timeout.rb: custom error message

* lib/timeout.rb (Timeout#timeout): add custom error message
  argument.  [Feature #11650]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56089 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Sep  7 17:21:55 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/timeout.rb (Timeout#timeout): add custom error message
+	  argument.  [Feature #11650]
+
 Wed Sep  7 17:13:05 2016  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
 	* common.mk: Updated Unicode version to 9.0.0 [Feature #12513]

lib/timeout.rb

@@ -60,6 +60,8 @@ module Timeout
   #         value of 0 or +nil+ will execute the block without any timeout.
   # +klass+:: Exception Class to raise if the block fails to terminate
   #           in +sec+ seconds.  Omitting will use the default, Timeout::Error
+  # +message+:: Error message to rasise with Exception Class.
+  #             Omitting will use the default, "execution expired"
   #
   # Returns the result of the block *if* the block completed before
   # +sec+ seconds, otherwise throws an exception, based on the value of +klass+.
@@ -70,9 +72,9 @@ module Timeout
   # Note that this is both a method of module Timeout, so you can <tt>include
   # Timeout</tt> into your classes so they have a #timeout method, as well as
   # a module method, so you can call it directly as Timeout.timeout().
-  def timeout(sec, klass = nil)   #:yield: +sec+
+  def timeout(sec, klass = nil, message = nil)   #:yield: +sec+
     return yield(sec) if sec == nil or sec.zero?
-    message = "execution expired".freeze
+    message ||= "execution expired".freeze
     from = "from #{caller_locations(1, 1)[0]}" if $DEBUG
     e = Error
     bl = proc do |exception|

test/test_timeout.rb

@@ -66,6 +66,11 @@ class TestTimeout < Test::Unit::TestCase
         sleep 3
       end
     end
+    assert_raise_with_message(err, /connection to rubylang.org expired/) do
+      Timeout.timeout 0.01, err, "connection to rubylang.org expired" do
+        sleep 3
+      end
+    end
   end
 
   def test_exit_exception