JAVA线程的生命周期和分析工具

线程的生命周期的六种状态

 其中一种 有效的方法就是看源码

1、NEW

在 虚拟机的 中创建对象，初始化 成员变量。

2、RUNNABLE

在虚拟中创建线程 私有的程序计数器，虚拟机栈， 等待虚拟机 线程调度器，分配时间片。

3、BLOCKED

等待monitor的锁，synchonized block/method

4、WAITING

* 

*   
{@link Object#wait() Object.wait} with no timeout
*   
{@link #join() Thread.join} with no timeout
*   
{@link LockSupport#park() LockSupport.park}
* 

5、TIME_WAITING

* 

*   
{@link #sleep Thread.sleep}
*   
{@link Object#wait(long) Object.wait} with timeout
*   
{@link #join(long) Thread.join} with timeout
*   
{@link LockSupport#parkNanos LockSupport.parkNanos}
*   
{@link LockSupport#parkUntil LockSupport.parkUntil}
* 

6、TERMINATED

    /**
     * A thread state.  A thread can be in one of the following states:
     * 

     * 
{@link #NEW}

     *     A thread that has not yet started is in this state.
     *     
     * 
{@link #RUNNABLE}

     *     A thread executing in the Java virtual machine is in this state.
     *     
     * 
{@link #BLOCKED}

     *     A thread that is blocked waiting for a monitor lock
     *     is in this state.
     *     
     * 
{@link #WAITING}

     *     A thread that is waiting indefinitely for another thread to
     *     perform a particular action is in this state.
     *     
     * 
{@link #TIMED_WAITING}

     *     A thread that is waiting for another thread to perform an action
     *     for up to a specified waiting time is in this state.
     *     
     * 
{@link #TERMINATED}

     *     A thread that has exited is in this state.
     *     
     * 
     *
     * 

     * A thread can be in only one state at a given point in time.
     * These states are virtual machine states which do not reflect
     * any operating system thread states.
     *
     * @since   1.5
     * @see #getState
     */
    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:
         * 

         *   
{@link Object#wait() Object.wait} with no timeout
         *   
{@link #join() Thread.join} with no timeout
         *   
{@link LockSupport#park() LockSupport.park}
         * 
         *
         * 
A thread in the waiting state is waiting for another thread to
         * perform a particular action.
         *
         * For example, a thread that has called Object.wait()
         * on an object is waiting for another thread to call
         * Object.notify() or Object.notifyAll() on
         * that object. A thread that has called Thread.join()
         * 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:
         * 

         *   
{@link #sleep Thread.sleep}
         *   
{@link Object#wait(long) Object.wait} with timeout
         *   
{@link #join(long) Thread.join} with timeout
         *   
{@link LockSupport#parkNanos LockSupport.parkNanos}
         *   
{@link LockSupport#parkUntil LockSupport.parkUntil}
         * 
         */
        TIMED_WAITING,

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

jstack分析工具

jstack用于生成虚拟机当时的线程快照，用于定位线程长时间等待的原因，如死锁，死循环，请求外部资源导致长 时间等待。

java命令--jstack 工具

高手是怎么使用jstack精确找到异常代码的