class PhusionPassenger::Utils::Lock

def initialize(mutex)
  @mutex = mutex
  @locked = false
end

def lock
  raise if @locked
  @mutex.lock
  @locked = true
end

def reset(mutex, lock_now = true)
  unlock if @locked
  @mutex = mutex
  lock if lock_now
end

def synchronize
  lock if !@locked
  begin
    yield(self)
  ensure
    unlock if @locked
  end
end

def unlock
  raise if !@locked
  @mutex.unlock
  @locked = false
end