Remove dependency on logger

* To fix the Ruby 3.3.5 warnings:
  #1061
* concurrent-ruby only uses 7 constants from Logger, so just copy those over.

Author: eregon

README.md

@@ -284,7 +284,7 @@ To use the tools in the Edge gem it must be required separately:
 require 'concurrent-edge'
 ```
 
-If the library does not behave as expected, `Concurrent.use_stdlib_logger(Logger::DEBUG)` could 
+If the library does not behave as expected, `Concurrent.use_simple_logger(:DEBUG)` could
 help to reveal the problem.
 
 ## Installation

docs-source/actor/celluloid_benchmark.rb

@@ -7,11 +7,7 @@
 # require 'stackprof'
 # require 'profiler'
 
-logger                          = Logger.new($stderr)
-logger.level                    = Logger::INFO
-Concurrent.configuration.logger = lambda do |level, progname, message = nil, &block|
-  logger.add level, message, progname, &block
-end
+Concurrent.use_simple_logger(:INFO)
 
 scale       = 1
 ADD_TO      = (100 * scale).to_i

docs-source/actor/io.in.rb

@@ -1,7 +1,6 @@
 require 'concurrent'
 
-# logger = Logger.new(STDOUT)
-# Concurrent.configuration.logger = logger.method(:add)
+# Concurrent.use_simple_logger(:WARN, STDOUT)
 
 # First option is to use operation pool
 

docs-source/actor/io.out.rb

@@ -1,7 +1,6 @@
 require 'concurrent'                               # => false
 
-# logger = Logger.new(STDOUT)
-# Concurrent.configuration.logger = logger.method(:add)
+# Concurrent.use_simple_logger(:WARN, STDOUT)
 
 # First option is to use operation pool
 

docs-source/actor/main.md

@@ -124,12 +124,12 @@ Spawned actor cannot be garbage-collected until it's terminated. There is a refe
 
 Actors are running on shared thread poll which allows user to create many actors cheaply.
 Downside is that these actors cannot be directly used to do IO or other blocking operations.
-Blocking operations could starve the `default_task_pool`. However there are two options:
+Blocking operations could starve the `global_fast_executor`. However there are two options:
 
-- Create an regular actor which will schedule blocking operations in `global_operation_pool`
+- Create an regular actor which will schedule blocking operations in `global_io_executor`
   (which is intended for blocking operations) sending results back to self in messages.
-- Create an actor using `global_operation_pool` instead of `global_task_pool`, e.g.
-  `AnIOActor.spawn name: :blocking, executor: Concurrent.configuration.global_operation_pool`.
+- Create an actor using `global_io_executor` instead of `global_fast_executor`, e.g.
+  `AnIOActor.spawn name: :blocking, executor: Concurrent.global_io_executor`.
 
 ### Example
 

examples/init.rb

@@ -4,4 +4,4 @@ def do_stuff(*args)
   :stuff
 end
 
-Concurrent.use_simple_logger Logger::DEBUG
+Concurrent.use_simple_logger :DEBUG

lib/concurrent-ruby-edge/concurrent/actor/context.rb

@@ -84,7 +84,7 @@ def default_reference_class
         Reference
       end
 
-      # override to se different default executor, e.g. to change it to global_operation_pool
+      # override to se different default executor, e.g. to change it to global_fast_executor
       # @return [Executor]
       def default_executor
         Concurrent.global_io_executor
@@ -109,7 +109,7 @@ def ask(message)
       # @example by option hash
       #   inc2 = AdHoc.spawn(name:     'increment by 2',
       #                      args:     [2],
-      #                      executor: Concurrent.configuration.global_task_pool) do |increment_by|
+      #                      executor: Concurrent.global_fast_executor) do |increment_by|
       #     lambda { |number| number + increment_by }
       #   end
       #   inc2.ask!(2) # => 4

lib/concurrent-ruby-edge/concurrent/actor/internal_delegations.rb

@@ -1,11 +1,11 @@
-require 'logger'
+require 'concurrent/concern/logging'
