The following is a synchronization problem with its solution You are required to implement a correct solution to solve t

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The following is a synchronization problem with its solution
You are required to implement a correct solution to solve this
problem. You should add a random player coming function (driver)
and show the behavior of the solution.
Assignment Script:
You are the organizer of a gaming exhibit at the E3 Electronic
Entertainment Expo. You want to allow the attendees to play your
startup’s new game demo. You model the attendees as threads, called
players, and your job is to synchronize access to a single copy of
the game, as follows:
- When a player arrives, he or she waits in a waiting area
- Once there are 4 or more players waiting to play, you allow
exactly 4 of them to leave the waiting area to begin playing. These
four leave the waiting area and approach the game console.
- When a player reaches the console, the player waits until all
four players are at the console, at which point all four players
begin playing.
- Players may finish playing at any time. However, you cannot
allow any new players to begin playing until all four players have
left.
- You do not need to let players out of the waiting area in the
order in which they arrived.
- You cannot assume that a player will ever finish playing.
- You decide to solve this synchronization problem using two
custom
synchronization primitives, which have “barrier-like”
semantics:
GameBarrier gb;
ConsoleBarrier cb;
Your task is to implement these synchronization primitives
according to the specifications listed below. Each player thread
has access to the two global barriers, and uses them in the
following sequence:
void Player(ThreadID tid, GameBarrier gb, ConsoleBarrier cb)
{
gb.waitToPlay();
cb.waitAtConsole();
play();
gb.donePlaying();
}
The GameBarrier can be in one of three states:
• GAME_NOTREADY: There are fewer than 4 players waiting to play.
When the barrier is in this state, no player can progress beyond
waitToPlay().
• GAME_FILLING: There are (or were) at least 4 players waiting
to play, and either we are in the first turn or else all four
players from the prior turn have departed (via donePlaying()). When
the barrier is in this state, a player can progress beyond
waitToPlay(), and in fact four players must progress beyond this
function. When exactly four players have progressed beyond this
function, the barrier enters the GAME_FILLED state.
• GAME_FILLED: Four players have been sent to the console, and
the turn is not over (meaning that the departure of all four from
the console via donePlaying() has not yet taken place). When the
barrier is in this state, no waiting player can progress beyond
waitToPlay()
The ConsoleBarrier can be in one of two states:
• CONSOLE_WAIT: Four players have not yet arrived at the console
in the current round. When the barrier is in this state, no player
can progress beyond waitAtConsole().
• CONSOLE_ALLOW: Four players have arrived in the current round.
When the barrier is in this state, all four waiting players must
progress beyond waitAtConsole(), after which the state reverts to
CONSOLE_WAIT. Your barrier will require the use of condition
variables. Recall that condition variables provide three
methods: Condition.wait(Lock mutex), Condition.signal(), and
Condition.broadcast().
Locks provide two methods: Lock.acquire() and Lock.release().
Note that part (but not all) of your work is to ensure that the
barriers make the correct state transitions. Below, where
indicated, fill out the variables and methods for the GameBarrier
and ConsoleBarrier objects.
public class GameBarrier {
private static final int GAME_NOTREADY = 0;
private static final int GAME_FILLING = 1;
private static final int GAME_FILLED = 2;
private Lock mutex;
private int state;
private Condition cv;
/* SPECIFY ANY OTHER CLASS VARIABLES */
private int NumWaiters;
private int NumPlayers;
public GameBarrier(Lock lock) {
his.mutex = lock;
this.state = GAME_NOTREADY;
this.cv = new Condition();
/* INITIALIZE ANY OTHER CLASS VARIABLES */
this.NumWaiters = 0;
this.NumPlayers = 0;
We deducted 1 pt each if your answer was missing either
NumWaiters or NumPlayers
}
public void waitToPlay() {
/* YOU MUST FILL IN THIS FUNCTION */
mutex.acquire();
NumWaiters++
if ((NumWaiters >= 4) && (state == GAME_NOTREADY))
{
state = GAME_FILLING;
cv.broadcast();
}
while (state != GAME_FILLING) {
cv.wait(mutex);
}
NumWaiters--;
NumPlayers++;
if (NumPlayers == 4) state = GAME_FILLED;
mutex.release();
}
public void donePlaying() {
/* YOU MUST FILL IN THIS FUNCTION */
mutex.acquire();
NumPlayers--;
if (NumPlayers = 0) {
state = GAME_NOT_READY;
if (NumWaiters >= 4) {
state = GAME_FILLING;
cv.broadcast(mutex);
} }
mutex.release();
} }
public class ConsoleBarrier {
private static final int CONSOLE_WAIT = 0;
private static final int CONSOLE_ALLOW = 1;
private Lock mutex;
private int state;
private Condition cv;
/* SPECIFY ANY OTHER CLASS VARIABLES */
int NumPlayers;
public ConsoleBarrier(Lock lock) {
this.mutex = lock;
this.state = CONSOLE_WAIT;
this.cv = new Condition();
/* INITIALIZE ANY OTHER CLASS VARIABLES */
this.NumPlayers = 0;
We deducted 2 pts if your answer was missing NumPlayers
}
public void waitToPlay() {
/* YOU MUST FILL IN THIS FUNCTION */
mutex.acquire();
NumWaiters++
if ((NumWaiters >= 4) && (state == GAME_NOTREADY))
{
state = GAME_FILLING;
cv.broadcast();
}
while (state != GAME_FILLING) {
cv.wait(mutex); }
NumWaiters--;
NumPlayers++;
if (NumPlayers == 4) state = GAME_FILLED; mutex.release();
}
public void donePlaying() {
/* YOU MUST FILL IN THIS FUNCTION */
mutex.acquire();
NumPlayers--;
if (NumPlayers = 0) {
state = GAME_NOT_READY;
if (NumWaiters >= 4) {
state = GAME_FILLING;
cv.broadcast(mutex);
} }
mutex.release();
} }
public class ConsoleBarrier {
private static final int CONSOLE_WAIT = 0;
private static final int CONSOLE_ALLOW = 1;
private Lock mutex; private int state;
private Condition cv;
/* SPECIFY ANY OTHER CLASS VARIABLES */
int NumPlayers;
public ConsoleBarrier(Lock lock) {
this.mutex = lock;
this.state = CONSOLE_WAIT;
this.cv = new Condition();
/* INITIALIZE ANY OTHER CLASS VARIABLES */
this.NumPlayers = 0;
We deducted 2 pts if your answer was missing NumPlayers
}