Synapse - aborting HTTPMethod
lazarus / 38-Networking and Web Programming

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Dibo · 2010-10-08 16:32

Hi,

I have THTTPSend created and running in thread. Can I somehow safely
abort connection from main thread when THTTSend.HTTPMethod takes too
long? This socket have procedure Abort:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     {:You
can call this method from OnStatus event for break current data   
 transfer. (or from another thread.)}    procedure Abort;   
But it doesn't work with HTTPMethod('GET',
'http://some.php.sleep.script');
Indy fails too. I tried change Timeout to 1 but doesn't help. Only
LNet have no-blocking mode but it can't post xml in body section.

Regards

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theo · 2010-10-08 17:03

Freeing the THTTPSend could do the job.

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Dibo · 2010-10-08 18:23

Produces such an error, that even sections of an except and finally
can't capture it

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99Percent · 2010-10-09 02:16

Try putting Application.Processmessages somewhere in your code.

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anna · 2012-07-02 12:12

Quote from: 99Percent on October 09, 2010, 04:16:36 amTry putting
Application.Processmessages somewhere in your code.
 Application.Processmessages and Abort do not help.
Look on attachment. Project fail on MessagesProc procedure (110 line
in unit1) , because  thread  still tryes to get data from internet
even when FREE called. In synapse there is another build-in timer = 9
seconds.

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anna · 2012-07-02 12:17

So in synapse there is no way to disconnect from internet, even if
web-server does not response. Synapse-programm will wait for 9 sec.

It's really stupid.

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Blestan · 2012-07-02 13:30

Do to use strong words for things that you do not understand 100% ...

Abort will not work because your are not in the middle of receiving
huge data packets but you are hanging  in a "connect" operation witch
timeout is controlled by the os kernel
if you run the http request code in a thread the wait is not a problem
... just leave the thread to finish or set a minimal timeout for
socket operations ...
you can do a "ping"  (even with empty request) prior any other
operations just to "know"" if the server is online and depending on
time needed to receive the response you can decide how many ms to wait
in future operations   or query another server.
in one project i used a similar approach - i have a list of servers to
choose from so first i run N threads to connect to the N servers ...
as soon as a thread connects to server it put the ip in a available
list ... then the request code waits just for the first server to be
available and start the operations .. on next request if more servers
are found by the rest of the threads  a round robin schema is used for
load balancing ...