When does socket.recv(recv_size) return?

Question

From test, I concluded that in following three cases the socket.recv(recv_size) will return.

1. After the connection was closed. For example, the

Answer 1

I think you conclusions are correct but not accurate.

As the docs indicates, socket.recv is majorly focused on the network buffers.

When socket is blocking, socket.recv will return as long as the network buffers have bytes. If bytes in the network buffers are more than socket.recv can handle, it will return the maximum number of bytes it can handle. If bytes in the network buffers are less than socket.recv can handle, it will return all the bytes in the network buffers.