Thanks, Rafael!
07.05.2015 16:47, Rafael Schloming пишет:
> That looks mostly correct to me. I've made a few notes inline...
>
> On Thu, May 7, 2015 at 9:27 AM, Michael Ivanov <iv...@logit-ag.de> wrote:
>
>> Hallo,
>>
>> I am trying to integrate proton messenger with a regular select-based
>> event loop.
>> Regrettably there's not much documentation about reading and sendingn
>> messages
>> in passive mode using selectors. Can you give a quick look to the
>> pseudo-code,
>> describing message input in my event loop and verify whether I understand
>> it
>> correctly?
>>
>> Here goes the pseudo-code:
>>
>> for (;;) {
>> foreach messenger:
>> messenger::recv(N); // Make sure message read
>> automata is started.
>> foreach selectable in messenger:
>> if (is_registered(selectable))
>> continue; // Selectable is already in use
>> by event loop
>> // Create an I/O object which refers to selectable
>> // and add it to the I/O list
>> iolist << new IO(selectable)
>>
>> foreach iolist item:
>> if is_terminal(item):
>> Remove item from iolist
>> pn_selectable_free(item::selectable)
>> continue;
>> if is_readable:
>> add selection fd to read mask
>> if is_writable:
>> add selection fd to write mask
>> if (selection has deadline)
>> schedule timer for this iolist item
>>
>> select(read_mask, write_mask, timeout)
>>
>> foreach iolist item:
>> if (read event signalled)
>> pn_selectable_readable(item::selection)
>> if (write event signalled)
>> pn_selectable_writable(item::selection)
>>
>
> You also want to do if (deadline for selectable expired)
> pn_selectable_expired(item::selection) here.
>
>
>>
>> If we had any read events check whether some messages
>> were placed into input queue. If no messages are available
>> pn_messenger_get() will not block, but rather will return
>> PN_EOS
>>
>> foreach messenger:
>> while pn_messenger_get(messenger, message) != PN_EOS
>> Handle input message
>>
>> Check whether some timers have expired. If expired timer
>> refers to the proton I/O object, delete this object
>> (this will also exclude it from iolist and select masks)
>>
>
> This isn't quite right. The timer expiring doesn't mean you should throw
> out the selectable, it simply means you should signal the timing event
> using the call to pn_selectable_expired as described above.
>
>
>>
>> }
>>
>> All messengers are created in non-blocking and passive mode.
>>
>> Some of the messengers are already subscribed to queues.
>>
>> To send messages I just use pn_messenger_put as usual and
>> pn_selectable_writable takes care about actual message delivery.
>>
>
>
> Other than the notes above, I believe this is correct.
>
> --Rafael
>
--
\ / | |
(OvO) | Михаил Иванов |
(^^^) | Тел.: +7(911) 223-1300 |
\^/ | E-mail: iv...@isle.spb.ru |
^ ^ | |
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@qpid.apache.org
For additional commands, e-mail: users-h...@qpid.apache.org