 require 'concurrent/actor/public_delegations'
 
 module Concurrent
   module Actor
     module InternalDelegations
       include PublicDelegations
-      include Logger::Severity
+      include Concurrent::Concern::Logging
 
       # @see Core#children
       def children

lib/concurrent-ruby-edge/concurrent/edge/erlang_actor.rb

@@ -674,7 +674,7 @@ def initialize(mailbox, environment, name, executor)
       end
 
       def tell_op(message)
-        log Logger::DEBUG, @Pid, told: message
+        log DEBUG, @Pid, told: message
         if (mailbox = @Mailbox)
           mailbox.push_op(message).then { @Pid }
         else
@@ -683,7 +683,7 @@ def tell_op(message)
       end
 
       def tell(message, timeout = nil)
-        log Logger::DEBUG, @Pid, told: message
+        log DEBUG, @Pid, told: message
         if (mailbox = @Mailbox)
           timed_out = mailbox.push message, timeout
           timeout ? timed_out : @Pid
@@ -693,7 +693,7 @@ def tell(message, timeout = nil)
       end
 
       def ask(message, timeout, timeout_value)
-        log Logger::DEBUG, @Pid, asked: message
+        log DEBUG, @Pid, asked: message
         if @Terminated.resolved?
           raise NoActor.new(@Pid)
         else
@@ -724,7 +724,7 @@ def ask(message, timeout, timeout_value)
       end
 
       def ask_op(message, probe)
-        log Logger::DEBUG, @Pid, asked: message
+        log DEBUG, @Pid, asked: message
         if @Terminated.resolved?
           probe.reject NoActor.new(@Pid), false
         else
@@ -1029,7 +1029,7 @@ def terminate_self(reason, value)
       end
 
       def after_termination(final_reason)
-        log Logger::DEBUG, @Pid, terminated: final_reason
+        log DEBUG, @Pid, terminated: final_reason
         clean_reply NoActor.new(@Pid)
         while true
           message = @Mailbox.try_pop NOTHING
@@ -1071,7 +1071,7 @@ def run(*args, &body)
         inner_run(*args, &body).
             run(Run::TEST).
             then(&method(:after_termination)).
-            rescue { |e| log Logger::ERROR, e }
+            rescue { |e| log ERROR, e }
       end
 
       def receive(*rules, timeout: nil, timeout_value: nil, keep: false, &given_block)
@@ -1163,7 +1163,7 @@ def internal_receive
                          end
 
         message_future.then(start, self) do |message, s, _actor|
-          log Logger::DEBUG, pid, got: message
+          log DEBUG, pid, got: message
           catch(JUMP) do
             if (message = consume_signal(message)) == NOTHING
               @timeout = [@timeout + s - Concurrent.monotonic_time, 0].max if s
@@ -1230,7 +1230,7 @@ def receive(*rules, timeout: nil, timeout_value: nil, &given_block)
         matcher       = -> m { m.is_a?(Ask) ? rules_matcher === m.message : rules_matcher === m }
         while true
           message = @Mailbox.pop_matching(matcher, timeout, TIMEOUT)
-          log Logger::DEBUG, pid, got: message
+          log DEBUG, pid, got: message
           unless (message = consume_signal(message)) == NOTHING
             rules.each do |rule, job|
               return eval_task(message, job) if rule === message
@@ -1535,7 +1535,7 @@ class NoReply < Error
     def self.create(type, channel, environment, name, executor)
       actor = KLASS_MAP.fetch(type).new(channel, environment, name, executor)
     ensure
-      log Logger::DEBUG, actor.pid, created: caller[1] if actor
+      log Concern::Logging::DEBUG, actor.pid, created: caller[1] if actor
     end
 
     KLASS_MAP = {

lib/concurrent-ruby/concurrent/concern/logging.rb

@@ -1,4 +1,3 @@
-require 'logger'
 require 'concurrent/atomic/atomic_reference'
 
 module Concurrent
@@ -8,10 +7,12 @@ module Concern
     #
     # @!visibility private
     module Logging
-      include Logger::Severity
+      # The same as Logger::Severity but we copy it here to avoid a dependency on the logger gem just for these 7 constants
