What is So_reuseaddr Python?

Java: JUnit – 5. Expected and Timeout

Hello everyone I have a problem it turns out that I’m doing a program cutlizando sockets but for some strange reason appears broken pipi error from what I’ve read this error usually happens when you write in a socket completely closed on the other side (client) but I do not understand poruqe me appears if the connections of both both the ssevidor and the client I have them open.

Also if you can explain me in detail what these two lines are for or what the hell I’m doing with that because I have found information on the internet or in the python socket api and it is not clear to me what it is used for.

In both cases the use of setsockopt() allows to enable or disable a special feature of a socket or a protocol. The final 1 indicates that it is being enabled, in this case. Let’s see what these features are.

It is a socket option. It indicates that if you later try to do the .bind((ip, port)) operation and discover that the ip and port were already being used, they will be reused anyway. Without this option the attempt to do .bind() on an IP and port in use would cause an exception and the program to abort.

What is so_reuseaddr python? online

Fortunately, Python implements a friendly sendall() method, unfortunately, no equivalent container is provided to call recv(), although it suffers from the same possibility of incomplete transmission.

That is why the recv() call has to be inside a loop. The operating system has no way of knowing that this client and server always use fixed-width 16 octet messages. Since it cannot guess when the incoming data might finally add up to what your program considers to be a complete message, it is given the data as soon as possible.

It is probably because fixed-length messages are so rare, a program often has to read or process part of the message before guessing how much more is coming in, these kinds of details are best left to your application rather than the Standard Library.

Remember there are two different types of streaming sockets: listening sockets, with which servers make a port available for incoming connections, and connected sockets, which represent a conversation a server is having with a particular client.

What is so_reuseaddr python? en línea

The address format required by a given socket object is automatically selected based on the address family specified when the socket object was created. Socket addresses are represented as follows:

A subclass of OSError, this exception occurs for address-related errors, i.e., for functions that use h_errno in the POSIX C API, including gethostbyname_ex() and gethostbyaddr(). The enclosed value is a pair (h_errno, string) representing an error returned by a library call. h_errno is a numeric value, while string represents the description of h_errno, returned by the hstrerror() C function.

These constants represent the families of addresses (and protocols), used for the first argument to socket(). If the constant AF_UNIX is not defined then this protocol is not supported. More constants may be available depending on the system.

These two constants, if defined, can be combined with the socket types and allow you to set some flags atomically (thus avoiding possible race conditions and the need for separate calls).

What is so_reuseaddr python? 2022

Continuing with the topic of using Python to write network applications and using as support for it the book I mentioned before “Python Network Programming Cookbook” I will show you how to create an application composed by a client and a server which communicate over a socket.

The server application creates a socket and binds it to an IP address and port, for this we will parse the -port parameter passed as an argument on the command line when invoking the script and use the local address of our computer.

First we create the socket object which receives as parameters the address families to use and the type of socket, by default they take the values of the constants socket.AF_INET and socket.SOCK_STREAM.

The next step is to specify that the address can be reused, setting this option tells the kernel that a socket whose timeout has not expired can be used, thus avoiding an error saying “Address already in use”.

It then waits for messages sent from the clients and (in this case) sends them back to them. Of course you could instead do any other task with the received data and send any other information to the clients.