Unisex Bathroom Problem

A bathroom is being designed for the use of both males and females in an office but requires the following constraints to be maintained:

• There cannot be men and women in the bathroom at the same time.
• There should never be more than three employees in the bathroom simultaneously.

The solution should avoid deadlocks. For now, though, don’t worry about starvation.

First let us come up with the skeleton of our Unisex Bathroom class. We want to model the problem programmatically first. We'll need two APIs, one that is called by a male to use the bathroom and another that is called by a female to use the bathroom. Initially, our class looks like the following:

class UnisexBathroomProblem

  def initialize()
  end

  def useBathroom(name)
  end

  def maleUseBathroom(name)

  end

  def femaleUseBathroom(name)
  end

end

Let us try to address the first problem of allowing either men or women to use the bathroom. We'll worry about the max employees later. We need to maintain state in a variable to track which gender is currently using the bathroom. Let's call this variable inUseBy. The variable inUseBy will take on the values female, male or none to denote the gender currently using the bathroom.

We'll also have a method useBathroom() that'll mock a person using the bathroom. The implementation of this ...