The real inventor of the monitor concept: A short note to correct the SP&E paper entitled 'An enhanced thread synchronization mechanism for Java'

(1)

SOFTWARE—PRACTICE AND EXPERIENCE

Softw. Pract. Exper. 2001; 31:1393 (DOI: 10.1002/spe.420)

Letter to the Editor

The real inventor of the monitor

concept: A short note to correct

the SP&E paper entitled

‘An enhanced thread

synchronization mechanism

for Java’

Hsin-Ta Chiao and Shyan-Ming Yuan

∗,†

Department of Computer and Information Science, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan

Several days ago, we received an e-mail from Professor P. Brinch Hansen. He mentioned that the paper we published [1] incorrectly attributes the invention of the monitor concept to C. A. R. Hoare. After checking the paper of Hoare in 1974 about monitors [2], we found that Hoare just further developed the original ideas of P. Brinch Hansen. Before this, P. Brinch Hansen had published in two papers the original concept of monitor in 1972 and 1973 [3,4]. In these two papers, P. Brinch Hansen offered the concepts of queuing variables and shared classes, which are the fundamentals of the subsequent monitor notation. In order to make sure of our points, we checked some books on concurrent programming and operating systems. We found that some famous computer scientists also believe that the invention of the monitor concept is P. Brinch Hansen’s achievement [5,6].

Hence, we would like to apologize to the inventor of the monitor concept, P. Brinch Hansen and to the Journal’s editors and readers.

REFERENCES

1. Chiao H, Yuan S. An enhanced thread synchronization mechanism for Java. Software—Practice and Experience 2001; 31(7):667–695.

2. Hoare C. Monitor: An operating system constructing concept. Communications of the ACM 1974; 17(10):549–557. 3. Brinch Hansen P. Structured multiprogramming. Communications of the ACM 1972; 15(7):574–578.

4. Brinch Hansen P. Section 7.2: Class concept. Operating System Principles. Prentice-Hall: Englewood Cliffs, NJ, 1973. 5. Andrews G. Concurrent Programming—Principles and Practice. Benjamin/Cummings: Redwood City, CA, 1991. 6. Silberschatz A, Peterson J, Galvin P. Operating System Concepts (3rd edn). Addison-Wesley: Reading, MA, 1991.

∗_{Correspondence to: Shyan-Ming Yuan, Department of Computer and Information Science, National Chiao Tung University,} 1001 Ta Hsueh Road, Hsinchu 300, Taiwan.

†_{E-mail: smyuan@cis.nctu.edu.tw}

Received 7 August 2001 Accepted 7 August 2001