Concurrency - Java: How to Program Early Objects - page 983

Consumer reads 3 3
Producer writes 4 10
Consumer reads 4 7
Producer writes 5 15

5 is lost
6 is lost

Producer writes 6 21
Producer writes 7 28

Consumer reads 7 14

Consumer reads 7 21 7 read again

Producer writes 8 36
Consumer reads 8 29

Consumer reads 8 37 8 read again

Producer writes 9 45

9 is lost

Producer writes 10 55

Producer done producing
Terminating Producer
Consumer reads 10 47

Consumer reads 10 57
Consumer reads 10 67
Consumer reads 10 77

10 read again
10 read again
10 read again

Consumer read values totaling 77
Terminating Consumer

Action Value Sum of Produced Sum of Consumed
------ ----- --------------- ---------------

reads -1 bad data

Consumer reads -1 -1

Producer writes 1 1
Consumer reads 1 0

Consumer reads 1 1
Consumer reads 1 2
Consumer reads 1 3
Consumer reads 1 4

1 read again
1 read again
1 read again
1 read again

Producer writes 2 3
Consumer reads 2 6
Producer writes 3 6
Consumer reads 3 9
Producer writes 4 10
Consumer reads 4 13
Producer writes 5 15

5 is lost

Producer writes 6 21

Consumer reads 6 19

Consumer read values totaling 19
Terminating Consumer

Producer writes 7 28
Producer writes 8 36
Producer writes 9 45
Producer writes 10 55

7 never read
8 never read
9 never read

10 never read

Producer done producing
Terminating Producer

Fig. 23.13 | Application with two threads manipulating an unsynchronized buffer. ( Caution:
The example of Figs. 23.9-23.13 is not thread safe.) (Part 2 of 2.)