ЛР1 Давыдов

.gitignore

@@ -39,4 +39,7 @@ bin/
 .vscode/
 
 ### Mac OS ###
-.DS_Store
+.DS_Store
+
+### Log files ###
+*.log

README.md

@@ -1,3 +1,4 @@
+[![Review Assignment Due Date](https://classroom.github.com/assets/deadline-readme-button-22041afd0340ce965d47ae6ef1cefeee28c7c493a6346c4f15d667ab976d596c.svg)](https://classroom.github.com/a/qcWcnElX)
 # Java concurrency
 
 # Цели и задачи л/р:

src/main/java/org/labs/App.java

@@ -0,0 +1,21 @@
+package org.labs;
+
+import org.labs.restaurant.Restaurant;
+
+public class App {
+    public static void main(String[] args) {
+        var restaurant = new Restaurant(Constants.PROGRAMMERS_COUNT, Constants.WAITERS_COUNT, Constants.PORTIONS_COUNT);
+        restaurant.startDinner();
+        var dinnerInfo = restaurant.getDinnerInfo();
+
+        for (var programmerInfo : dinnerInfo.programmersEatenPortions().entrySet()) {
+            System.out.println(new StringBuilder().append("Программист ").append(programmerInfo.getKey())
+                    .append(" съел ").append(programmerInfo.getValue()).append(" порций").toString());
+        }
+
+        for (var portion : dinnerInfo.waitersServedPortions().entrySet()) {
+            System.out.println(new StringBuilder().append("Официант ").append(portion.getKey())
+                    .append(" разнес ").append(portion.getValue()).append(" порций").toString());
+        }
+    }
+}

src/main/java/org/labs/Constants.java

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+package org.labs;
+
+public class Constants {
+    public static final Integer MAX_EATING_TIME_MS = 100;
+    public static final Integer MAX_SERVER_TIME_MS = 100;
+
+    public static final Integer PORTIONS_COUNT = 1_000_000;
+    public static final Integer PROGRAMMERS_COUNT = 7;
+    public static final Integer WAITERS_COUNT = 2;
+}

src/main/java/org/labs/logger/ConsoleLogger.java

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+package org.labs.logger;
+
+public class ConsoleLogger implements Logger {
+    private String name;
+
+    public ConsoleLogger() {
+        this("");
+    }
+
+    public ConsoleLogger(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public void log(String... messages) {
+        final var prefix = !name.isEmpty() ? name + " " : "";
+        System.out.println(prefix + String.join(" ", messages));
+    }
+}

src/main/java/org/labs/logger/Logger.java

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+package org.labs.logger;
+
+public interface Logger {
+    void log(String... messages);
+}

src/main/java/org/labs/programmer/Programmer.java

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+package org.labs.programmer;
+
+import java.util.Random;
+
+import org.labs.Constants;
+import org.labs.logger.ConsoleLogger;
+import org.labs.logger.Logger;
+import org.labs.spoon.Spoon;
+import org.labs.waiter.WaiterService;
+
+public class Programmer extends Thread {
+    private final Integer id;
+    private final Logger logger;
+    private final Random random = new Random();
+
+    private Integer eatenPortions = 0;
+
+    private final WaiterService waiters;
+    private final Spoon firstSpoon;
+    private final Spoon secondSpoon;
+
+    public Programmer(Integer id, WaiterService waiters, Spoon leftSpoon, Spoon rightSpoon) {
+        super("Программист " + id);
+
+        this.id = id;
+        this.waiters = waiters;
+
+        if (leftSpoon.getId() < rightSpoon.getId()) {
+            this.firstSpoon = leftSpoon;
+            this.secondSpoon = rightSpoon;
+        } else {
+            this.firstSpoon = rightSpoon;
+            this.secondSpoon = leftSpoon;
+        }
+
+        this.logger = new ConsoleLogger(getName());
+    }
+
+    @Override
+    public void run() {
+        try {
+            logger.log("начал есть");
+            while (true) {
+
+                logger.log("просит новую порцию");
+                try {
+                    if (!waiters.getPortion(getName())) {
+                        break;
+                    }
+                } catch (Exception e) {
+                    break;
+                }
+
+                firstSpoon.take(getName());
+                secondSpoon.take(getName());
+
+                Thread.sleep(random.nextInt(Constants.MAX_EATING_TIME_MS));
+                eatenPortions++;
+                logger.log("доел порцию");
+
+                secondSpoon.put(getName());
+                firstSpoon.put(getName());
+            }
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public Integer getProgrammerId() {
+        return id;
+    }
+
+    public Integer getEatenPortions() {
+        return eatenPortions;
+    }
+}

src/main/java/org/labs/restaurant/DinnerInfo.java

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+package org.labs.restaurant;
+
+import java.util.Map;
+
+public record DinnerInfo(Map<Integer, Integer> programmersEatenPortions, Map<Integer, Integer> waitersServedPortions) {
+}

