JAVA-BASED REAL-TIME PROGRAMMING

Contents
3.2.1 Semaphore methods . . . . . . . . . . . . . . . . . . . . 56
3.2.2 Using semaphores . . . . . . . . . . . . . . . . . . . . . 58
3.2.3 The semaphores package . . . . . . . . . . . . . . . . . 63
3.3 Objects providing mutual exclusion – Monitors . . . . . . . . . 66
3.3.1 Synchronized . . . . . . . . . . . . . . . . . . . . . . . . 66
3.3.2 Conditions – wait and notify . . . . . . . . . . . . . . . 74
3.3.3 More on monitor programming . . . . . . . . . . . . . . 83
3.4 Message-based communication – Mailboxes . . . . . . . . . . . 85
3.4.1 More on object interaction . . . . . . . . . . . . . . . . 86
3.4.2 Events and buffers . . . . . . . . . . . . . . . . . . . . . 87
3.4.3 Threads and event-based communication . . . . . . . . 95
II Exercises and Labs 97
4 Exercises and Labs 99
4.1 Exercise 1 – Semaphores . . . . . . . . . . . . . . . . . . . . . . 99
4.2 Exercise 2 – Lab 1 preparation . . . . . . . . . . . . . . . . . . 103
4.3 Lab 1 – Alarmclock . . . . . . . . . . . . . . . . . . . . . . . . . 108
4.4 Exercise 3 - Monitor and Wait/Notify . . . . . . . . . . . . . . 112
4.5 Exercise 4 - Deadlock analysis and lab 2 preparation . . . . . . 116
4.6 Lab 2 – Lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
4.7 Exercise 5 - Mailbox and lab 3 preparation . . . . . . . . . . . 123
4.8 Exercise 6 - Scheduling analysis . . . . . . . . . . . . . . . . . . 137
4.9 Lab 3 – Washing machine . . . . . . . . . . . . . . . . . . . . . 139
5 Solutions 141
5.1 Solution to exercise 1 . . . . . . . . . . . . . . . . . . . . . . . . 141
5.2 Solution to exercise 3 . . . . . . . . . . . . . . . . . . . . . . . . 144
5.3 Solution to exercise 4 . . . . . . . . . . . . . . . . . . . . . . . . 147
5.4 Solution to exercise 6 . . . . . . . . . . . . . . . . . . . . . . . . 148
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