Ticket 49765 - Async operations can hang when the server is running nunc-stans
The fix https://pagure.io/389-ds-base/issue/48184 allowed to schedule
several NS handlers where each handler waits for the dispatch of the
previous handler before being schedule.
In case the current handler is never called (connection inactivity)
those that are waiting can wait indefinitely (until timeout or connection
closure). But those that are waiting delay the processing of the operation
when the scheduling is called by connection_threadmain.
The some operations can appear hanging.
This scenario happens with async operations
Instead of waiting for the completion of the scheduled handler,
evaluates if the scheduled handler needs to be cleared (ns_job_done)
or the waiting handler to be canceled.
Reviewed by: Mark Reynolds (thanks Mark !)
Platforms tested: F26
Flag Day: no
Doc impact: no