monitor : Java Glossary

by Roedy Green ©1996-2008 Canadian Mind Products
Go to : punctuation 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z (all)

monitor: Java uses monitors to co-ordinate threads to make sure they don’t trip over each other accessing the same data. With monitors, you either lock objects, critical sections of code or you lock entire methods by declaring them synchronised. Monitors have hardware test and set support behind them to ensure a thread checks to see if a monitor is already locked and if not, seize the lock all in one non-interruptible atomic operation. Without atomicity, a thread might check see if the monitor is unlocked, and have some other thread grab the monitor before it gets a chance to lock it. Purists will point out that a monitor is not actually the lock, but rather the way that lock is used to protect critical sections of code.
CRT or LCD monitors are called raster screens in Java, the glass displays you look at.
condition variable
monitor
mutex
queue: java.util.concurrent
semaphore
synchronized
Thread
thread safe code

	Please email your feedback for publication, errors, omissions, broken/redirected link reports and suggestions to improve this page to Roedy Green :
	Canadian Mind Products
	mindprod.com IP:[65.110.21.43]
	Your face IP:[38.103.63.16]	The information on this page is for non-military use only.
	You are visitor number 22,146.	Military use includes use by defence contractors.
	You can get a fresh copy of this page from:	or possibly from your local J: drive (Java virtual drive/Mindprod website mirror)
	http://mindprod.com/jgloss/monitor.html	J:\mindprod\jgloss\monitor.html