| 45 |
|
*/ |
| 46 |
|
|
| 47 |
|
/** |
| 48 |
< |
* The run state of this task, initially UNDECIDED. The run state |
| 48 |
> |
* The run state of this task, initially NEW. The run state |
| 49 |
|
* transitions to a terminal state only in method setCompletion. |
| 50 |
|
* During setCompletion, state may take on transient values of |
| 51 |
|
* COMPLETING (while outcome is being set) or INTERRUPTING (only |
| 53 |
|
* State values are highly order-dependent to simplify checks. |
| 54 |
|
* |
| 55 |
|
* Possible state transitions: |
| 56 |
< |
* UNDECIDED -> NORMAL |
| 57 |
< |
* UNDECIDED -> COMPLETING -> NORMAL |
| 58 |
< |
* UNDECIDED -> COMPLETING -> EXCEPTIONAL |
| 59 |
< |
* UNDECIDED -> CANCELLED |
| 60 |
< |
* UNDECIDED -> INTERRUPTING -> INTERRUPTED |
| 56 |
> |
* NEW -> NORMAL |
| 57 |
> |
* NEW -> COMPLETING -> NORMAL |
| 58 |
> |
* NEW -> COMPLETING -> EXCEPTIONAL |
| 59 |
> |
* NEW -> CANCELLED |
| 60 |
> |
* NEW -> INTERRUPTING -> INTERRUPTED |
| 61 |
|
*/ |
| 62 |
|
private volatile int state; |
| 63 |
< |
private static final int UNDECIDED = 0; |
| 63 |
> |
private static final int NEW = 0; |
| 64 |
|
private static final int COMPLETING = 1; |
| 65 |
|
private static final int NORMAL = 2; |
| 66 |
|
private static final int EXCEPTIONAL = 3; |
| 84 |
|
* |
| 85 |
|
* @param x the outcome |
| 86 |
|
* @param mode the completion state value |
| 87 |
< |
* @return true if this call caused transition from UNDECIDED to completed |
| 87 |
> |
* @return true if this call caused transition from NEW to completed |
| 88 |
|
*/ |
| 89 |
|
private boolean setCompletion(Object x, int mode) { |
| 90 |
|
// set up transient states |
| 91 |
|
int next = (x != null) ? COMPLETING : mode; |
| 92 |
< |
if (!UNSAFE.compareAndSwapInt(this, stateOffset, UNDECIDED, next)) |
| 92 |
> |
if (!UNSAFE.compareAndSwapInt(this, stateOffset, NEW, next)) |
| 93 |
|
return false; |
| 94 |
|
if (next == INTERRUPTING) { |
| 95 |
|
// Must check after CAS to avoid missed interrupt |
| 156 |
|
} |
| 157 |
|
|
| 158 |
|
public boolean isDone() { |
| 159 |
< |
return state != UNDECIDED; |
| 159 |
> |
return state != NEW; |
| 160 |
|
} |
| 161 |
|
|
| 162 |
|
public boolean cancel(boolean mayInterruptIfRunning) { |
| 163 |
< |
return state == UNDECIDED && |
| 163 |
> |
return state == NEW && |
| 164 |
|
setCompletion(null, |
| 165 |
|
mayInterruptIfRunning ? INTERRUPTING : CANCELLED); |
| 166 |
|
} |
| 226 |
|
} |
| 227 |
|
|
| 228 |
|
public void run() { |
| 229 |
< |
if (state != UNDECIDED || |
| 229 |
> |
if (state != NEW || |
| 230 |
|
!UNSAFE.compareAndSwapObject(this, runnerOffset, |
| 231 |
|
null, Thread.currentThread())) |
| 232 |
|
return; |
| 233 |
|
|
| 234 |
|
try { |
| 235 |
|
// Recheck to avoid missed interrupt. |
| 236 |
< |
if (state != UNDECIDED) |
| 236 |
> |
if (state != NEW) |
| 237 |
|
return; |
| 238 |
|
V result; |
| 239 |
|
try { |
| 264 |
|
* @return true if successfully run and reset |
| 265 |
|
*/ |
| 266 |
|
protected boolean runAndReset() { |
| 267 |
< |
if (state != UNDECIDED || |
| 267 |
> |
if (state != NEW || |
| 268 |
|
!UNSAFE.compareAndSwapObject(this, runnerOffset, |
| 269 |
|
null, Thread.currentThread())) |
| 270 |
|
return false; |
| 271 |
|
|
| 272 |
|
try { |
| 273 |
|
// Recheck to avoid missed interrupt. |
| 274 |
< |
if (state != UNDECIDED) |
| 274 |
> |
if (state != NEW) |
| 275 |
|
return false; |
| 276 |
|
try { |
| 277 |
|
callable.call(); // don't set result |
| 278 |
< |
return (state == UNDECIDED); |
| 278 |
> |
return (state == NEW); |
| 279 |
|
} catch (Throwable ex) { |
| 280 |
|
setException(ex); |
| 281 |
|
return false; |
