/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file: * * 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.util.Objects; // BEGIN android-note // removed java 9 ChronoUnit related code // END android-note /** * 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. * *
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: * *
{@code * Lock lock = ...; * if (lock.tryLock(50L, TimeUnit.MILLISECONDS)) ...}* * while this code will timeout in 50 seconds: *
{@code * 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 {@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. * @since 1.6 */ 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. * @since 1.6 */ 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. * @since 1.6 */ 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. * *
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. * *
For example, you could implement a blocking {@code poll} * method (see {@link BlockingQueue#poll BlockingQueue.poll}) * using: * *
{@code * 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 */ 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); } } }