[ruby/reline] Thread safe readline

(https://github.com/ruby/reline/pull/669)

Block until other Reline.readline or Reline.readmultiline finish

ebab2875f1

lib/reline.rb

@@ -75,6 +75,7 @@ module Reline
 
     def initialize
       self.output = STDOUT
+      @mutex = Mutex.new
       @dialog_proc_list = {}
       yield self
       @completion_quote_character = nil
@@ -254,6 +255,7 @@ module Reline
     Reline::DEFAULT_DIALOG_CONTEXT = Array.new
 
     def readmultiline(prompt = '', add_hist = false, &confirm_multiline_termination)
+      @mutex.synchronize do
         unless confirm_multiline_termination
           raise ArgumentError.new('#readmultiline needs block to confirm multiline termination')
         end
@@ -277,8 +279,10 @@ module Reline
           whole_buffer
         end
       end
+    end
 
     def readline(prompt = '', add_hist = false)
+      @mutex.synchronize do
         Reline.update_iogate
         io_gate.with_raw_input do
           inner_readline(prompt, add_hist, false)
@@ -293,6 +297,7 @@ module Reline
         line_editor.reset_line if line_editor.line.nil?
         line
       end
+    end
 
     private def inner_readline(prompt, add_hist, multiline, &confirm_multiline_termination)
       if ENV['RELINE_STDERR_TTY']

test/reline/yamatanooroti/test_rendering.rb

@@ -1690,6 +1690,23 @@ begin
       EOC
     end
 
+    def test_thread_safe
+      start_terminal(6, 30, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl --auto-indent}, startup_message: 'Multiline REPL.')
+      write("[Thread.new{Reline.readline'>'},Thread.new{Reline.readmultiline('>'){true}}].map(&:join).size\n")
+      write("exit\n")
+      write("exit\n")
+      write("42\n")
+      close
+      assert_screen(<<~EOC)
+        >exit
+        >exit
+        => 2
+        prompt> 42
+        => 42
+        prompt>
+      EOC
+    end
+
     def write_inputrc(content)
       File.open(@inputrc_file, 'w') do |f|
         f.write content