| 1 |
/* |
| 2 |
* 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 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
| 5 |
*/ |
| 6 |
|
| 7 |
package java.util.concurrent; |
| 8 |
|
| 9 |
/** |
| 10 |
* A {@code TimeUnit} represents time durations at a given unit of |
| 11 |
* granularity and provides utility methods to convert across units, |
| 12 |
* and to perform timing and delay operations in these units. A |
| 13 |
* {@code TimeUnit} does not maintain time information, but only |
| 14 |
* helps organize and use time representations that may be maintained |
| 15 |
* separately across various contexts. A nanosecond is defined as one |
| 16 |
* thousandth of a microsecond, a microsecond as one thousandth of a |
| 17 |
* millisecond, a millisecond as one thousandth of a second, a minute |
| 18 |
* as sixty seconds, an hour as sixty minutes, and a day as twenty four |
| 19 |
* hours. |
| 20 |
* |
| 21 |
* <p>A {@code TimeUnit} is mainly used to inform time-based methods |
| 22 |
* how a given timing parameter should be interpreted. For example, |
| 23 |
* the following code will timeout in 50 milliseconds if the {@link |
| 24 |
* java.util.concurrent.locks.Lock lock} is not available: |
| 25 |
* |
| 26 |
* <pre> {@code |
| 27 |
* Lock lock = ...; |
| 28 |
* if (lock.tryLock(50L, TimeUnit.MILLISECONDS)) ...}</pre> |
| 29 |
* |
| 30 |
* while this code will timeout in 50 seconds: |
| 31 |
* <pre> {@code |
| 32 |
* Lock lock = ...; |
| 33 |
* if (lock.tryLock(50L, TimeUnit.SECONDS)) ...}</pre> |
| 34 |
* |
| 35 |
* Note however, that there is no guarantee that a particular timeout |
| 36 |
* implementation will be able to notice the passage of time at the |
| 37 |
* same granularity as the given {@code TimeUnit}. |
| 38 |
* |
| 39 |
* @since 1.5 |
| 40 |
* @author Doug Lea |
| 41 |
*/ |
| 42 |
public enum TimeUnit { |
| 43 |
NANOSECONDS { |
| 44 |
public long toNanos(long d) { return d; } |
| 45 |
public long toMicros(long d) { return d/(C1/C0); } |
| 46 |
public long toMillis(long d) { return d/(C2/C0); } |
| 47 |
public long toSeconds(long d) { return d/(C3/C0); } |
| 48 |
public long toMinutes(long d) { return d/(C4/C0); } |
| 49 |
public long toHours(long d) { return d/(C5/C0); } |
| 50 |
public long toDays(long d) { return d/(C6/C0); } |
| 51 |
public long convert(long d, TimeUnit u) { return u.toNanos(d); } |
| 52 |
int excessNanos(long d, long m) { return (int)(d - (m*C2)); } |
| 53 |
}, |
| 54 |
MICROSECONDS { |
| 55 |
public long toNanos(long d) { return x(d, C1/C0, MAX/(C1/C0)); } |
| 56 |
public long toMicros(long d) { return d; } |
| 57 |
public long toMillis(long d) { return d/(C2/C1); } |
| 58 |
public long toSeconds(long d) { return d/(C3/C1); } |
| 59 |
public long toMinutes(long d) { return d/(C4/C1); } |
| 60 |
public long toHours(long d) { return d/(C5/C1); } |
| 61 |
public long toDays(long d) { return d/(C6/C1); } |
| 62 |
public long convert(long d, TimeUnit u) { return u.toMicros(d); } |
| 63 |
int excessNanos(long d, long m) { return (int)((d*C1) - (m*C2)); } |
| 64 |
}, |
| 65 |
MILLISECONDS { |
| 66 |
public long toNanos(long d) { return x(d, C2/C0, MAX/(C2/C0)); } |
| 67 |
public long toMicros(long d) { return x(d, C2/C1, MAX/(C2/C1)); } |
| 68 |
public long toMillis(long d) { return d; } |
| 69 |
public long toSeconds(long d) { return d/(C3/C2); } |
| 70 |
public long toMinutes(long d) { return d/(C4/C2); } |
| 71 |
public long toHours(long d) { return d/(C5/C2); } |
| 72 |
public long toDays(long d) { return d/(C6/C2); } |
| 73 |
public long convert(long d, TimeUnit u) { return u.toMillis(d); } |
| 74 |
int excessNanos(long d, long m) { return 0; } |
| 75 |
}, |
| 76 |
