// 暂停当前线程LockSupport.park(); 
// 恢复某个线程的运行LockSupport.unpark(暂停线程对象)

packagecom.gzczy.concurrent.week3;
importlombok.extern.slf4j.Slf4j;
importjava.util.concurrent.TimeUnit;
importjava.util.concurrent.locks.LockSupport;
/*** @Description Park和Unpark* @Author chenzhengyu* @Date 2020-11-05 19:15*/@Slf4j(topic="c.ParkAndUnParkDemo")
publicclassParkAndUnParkDemo {
publicstaticvoidmain(String[] args) {
//        demo1();demo2();
    }
publicstaticvoiddemo1(){
Threadt1=newThread(() -> {
log.debug("start...");
try {
TimeUnit.SECONDS.sleep(1);
            } catch (InterruptedExceptione) {
e.printStackTrace();
            }
log.debug("park...");
LockSupport.park();
log.debug("resume...");
        },"t1");
t1.start();
try {
TimeUnit.SECONDS.sleep(2);
        } catch (InterruptedExceptione) {
e.printStackTrace();
        }
log.debug("unpark...");
LockSupport.unpark(t1);
    }
//先Unpark再Parkpublicstaticvoiddemo2(){
Threadt1=newThread(() -> {
log.debug("start...");
try {
TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedExceptione) {
e.printStackTrace();
            }
log.debug("park...");
LockSupport.park();
log.debug("resume...");
        }, "t1");
t1.start();
try {
TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedExceptione) {
e.printStackTrace();
        }
log.debug("unpark...");
LockSupport.unpark(t1);
    }
}

/*** Disables the current thread for thread scheduling purposes unless the* permit is available.** <p>If the permit is available then it is consumed and the call returns* immediately; otherwise* the current thread becomes disabled for thread scheduling* purposes and lies dormant until one of three things happens:** <ul>* <li>Some other thread invokes {@link #unpark unpark} with the* current thread as the target; or** <li>Some other thread {@linkplain Thread#interrupt interrupts}* the current thread; or** <li>The call spuriously (that is, for no reason) returns.* </ul>** <p>This method does <em>not</em> report which of these caused the* method to return. Callers should re-check the conditions which caused* the thread to park in the first place. Callers may also determine,* for example, the interrupt status of the thread upon return.** @param blocker the synchronization object responsible for this*        thread parking* @since 1.6*/publicstaticvoidpark(Objectblocker) {
Threadt=Thread.currentThread();
setBlocker(t, blocker);
UNSAFE.park(false, 0L);
setBlocker(t, null);
    }

/*** Makes available the permit for the given thread, if it* was not already available.  If the thread was blocked on* {@code park} then it will unblock.  Otherwise, its next call* to {@code park} is guaranteed not to block. This operation* is not guaranteed to have any effect at all if the given* thread has not been started.** @param thread the thread to unpark, or {@code null}, in which case*        this operation has no effect*/publicstaticvoidunpark(Threadthread) {
if (thread!=null)
UNSAFE.unpark(thread);
    }

packagecom.gzczy.concurrent.heima.b.wait;
importlombok.extern.slf4j.Slf4j;
importjava.util.concurrent.TimeUnit;
/*** @Description wait notify 测试阻塞* @Author chenzhengyu* @Date 2021年01月31日 14:12:08*/@Slf4j(topic="c.WaitNotifyDemo")
publicclassWaitNotifyDemo2 {
finalstaticObjectobj=newObject();
publicstaticvoidmain(String[] args) throwsException {
newThread(() -> {
try {
TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedExceptione) {
e.printStackTrace();
            }
synchronized (obj) {
log.debug("执行....");
try {
obj.wait(); // 让线程在obj上一直等待下去                } catch (InterruptedExceptione) {
e.printStackTrace();
                }
log.debug("其它代码....");
            }
        },"t1").start();
newThread(() -> {
synchronized (obj) {
log.debug("执行....");
obj.notify(); // 让线程在obj上一直等待下去log.debug("其它代码....");
            }
        },"t2").start();
    }
}

packagecom.gzczy.concurrent.heima.b.wait;
importlombok.extern.slf4j.Slf4j;
importjava.util.concurrent.TimeUnit;
importjava.util.concurrent.locks.LockSupport;
/*** @Description LockSupport Demo 进行线程阻塞* @Author chenzhengyu* @Date 2021-01-31 14:22*/@Slf4j(topic="c.LockSupportDemo")
publicclassLockSupportDemo {
publicstaticvoidmain(String[] args) throwsInterruptedException {
//默认是permit 0Threadt1=newThread(() -> {
try {
TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedExceptione) {
e.printStackTrace();
            }
log.debug("执行....是否打断--->"+Thread.currentThread().isInterrupted());
// 调用一次park就会消费permit 由刚刚的1变为0 你继续运行下去吧LockSupport.park();
log.debug("其它代码,是否打断--->"+Thread.currentThread().isInterrupted());
//再次打住 目前没有许可了 许可为0 那就不放你继续运行啦LockSupport.park();
log.debug("再次park,是否打断--->"+Thread.currentThread().isInterrupted());
//被打断后会发现无法park住，打断标记已经为true 线程已经被打断了LockSupport.park();
        }, "t1");
t1.start();
newThread(() -> {
log.debug("执行....");
//调用一次unpark就加1变成1，线程还在运行 没毛病老铁 你继续运行吧LockSupport.unpark(t1);
log.debug("其它代码....");
        }, "t2").start();
try {
TimeUnit.SECONDS.sleep(4);
log.debug("打断t1线程....");
t1.interrupt();
        } catch (InterruptedExceptione) {
e.printStackTrace();
        }
    }
}