Better global thread pool configuration during tests.

Author: jdantonio

lib/concurrent/configuration.rb

@@ -15,28 +15,30 @@ class Configuration
     attr_accessor :global_operation_pool
 
     def initialize
-      task_pool_config = {
+    end
+
+    def cores
+      @cores ||= Concurrent::processor_count
+    end
+
+    def global_task_pool
+      @global_task_pool ||= Concurrent::ThreadPoolExecutor.new(
         min_threads: [2, cores].max,
         max_threads: [20, cores * 15].max,
         idletime: 2 * 60,                  # 2 minutes
         max_queue: 0,                      # unlimited
         overflow_policy: :abort            # raise an exception
-      }
+      )
+    end
 
-      operation_pool_config = {
+    def global_operation_pool
+      @global_operation_pool = Concurrent::ThreadPoolExecutor.new(
         min_threads: [2, cores].max,
         max_threads: [2, cores].max,
         idletime: 10 * 60,                 # 10 minutes
         max_queue: [20, cores * 15].max,
         overflow_policy: :abort            # raise an exception
-      }
-
-      @global_task_pool = Concurrent::ThreadPoolExecutor.new(task_pool_config)
-      @global_operation_pool = Concurrent::ThreadPoolExecutor.new(operation_pool_config)
-    end
-
-    def cores
-      @cores ||= Concurrent::processor_count
+      )
     end
 
     def global_task_pool=(executor)

spec/concurrent/configuration_spec.rb

@@ -22,6 +22,17 @@ module Concurrent
 
   describe Configuration do
 
+    context 'configure' do
+
+      it 'raises an exception if called twice'
+
+      it 'raises an exception if called after tasks post to the thread pool'
+
+      it 'raises an exception if called after operations post to the thread pool'
+
+      it 'allows reconfiguration if set to :test mode'
+    end
+
     context '#global_task_pool' do
       pending
     end

spec/concurrent/dataflow_spec.rb

@@ -6,6 +6,12 @@ module Concurrent
 
     let(:executor) { ImmediateExecutor.new }
 
+    before(:each) do
+      Concurrent.configure do |config|
+        config.global_operation_pool = Concurrent::ImmediateExecutor.new
+      end
+    end
+
     it 'raises an exception when no block given' do
       expect { Concurrent::dataflow }.to raise_error(ArgumentError)
     end

spec/spec_helper.rb

@@ -27,16 +27,17 @@
   end
 
   config.before(:each) do
-    Concurrent.configure do |config|
-      config.global_task_pool = Concurrent::FixedThreadPool.new(5)
-      config.global_operation_pool = Concurrent::FixedThreadPool.new(5)
-    end
   end
 
   config.after(:each) do
     Thread.list.each do |thread|
       thread.kill unless thread == Thread.current
     end
+
+    Concurrent.configure do |config|
+      config.global_task_pool = nil
+      config.global_operation_pool = nil
+    end
   end
 
   config.after(:suite) do