How to know if all pending tevent_req requests have completed?

[Amitay Isaacs]

On Thu, Feb 23, 2017 at 5:45 PM, Ralph Böhme <slow at samba.org> wrote:

> On Thu, Feb 23, 2017 at 11:18:41AM +1100, Amitay Isaacs wrote:
> > Hi tevent experts,
> >
> > tevent_req_poll() allows to wait for a specific request.
> >
> > If I want to create n requests and wait for all of them to finish, is
> there
> > an easy way to do it?
> >
> > Here is an example computation:
> >
> > run_event_send()
> >    ... run scripts one after the other ...
> >
> >    if (timer expires) {
> >       run_debug_send()
> >       tevent_req_done()
> >    }
> >
> > In this case, run_debug_send() computation is *not* hanging off the
> > run_event_send() request.
> > The calling code needs to know that run_event computation has timed out,
> > but doesn't really care whether debugging computation is over or not.
> The
> > debug program can run in the background and log useful debug information
> > without affecting the caller.
>
> maybe I don't understand what you're trying to do, but you have N
> run_event_send
> subreqs and each of those requests either calls tevent_req_done or
> tevent_req_error(ETIMEDOUT) in case of a timeout.
>

I am not worried about the requests created by run_event_send().  Those
calls are made by the caller and caller can deal with them when the request
is done.  However, the (sub) requests created by run_debug_send() are of
interest here.  They are created internally and no external caller is
really waiting on them.  Looks like I have to keep track of those (sub)
requests internally.


>
> The caller must have a state with the number of in-flight subrequests and
> then
> you can just count the number of successfull calls and failures in the
> subreq
> callback.
>

As I said before, from the caller point of view the request is over.  The
debugging (sub) request cannot hold off the caller, so it has to be dealt
with internally.

Amitay.