Question

I’m writing an application in C# where I want to maintain a large number of open socket-connections (tcp), and be able to respond to data that comes in from all of them. Now, the normal thing to do (afaik) would be to call BeginRead on all of them, but as far as I know BeginRead spawns a thread and sits and waits for data in that thread, and I’ve read that threads don’t tend to scale very well when using a lot of them. Though I might be wrong about this, if that’s the case please just tell me.

This will probably sound idiotic, but what I want is to be able to maintain as many open socket-connections as possible (as my machine/os allows), while still being able to react to data coming in from any of them as fast as possible, and using as little system-resources as possible doing this.

What I’ve thought about is to put all of them in some kind of list, and then run a single thread in loop over them checking for new data and acting on that new data (if there is any), though I’d think that a loop like that will end up frying my cpu (cause there is nothing in the loop that blocks). Is there any way (simple or not, I don’t mind getting into some more complex algorithms to solve this) that I can achieve this? Any help would be appreciated.

Answer 1

No. The asynchronous methods do not spawn threads, they use IO Completion Ports.

The BeginXXX methods have been deprecated. Use the XxxxAsync methods instead.

• http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.sendasync.aspx
• http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.receiveasync.aspx