1 | import java.util.Random;
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2 | import java.util.concurrent.Semaphore;
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3 |
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4 | import static mk.ukim.finki.os.synchronization.exam17.s3.g1.Reader.lock;
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5 |
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6 | public class Reader extends Thread {
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7 |
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8 | public static Random random = new Random();
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9 | public static Semaphore lock = new Semaphore(1);
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10 | public static Semaphore signal = new Semaphore(0);
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11 |
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12 | public static void main(String[] args) throws InterruptedException {
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13 | // TODO: kreirajte Reader i startuvajte go negovoto pozadinsko izvrsuvanje
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14 | Reader reader = new Reader();
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15 | reader.start();
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16 |
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17 | for (int i = 0; i < 100; i++) {
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18 | Writer writer = new Writer();
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19 | //TODO: startuvajte go writer-ot
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20 | writer.start();
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21 |
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22 | }
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23 |
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24 |
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25 | // TODO: Cekajte 10000ms za Reader-ot da zavrsi
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26 | reader.join(10_000);
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27 |
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28 | // TODO: ispisete go statusot od izvrsuvanjeto
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29 | if (reader.isAlive()) {
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30 | System.out.println("reader will be interrupted");
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31 | reader.interrupt();
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32 | } else {
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33 | System.out.println("reader is done");
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34 | }
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35 |
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36 | }
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37 |
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38 | /**
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39 | * Ne smee da bide izvrsuva paralelno so write() metodot
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40 | */
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41 | public static void read() {
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42 | System.out.println("reading");
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43 | }
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44 |
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45 |
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46 | public void run() {
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47 | int pendingReading = 100;
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48 | while (pendingReading > 0) {
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49 | pendingReading--;
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50 | try {
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51 | // TODO: cekanje na nov zapisan podatok
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52 | signal.acquire();
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53 |
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54 | lock.acquire();
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55 | // TODO: read() metodot ne smee da se izvrsuva paralelno so write() od Writer klasata
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56 | read();
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57 | lock.release();
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58 | } catch (InterruptedException e) {
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59 | e.printStackTrace();
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60 | break;
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61 | }
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62 | }
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63 |
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64 | System.out.println("Done scheduling!");
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65 | }
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66 | }
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67 |
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68 |
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69 | class Writer extends Thread {
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70 |
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71 | public Integer duration;
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72 |
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73 | public Writer() throws InterruptedException {
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74 | this.duration = Reader.random.nextInt(1000);
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75 | }
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76 |
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77 |
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78 | /**
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79 | * Ne smee da bide povikan paralelno
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80 | */
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81 | public static void write() {
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82 | System.out.println("writting");
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83 | }
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84 |
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85 | @Override
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86 | public void run() {
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87 | try {
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88 | Thread.sleep(this.duration);
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89 |
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90 | lock.acquire();
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91 | write();
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92 | lock.release();
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93 | Reader.signal.release();
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94 | } catch (InterruptedException e) {
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95 | e.printStackTrace();
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96 | }
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97 | }
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98 | } |
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