| 17 |
|
* {@link java.util.concurrent.CountDownLatch CountDownLatch} |
| 18 |
|
* but supporting more flexible usage. |
| 19 |
|
* |
| 20 |
< |
* <p> <b>Registration.</b> Unlike the case for other barriers, the |
| 20 |
> |
* <p><b>Registration.</b> Unlike the case for other barriers, the |
| 21 |
|
* number of parties <em>registered</em> to synchronize on a phaser |
| 22 |
|
* may vary over time. Tasks may be registered at any time (using |
| 23 |
|
* methods {@link #register}, {@link #bulkRegister}, or forms of |
| 30 |
|
* (However, you can introduce such bookkeeping by subclassing this |
| 31 |
|
* class.) |
| 32 |
|
* |
| 33 |
< |
* <p> <b>Synchronization.</b> Like a {@code CyclicBarrier}, a {@code |
| 33 |
> |
* <p><b>Synchronization.</b> Like a {@code CyclicBarrier}, a {@code |
| 34 |
|
* Phaser} may be repeatedly awaited. Method {@link |
| 35 |
|
* #arriveAndAwaitAdvance} has effect analogous to {@link |
| 36 |
|
* java.util.concurrent.CyclicBarrier#await CyclicBarrier.await}. Each |
| 74 |
|
* |
| 75 |
|
* </ul> |
| 76 |
|
* |
| 77 |
< |
* <p> <b>Termination.</b> A phaser may enter a <em>termination</em> |
| 77 |
> |
* <p><b>Termination.</b> A phaser may enter a <em>termination</em> |
| 78 |
|
* state, that may be checked using method {@link #isTerminated}. Upon |
| 79 |
|
* termination, all synchronization methods immediately return without |
| 80 |
|
* waiting for advance, as indicated by a negative return value. |
| 89 |
|
* also available to abruptly release waiting threads and allow them |
| 90 |
|
* to terminate. |
| 91 |
|
* |
| 92 |
< |
* <p> <b>Tiering.</b> Phasers may be <em>tiered</em> (i.e., |
| 92 |
> |
* <p><b>Tiering.</b> Phasers may be <em>tiered</em> (i.e., |
| 93 |
|
* constructed in tree structures) to reduce contention. Phasers with |
| 94 |
|
* large numbers of parties that would otherwise experience heavy |
| 95 |
|
* synchronization contention costs may instead be set up so that |
| 1142 |
|
private static sun.misc.Unsafe getUnsafe() { |
| 1143 |
|
try { |
| 1144 |
|
return sun.misc.Unsafe.getUnsafe(); |
| 1145 |
< |
} catch (SecurityException se) { |
| 1146 |
< |
try { |
| 1147 |
< |
return java.security.AccessController.doPrivileged |
| 1148 |
< |
(new java.security |
| 1149 |
< |
.PrivilegedExceptionAction<sun.misc.Unsafe>() { |
| 1150 |
< |
public sun.misc.Unsafe run() throws Exception { |
| 1151 |
< |
java.lang.reflect.Field f = sun.misc |
| 1152 |
< |
.Unsafe.class.getDeclaredField("theUnsafe"); |
| 1153 |
< |
f.setAccessible(true); |
| 1154 |
< |
return (sun.misc.Unsafe) f.get(null); |
| 1155 |
< |
}}); |
| 1156 |
< |
} catch (java.security.PrivilegedActionException e) { |
| 1157 |
< |
throw new RuntimeException("Could not initialize intrinsics", |
| 1158 |
< |
e.getCause()); |
| 1159 |
< |
} |
| 1145 |
> |
} catch (SecurityException tryReflectionInstead) {} |
| 1146 |
> |
try { |
| 1147 |
> |
return java.security.AccessController.doPrivileged |
| 1148 |
> |
(new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() { |
| 1149 |
> |
public sun.misc.Unsafe run() throws Exception { |
| 1150 |
> |
Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class; |
| 1151 |
> |
for (java.lang.reflect.Field f : k.getDeclaredFields()) { |
| 1152 |
> |
f.setAccessible(true); |
| 1153 |
> |
Object x = f.get(null); |
| 1154 |
> |
if (k.isInstance(x)) |
| 1155 |
> |
return k.cast(x); |
| 1156 |
> |
} |
| 1157 |
> |
throw new NoSuchFieldError("the Unsafe"); |
| 1158 |
> |
}}); |
| 1159 |
> |
} catch (java.security.PrivilegedActionException e) { |
| 1160 |
> |
throw new RuntimeException("Could not initialize intrinsics", |
| 1161 |
> |
e.getCause()); |
| 1162 |
|
} |
| 1163 |
|
} |
| 1164 |
|
} |