src/main/java/org/labs/restaurant/Restaurant.java

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+package org.labs.restaurant;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.labs.logger.ConsoleLogger;
+import org.labs.logger.Logger;
+import org.labs.programmer.Programmer;
+import org.labs.spoon.Spoon;
+import org.labs.waiter.WaiterService;
+
+public class Restaurant {
+    private final Logger logger;
+
+    private final WaiterService waiters;
+    private final List<Spoon> spoons = new ArrayList<>();
+    private final List<Programmer> programmers = new ArrayList<>();
+
+    public Restaurant(Integer programmresCount, Integer waitersCount, Integer portionsCount) {
+        logger = new ConsoleLogger("Ресторан");
+
+        waiters = new WaiterService(waitersCount, portionsCount);
+
+        for (Integer i = 0; i < programmresCount; i++) {
+            spoons.add(new Spoon(i));
+        }
+
+        for (Integer i = 0; i < programmresCount; i++) {
+            Integer leftSpoonIdx = i;
+            Integer rightSpoonIdx = (i + 1) % spoons.size();
+
+            programmers.add(new Programmer(i, waiters, spoons.get(leftSpoonIdx), spoons.get(rightSpoonIdx)));
+        }
+    }
+
+    public void startDinner() {
+        for (var p : programmers) {
+            p.start();
+        }
+
+        logger.log("начал ужин");
+
+        for (var p : programmers) {
+            try {
+                p.join();
+            } catch (InterruptedException e) {
+            }
+        }
+
+        logger.log("закончил ужин");
+    }
+
+    public DinnerInfo getDinnerInfo() {
+        Map<Integer, Integer> programmersEatenPortions = programmers.stream()
+                .collect(Collectors.toMap(Programmer::getProgrammerId, Programmer::getEatenPortions));
+        Map<Integer, Integer> waitersServedPortions = waiters.getServedPortions();
+        return new DinnerInfo(programmersEatenPortions, waitersServedPortions);
+    }
+}

src/main/java/org/labs/spoon/Spoon.java

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+package org.labs.spoon;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+import org.labs.logger.ConsoleLogger;
+import org.labs.logger.Logger;
+
+public class Spoon {
+    private final Integer id;
+    private final Logger logger;
+    private Lock lock = new ReentrantLock();
+
+    public Spoon(Integer id) {
+        this.id = id;
+        this.logger = new ConsoleLogger("Ложка " + id);
+    }
+
+    public void take(String actor) {
+        logger.log(actor, "пытается взять ложку");
+        lock.lock();
+        logger.log(actor, "взял ложку");
+    }
+
+    public void put(String actor) {
+        lock.unlock();
+        logger.log(actor, "положил ложку");
+    }
+
+    public Integer getId() {
+        return id;
+    }
+}

src/main/java/org/labs/waiter/Waiter.java

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+package org.labs.waiter;
+
+import java.util.Random;
+
+import org.labs.Constants;
+import org.labs.logger.ConsoleLogger;
+import org.labs.logger.Logger;
+
+class Waiter {
+    private final Integer id;
+
+    private final Logger logger;
+    private final Random random = new Random();
+
+    private Integer serverPortions = 0;
+
+    public Waiter(Integer id) {
+        this.id = id;
+        this.logger = new ConsoleLogger("Официант " + id);
+    }
+
+    public synchronized void serverPortion(String client) throws Exception {
+        logger.log("понес порцию", client);
+        Thread.sleep(random.nextInt(Constants.MAX_SERVER_TIME_MS));
+        serverPortions++;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public Integer getServedPortions() {
+        return serverPortions;
+    }
+}

src/main/java/org/labs/waiter/WaiterService.java

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+package org.labs.waiter;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
+
+import org.labs.logger.ConsoleLogger;
+import org.labs.logger.Logger;
+
+public class WaiterService {
+    private final Logger logger;
+
+    private final AtomicInteger portionsCount;
+
+    private final List<Waiter> waiters;
+    private final AtomicInteger nextWaiter;
+
+    public WaiterService(Integer waitersCount, Integer portionsCount) {
+        Waiter[] mutableWaiters = new Waiter[waitersCount];
+        for (Integer i = 0; i < waitersCount; i++) {
+            mutableWaiters[i] = new Waiter(i);
+        }
+        waiters = List.of(mutableWaiters);
+        nextWaiter = new AtomicInteger(0);
+        this.portionsCount = new AtomicInteger(portionsCount);
+        logger = new ConsoleLogger("Сервис официантов");
+    }
+
+    public Boolean getPortion(String client) throws Exception {
+        logger.log(client, "просит порцию");
+
+        var idx = nextWaiter.getAndUpdate((val) -> (val + 1) % waiters.size());
+        var waiter = waiters.get(idx);
+
+        Integer remainingPortions = portionsCount.decrementAndGet();
+        if (remainingPortions < 0) {
+            logger.log(client, "узнал, что еда закончилась");
+            return false;
+        }
+
+        waiter.serverPortion(client);
+        logger.log(client, "получил порцию");
+        logger.log("порций осталось", remainingPortions.toString());
+        return true;
+    }
+
+    public Map<Integer, Integer> getServedPortions() {
+        return waiters.stream().collect(Collectors.toMap(Waiter::getId, Waiter::getServedPortions));
+    }
+}

src/test/java/org/labs/TestConstants.java

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+package org.labs;
+
+public class TestConstants {
+    public static final Integer MAX_EATING_TIME_MS = 1;
+    public static final Integer MAX_SERVER_TIME_MS = 1;
+
+    public static final Integer PORTIONS_COUNT = 100;
+    public static final Integer PROGRAMMERS_COUNT = 7;
+    public static final Integer WAITERS_COUNT = 2;
+
+    public static final Float AVERAGE_DELTA_PERCENT = 0.1f;
+    public static final Float DIFF_PERCENT = 0.25f;
+}