reverted Rakefile & added spec for subproces

Author: fzakaria

Rakefile

@@ -61,23 +61,12 @@ Gem::PackageTask.new(edge_gemspec) {} if edge_gemspec
 
 CLEAN.include('lib/concurrent-ruby/concurrent/2.*', 'lib/concurrent-ruby/concurrent/*.jar')
 
-
-
 begin
   require 'rspec'
   require 'rspec/core/rake_task'
-  require "rake/testtask"
-
-  Rake::TestTask.new(:minitest) do |t|
-    t.libs << "test"
-    t.test_files = FileList['test/**/test*.rb']
-  end
 
   RSpec::Core::RakeTask.new(:spec)
 
-  desc "Run both minitest & rspec tests"
-  task test: %w[minitest spec]
-
   namespace :spec do
     desc '* Configured for ci'
     RSpec::Core::RakeTask.new(:ci) do |t|

spec/concurrent/executor/cached_thread_pool_spec.rb

@@ -201,6 +201,29 @@ module Concurrent
         end
       end
 
+      context 'auto terminate' do
+
+        # https://github.com/ruby-concurrency/concurrent-ruby/issues/817
+        # https://github.com/ruby-concurrency/concurrent-ruby/issues/839
+        it 'does not stop shutdown ' do
+          Timeout::timeout(10) do
+            `
+          bundle exec ruby -e "
+            require 'concurrent-ruby'
+            # the test relies on replicating that Minitest messed up the AtExit handling
+            Concurrent.disable_at_exit_handlers!
+            pool = Concurrent::CachedThreadPool.new
+            pool.post do
+              sleep # sleep indefinitely
+            end
+            # the process main thread should quit out which should kill the daemon CachedThreadPool
+          "
+          `
+          end
+        end
+
+      end
+
       context 'stress', notravis: true do
         configurations = [
             { min_threads:    2,