From d07916a292c942d6321d61a92bdf3e80302af3a3 Mon Sep 17 00:00:00 2001
From: Denis Defreyne <denis.defreyne@stoneship.org>
Date: Sat, 17 Feb 2018 10:36:27 +0100
Subject: [PATCH] Add mutex to logger

---
 nanoc/lib/nanoc/cli/logger.rb | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/nanoc/lib/nanoc/cli/logger.rb b/nanoc/lib/nanoc/cli/logger.rb
index 95dac9a27b..d74d69ad5d 100644
--- a/nanoc/lib/nanoc/cli/logger.rb
+++ b/nanoc/lib/nanoc/cli/logger.rb
@@ -28,6 +28,7 @@ class Logger
 
     def initialize
       @level = :high
+      @mutex = Mutex.new
     end
 
     # Logs a file-related action.
@@ -63,11 +64,12 @@ def file(level, action, name, duration = nil)
     #
     # @return [void]
     def log(level, message, io = $stdout)
-      # Don't log when logging is disabled
       return if @level == :off
+      return if @level != :low && @level != level
 
-      # Log when level permits it
-      io.puts(message) if @level == :low || @level == level
+      @mutex.synchronize do
+        io.puts(message)
+      end
     end
   end
 end