values.length; i++) {
if (values[i].name.equals(name)) {
return values[i];
}
}
throw new IllegalArgumentException("No enum const TimeUnit." + name);
}
/**
* The ordinal of this unit. This is useful both for {@link #ordinal()}
* and to maintain serialization consistence with earlier versions.
*/
private final int index;
/** name of this unit */
private final String name;
/** Internal constructor */
TimeUnit(int index, String name) {
this.index = index;
this.name = name;
}
// Handy constants for conversion methods
static final long C0 = 1;
static final long C1 = C0 * 1000;
static final long C2 = C1 * 1000;
static final long C3 = C2 * 1000;
static final long C4 = C3 * 60;
static final long C5 = C4 * 60;
static final long C6 = C5 * 24;
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;
}
/**
* Convert the given time duration in the given unit to this
* unit. Conversions from finer to coarser granularities
* truncate, so lose precision. For example converting
* 999 milliseconds to seconds results in
* 0. Conversions from coarser to finer granularities
* with arguments that would numerically overflow saturate to
* Long.MIN_VALUE if negative or Long.MAX_VALUE
* if positive.
*
* For example, to convert 10 minutes to milliseconds, use:
* TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)
*
* @param sourceDuration the time duration in the given sourceUnit
* @param sourceUnit the unit of the sourceDuration argument
* @return the converted duration in this unit,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
*/
public abstract long convert(long sourceDuration, TimeUnit sourceUnit);
/**
* Equivalent to NANOSECONDS.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
*/
public abstract long toNanos(long duration);
/**
* Equivalent to MICROSECONDS.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
*/
public abstract long toMicros(long duration);
/**
* Equivalent to MILLISECONDS.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
*/
public abstract long toMillis(long duration);
/**
* Equivalent to SECONDS.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
*/
public abstract long toSeconds(long duration);
/**
* Equivalent to MINUTES.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
* @since 1.6
*/
public abstract long toMinutes(long duration);
/**
* Equivalent to HOURS.convert(duration, this).
* @param duration the duration
* @return the converted duration,
* or Long.MIN_VALUE if conversion would negatively
* overflow, or Long.MAX_VALUE if it would positively overflow.
* @see #convert
* @since 1.6
*/
public abstract long toHours(long duration);
/**
* Equivalent to DAYS.convert(duration, this).
* @param duration the duration
* @return the converted duration
* @see #convert
* @since 1.6
*/
public abstract long toDays(long duration);
/**
* 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);
/**
* Returns the name of this enum constant, exactly as declared in its enum
* declaration. Most programmers should use the
* {@link #toString()} method in preference to this one, as the toString
* method may return a more user-friendly name. This method is
* designed primarily for use in specialized situations where correctness
* depends on getting the exact name, which will not vary from release to
* release.
*
* @return the name of this enum constant
*/
public String name() {
return name;
}
/**
* Returns the ordinal of this enumeration constant (its position in its
* enum declaration, where the initial constant is assigned an ordinal of
* zero). Most programmers will have no use for this method. It is
* designed for use by sophisticated enum-based data structures, such as
* EnumSet and EnumMap.
*
* @return the ordinal of this enumeration constant
*/
public int ordinal() {
return index;
}
/*
* Guarantees that deserialized objects will be referentially equal to the
* standard enumeration objects.
*/
protected Object readResolve() throws ObjectStreamException {
try {
return valueOf(name);
} catch (IllegalArgumentException e) {
throw new InvalidObjectException(name
+ " is not a valid enum for TimeUnit");
}
}
/**
* Performs a timed Object.wait using this time unit.
* This is a convenience method that converts timeout arguments
* into the form required by the Object.wait method.
*
*
For example, you could implement a blocking poll
* method (see {@link BlockingQueue#poll BlockingQueue.poll})
* using:
*
*
public synchronized Object poll(long timeout, TimeUnit unit) throws InterruptedException {
* while (empty) {
* unit.timedWait(this, timeout);
* ...
* }
* }
*
* @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.
* @see java.lang.Object#wait(long, int)
*/
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 Thread.join using this time unit.
* This is a convenience method that converts time arguments into the
* form required by the 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.
* @see java.lang.Thread#join(long, int)
*/
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 Thread.sleep using this unit.
* This is a convenience method that converts time arguments into the
* form required by the Thread.sleep method.
* @param timeout the maximum time to sleep. If less than
* or equal to zero, do not sleep at all.
* @throws InterruptedException if interrupted while sleeping.
* @see java.lang.Thread#sleep
*/
public void sleep(long timeout) throws InterruptedException {
if (timeout > 0) {
long ms = toMillis(timeout);
int ns = excessNanos(timeout, ms);
Thread.sleep(ms, ns);
}
}
public String toString() {
return name;
}
}