Explicit support for Restart.

Author: ioquatix

guides/getting-started/readme.md

@@ -74,6 +74,8 @@ controller.run
 
 ## Signal Handling
 
+`SIGINT` is the reload signal. You may send this to a program to request that it reload its configuration. The default behavior is to gracefully reload the container.
+
 `SIGINT` is the interrupt signal. The terminal sends it to the foreground process when the user presses **ctrl-c**. The default behavior is to terminate the process, but it can be caught or ignored. The intention is to provide a mechanism for an orderly, graceful shutdown.
 
 `SIGQUIT` is the dump core signal. The terminal sends it to the foreground process when the user presses **ctrl-\\**. The default behavior is to terminate the process and dump core, but it can be caught or ignored. The intention is to provide a mechanism for the user to abort the process. You can look at `SIGINT` as "user-initiated happy termination" and `SIGQUIT` as "user-initiated unhappy termination."

lib/async/container/controller.rb

@@ -219,18 +219,18 @@ def run
 
 				interrupt_action = Signal.trap(:INT) do
 					# We use `Thread.current.raise(...)` so that exceptions are filtered through `Thread.handle_interrupt` correctly.
-					# $stderr.puts "Received Interrupt signal, terminating...", caller
+					# $stderr.puts "Received INT signal, interrupting...", caller
 					::Thread.current.raise(Interrupt)
 				end
 
 				terminate_action = Signal.trap(:TERM) do
-					# $stderr.puts "Received Terminate signal, terminating...", caller
+					# $stderr.puts "Received TERM signal, terminating...", caller
 					::Thread.current.raise(Terminate)
 				end
 
 				hangup_action = Signal.trap(:HUP) do
-					# $stderr.puts "Received Hangup signal, restarting...", caller
-					::Thread.current.raise(Hangup)
+					# $stderr.puts "Received HUP signal, restarting...", caller
+					::Thread.current.raise(Restart)
 				end
 
 				::Thread.handle_interrupt(SignalException => :never) do

lib/async/container/error.rb

@@ -19,7 +19,7 @@ def initialize
 			end
 		end
 
-		class Hangup < SignalException
+		class Restart < SignalException
 			SIGHUP = Signal.list["HUP"]
 
 			def initialize

lib/async/container/process.rb

@@ -68,7 +68,7 @@ def self.fork(**options)
 						# We use `Thread.current.raise(...)` so that exceptions are filtered through `Thread.handle_interrupt` correctly.
 						Signal.trap(:INT) {::Thread.current.raise(Interrupt)}
 						Signal.trap(:TERM) {::Thread.current.raise(Terminate)}
-						Signal.trap(:HUP) {::Thread.current.raise(Hangup)}
+						Signal.trap(:HUP) {::Thread.current.raise(Restart)}
 
 						# This could be a configuration option:
 						::Thread.handle_interrupt(SignalException => :immediate) do
@@ -153,6 +153,13 @@ def terminate!
 				end
 			end
 
+			# Send `SIGHUP` to the child process.
+			def restart!
+				unless @status
+					::Process.kill(:HUP, @pid)
+				end
+			end
+			
 			# Wait for the child process to exit.
 			# @asynchronous This method may block.
 			#

lib/async/container/thread.rb

@@ -152,6 +152,11 @@ def terminate!
 				@thread.raise(Terminate)
 			end
 
+			# Raise {Restart} in the child thread.
+			def restart!
+				@thread.raise(Restart)
+			end
+			
 			# Wait for the thread to exit and return he exit status.
 			# @returns [Status]
 			def wait