An event when there is data to read on a socket?

Yeah, I’m coding in C. It looks like moving to assembler would be the best bet.

Not really. Remove the stuff about the C runtime, all the rest still applies.

I grew up coding in assembly, 6502 then ARM.

Hehe, anybody that wanted anything done sensibly in the ’80s used assembler.

But I also need to be realistic about my skills and time.

I’m not the world’s greatest when it comes to assembler. I probably rank as “immature schoolgirl” compared to Jeffrey, Sophie, etc. What I can tell you, though, is that debugging assembler is a whole different story. Given that most of the points raised will still apply, you might as well stick with C.

I like Ricks final point “Do whatever you do quickly.” All I need to do is update 1 data structure and copy a 17k (at most) buffer per internet event.

Then that’s okay. The Event is just telling you something happened. Schedule a CallBack, then you can recv() and write at your leisure.

Then I need to work out how to trigger an event similar to wimp pollidle but for modules.

How do you mean? To be called at regular intervals? OS_CallAfter for one-offs, and OS_CallEvery for a repeated call (if you want 1cs calls, you will need to hook into TickerV).

Note, however, that CallAfter/CallEvery have restrictions on use. Yup, you guessed it. :-)

I’ve got a week on holiday to spend trawling through a pdf and PRMS, what better way to relax ;-)

Word of advice – don’t. Unless you are bored with your surroundings and hate the people you are with, enjoy your holiday time and leave this stuff until holiday is done with. Holidays are special and should be considered sacrosanct.
A person asked me if I ever get to Japan, would I write blog articles about it. My first thought was “yeah, that’ll be fun”. My second thought was “hell NO!!!”. If I save up forever and a day and make it all the way over there, I’d be institutionalisably mental if I am going to spend my time there writing about spending my time there. That would be nuts.
So, for you, on holiday. Leave the PRMs behind. I don’t mean pretend not to read them, I mean actually delete the files from whatever you would be reading them on. Don’t fret about these things. Enjoy your holiday, take photos, make good memories, worry about CMHG later.

Looks like Rick got in there pretty quick! Thanks!

You’re welcome. That was my second try, since I pressed a key while trying not to drop a big cheesy bit of pizza and Firefox went back a page and threw away my text. Oh well, the second version was better anyhow. ;-)

I’ve kind of worked out some logic (locking) to deal with data being out of sync.

Sounds like you’re trying to do too much in the event handler. Just note that “socket XXX needs attention”. Defer everything else until RISC OS prods you. Then, so long as the socket descriptor is valid, there shouldn’t be a problem.

If you feel the need to use the Internet event to inform your application of internet events then the event handler just needs to set set a word that you register with it to non zero and you pass that block of memory to wimp poll and use the wimp poll non zero wimp event. Doing the data transfer in the module won’t make the transfer any faster and application space gives you control of how often to poll if data transfer is too slow or too fast – too fast stalls the wimp on large transfers, too slow and you can add a wimp poll while you wait. You could register more than a 4 byte pollword with the module and have the module fill in the other fields to the internet event data when the handler sets the pollword to non zero – not much point though.

On receipt of a pollword non zero wimp event you can do what you need to do and multitask with the occasional wimp poll. Once you are transferring data you can ignore the internet event – it’s only really useful for a listening socket to notify connections. But you can get away without it.

Personally I wouldn’t use a module if I didn’t have to.

I currently do the data transfer on the application side, I’ve found putting that level of complexity in the application is making my programs too bloated. Using a module allows a cleaner abstraction.
Also I can have better control of download/flow rates if it is in a central point.
For one simple application doing it just in the application is just fine.
For example my NewsUK application downloads the RSS data, then parses the data and downloads each file in serial.
For a full RSS reader I need some more complex behaviour, I need to:
1. Download multiple RSS feeds and images in parallel
2. Cache the downloads so if images or RSS feeds haven’t been updated they are not downloaded again
3. Allow a cap on the bandwidth
4. cap on number of connections in RISCOS
5. cap the number of connections per endpoint
6. pipeline n connections per endpoint
7. The whole lot needs to be async (DNS currently isn’t)

I’m using the module to do the whole lot, the DNS lookup and handle the download/streaming and then send a wimp event.
There are currently two scenarios I need it for:
1) Please download this [insert protocol] file and save it here and tell me when it’s complete (you can ask it for an update on progress) – RSS Reader/imap/pop
2) Please stream this endpoint into this buffer and tell me when there is either x amount of data, socket is closed or some data is read (depending on what you want) – Jabber client

My hope is to allow “plugins” which will be non-module wimp based to decode the various protocols and can hook into the module to extend and control it.
Just thinking it out is taking awhile, but it’s fun and that’s the point ;-)

Just thinking it out is taking awhile, but it’s fun and that’s the point ;-)

Looks complicated, enjoy.

I’ve managed to get more than an hour to look at programming again ;-)
I’ve not been able to find the declarations for:
EventV
Event_Enable
Internet_Event

I’ve done a search in the header files and these don’t seem to exist.
However the PRMS (5a-359) and Rick’s code seem to indicate they are defined somewhere.
For the moment I’m going to manually define them in my header file

I use a couple of modules I wrote back in 1998 which I have recently dusted off and converted for 32bit addressing. One is for managing Pollwords the other for managing AsyncSockets. What you have to do is register your task with the Pollword module and then pass the returned address to the AsyncSocket module along with the socket descriptor. The AsyncSocket module takes care of enabling and disabling the Internet event so you don’t have to do this in your own tasks. When an Internet event happens the AsyncSocket module modifies the tasks Pollword which in turn the task is switched in within the Wimp Poll loop. The originals were written in assembler and have been updated but recently I have been experimenting writing the AsyncSocket module in C, still works but a bug stops the module being killed after it has been used, the assembler version works.

If you want copies of these then let me know.

@Bill, not sure you’re still around – but if you are I would love a copy of the modules.
After a slightly embarassing mistake, where I thought I’d cracked it. It turned out I was using my old code to handle the internet part.
Now I’m just getting a crash when the event handler gets called! I’ve even cut it down to a point where I just return(1) and that still crashes it!
So anything I can use to see where I’m going wrong would be great.

Yes, still around. I’ll upload the code and modules to my website for download, I’ll post the link on the forum when it’s there.
I haven’t looked at this forum until today so it’s fortuitous I dropped in so soon after your reply.

Here is the link:
http://www.beaconhillcott.net/index.php?option=com_content&view=category&layout=blog&id=37&Itemid=70

You register your wimp applications task handle with the Pollword module then you pass the pollword address returned to the AsyncSocket module along with the socket descriptor. Finally set up your mask and enter the poll loop.

This enables you to use pollwords without having to make your wimp task a module task and still have the pollword location in a static place all the time, therefore not being paged out.

When an Internet event happens the associated tasks pollword is modified and therefore your task is polled and gains control to service the event.

It’s strange Acorn never wrote a module to manage pollwords and built it into RiscOS in the first place, I’m sure they would have done a better job.

The download is compatible with SparkFS, just remove the .zip extension. Note, not all of the daemons have been rewritten for the current C/C++ libraries, they used to use the UNIXLib. Check the configuration file inside !Inetd for the ones that currently work.

By the way, the SWI numbers are registered for both modules so there should be no clashes with any you may write.