【并发】【01】JVM 线程模型、线程的状态

1.线程模型

线程分为内核级线程模型KLT ，和用户级别线程模型 ULT
jvm使用KLT
线程内核维护，一个Thread对象对应一个内核的线程

2.线程的状态

public enum State {
     
	/**
	 * Thread state for a thread which has not yet started.
	 */
	NEW,

	/**
	 * Thread state for a runnable thread.  A thread in the runnable
	 * state is executing in the Java virtual machine but it may
	 * be waiting for other resources from the operating system
	 * such as processor.
	 */
	RUNNABLE,

	/**
	 * Thread state for a thread blocked waiting for a monitor lock.
	 * A thread in the blocked state is waiting for a monitor lock
	 * to enter a synchronized block/method or
	 * reenter a synchronized block/method after calling
	 * {
     @link Object#wait() Object.wait}.
	 */
	BLOCKED,

	/**
	 * Thread state for a waiting thread.
	 * A thread is in the waiting state due to calling one of the
	 * following methods:
	 * <ul>
	 *   <li>{
     @link Object#wait() Object.wait} with no timeout
	 *   <li>{
     @link #join() Thread.join} with no timeout
	 *   <li>{
     @link LockSupport#park() LockSupport.park}
	 * </ul>
	 *
	 * <p>A thread in the waiting state is waiting for another thread to
	 * perform a particular action.
	 *
	 * For example, a thread that has called <tt>Object.wait()</tt>
	 * on an object is waiting for another thread to call
	 * <tt>Object.notify()</tt> or <tt>Object.notifyAll()</tt> on
	 * that object. A thread that has called <tt>Thread.join()</tt>
	 * is waiting for a specified thread to terminate.
	 */
	WAITING,

	/**
	 * Thread state for a waiting thread with a specified waiting time.
	 * A thread is in the timed waiting state due to calling one of
	 * the following methods with a specified positive waiting time:
	 * <ul>
	 *   <li>{
     @link #sleep Thread.sleep}
	 *   <li>{
     @link Object#wait(long) Object.wait} with timeout
	 *   <li>{
     @link #join(long) Thread.join} with timeout
	 *   <li>{
     @link LockSupport#parkNanos LockSupport.parkNanos}
	 *   <li>{
     @link LockSupport#parkUntil LockSupport.parkUntil}
	 * </ul>
	 */
	TIMED_WAITING,

	/**
	 * Thread state for a terminated thread.
	 * The thread has completed execution.
	 */
	TERMINATED;
}