A look at C++14, part 1 [LWN.net]

A look at C++14, part 1

Posted Mar 31, 2013 13:59 UTC (Sun) by Cyberax (✭ supporter ✭, #52523)
In reply to: A look at C++14, part 1 by simlo
Parent article: A look at C++14, part 1

I haven't seen real Java apps using separate threads to receive and send data. That's simply stupid in most cases. However, I did see asynchronous servers die under a high load with all but one CPU completely idle.

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A look at C++14, part 1

Posted Mar 31, 2013 21:08 UTC (Sun) by simlo (subscriber, #10866) [Link]

Well, as I work with _real_ Java programs (written before select() came to Java), I know it is needed.

For instance: I have some data I have to send to different clients via TCP sockets. Naive solution: Loop through the clients and perform write() on each socket. Problem: If one client is not taking data the write() operation will block halting data for any other client as well.
Therefore I have to make a thread in which to execute write() for each client. And a message queue for each client to get data from the data producing thread(s) to the write thread.
Similarly, the read option is blocking so I have to have a receive thread per client.
And all this is hard to make work in all cases where clients can close the connection, the link is lost or what ever where the different thread are in different states.

On a proper OS (i.e. UNIX) in C++, I can use select() and therefore contain everything in one thread and have a clear picture of my possible states.