class ReentrantMutex

# File lib/reentrant_mutex.rb, line 2
def initialize
  @count_mutex = Mutex.new
  @counts = Hash.new(0)

  super
end

# File lib/reentrant_mutex.rb, line 20
def lock
  c = increase_count Thread.current
  super if c <= 1
end

# File lib/reentrant_mutex.rb, line 9
def synchronize
  raise ThreadError, 'Must be called with a block' unless block_given?

  begin
    lock
    yield
  ensure
    unlock
  end
end

# File lib/reentrant_mutex.rb, line 25
def unlock
  c = decrease_count Thread.current
  if c <= 0
    super
    delete_count Thread.current
  end
end

# File lib/reentrant_mutex.rb, line 39
def decrease_count(thread)
  @count_mutex.synchronize { @counts[thread] -= 1 }
end

# File lib/reentrant_mutex.rb, line 43
def delete_count(thread)
  @count_mutex.synchronize { @counts.delete(thread) }
end

# File lib/reentrant_mutex.rb, line 35
def increase_count(thread)
  @count_mutex.synchronize { @counts[thread] += 1 }
end