diff options
Diffstat (limited to 'activesupport')
-rw-r--r-- | activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb | 17 | ||||
-rw-r--r-- | activesupport/test/concurrency/load_interlock_aware_monitor_test.rb | 55 |
2 files changed, 72 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb b/activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb new file mode 100644 index 0000000000..a8455c0048 --- /dev/null +++ b/activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb @@ -0,0 +1,17 @@ +# frozen_string_literal: true + +require "monitor" + +module ActiveSupport + module Concurrency + # A monitor that will permit dependency loading while blocked waiting for + # the lock. + class LoadInterlockAwareMonitor < Monitor + # Enters an exclusive section, but allows dependency loading while blocked + def mon_enter + mon_try_enter || + ActiveSupport::Dependencies.interlock.permit_concurrent_loads { super } + end + end + end +end diff --git a/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb b/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb new file mode 100644 index 0000000000..2d0f45ec5f --- /dev/null +++ b/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb @@ -0,0 +1,55 @@ +# frozen_string_literal: true + +require "abstract_unit" +require "concurrent/atomic/count_down_latch" +require "active_support/concurrency/load_interlock_aware_monitor" + +module ActiveSupport + module Concurrency + class LoadInterlockAwareMonitorTest < ActiveSupport::TestCase + def setup + @monitor = ActiveSupport::Concurrency::LoadInterlockAwareMonitor.new + end + + def test_entering_with_no_blocking + assert @monitor.mon_enter + end + + def test_entering_with_blocking + load_interlock_latch = Concurrent::CountDownLatch.new + monitor_latch = Concurrent::CountDownLatch.new + + able_to_use_monitor = false + able_to_load = false + + thread_with_load_interlock = Thread.new do + ActiveSupport::Dependencies.interlock.running do + load_interlock_latch.count_down + monitor_latch.wait + + @monitor.synchronize do + able_to_use_monitor = true + end + end + end + + thread_with_monitor_lock = Thread.new do + @monitor.synchronize do + monitor_latch.count_down + load_interlock_latch.wait + + ActiveSupport::Dependencies.interlock.loading do + able_to_load = true + end + end + end + + thread_with_load_interlock.join + thread_with_monitor_lock.join + + assert able_to_use_monitor + assert able_to_load + end + end + end +end |