SECONDS { |
| 77 |
public long toNanos(long d) { return x(d, C3/C0, MAX/(C3/C0)); } |
| 78 |
public long toMicros(long d) { return x(d, C3/C1, MAX/(C3/C1)); } |
| 79 |
public long toMillis(long d) { return x(d, C3/C2, MAX/(C3/C2)); } |
| 80 |
public long toSeconds(long d) { return d; } |
| 81 |
public long toMinutes(long d) { return d/(C4/C3); } |
| 82 |
public long toHours(long d) { return d/(C5/C3); } |
| 83 |
public long toDays(long d) { return d/(C6/C3); } |
| 84 |
public long convert(long d, TimeUnit u) { return u.toSeconds(d); } |
| 85 |
int excessNanos(long d, long m) { return 0; } |
| 86 |
}, |
| 87 |
MINUTES { |
| 88 |
public long toNanos(long d) { return x(d, C4/C0, MAX/(C4/C0)); } |
| 89 |
public long toMicros(long d) { return x(d, C4/C1, MAX/(C4/C1)); } |
| 90 |
public long toMillis(long d) { return x(d, C4/C2, MAX/(C4/C2)); } |
| 91 |
public long toSeconds(long d) { return x(d, C4/C3, MAX/(C4/C3)); } |
| 92 |
public long toMinutes(long d) { return d; } |
| 93 |
public long toHours(long d) { return d/(C5/C4); } |
| 94 |
public long toDays(long d) { return d/(C6/C4); } |
| 95 |
public long convert(long d, TimeUnit u) { return u.toMinutes(d); } |
| 96 |
int excessNanos(long d, long m) { return 0; } |
| 97 |
}, |
| 98 |
HOURS { |
| 99 |
public long toNanos(long d) { return x(d, C5/C0, MAX/(C5/C0)); } |
| 100 |
public long toMicros(long d) { return x(d, C5/C1, MAX/(C5/C1)); } |
| 101 |
public long toMillis(long d) { return x(d, C5/C2, MAX/(C5/C2)); } |
| 102 |
public long toSeconds(long d) { return x(d, C5/C3, MAX/(C5/C3)); } |
| 103 |
public long toMinutes(long d) { return x(d, C5/C4, MAX/(C5/C4)); } |
| 104 |
public long toHours(long d) { return d; } |
| 105 |
public long toDays(long d) { return d/(C6/C5); } |
| 106 |
public long convert(long d, TimeUnit u) { return u.toHours(d); } |
| 107 |
int excessNanos(long d, long m) { return 0; } |
| 108 |
}, |
| 109 |
DAYS { |
| 110 |
public long toNanos(long d) { return x(d, C6/C0, MAX/(C6/C0)); } |
| 111 |
public long toMicros(long d) { return x(d, C6/C1, MAX/(C6/C1)); } |
| 112 |
public long toMillis(long d) { return x(d, C6/C2, MAX/(C6/C2)); } |
| 113 |
public long toSeconds(long d) { return x(d, C6/C3, MAX/(C6/C3)); } |
| 114 |
public long toMinutes(long d) { return x(d, C6/C4, MAX/(C6/C4)); } |
| 115 |
public long toHours(long d) { return x(d, C6/C5, MAX/(C6/C5)); } |
| 116 |
public long toDays(long d) { return d; } |
| 117 |
public long convert(long d, TimeUnit u) { return u.toDays(d); } |
| 118 |
int excessNanos(long d, long m) { return 0; } |
| 119 |
}; |
| 120 |
|
| 121 |
// Handy constants for conversion methods |
| 122 |
static final long C0 = 1L; |
| 123 |
static final long C1 = C0 * 1000L; |
| 124 |
static final long C2 = C1 * 1000L; |
| 125 |
static final long C3 = C2 * 1000L; |
| 126 |
static final long C4 = C3 * 60L; |
| 127 |
static final long C5 = C4 * 60L; |
| 128 |
static final long C6 = C5 * 24L; |
| 129 |
|
| 130 |
static final long MAX = Long.MAX_VALUE; |
| 131 |
|
| 132 |
/** |
| 133 |
* Scale d by m, checking for overflow. |
| 134 |
* This has a short name to make above code more readable. |
| 135 |
*/ |
| 136 |
static long x(long d, long m, long over) { |
| 137 |
if (d > over) return Long.MAX_VALUE; |
| 138 |
if (d < -over) return Long.MIN_VALUE; |
| 139 |
return d * m; |
| 140 |
} |
| 141 |
|
| 142 |
// To maintain full signature compatibility with 1.5, and to improve the |
| 143 |
// clarity of the generated javadoc (see 6287639: Abstract methods in |
| 144 |
// enum classes should not be listed as abstract), method convert |
| 145 |
// etc. are not declared abstract but otherwise act as abstract methods. |
| 146 |
|
| 147 |
