diff options
Diffstat (limited to 'activesupport/lib/active_support')
7 files changed, 211 insertions, 10 deletions
diff --git a/activesupport/lib/active_support/dependencies/interlock.rb b/activesupport/lib/active_support/dependencies/interlock.rb index 47bcecbb35..f1865ca2f8 100644 --- a/activesupport/lib/active_support/dependencies/interlock.rb +++ b/activesupport/lib/active_support/dependencies/interlock.rb @@ -19,14 +19,12 @@ module ActiveSupport #:nodoc: end end - # Attempt to obtain an "unloading" (exclusive) lock. If possible, - # execute the supplied block while holding the lock. If there is - # concurrent activity, return immediately (without executing the - # block) instead of waiting. - def attempt_unloading - @lock.exclusive(purpose: :unload, compatible: [:load, :unload], after_compatible: [:load, :unload], no_wait: true) do - yield - end + def start_unloading + @lock.start_exclusive(purpose: :unload, compatible: [:load, :unload]) + end + + def done_unloading + @lock.stop_exclusive(compatible: [:load, :unload]) end def start_running diff --git a/activesupport/lib/active_support/evented_file_update_checker.rb b/activesupport/lib/active_support/evented_file_update_checker.rb index 315be85fb3..63f4f7e277 100644 --- a/activesupport/lib/active_support/evented_file_update_checker.rb +++ b/activesupport/lib/active_support/evented_file_update_checker.rb @@ -37,6 +37,7 @@ module ActiveSupport def execute_if_updated if updated? + yield if block_given? execute true end diff --git a/activesupport/lib/active_support/execution_wrapper.rb b/activesupport/lib/active_support/execution_wrapper.rb new file mode 100644 index 0000000000..e784556abf --- /dev/null +++ b/activesupport/lib/active_support/execution_wrapper.rb @@ -0,0 +1,69 @@ +require 'active_support/callbacks' + +module ActiveSupport + class ExecutionWrapper + include ActiveSupport::Callbacks + + define_callbacks :run + define_callbacks :complete + + def self.to_run(*args, &block) + set_callback(:run, *args, &block) + end + + def self.to_complete(*args, &block) + set_callback(:complete, *args, &block) + end + + # Run this execution. + # + # Returns an instance, whose +complete!+ method *must* be invoked + # after the work has been performed. + # + # Where possible, prefer +wrap+. + def self.run! + new.tap(&:run!) + end + + # Perform the work in the supplied block as an execution. + def self.wrap + return yield if active? + + state = run! + begin + yield + ensure + state.complete! + end + end + + class << self # :nodoc: + attr_accessor :active + end + + def self.inherited(other) # :nodoc: + super + other.active = Concurrent::Hash.new(0) + end + + self.active = Concurrent::Hash.new(0) + + def self.active? # :nodoc: + @active[Thread.current] > 0 + end + + def run! # :nodoc: + self.class.active[Thread.current] += 1 + run_callbacks(:run) + end + + # Complete this in-flight execution. This method *must* be called + # exactly once on the result of any call to +run!+. + # + # Where possible, prefer +wrap+. + def complete! + run_callbacks(:complete) + self.class.active.delete Thread.current if (self.class.active[Thread.current] -= 1) == 0 + end + end +end diff --git a/activesupport/lib/active_support/executor.rb b/activesupport/lib/active_support/executor.rb new file mode 100644 index 0000000000..602fb11a44 --- /dev/null +++ b/activesupport/lib/active_support/executor.rb @@ -0,0 +1,6 @@ +require 'active_support/execution_wrapper' + +module ActiveSupport + class Executor < ExecutionWrapper + end +end diff --git a/activesupport/lib/active_support/file_update_checker.rb b/activesupport/lib/active_support/file_update_checker.rb index 1fa9335080..dc7434fcac 100644 --- a/activesupport/lib/active_support/file_update_checker.rb +++ b/activesupport/lib/active_support/file_update_checker.rb @@ -81,6 +81,7 @@ module ActiveSupport # Execute the block given if updated. def execute_if_updated if updated? + yield if block_given? execute true else diff --git a/activesupport/lib/active_support/i18n_railtie.rb b/activesupport/lib/active_support/i18n_railtie.rb index 82aacf3b24..6cc7c90c12 100644 --- a/activesupport/lib/active_support/i18n_railtie.rb +++ b/activesupport/lib/active_support/i18n_railtie.rb @@ -64,8 +64,8 @@ module I18n end app.reloaders << reloader - ActionDispatch::Reloader.to_prepare do - reloader.execute_if_updated + app.reloader.to_run do + reloader.execute_if_updated { require_unload_lock! } # TODO: remove the following line as soon as the return value of # callbacks is ignored, that is, returning `false` does not # display a deprecation warning or halts the callback chain. diff --git a/activesupport/lib/active_support/reloader.rb b/activesupport/lib/active_support/reloader.rb new file mode 100644 index 0000000000..639b987ba8 --- /dev/null +++ b/activesupport/lib/active_support/reloader.rb @@ -0,0 +1,126 @@ +require 'active_support/execution_wrapper' + +module ActiveSupport + #-- + # This class defines several callbacks: + # + # to_prepare -- Run once at application startup, and also from + # +to_run+. + # + # to_run -- Run before a work run that is reloading. If + # +reload_classes_only_on_change+ is true (the default), the class + # unload will have already occurred. + # + # to_complete -- Run after a work run that has reloaded. If + # +reload_classes_only_on_change+ is false, the class unload will + # have occurred after the work run, but before this callback. + # + # before_class_unload -- Run immediately before the classes are + # unloaded. + # + # after_class_unload -- Run immediately after the classes are + # unloaded. + # + class Reloader < ExecutionWrapper + Null = Class.new(ExecutionWrapper) # :nodoc: + + define_callbacks :prepare + + define_callbacks :class_unload + + def self.to_prepare(*args, &block) + set_callback(:prepare, *args, &block) + end + + def self.before_class_unload(*args, &block) + set_callback(:class_unload, *args, &block) + end + + def self.after_class_unload(*args, &block) + set_callback(:class_unload, :after, *args, &block) + end + + to_run(:after) { self.class.prepare! } + + # Initiate a manual reload + def self.reload! + executor.wrap do + new.tap(&:run!).complete! + end + prepare! + end + + def self.run! # :nodoc: + if check! + super + else + Null.run! + end + end + + # Run the supplied block as a work unit, reloading code as needed + def self.wrap + executor.wrap do + super + end + end + + class << self + attr_accessor :executor + attr_accessor :check + end + self.executor = Executor + self.check = lambda { false } + + def self.check! # :nodoc: + @should_reload ||= check.call + end + + def self.reloaded! # :nodoc: + @should_reload = false + end + + def self.prepare! # :nodoc: + new.run_callbacks(:prepare) + end + + def initialize + super + @locked = false + end + + # Acquire the ActiveSupport::Dependencies::Interlock unload lock, + # ensuring it will be released automatically + def require_unload_lock! + unless @locked + ActiveSupport::Dependencies.interlock.start_unloading + @locked = true + end + end + + # Release the unload lock if it has been previously obtained + def release_unload_lock! + if @locked + @locked = false + ActiveSupport::Dependencies.interlock.done_unloading + end + end + + def run! # :nodoc: + super + release_unload_lock! + end + + def class_unload!(&block) # :nodoc: + require_unload_lock! + run_callbacks(:class_unload, &block) + end + + def complete! # :nodoc: + super + self.class.reloaded! + ensure + release_unload_lock! + end + end +end |