diff --git a/lib/async/container/controller.rb b/lib/async/container/controller.rb
index 5860109..813d312 100644
--- a/lib/async/container/controller.rb
+++ b/lib/async/container/controller.rb
@@ -46,6 +46,7 @@ class Controller
 			def initialize(startup_duration: nil)
 				@container = nil
 				
+				# If there is no `NOTIFY_SOCKET` this will be nil:
 				@notify = Notify::Client.open
 				
 				@signals = {}
diff --git a/lib/async/container/forked/group.rb b/lib/async/container/forked/group.rb
index 5717be6..ed88449 100644
--- a/lib/async/container/forked/group.rb
+++ b/lib/async/container/forked/group.rb
@@ -25,7 +25,7 @@ module Async
 	module Container
 		module Forked
 			class Group < Async::Container::Group
-				def initialize
+				def initialize(**options)
 					@pgid = nil
 					
 					super
@@ -34,10 +34,13 @@ def initialize
 				def spawn(*arguments, **options)
 					self.yield
 					
-					arguments = self.prepare_for_spawn(arguments)
+					# Arguments are modified in place.
+					Notify.before_spawn(@notify, arguments)
 					
 					pid = ::Process.spawn(*arguments, **options)
 					
+					@context&.add(pid)
+					
 					return Process.new(self, pid)
 				end
 				
@@ -45,11 +48,13 @@ def fork(&block)
 					self.yield
 					
 					pid = ::Process.fork do
-						self.after_fork
+						Notify.after_fork(@notify)
 						
 						yield
 					end
 					
+					@context&.add(pid)
+					
 					return Process.new(self, pid)
 				end
 				
@@ -110,6 +115,7 @@ def wait_one(blocking = true)
 					
 					return if !blocking && pid == nil
 					
+					@context&.delete(pid)
 					fiber = @running.delete(pid)
 					
 					if @running.empty?
diff --git a/lib/async/container/forked/instance.rb b/lib/async/container/forked/instance.rb
index 42c2ab7..95371d5 100644
--- a/lib/async/container/forked/instance.rb
+++ b/lib/async/container/forked/instance.rb
@@ -32,9 +32,9 @@ def name= name
 					::Process.setproctitle(@name)
 				end
 				
-				def exec(*arguments)
-					::Process.exec(*arguments)
-				end
+				# def exec(*arguments)
+				# 	::Process.exec(*arguments)
+				# end
 				
 				def to_s
 					"\#<#{self.class}: #{@name}>"
diff --git a/lib/async/container/group.rb b/lib/async/container/group.rb
index 62a676d..c3c32c0 100644
--- a/lib/async/container/group.rb
+++ b/lib/async/container/group.rb
@@ -23,14 +23,21 @@
 module Async
 	module Container
 		class Group
-			def initialize
+			def initialize(notify: false)
 				@running = {}
 				
 				# This queue allows us to wait for processes to complete, without spawning new processes as a result.
 				@queue = nil
 				
-				@notify = Notify::Server.open
-				@context = @notify.bind
+				if notify == true
+					@notify = Notify::Server.open
+				elsif notify
+					@notify = notify
+				else
+					@notify = nil
+				end
+				
+				@context = @notify&.context
 			end
 			
 			def any?
@@ -41,16 +48,12 @@ def empty?
 				@running.empty?
 			end
 			
-			def pids
-				@running.keys
-			end
-			
 			# This method sleeps for the specified duration, then 
 			def sleep(duration)
 				self.resume
 				self.suspend
 				
-				self.wait_for_children(self.pids, duration || 1)
+				self.wait_for_children(duration)
 				
 				# This waits for any process to exit.
 				while self.wait_one(false)
@@ -89,24 +92,16 @@ def close
 			
 			protected
 			
-			def after_fork
-				ENV.update(@notify.export)
-			end
-			
-			def prepare_for_spawn(arguments)
-				if arguments.first.is_a?(Hash)
-					arguments[0] = arguments[0].merge(@notify.export)
-				else
-					arguments.unshift(@notify.export)
+			def wait_for_children(duration)
+				if @notify
+					self.wait_until_ready(duration)
+				elsif duration
+					Kernel::sleep(duration)
 				end
-				
-				return arguments
 			end
 			
-			def wait_for_children(pids, duration)
-				@context.clear
-				
-				puts "Waiting on #{self.pids}"
+			def wait_until_ready(duration)
+				puts "Waiting on #{@context.pids}"
 				
