temporary workaround for https://bugs.ruby-lang.org/issues/13632 (#1345)

* temporary workaround for https://bugs.ruby-lang.org/issues/13632
Purging interrupt queue if IOError was caught.

* fixing only if mri

* optimization to avoid redundant checks in empty queue

* scoping fix to only affected versions

* serving ruby version from mkmf

* safe invoking for the workaround

* switching to preprocessor vars

* purging queue on runtime error

* rubocop fix

* covering workaround

* improving names

* styling

* rubocop fixes

* improved test reporting

* wording

* condition

* improving comment

* bugfix moved to separate gem: https://rubygems.org/gems/stopgap_13632

* using stopgap_13632 in gemfile to fix the builds

* requiring stopgap for tests

Gemfile

@@ -14,3 +14,7 @@ gem "minitest", "~> 5.9"
 gem "jruby-openssl", :platform => "jruby"
 
 gem "rubocop", "~> 0.49.1"
+
+if %w(2.2.7 2.3.4 2.4.1).include? RUBY_VERSION
+  gem "stopgap_13632", "~> 1.0", :platform => "mri"
+end

lib/puma/client.rb

@@ -111,6 +111,7 @@ def close
       begin
         @io.close
       rescue IOError
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
       end
     end
 

lib/puma/cluster.rb

@@ -224,6 +224,7 @@ def wakeup!
       begin
         @wakeup.write "!" unless @wakeup.closed?
       rescue SystemCallError, IOError
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
       end
     end
 
@@ -267,6 +268,7 @@ def worker(index, master)
       begin
         @worker_write << "b#{Process.pid}\n"
       rescue SystemCallError, IOError
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
         STDERR.puts "Master seems to have exited, exiting."
         return
       end
@@ -282,6 +284,7 @@ def worker(index, master)
             payload = %Q!#{base_payload}{ "backlog":#{b}, "running":#{r} }\n!
             io << payload
           rescue IOError
+            Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
             break
           end
         end

lib/puma/minissl.rb

@@ -118,6 +118,7 @@ def close
             return if read_and_drop(1) == :timeout
           end
         rescue IOError, SystemCallError
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
           # nothing
         ensure
           @socket.close

lib/puma/reactor.rb

@@ -28,6 +28,7 @@ def run_internal
         begin
           ready = IO.select sockets, nil, nil, @sleep_for
         rescue IOError => e
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
           if sockets.any? { |socket| socket.closed? }
             STDERR.puts "Error in select: #{e.message} (#{e.class})"
             STDERR.puts e.backtrace
@@ -195,13 +196,15 @@ def clear!
       begin
         @trigger << "c"
       rescue IOError
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
       end
     end
 
     def shutdown
       begin
         @trigger << "!"
       rescue IOError
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
       end
 
       @thread.join

lib/puma/server.rb

@@ -110,13 +110,15 @@ def cork_socket(socket)
         begin
           socket.setsockopt(6, 3, 1) if socket.kind_of? TCPSocket
         rescue IOError, SystemCallError
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
         end
       end
 
       def uncork_socket(socket)
         begin
           socket.setsockopt(6, 3, 0) if socket.kind_of? TCPSocket
         rescue IOError, SystemCallError
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
         end
       end
 
@@ -127,6 +129,7 @@ def closed_socket?(socket)
         begin
           tcp_info = socket.getsockopt(Socket::SOL_TCP, Socket::TCP_INFO)
         rescue IOError, SystemCallError
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
           @precheck_closing = false
           false
         else
@@ -490,6 +493,7 @@ def process_client(client, buffer)
         begin
           client.close if close_socket
         rescue IOError, SystemCallError
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
           # Already closed
         rescue StandardError => e
           @events.unknown_error self, e, "Client"
@@ -896,11 +900,15 @@ def notify_safely(message)
       begin
         @notify << message
       rescue IOError
-        # The server, in another thread, is shutting down
+         # The server, in another thread, is shutting down
+        Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
       rescue RuntimeError => e
-        # The server, in another thread, has been shut down during the system call
-        # https://github.com/puma/puma/pull/1206
-        raise e unless e.message.include?('IOError')
+        # Temporary workaround for https://bugs.ruby-lang.org/issues/13239
+        if e.message.include?('IOError')
+          Thread.current.purge_interrupt_queue if Thread.current.respond_to? :purge_interrupt_queue
+        else
+          raise e
+        end
       end
     end
     private :notify_safely

test/helper.rb

@@ -1,6 +1,8 @@
 # Copyright (c) 2011 Evan Phoenix
 # Copyright (c) 2005 Zed A. Shaw
 
+require 'stopgap_13632' if %w(2.2.7 2.3.4 2.4.1).include? RUBY_VERSION
+
 begin
   require "bundler/setup"
 rescue LoadError