Sockets¶

Woxi implements the Wolfram Language's TCP socket functions natively, over std::net — no external library and no event loop of its own.

A socket is a SocketObject, printed with its UUID: SocketOpen binds and listens (its UUID carries a TCPSERVER- prefix), SocketConnect opens the near end of an outgoing connection. SocketListen attaches handler functions to a socket and returns a SocketListener.

Handlers run on the thread that evaluates Wolfram code, so they fire wherever evaluation waits: inside Pause, inside a blocking read such as SocketReadMessage, inside SocketWaitNext and SocketWaitAll, and between two top-level statements. Nothing runs a handler in the background behind a long computation, which is also how wolframscript behaves.

• SocketOpen
• SocketConnect
• SocketListen
• SocketReadMessage
• Sockets

Throughput¶

Measured over loopback in a release build, pushing 1 GiB through a SocketListen handler in 64 KiB chunks:

• ~435 MB/s when the handler does not look at the payload. This is what the transport itself sustains, including the one base64 encode per chunk that building DataByteArray costs.
• ~142 MB/s when the handler reads the payload back out (Length[#["DataByteArray"]]).

The gap between the two is not the socket code: a ByteArray is stored as a base64 string, so every read of one decodes it again. A handler that needs the bytes only once should take them once.

Sockets also work with the ordinary stream functions: WriteString, WriteLine, Write and BinaryWrite send to one, and ReadString, ReadLine, Read and BinaryReadList read from one. SocketReadyQ asks whether a read would find anything, Close shuts a socket down and Sockets[] lists what is still open.