net: tcp2: work around limitations of legacy API
The tcp2 infrastructure is using the legacy delayed work API, and
relies heavily on the transient state indicated by an estimate of
delayed time remaining to determine whether a delayed work item is
still active. While the wrappers for this work in most cases, one use
is unsanctioned: directly accessing the fields of k_delayed_work
structure to satisfy the calling parameters of the handler when
invoked directly.
The chosen solution for this specific need in the new API is to use a
schedule (rather than reschedule) operation, which leaves any previous
timer unchanged but allows immediate submission if the work is idle.
This changes behavior in that the resend is delegated to the work
queue, rather than done immediately. The former behavior can be
supported by further refactoring that turns the work handler into a
wrapper around a function that takes a connection reference, and
invoking that here, while the handler invokes it after reconstructing
the connection from the contained work item.
For now put in a hack that also uses the non-public fields of the
delayed work structure to implement the required behavior. The
complete fix if this solution is used requires replacing all use of
k_delayed_work in this module with k_work_delayable, leveraging the
new functionality of the API to avoid having to guess about the true
state of a work item based on its transient timer or flag states.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
1 file changed
