fix issue with @seen in wait_logger on JRuby

(thanks Mark Wotton)

closes gh-77

CHANGELOG.txt

@@ -4,6 +4,7 @@
 
 == ruote - 2.3.1    not yet released
 
+- fix issue with @seen in wait_logger on JRuby (thanks Mark Wotton)
 - Receiver#flunk accepts stacktrace as final argument
 - allow for "1x == 2x" (turn it into "'1x' == '2x'") (== and !=)
 - fix parsing '2013-02-08T17:36:10Z' (reported by Hartog de Mik)

CREDITS.txt

@@ -58,6 +58,7 @@ Richard Jennings
 
 == Feedback
 
+Mark Wotton - https://github.com/mwotton - issue with @seen on JRuby
 Herve Chardenoux - tests on Windows
 Larry Marburger - await attribute clarifications
 Tobias Neubert - jump to participant 'x'

lib/ruote/log/wait_logger.rb

@@ -87,6 +87,7 @@ def initialize(context)
       @log_max = context['wait_logger_max'] || 77
       @timeout = context['wait_logger_timeout'] || 60 # in seconds
 
+      @on_msg_mutex = Mutex.new
       @check_mutex = Mutex.new
     end
 
@@ -99,11 +100,14 @@ def on_msg(msg)
 
       return if msg['action'] == 'noop'
 
-      @seen << msg
-      @log << msg
+      @on_msg_mutex.synchronize do
 
-      while @log.size > @log_max; @log.shift; end
-      while @seen.size > @log_max; @seen.shift; end
+        @seen << msg
+        @log << msg
+
+        while @log.size > @log_max; @log.shift; end
+        while @seen.size > @log_max; @seen.shift; end
+      end
     end
 
     # Returns an array of the latest msgs, but fancy-printed. The oldest