On 15 March 2017 at 12:58, Evgeny Grin <k...@yandex.ru> wrote:
> Why do you want to play with timeout during connection suspend?
> Function description explicitly state:
> "Suspended connections will NOT time out; timeouts will restart when the
> connection handling is resumed."
That's right. This is why after resuming a connection and if it is
timed outed because the MHD thinks so.
There is only one place where MHD send the INTERNAL_ERROR message:
src/microhttpd/connection.c
1358 static void
1359 MHD_connection_update_event_loop_info (struct MHD_Connection
*connection)
1360 {
1361 while (1)
1362 {
...
1408 case MHD_CONNECTION_CONTINUE_SENT:
1409 if (connection->read_buffer_offset ==
connection->read_buffer_size)
1410 {
1411 if ((MHD_YES != try_grow_read_buffer (connection)) &&
1412 (0 != (connection->daemon->options &
1413 MHD_USE_INTERNAL_POLLING_THREAD)))
1414 {
1415 /* failed to grow the read buffer, and the
1416 client which is supposed to handle the
1417 received data in a *blocking* fashion
1418 (in this mode) did not handle the data as
1419 it was supposed to!
1420 => we would either have to do busy-waiting
1421 (on the client, which would likely fail),
1422 or if we do nothing, we would just timeout
1423 on the connection (if a timeout is even
1424 set!).
1425 Solution: we kill the connection with an error */
1426 transmit_error_response (connection,
1427
MHD_HTTP_INTERNAL_SERVER_ERROR,
1428 INTERNAL_ERROR);
1429 continue;
1430 }
1431 }
A TCP connection might be active and clients are waiting for
responses. But MHD thinks its smarter then a man :) No offend.
> Could you describe in details: what do you want to get, how did you
> start MHD and what is not working?
The idea is that the server is able to handle only one POST (upload
file) request per a time from clients. Others clients are suspended
when there is at least one active upload.
Suspending/resuming is a practical recommended by the Reference Manual.
I want to suspend a connection by some amount of time which may vary
per a program basis. Current implementation sets timeout to 0 before
suspending the connection. Otherwise, as I said previously, in case if
the connection is timed out, then MHD will send a response with the
hardcoded text above.
Setting the connection timeout to 0 leads to problems for clients:
1. They just closing a connection by its own timeout value.
2. The server might have time to send response to a suspended client if
Why I want to get/set connection timeout per a connection basis?
1. Because, it is simpler then writing more code than the task requires.
2. Because there is a function to set connection timeout and none to
get one's value.
I can implement the get function in my program easily. I just asked
for a feature request. If you see that is useless, then ok, just say
so. I will not be disappointed much.
I suppose we may close the question in the next way. I will implement
everything as I want, e.g. will made local patch to MHD and will test
within some kind amount of time (weeks, months). And in the case if I
would like see this feature in MHD-core I will send a patch.
Ok?
> In one thread you are asking about external polling, in another - about
> timeout and suspend/resume. Are those questions connected or independent
> situations?
I am working on one MHD project at the moment. All questions are
connected with each other.
There is a strong connection between suspend/resume and a connection
timeout, see above.
--
With Best Regards,
Vitaliy V. Tokarev
