module Concurrent
  module ThreadSafe
    module Test

      THREADS = (RUBY_ENGINE == 'ruby' ? 100 : 10)

      class Barrier
        def initialize(count = 1)
          @count = count
          @mutex = Mutex.new
          @cond  = ConditionVariable.new
        end

        def release
          @mutex.synchronize do
            @count -= 1 if @count > 0
            @cond.broadcast if @count.zero?
          end
        end

        def await
          @mutex.synchronize do
            if @count.zero? # fall through
            elsif @count > 0
              @count -= 1
              @count.zero? ? @cond.broadcast : @cond.wait(@mutex)
            end
          end
        end
      end

      class HashCollisionKey
        attr_reader :hash, :key
        def initialize(key, hash = key.hash % 3)
          @key  = key
          @hash = hash
        end

        def eql?(other)
          other.kind_of?(self.class) && @key.eql?(other.key)
        end

        def even?
          @key.even?
        end

        def <=>(other)
          @key <=> other.key
        end
      end

      # having 4 separate HCK classes helps for a more thorough CHMV8 testing
      class HashCollisionKey2 < HashCollisionKey; end
      class HashCollisionKeyNoCompare < HashCollisionKey
        def <=>(other)
          0
        end
      end
      class HashCollisionKey4 < HashCollisionKeyNoCompare; end

      HASH_COLLISION_CLASSES = [HashCollisionKey, HashCollisionKey2, HashCollisionKeyNoCompare, HashCollisionKey4]

      def self.HashCollisionKey(key, hash = key.hash % 3)
        HASH_COLLISION_CLASSES[rand(4)].new(key, hash)
      end

      class HashCollisionKeyNonComparable < HashCollisionKey
        undef <=>
      end
    end
  end
end