On the JVM, threads are the de-facto, fundamental instrument of concurrency. Multiple threads live in the same JVM; they share the heap space and compete for resources.
JVM threads are the operating system threads. Java wraps an underlying OS thread as an instance of the java.lang.Thread
class and builds up an API around it to work with threads. A thread on the JVM has a number of states:
New
,
Runnable
,
Blocked
,
Waiting
,
Timed_Waiting
, and
Terminated
. A thread is instantiated by overriding the run()
method of the Thread
class or by passing an instance of the java.lang.Runnable
interface to the constructor of the Thread
class. Invoking the start()
method of a Thread
instance starts its execution in a new thread. Even when just a single thread is running in the JVM, the JVM would not shut down. Calling the setDaemon(boolean)
method of a thread with the argument true
tags the thread as a daemon that can be automatically shut down if no other...