require "active_support/callbacks" require "active_support/core_ext/module/attribute_accessors_per_thread" require "concurrent" module ActionCable module Server # Worker used by Server.send_async to do connection work in threads. class Worker # :nodoc: include ActiveSupport::Callbacks thread_mattr_accessor :connection define_callbacks :work include ActiveRecordConnectionManagement attr_reader :executor def initialize(max_size: 5) @executor = Concurrent::ThreadPoolExecutor.new( min_threads: 1, max_threads: max_size, max_queue: 0, ) end # Stop processing work: any work that has not already started # running will be discarded from the queue def halt @executor.kill end def stopping? @executor.shuttingdown? end def work(connection) self.connection = connection run_callbacks :work do yield end ensure self.connection = nil end def async_exec(receiver, *args, connection:, &block) async_invoke receiver, :instance_exec, *args, connection: connection, &block end def async_invoke(receiver, method, *args, connection: receiver, &block) @executor.post do invoke(receiver, method, *args, connection: connection, &block) end end def invoke(receiver, method, *args, connection:, &block) work(connection) do begin receiver.send method, *args, &block rescue Exception => e logger.error "There was an exception - #{e.class}(#{e.message})" logger.error e.backtrace.join("\n") receiver.handle_exception if receiver.respond_to?(:handle_exception) end end end private def logger ActionCable.server.logger end end end end