MULTITHREADING AND PARALLEL PROGRAMMING - Introduction to Java Programming: Comprehensive Version - page 1121

36 try {
37 while ( true ) {
38 System.out.println( "\t\t\tConsumer reads " + buffer.read());
39 // Put the thread into sleep
40 Thread.sleep(( int )(Math.random() * 10000 ));
41 }
42 }
43 catch (InterruptedException ex) {
44 ex.printStackTrace();
45 }
46 }
47 }
48
49

// An inner class for buffer

50 private static class Buffer {

51 private static final int CAPACITY = 1 ; // buffer size

52 private java.util.LinkedList<Integer> queue =

53 new java.util.LinkedList<>();

54
55 // Create a new lock

56 private static Lock lock = new ReentrantLock(); create a lock

57
58

// Create two conditions

59 private static Condition notEmpty = lock.newCondition();

create a condition
create a condition 60 private static Condition notFull = lock.newCondition();

61
62 public void write( int value) {
63 lock.lock(); // Acquire the lock
64 try {
65 while (queue.size() == CAPACITY) {
66 System.out.println( "Wait for notFull condition" );
67

acquire the lock

notFull.await(); wait for notFull

68 }
69
70 queue.offer(value);
71 notEmpty.signal(); // Signal notEmpty condition signal notEmpty

72 }
73 catch (InterruptedException ex) {
74 ex.printStackTrace();
75 }
76 finally {

77 lock.unlock(); // Release the lock release the lock

78 }
79 }
80
81 public int read() {
82 int value = 0 ;
83 lock.lock(); // Acquire the lock
84 try {
85 while (queue.isEmpty()) {
86 System.out.println( "\t\t\tWait for notEmpty condition" );
87

acquire the lock

notEmpty.await(); wait for notEmpty

88 }
89
90 value = queue.remove();
91 notFull.signal(); // Signal notFull condition signal notFull

92 }
93 catch (InterruptedException ex) {
94 ex.printStackTrace();
95 }