There are two kinds of threads, oxygen
and hydrogen
. Your goal is
to group these threads to form water molecules. There is a barrier where each thread
has to wait until a complete molecule can be formed. Hydrogen and oxygen threads will
be given releaseHydrogen
and releaseOxygen
methods
respectively, which will allow them to pass the barrier. These threads should pass the
barrier in groups of three, and they must be able to immediately bond with each other to
form a water molecule. You must guarantee that all the threads from one molecule bond
before any other threads from the next molecule do.
In other words:
We don’t have to worry about matching the threads up explicitly; that is, the threads do not necessarily know which other threads they are paired up with. The key is just that threads pass the barrier in complete sets; thus, if we examine the sequence of threads that bond and divide them into groups of three, each group should contain one oxygen and two hydrogen threads.
Write synchronization code for oxygen and hydrogen molecules that enforces these constraints.