adding active_connections? to the connection pool for finding open connections

activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb

@@ -352,6 +352,12 @@ def establish_connection(name, spec)
         @connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)
       end
 
+      # Returns true if there are any active connections among the connection
+      # pools that the ConnectionHandler is managing.
+      def active_connections?
+        connection_pools.values.any? { |pool| pool.active_connection? }
+      end
+
       # Returns any connections in use by the current thread back to the pool,
       # and also returns connections to the pool cached by threads that are no
       # longer alive.

activerecord/test/cases/connection_adapters/connection_handler_test.rb

+require "cases/helper"
+
+module ActiveRecord
+  module ConnectionAdapters
+    class ConnectionHandlerTest < ActiveRecord::TestCase
+      def setup
+        @handler = ConnectionHandler.new
+        @handler.establish_connection 'america', Base.connection_pool.spec
+        @klass = Struct.new(:name).new('america')
+      end
+
+      def test_retrieve_connection
+        assert @handler.retrieve_connection(@klass)
+      end
+
+      def test_active_connections?
+        assert !@handler.active_connections?
+        assert @handler.retrieve_connection(@klass)
+        assert @handler.active_connections?
+        @handler.clear_active_connections!
+        assert !@handler.active_connections?
+      end
+
+      def test_retrieve_connection_pool_with_ar_base
+        assert_nil @handler.retrieve_connection_pool(ActiveRecord::Base)
+      end
+
+      def test_retrieve_connection_pool
+        assert_not_nil @handler.retrieve_connection_pool(@klass)
+      end
+    end
+  end
+end