[Opensim-dev] Is it OK performance-wise to long-poll a money module?

[Melanie]

You can use the PollServiceManager to do this. It's the same
mechanism the viewer uses.

However, if only one instance of the application long-polls, that is
one thread so you don't need to worry about resources too much.

Melanie

On 15/09/2012 11:53, Dahlia Trimble wrote:
> I've had excellent luck serving many simultaneous long-poll requests with
> the HTTP server that comes with OpenSimulator. Bear in mind though that
> each active request may consume a thread so you might need to increase
> available threads if you see problems. I'm not certain if the request
> threads are managed by the threadpool in OpenSimulator or if they are
> direct calls into .NET framework. I did search through the code once and
> found many threads that were not treadpool managed but I can't remember if
> HTTP threads were or not.
> 
> 
> On Fri, Sep 14, 2012 at 9:07 PM, Edmund Edgar <ed at avatarclassroom.com>wrote:
> 
>> I've got a situation with the money module I'm working on where I'd
>> like an external program (running on the client PC in parallel to the
>> viewer) to be able to be in almost constant contact with the server
>> while the user is logged in. (I want it to be able to find out
>> whenever the user wanted to buy something.)
>>
>> I figure I can do this by having the external program long-poll the
>> OpenSim server. (The external program makes a request, the server
>> waits such time as it has something to tell the external program, then
>> responds. It gives up and responds if there's nothing to say after 30
>> seconds or so, at which point the external program will make a new
>> request and start the cycle again.)
>>
>> At this point if I was serving a web application with Apache I'd start
>> worrying that I was hogging a bunch of threads and eating through the
>> memory. Is this the kind of thing I should be worrying about with
>> OpenSim, or can I merrily go ahead and long-poll without worrying?
>>
>> The kind of thing I'm thinking of follows:
>>
>>
>> public void FirstRegionLoaded ()
>>
>>         MainServer.Instance.AddHTTPHandler ("/checkfortransactions/",
>> CheckForTransactions);
>>
>> }
>>
>> public Hashtable CheckForTransactions(Hashtable request) {
>>
>>         UUID userUUID = (get a user id using a session ID passed in the
>> request or something);
>>
>>         int i;
>>         // poll for 30 seconds then give up
>>         for (i=0; i<30; i++) {
>>                 if
>> (m_transactionsAwaitingNotification.containsKey("userUUID")) {
>>                         // Reply to the request
>>                         Hashtable reply = new Hashtable ();
>>                         reply["int_response_code"] = 200;
>>                         reply["str_response_string"] = "{ Some JSON goes
>> here }";
>>                         reply["content_type"] = "text/json";
>>                         return reply;
>>                 }
>>                 Thread.Sleep (1000);
>>         }
>>
>>         Hashtable reply = new Hashtable ();
>>         reply["int_response_code"] = 204; // No Content
>>         return reply;
>>
>>         // The client will get this reply then hit /checkfortransactions/
>> again.
>>
>> }
>>
>> PS. Thanks for the replies to my C#-ignorant questions on previous threads.
>>
>> --
>> Edmund Edgar
>> Avatar Classroom
>> Your classroom, on the web, in a virtual world.
>>
>> ed at avatarclassroom.com
>> +81 090 3912 3380
>> Skype: edmundedgar
>> Second Life: Edmund Earp
>> Linked In: edmundedgar
>> Twitter: @edmundedgar
>> http://www.avatarclassroom.com
>> _______________________________________________
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>>
> 
> 
> 
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