 				Sync do |task|
 					waiting_task = nil
@@ -117,7 +112,7 @@ def wait_for_children(pids, duration)
 							
 							yield message
 							
-							break if @context.ready?(self.pids)
+							break if @context.ready?
 						end
 						
 						waiting_task&.stop
diff --git a/lib/async/container/notify.rb b/lib/async/container/notify.rb
index 36a2abd..d74d51a 100644
--- a/lib/async/container/notify.rb
+++ b/lib/async/container/notify.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+#
 # Copyright, 2020, by Samuel G. D. Williams. <http://www.codeotaku.com>
 # 
 # Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -28,6 +30,7 @@
 module Async
 	module Container
 		module Notify
+			NOTIFY_SOCKET = 'NOTIFY_SOCKET'
 			MAXIMUM_MESSAGE_SIZE = 4096
 			
 			def self.load(message)
@@ -38,8 +41,35 @@ def self.load(message)
 				]
 			end
 			
+			# Sets or clears NOTIFY_SOCKET environment variable depending on whether the server exists (and in theory bound).
+			def self.after_fork(server, environment = ENV)
+				if server
+					# Set the environment variable:
+					environment[NOTIFY_SOCKET] = server.path
+				else
+					# Unset the environment variable (this doesn't actually set it to nil):
+					environment[NOTIFY_SOCKET] = nil
+				end
+				
+				return environment
+			end
+			
+			# Inserts or duplicates the environment given an argument array.
+			# Sets or clears it in a way that is suitable for {::Process.spawn}.
+			def self.before_spawn(server, arguments)
+				if arguments.first.is_a?(Hash)
+					environment = arguments.first = arguments.first.dup
+				else
+					arguments.unshift(environment = Hash.new)
+				end
+				
+				after_fork(server, arguments.first)
+				
+				return arguments
+			end
+			
 			class Client
-				def self.open(path = ENV['NOTIFY_SOCKET'])
+				def self.open(path = ENV[NOTIFY_SOCKET])
 					if path
 						self.new(
 							IO::Endpoint.unix(path, Socket::SOCK_DGRAM)
@@ -107,10 +137,6 @@ def initialize(path)
 				
 				attr :path
 				
-				def export
-					{'NOTIFY_SOCKET' => @path}
-				end
-				
 				def bind
 					Context.new(@path)
 				end
@@ -133,6 +159,24 @@ def clear
 						@status.clear
 					end
 					
+					def pids
+						@state.keys
+					end
+					
+					def add(pid)
+						@state[pid] = :preparing
+					end
+					
+					def fail(pid, reason = nil)
+						@state[pid] = :failed
+						@status[pid] = reason
+					end
+					
+					def remove(pid)
+						@state.delete(pid)
+						@status.delete(pid)
+					end
+					
 					attr :state
 					attr :status
 					
@@ -142,7 +186,7 @@ def update(pid, message)
 						end
 						
 						if message['RELOADING'] == '1'
-							@state[pid] = :reloading
+							@state[pid] = :preparing
 						end
 						
 						if message['READY'] == '1'
@@ -155,7 +199,7 @@ def update(pid, message)
 					end
 					
 					def ready?(pids)
-						pids.all?{|pid| @state[pid] == :ready}
+						pids.all?{|pid| @state[pid] != :preparing}
 					end
 					
 					def close
diff --git a/lib/async/container/threaded/group.rb b/lib/async/container/threaded/group.rb
index 0dce368..8c253bb 100644
--- a/lib/async/container/threaded/group.rb
+++ b/lib/async/container/threaded/group.rb
@@ -28,32 +28,28 @@ module Async
 	module Container
 		module Threaded
 			class Group < Async::Container::Group
-				def initialize
+				def initialize(**options)
 					@finished = Thread::Queue.new
 					@pids = Set.new
 					
 					super
 				end
 				
-				def self.pids
-					@pids
-				end
-				
 				def finished(*arguments)
 					@finished.push(arguments)
 				end
 				
 				def spawn(*arguments, **options)
-					arguments = prepare_for_spawn(arguments)
+					# Arguments are modified in place:
+					Notify.before_spawn(@notify, arguments)
+					
+					pid = ::Process.spawn(*arguments)
+					@context&.add(pid)
 					
 					self.fork do
 						begin
-							pid = ::Process.spawn(*arguments)
-							@pids.add(pid)
-							
 							::Process.waitpid(pid)
 						ensure
-							@pids.delete(pid)
 							::Process.kill(:TERM, pid)
 						end
 					end
diff --git a/lib/async/container/threaded/instance.rb b/lib/async/container/threaded/instance.rb
index ab4417b..25ffe9d 100644
--- a/lib/async/container/threaded/instance.rb
+++ b/lib/async/container/threaded/instance.rb
@@ -30,13 +30,13 @@ def name= value
 					@thread.name = value
 				end
 				
-				def exec(*arguments)
-					pid = ::Process.spawn(*arguments)
-					
-					::Process.waitpid(pid)
-				ensure
-					::Process.kill(:TERM, pid)
-				end
+				# def exec(*arguments)
+				# 	pid = ::Process.spawn(*arguments)
+				# 
+				# 	::Process.waitpid(pid)
+				# ensure
+				# 	::Process.kill(:TERM, pid)
+				# end
 				
 				def to_s
 					"\#<#{self.class}: #{@thread.name}>"