Merge pull request rails#38069 from y-yagi/make_load_interlock_aware_monitor_work_in_ruby27

Make `LoadInterlockAwareMonitor` work in Ruby 2.7

Author: y-yagi

activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb

@@ -7,11 +7,29 @@ module Concurrency
     # A monitor that will permit dependency loading while blocked waiting for
     # the lock.
     class LoadInterlockAwareMonitor < Monitor
+      EXCEPTION_NEVER = { Exception => :never }.freeze
+      EXCEPTION_IMMEDIATE = { Exception => :immediate }.freeze
+      private_constant :EXCEPTION_NEVER, :EXCEPTION_IMMEDIATE
+
       # Enters an exclusive section, but allows dependency loading while blocked
       def mon_enter
         mon_try_enter ||
           ActiveSupport::Dependencies.interlock.permit_concurrent_loads { super }
       end
+
+      def synchronize
+        Thread.handle_interrupt(EXCEPTION_NEVER) do
+          mon_enter
+
+          begin
+            Thread.handle_interrupt(EXCEPTION_IMMEDIATE) do
+              yield
+            end
+          ensure
+            mon_exit
+          end
+        end
+      end
     end
   end
 end