waitpid() called when stopping services.

src/service/service.cr

@@ -15,6 +15,19 @@ def split_command(string)
 		return command, args
 end
 
+lib C
+	fun waitpid(pid : Int32, status_ptr : Int32*, options : Int32) : Int32
+end
+
+class Process
+	def self.waitpid(pid)
+		options = 0
+		status_ptr = uninitialized Int32
+
+		C.waitpid(pid, pointerof(status_ptr), options)
+	end
+end
+
 class Service
 	getter environment : Environment
 	getter providers = ProvidersList.new
@@ -295,6 +308,8 @@ class Service
 			else
 				Process.kill Signal::TERM, _pid
 			end
+
+			Process.waitpid _pid
 		else
 			# Already stopped or dead, nothing to be done here.
 		end