require "monitor" module ActionCable module Server # A singleton ActionCable::Server instance is available via ActionCable.server. It's used by the Rack process that starts the Action Cable server, but # is also used by the user to reach the RemoteConnections object, which is used for finding and disconnecting connections across all servers. # # Also, this is the server instance used for broadcasting. See Broadcasting for more information. class Base include ActionCable::Server::Broadcasting include ActionCable::Server::Connections cattr_accessor(:config, instance_accessor: true) { ActionCable::Server::Configuration.new } def self.logger; config.logger; end delegate :logger, to: :config attr_reader :mutex def initialize @mutex = Monitor.new @remote_connections = @event_loop = @worker_pool = @pubsub = nil end # Called by Rack to setup the server. def call(env) setup_heartbeat_timer config.connection_class.call.new(self, env).process end # Disconnect all the connections identified by `identifiers` on this server or any others via RemoteConnections. def disconnect(identifiers) remote_connections.where(identifiers).disconnect end def restart connections.each(&:close) @mutex.synchronize do worker_pool.halt if @worker_pool @worker_pool = nil end end # Gateway to RemoteConnections. See that class for details. def remote_connections @remote_connections || @mutex.synchronize { @remote_connections ||= RemoteConnections.new(self) } end def event_loop @event_loop || @mutex.synchronize { @event_loop ||= ActionCable::Connection::StreamEventLoop.new } end # The worker pool is where we run connection callbacks and channel actions. We do as little as possible on the server's main thread. # The worker pool is an executor service that's backed by a pool of threads working from a task queue. The thread pool size maxes out # at 4 worker threads by default. Tune the size yourself with config.action_cable.worker_pool_size. # # Using Active Record, Redis, etc within your channel actions means you'll get a separate connection from each thread in the worker pool. # Plan your deployment accordingly: 5 servers each running 5 Puma workers each running an 8-thread worker pool means at least 200 database # connections. # # Also, ensure that your database connection pool size is as least as large as your worker pool size. Otherwise, workers may oversubscribe # the database connection pool and block while they wait for other workers to release their connections. Use a smaller worker pool or a larger # database connection pool instead. def worker_pool @worker_pool || @mutex.synchronize { @worker_pool ||= ActionCable::Server::Worker.new(max_size: config.worker_pool_size) } end # Adapter used for all streams/broadcasting. def pubsub @pubsub || @mutex.synchronize { @pubsub ||= config.pubsub_adapter.new(self) } end # All of the identifiers applied to the connection class associated with this server. def connection_identifiers config.connection_class.call.identifiers end end ActiveSupport.run_load_hooks(:action_cable, Base.config) end end