fix TSTP -> CONT signal handling

lib/outboxer/publisher.rb

@@ -9,6 +9,10 @@ def terminating?
       @status == Status::TERMINATING
     end
 
+    def publishing?
+      @status == Status::PUBLISHING
+    end
+
     # Parses command line arguments to configure the publisher.
     # @param args [Array<String>] The arguments passed via the command line.
     # @return [Hash] The parsed options.
@@ -549,28 +553,33 @@ def create_publisher_thread(id:, index:,
           # Thread.current.report_on_exception = true
 
           while !terminating?
-            begin
-              published_message = Message.publish(logger: logger) do |message|
-                block.call({ id: id }, message)
-              end
-            rescue StandardError => error
-              logger.error(
-                "#{error.class}: #{error.message}\n" \
-                "#{error.backtrace.join("\n")}")
-
-              Publisher.sleep(
-                poll_interval,
-                tick_interval: tick_interval,
-                process: process,
-                kernel: kernel)
-            else
-              if published_message.nil?
+            if publishing?
+              begin
+                published_message = Message.publish(logger: logger) do |message|
+                  block.call({ id: id }, message)
+                end
+              rescue StandardError => error
+                logger.error(
+                  "#{error.class}: #{error.message}\n" \
+                  "#{error.backtrace.join("\n")}")
+
                 Publisher.sleep(
                   poll_interval,
                   tick_interval: tick_interval,
                   process: process,
                   kernel: kernel)
+              else
+                if published_message.nil?
+                  Publisher.sleep(
+                    poll_interval,
+                    tick_interval: tick_interval,
+                    process: process,
+                    kernel: kernel)
+                end
               end
+            else
+              Publisher.sleep(tick_interval, tick_interval: tick_interval,
+                process: process, kernel: kernel)
             end
           end
         rescue ::Exception => error