Can a socket have multiple connections?

Irrespective of stateful or stateless protocols, two clients can connect to same server port because for each client we can assign a different socket (as client IP will definitely differ). Same client can also have two sockets connecting to same server port – since such sockets differ by SRC-PORT .

How do you implement a multithreaded socket?

Your server code should address implement below functionalities.

  1. Keep accepting socket from ServerSocket in a while loop.
  2. Create new thread after accept() call by passing client socket i.e Socket.
  3. Do IO processing in client socket thread e.g ClientWorker in your case.

Are Linux sockets thread safe?

Sockets are not part of C++ Standard so it depends on implementation. Generally they are not thread safe since send is not an atomic operation.

How do you create multiple threads in C++?

To start a thread we simply need to create a new thread object and pass the executing code to be called (i.e, a callable object) into the constructor of the object. Once the object is created a new thread is launched which will execute the code specified in callable. After defining callable, pass it to the constructor.

Can two sockets bind same port?

Yes. Multiple listening TCP sockets, all bound to the same port, can co-exist, provided they are all bound to different local IP addresses. Clients can connect to whichever one they need to.

How many sockets can be opened at once?

For most socket interfaces, the maximum number of sockets allowed per each connection between an application and the TCP/IP sockets interface is 65535.

Why we use multithreading in socket programming?

Each part of such a program is called a thread, and each thread defines a separate path of execution. Multithreaded Socket Programming describes that a Multithreaded Socket Server can communicate with more than one client at the same time in the same network.

Is socket accept thread-safe?

accept is declared as MT-Safe, according to doc: MT-Safe or Thread-Safe functions are safe to call in the presence of other threads.

Is Sendmsg thread-safe?

SendMessage and SendMessageTimeout are blocking functions: They pause the sender until the receiver has processed the message and returned. So there is no concurrent access to anything, hence the operation is thread-safe.