+      DEBUG, INFO, WARN, ERROR, FATAL, UNKNOWN = 0, 1, 2, 3, 4, 5
+      SEV_LABEL = %w[DEBUG INFO WARN ERROR FATAL ANY].freeze
 
       # Logs through {Concurrent.global_logger}, it can be overridden by setting @logger
-      # @param [Integer] level one of Logger::Severity constants
+      # @param [Integer] level one of Concurrent::Concern::Logging constants
       # @param [String] progname e.g. a path of an Actor
       # @param [String, nil] message when nil block is used to generate the message
       # @yieldreturn [String] a message
@@ -23,7 +24,7 @@ def log(level, progname, message = nil, &block)
                  end
         logger.call level, progname, message, &block
       rescue => error
-        $stderr.puts "`Concurrent.configuration.logger` failed to log #{[level, progname, message, block]}\n" +
+        $stderr.puts "`Concurrent.global_logger` failed to log #{[level, progname, message, block]}\n" +
           "#{error.message} (#{error.class})\n#{error.backtrace.join "\n"}"
       end
     end
@@ -33,8 +34,10 @@ def log(level, progname, message = nil, &block)
 module Concurrent
   extend Concern::Logging
 
-  # @return [Logger] Logger with provided level and output.
-  def self.create_simple_logger(level = Logger::FATAL, output = $stderr)
+  # Create a simple logger with provided level and output.
+  def self.create_simple_logger(level = :FATAL, output = $stderr)
+    level = Concern::Logging.const_get(level) unless level.is_a?(Integer)
+
     # TODO (pitr-ch 24-Dec-2016): figure out why it had to be replaced, stdlogger was deadlocking
     lambda do |severity, progname, message = nil, &block|
       return false if severity < level
@@ -52,21 +55,23 @@ def self.create_simple_logger(level = Logger::FATAL, output = $stderr)
 
       output.print format "[%s] %5s -- %s: %s\n",
                           Time.now.strftime('%Y-%m-%d %H:%M:%S.%L'),
-                          Logger::SEV_LABEL[severity],
+                          Concern::Logging::SEV_LABEL[severity],
                           progname,
                           formatted_message
       true
     end
   end
 
   # Use logger created by #create_simple_logger to log concurrent-ruby messages.
-  def self.use_simple_logger(level = Logger::FATAL, output = $stderr)
+  def self.use_simple_logger(level = :FATAL, output = $stderr)
     Concurrent.global_logger = create_simple_logger level, output
   end
 
-  # @return [Logger] Logger with provided level and output.
+  # Create a stdlib logger with provided level and output.
+  # If you use this deprecated method you might need to add logger to your Gemfile to avoid warnings from Ruby 3.3.5+.
   # @deprecated
-  def self.create_stdlib_logger(level = Logger::FATAL, output = $stderr)
+  def self.create_stdlib_logger(level = :FATAL, output = $stderr)
+    require 'logger'
     logger           = Logger.new(output)
     logger.level     = level
     logger.formatter = lambda do |severity, datetime, progname, msg|
@@ -93,7 +98,7 @@ def self.create_stdlib_logger(level = Logger::FATAL, output = $stderr)
 
   # Use logger created by #create_stdlib_logger to log concurrent-ruby messages.
   # @deprecated
-  def self.use_stdlib_logger(level = Logger::FATAL, output = $stderr)
+  def self.use_stdlib_logger(level = :FATAL, output = $stderr)
     Concurrent.global_logger = create_stdlib_logger level, output
   end
 
@@ -103,7 +108,7 @@ def self.use_stdlib_logger(level = Logger::FATAL, output = $stderr)
   NULL_LOGGER   = lambda { |level, progname, message = nil, &block| }
 
   # @!visibility private
-  GLOBAL_LOGGER = AtomicReference.new(create_simple_logger(Logger::WARN))
+  GLOBAL_LOGGER = AtomicReference.new(create_simple_logger(:WARN))
   private_constant :GLOBAL_LOGGER
 
   def self.global_logger