Feature #21837: Introduce socket hooks in Fiber Scheduler interface

• Status: Open
• Assignee: -
• Target version: -

[noteflakes (Sharon Rosner)]

Currently the fiber scheduler interface does not support any socket operations. The stock Ruby socket implementation performs all operations in a non-blocking way, and invokes the #io_wait fiber scheduler hook in order to wait for readiness. I propose adding the following hooks:

• #socket_recv(sock, buffer, length, flags, recvfrom): performs a recv or recvfrom. The recvfrom argument is a boolean denoting whether a recvfrom should be performed. When true, the hook should return an array containing the number of bytes received and the source address. When false, the hook should return the number of bytes received.
• #socket_send(sock, dest, buffer, length, flags): performs a send or sendto. The dest argument is nil for a send. When not nil, a sendto operation should be done.
• #socket_connect(sock, addr): performs a connect.
• #socket_accept(sock, client_sockaddr) - performs an accept. The client_sockaddr argument is an IO::Buffer that receives the peer addrinfo.

The PR for this feature: https://github.com/ruby/ruby/pull/15865