/** |
| 148 |
* Converts the given time duration in the given unit to this unit. |
| 149 |
* Conversions from finer to coarser granularities truncate, so |
| 150 |
* lose precision. For example, converting {@code 999} milliseconds |
| 151 |
* to seconds results in {@code 0}. Conversions from coarser to |
| 152 |
* finer granularities with arguments that would numerically |
| 153 |
* overflow saturate to {@code Long.MIN_VALUE} if negative or |
| 154 |
* {@code Long.MAX_VALUE} if positive. |
| 155 |
* |
| 156 |
* <p>For example, to convert 10 minutes to milliseconds, use: |
| 157 |
* {@code TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)} |
| 158 |
* |
| 159 |
* @param sourceDuration the time duration in the given {@code sourceUnit} |
| 160 |
* @param sourceUnit the unit of the {@code sourceDuration} argument |
| 161 |
* @return the converted duration in this unit, |
| 162 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 163 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 164 |
*/ |
| 165 |
public long convert(long sourceDuration, TimeUnit sourceUnit) { |
| 166 |
throw new AbstractMethodError(); |
| 167 |
} |
| 168 |
|
| 169 |
/** |
| 170 |
* Equivalent to |
| 171 |
* {@link #convert(long, TimeUnit) NANOSECONDS.convert(duration, this)}. |
| 172 |
* @param duration the duration |
| 173 |
* @return the converted duration, |
| 174 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 175 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 176 |
*/ |
| 177 |
public long toNanos(long duration) { |
| 178 |
throw new AbstractMethodError(); |
| 179 |
} |
| 180 |
|
| 181 |
/** |
| 182 |
* Equivalent to |
| 183 |
* {@link #convert(long, TimeUnit) MICROSECONDS.convert(duration, this)}. |
| 184 |
* @param duration the duration |
| 185 |
* @return the converted duration, |
| 186 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 187 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 188 |
*/ |
| 189 |
public long toMicros(long duration) { |
| 190 |
throw new AbstractMethodError(); |
| 191 |
} |
| 192 |
|
| 193 |
/** |
| 194 |
* Equivalent to |
| 195 |
* {@link #convert(long, TimeUnit) MILLISECONDS.convert(duration, this)}. |
| 196 |
* @param duration the duration |
| 197 |
* @return the converted duration, |
| 198 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 199 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 200 |
*/ |
| 201 |
public long toMillis(long duration) { |
| 202 |
throw new AbstractMethodError(); |
| 203 |
} |
| 204 |
|
| 205 |
/** |
| 206 |
* Equivalent to |
| 207 |
* {@link #convert(long, TimeUnit) SECONDS.convert(duration, this)}. |
| 208 |
* @param duration the duration |
| 209 |
* @return the converted duration, |
| 210 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 211 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 212 |
*/ |
| 213 |
public long toSeconds(long duration) { |
| 214 |
throw new AbstractMethodError(); |
| 215 |
} |
| 216 |
|
| 217 |
/** |
| 218 |
* Equivalent to |
| 219 |
* {@link #convert(long, TimeUnit) MINUTES.convert(duration, this)}. |
| 220 |
* @param duration the duration |
| 221 |
* @return the converted duration, |
| 222 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 223 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 224 |
* @since 1.6 |
| 225 |
*/ |
| 226 |
public long toMinutes(long duration) { |
| 227 |
throw new AbstractMethodError(); |
| 228 |
} |
| 229 |
|
| 230 |
/** |
| 231 |
* Equivalent to |
| 232 |
* {@link #convert(long, TimeUnit) HOURS.convert(duration, this)}. |
| 233 |
* @param duration the duration |
| 234 |
* @return the converted duration, |
| 235 |
* or {@code Long.MIN_VALUE} if conversion would negatively |
