Move Signals module under Supervisor namespace, out of Processes

As it's just for the supervisor.

Author: rosa

lib/solid_queue/processes/signals.rb

@@ -2,7 +2,7 @@
 
 module SolidQueue
   class Supervisor < Processes::Base
-    include Processes::Signals
+    include Signals
 
     class << self
       def start(mode: :fork, load_configuration_from: nil)
@@ -25,9 +25,9 @@ def start
       launch_maintenance_task
 
       supervise
-    rescue Processes::GracefulTerminationRequested
+    rescue GracefulTerminationRequested
       graceful_termination
-    rescue Processes::ImmediateTerminationRequested
+    rescue ImmediateTerminationRequested
       immediate_termination
     ensure
       run_callbacks(:shutdown) { shutdown }

lib/solid_queue/supervisor.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+module SolidQueue
+  class Supervisor
+    class GracefulTerminationRequested < Interrupt; end
+    class ImmediateTerminationRequested < Interrupt; end
+
+    module Signals
+      extend ActiveSupport::Concern
+
+      private
+        SIGNALS = %i[ QUIT INT TERM ]
+
+        def register_signal_handlers
+          SIGNALS.each do |signal|
+            trap(signal) do
+              signal_queue << signal
+              interrupt
+            end
+          end
+        end
+
+        def restore_default_signal_handlers
+          SIGNALS.each do |signal|
+            trap(signal, :DEFAULT)
+          end
+        end
+
+        def process_signal_queue
+          while signal = signal_queue.shift
+            handle_signal(signal)
+          end
+        end
+
+        def handle_signal(signal)
+          case signal
+          when :TERM, :INT
+            request_graceful_termination
+          when :QUIT
+            request_immediate_termination
+          else
+            SolidQueue.instrument :unhandled_signal_error, signal: signal
+          end
+        end
+
+        def request_graceful_termination
+          raise GracefulTerminationRequested
+        end
+
+        def request_immediate_termination
+          raise ImmediateTerminationRequested
+        end
+
+        def signal_processes(pids, signal)
+          pids.each do |pid|
+            signal_process pid, signal
+          end
+        end
+
+        def signal_process(pid, signal)
+          ::Process.kill signal, pid
+        rescue Errno::ESRCH
+          # Ignore, process died before
+        end
+
+        def signal_queue
+          @signal_queue ||= []
+        end
+    end
+  end
+end