[jboss-jira] [JBoss JIRA] (JGRP-1553) TimeScheduler3

[Bela Ban (JIRA)]

Bela Ban created JGRP-1553:
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             Summary: TimeScheduler3
                 Key: JGRP-1553
                 URL: https://issues.jboss.org/browse/JGRP-1553
             Project: JGroups
          Issue Type: Enhancement
            Reporter: Bela Ban
            Assignee: Bela Ban
             Fix For: 3.3


The current TimeScheduler2 class has a few deficiencies:
- taskReady() should only set next-execution-time if its argument is less than next-execution-time
- no_tasks: when setting this CAS, the result is only checked in 1 location, but not the other
- Potential loss of task: when calling schedule() on an existing Entry (same execution time), and - before adding the task to Entry - Entry is removed by _run() as it was executed, then the newly added task will never get to run !
- Simplification: instead of headMap(), just use firstEntry(), removeFirstEntry(). See pseudo code below.


As a workaround, timer_type="old" will switch back to the previous default timer. The reason for TimeScheduler3 (versus changing TimeScheduler2) is that we can simply switch to the new impl by setting (a new) timer_type="new2". Should this have a bug, we can simply switch back to "new" or "old" (or "wheel".

Over time, TimeScheduler2 will get removed.

Pseudo code:
* loop while has tasks
** get the first task
** if its time is less than the current time: execute it and remove it
** else block (on the next task or 10s) until an element is added


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