606 |
|
/** |
607 |
|
* If the lock state matches the given stamp then performs one of |
608 |
|
* the following actions. If the stamp represents holding a write |
609 |
< |
* lock, returns it. Or, if a read lock, if the write lock is |
610 |
< |
* available, releases the read and returns a write stamp. Or, if |
611 |
< |
* an optimistic read, returns a write stamp only if immediately |
612 |
< |
* available. This method returns zero in all other cases. |
609 |
> |
* lock, returns it. Or, if a read lock, if the write lock is |
610 |
> |
* available, releases the read lock and returns a write stamp. |
611 |
> |
* Or, if an optimistic read, returns a write stamp only if |
612 |
> |
* immediately available. This method returns zero in all other |
613 |
> |
* cases. |
614 |
|
* |
615 |
|
* @param stamp a stamp |
616 |
|
* @return a valid write stamp, or zero on failure |