[Truffle] Make IO#puts write atomically the contents and the \n.

* So at least we do not have a race in a single #puts with multiple threads.
jruby · Jul 17, 2015 · 102da2f · 102da2f · nirvdrum · Jul 19, 2015
1 parent 431c4f4
commit 102da2f
Showing 1 changed file with 47 additions and 0 deletions.
diff --git a/truffle/src/main/ruby/core/rubinius/api/shims/io.rb b/truffle/src/main/ruby/core/rubinius/api/shims/io.rb
@@ -74,4 +74,51 @@ def self.setup(io, fd, mode=nil, sync=false)
     end
   end
 
+  ##
+  # Writes the given objects to ios as with IO#print.
+  # Writes a record separator (typically a newline)
+  # after any that do not already end with a newline
+  # sequence. If called with an array argument, writes
+  # each element on a new line. If called without arguments,
+  # outputs a single record separator.
+  #
+  #  $stdout.puts("this", "is", "a", "test")
+  # produces:
+  #
+  #  this
+  #  is
+  #  a
+  #  test
+  def puts(*args)
+    if args.empty?
+      write DEFAULT_RECORD_SEPARATOR
+    else
+      args.each do |arg|
+        if arg.equal? nil
+          str = ""
+        elsif Thread.guarding? arg
+          str = "[...]"
+        elsif arg.kind_of?(Array)
+          Thread.recursion_guard arg do
+            arg.each do |a|
+              puts a
+            end
+          end
+        else
+          str = arg.to_s
+        end
+
+        if str
+          # Truffle: write the string + record separator (\n) atomically so multithreaded #puts is bearable
+          unless str.suffix?(DEFAULT_RECORD_SEPARATOR)
+            str += DEFAULT_RECORD_SEPARATOR
+          end
+          write str
+        end
+      end
+    end
+
+    nil
+  end
+
 end