This commit fixes an issue where a tasklet could not be successfully
unposted if it was already scheduled for execution in the current
event loop iteration.
Previously, `Scheduler::ProcessQueuedTasklets()` copied and cleared the
queued tasklets before running them. If a running tasklet called
`Unpost()` on another tasklet that was also in the copied list, the
unpost operation would fail to remove it because it only checked the
main queue.
To address this, the `Scheduler` now explicitly maintains two separate
queues: `mPostedQueue` and `mRuningQueue`. The `Tasklet::Unpost()`
method is updated to remove the target tasklet from both queues,
ensuring it is correctly dequeued even if it is pending in the running
list.
The queue logic is encapsulated into a nested `Queue` class to manage
the circular singly linked-list operations cleanly. Additionally, unit
tests are expanded to cover scenarios where tasklets post or unpost
other tasklets during execution.
Moves the management of MeshCoP service TXT data from the
`BorderAgent::Manager` class into the `TxtData` class.
This change improves separation of concerns by isolating all TXT
data-related logic, including vendor TXT data, change callbacks, and
notifier event handling, within the `TxtData` class. The
`BorderAgent::Manager` is simplified and its responsibilities are
more focused.
A new public method, `Refresh()`, is introduced on `TxtData` to
provide a clear API for other modules to signal that the MeshCoP
service TXT data needs to be re-evaluated and updated.
This commit adds `Tasklet::Unpost()` to remove a tasklet from the
tasklet scheduler run queue if previously posted.
It also adds a detailed unit test, `test_tasklet`, covering various
uses of `Tasklet`, such as posting single or multiple tasks.,
re-posting a task from its own handler, Un-posting tasks in different
orders.
Abtin Keshavarzian