| 236 |
* overflow, or {@code Long.MAX_VALUE} if it would positively overflow. |
| 237 |
* @since 1.6 |
| 238 |
*/ |
| 239 |
public long toHours(long duration) { |
| 240 |
throw new AbstractMethodError(); |
| 241 |
} |
| 242 |
|
| 243 |
/** |
| 244 |
* Equivalent to |
| 245 |
* {@link #convert(long, TimeUnit) DAYS.convert(duration, this)}. |
| 246 |
* @param duration the duration |
| 247 |
* @return the converted duration |
| 248 |
* @since 1.6 |
| 249 |
*/ |
| 250 |
public long toDays(long duration) { |
| 251 |
throw new AbstractMethodError(); |
| 252 |
} |
| 253 |
|
| 254 |
/** |
| 255 |
* Utility to compute the excess-nanosecond argument to wait, |
| 256 |
* sleep, join. |
| 257 |
* @param d the duration |
| 258 |
* @param m the number of milliseconds |
| 259 |
* @return the number of nanoseconds |
| 260 |
*/ |
| 261 |
abstract int excessNanos(long d, long m); |
| 262 |
|
| 263 |
/** |
| 264 |
* Performs a timed {@link Object#wait(long, int) Object.wait} |
| 265 |
* using this time unit. |
| 266 |
* This is a convenience method that converts timeout arguments |
| 267 |
* into the form required by the {@code Object.wait} method. |
| 268 |
* |
| 269 |
* <p>For example, you could implement a blocking {@code poll} |
| 270 |
* method (see {@link BlockingQueue#poll BlockingQueue.poll}) |
| 271 |
* using: |
| 272 |
* |
| 273 |
* <pre> {@code |
| 274 |
* public synchronized Object poll(long timeout, TimeUnit unit) |
| 275 |
* throws InterruptedException { |
| 276 |
* while (empty) { |
| 277 |
* unit.timedWait(this, timeout); |
| 278 |
* ... |
| 279 |
* } |
| 280 |
* }}</pre> |
| 281 |
* |
| 282 |
* @param obj the object to wait on |
| 283 |
* @param timeout the maximum time to wait. If less than |
| 284 |
* or equal to zero, do not wait at all. |
| 285 |
* @throws InterruptedException if interrupted while waiting |
| 286 |
*/ |
| 287 |
public void timedWait(Object obj, long timeout) |
| 288 |
throws InterruptedException { |
| 289 |
if (timeout > 0) { |
| 290 |
long ms = toMillis(timeout); |
| 291 |
int ns = excessNanos(timeout, ms); |
| 292 |
obj.wait(ms, ns); |
| 293 |
} |
| 294 |
} |
| 295 |
|
| 296 |
/** |
| 297 |
* Performs a timed {@link Thread#join(long, int) Thread.join} |
| 298 |
* using this time unit. |
| 299 |
* This is a convenience method that converts time arguments into the |
| 300 |
* form required by the {@code Thread.join} method. |
| 301 |
* |
| 302 |
* @param thread the thread to wait for |
| 303 |
* @param timeout the maximum time to wait. If less than |
| 304 |
* or equal to zero, do not wait at all. |
| 305 |
* @throws InterruptedException if interrupted while waiting |
| 306 |
*/ |
| 307 |
public void timedJoin(Thread thread, long timeout) |
| 308 |
throws InterruptedException { |
| 309 |
if (timeout > 0) { |
| 310 |
long ms = toMillis(timeout); |
| 311 |
int ns = excessNanos(timeout, ms); |
| 312 |
thread.join(ms, ns); |
| 313 |
} |
| 314 |
} |
| 315 |
|
| 316 |
/** |
| 317 |
* Performs a {@link Thread#sleep(long, int) Thread.sleep} using |
| 318 |
* this time unit. |
| 319 |
* This is a convenience method that converts time arguments into the |
| 320 |
* form required by the {@code Thread.sleep} method. |
| 321 |
* |
| 322 |
* @param timeout the minimum time to sleep. If less than |
| 323 |
* or equal to zero, do not sleep at all. |
| 324 |
* @throws InterruptedException if interrupted while sleeping |
| 325 |
*/ |
| 326 |
public void sleep(long timeout) throws InterruptedException { |
| 327 |
if (timeout > 0) { |
| 328 |
long ms = toMillis(timeout); |
| 329 |
int ns = excessNanos(timeout, ms); |
| 330 |
Thread.sleep(ms, ns); |
| 331 |
} |
| 332 |
} |
| 333 |
|
| 334 |
} |
