| 444 |
|
* next task in queue, or if there is none, the given task. |
| 445 |
|
* @param firstTask the task the new thread should run first (or |
| 446 |
|
* null if none) |
| 447 |
< |
* @return null on failure, else the first task to be run by new thread. |
| 447 |
> |
* @return 0 if a new thread cannot be created, a positive number |
| 448 |
> |
* if firstTask will be run in a new thread, or a negative number |
| 449 |
> |
* if a new thread was created but is running some other task, in |
| 450 |
> |
* which case the caller must try some other way to run firstTask |
| 451 |
> |
* (perhaps by calling this method again). |
| 452 |
|
*/ |
| 453 |
< |
private Runnable addIfUnderMaximumPoolSize(Runnable firstTask) { |
| 453 |
> |
private int addIfUnderMaximumPoolSize(Runnable firstTask) { |
| 454 |
|
Thread t = null; |
| 455 |
< |
Runnable next = null; |
| 455 |
> |
int status = 0; |
| 456 |
|
final ReentrantLock mainLock = this.mainLock; |
| 457 |
|
mainLock.lock(); |
| 458 |
|
try { |
| 459 |
|
if (poolSize < maximumPoolSize) { |
| 460 |
< |
next = workQueue.poll(); |
| 461 |
< |
if (next == null) |
| 460 |
> |
Runnable next = workQueue.poll(); |
| 461 |
> |
if (next == null) { |
| 462 |
|
next = firstTask; |
| 463 |
+ |
status = 1; |
| 464 |
+ |
} else |
| 465 |
+ |
status = -1; |
| 466 |
|
t = addThread(next); |
| 467 |
|
} |
| 468 |
|
} finally { |
| 469 |
|
mainLock.unlock(); |
| 470 |
|
} |
| 471 |
|
if (t == null) |
| 472 |
< |
return null; |
| 472 |
> |
return 0; |
| 473 |
|
t.start(); |
| 474 |
< |
return next; |
| 474 |
> |
return status; |
| 475 |
|
} |
| 476 |
|
|
| 477 |
|
|
| 876 |
|
return; |
| 877 |
|
if (workQueue.offer(command)) |
| 878 |
|
return; |
| 879 |
< |
Runnable r = addIfUnderMaximumPoolSize(command); |
| 880 |
< |
if (r == command) |
| 879 |
> |
int status = addIfUnderMaximumPoolSize(command); |
| 880 |
> |
if (status > 0) // created new thread |
| 881 |
|
return; |
| 882 |
< |
if (r == null) { |
| 882 |
> |
if (status == 0) { // failed to create thread |
| 883 |
|
reject(command); |
| 884 |
|
return; |
| 885 |
|
} |
| 886 |
< |
// else retry |
| 886 |
> |
// Retry if created a new thread but it is busy with another task |
| 887 |
|
} |
| 888 |
|
} |
| 889 |
|
|
