ReentrantLock的使用 - morris131/morris-book GitHub Wiki
ReentrantLock实现synchronized代码块的功能。
package com.morris.ch4;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class ReentrantLockTest {
private static int count = 10;
private static Lock lock = new ReentrantLock();
public static void main(String[] args) {
new A().start();
new A().start();
new A().start();
}
static class A extends Thread {
@Override
public void run() {
while (true) {
lock.lock();
try {
if (0 == count) {
break;
}
System.out.println(count--);
} finally {
lock.unlock();
}
}
}
}
}Condition类的await()方法相当于Object类的wait()方法。
Condition类的await(long time, TimeUnit unit)方法相当于Object类的wait(long timeout)方法。
Condition类的signal()方法相当于Object类的notify()方法。
Condition类的signalAll()方法相当于Object类的notifyAll()方法。
package com.morris.ch4;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class OneConditionWaitNotifyTest {
private static Lock lock = new ReentrantLock();
private static Condition condition = lock.newCondition();
public static void main(String[] args) throws InterruptedException {
A a = new A();
a.start();
Thread.sleep(1000);
a.signal();
}
static class A extends Thread {
@Override
public void run() {
await();
}
public void await() {
lock.lock();
try {
try {
System.out.println("thread A is waiting...");
condition.await();
System.out.println("thread A is stoped");
} catch (InterruptedException e) {
e.printStackTrace();
}
} finally {
lock.unlock();
}
}
public void signal() {
lock.lock();
try {
System.out.println("notify thread a...");
condition.signal();
} finally {
lock.unlock();
}
}
}
}package com.morris.ch4;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class MoreConditionWaitNotifyTest {
private static Lock lock = new ReentrantLock();
private static Condition conditionA = lock.newCondition();
private static Condition conditionB = lock.newCondition();
public static void main(String[] args) throws InterruptedException {
A a = new A();
a.start();
B b = new B();
b.start();
Thread.sleep(1000);
a.signal();
}
static class A extends Thread {
@Override
public void run() {
await();
}
public void await() {
lock.lock();
try {
try {
System.out.println("thread A is waiting...");
conditionA.await();
System.out.println("thread A is stoped");
} catch (InterruptedException e) {
e.printStackTrace();
}
} finally {
lock.unlock();
}
}
public void signal() {
lock.lock();
try {
System.out.println("notify thread A...");
conditionA.signalAll();
} finally {
lock.unlock();
}
}
}
static class B extends Thread {
@Override
public void run() {
await();
}
public void await() {
lock.lock();
try {
try {
System.out.println("thread B is waiting...");
conditionB.await();
System.out.println("thread B is stoped");
} catch (InterruptedException e) {
e.printStackTrace();
}
} finally {
lock.unlock();
}
}
public void signal() {
lock.lock();
try {
System.out.println("notify thread B...");
conditionB.signalAll();
} finally {
lock.unlock();
}
}
}
}package com.morris.ch4;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class ConditionOneProvider2OneConsumer {
private static Lock lock = new ReentrantLock();
private static Condition condition = lock.newCondition();
private static String value;
public static void main(String[] args) {
new Provider().start();
new Consumer().start();
}
static class Provider extends Thread {
@Override
public void run() {
while(true) {
lock.lock();
try {
if(null == value) {
value = System.currentTimeMillis() + "";
System.out.println("provider set :" + value);
condition.signal();
} else {
condition.await();
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}
}
static class Consumer extends Thread {
@Override
public void run() {
while(true) {
lock.lock();
try {
if(null == value) {
condition.await();
} else {
System.out.println("consumer get value:" + value);
value = null;
condition.signal();
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}
}
}
package com.morris.ch4;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class ConditionMoreProvider2MoreConsumer {
private static Lock lock = new ReentrantLock();
private static String value;
private static Condition condition = lock.newCondition();
public static void main(String[] args) {
for(int i = 0; i < 3; i++) {
new Provider().start();
new Consumer().start();
}
}
static class Provider extends Thread {
@Override
public void run() {
lock.lock();
try {
while(true) {
if(null == value) {
value = Thread.currentThread().getName() + " " + System.currentTimeMillis();
System.out.println(Thread.currentThread().getName() + " set value:" + value);
condition.signalAll();
} else {
condition.await();
}
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}
static class Consumer extends Thread {
@Override
public void run() {
lock.lock();
try {
while(true) {
if(null != value) {
System.out.println(Thread.currentThread().getName() + " get value:" + value);
value = null;
condition.signalAll();
} else {
condition.await();
}
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}
}