Java-使用ReentrantLock异步运行作业?
下面的代码允许我们运行Java-使用ReentrantLock异步运行作业?,java,asynchronous,reentrantlock,Java,Asynchronous,Reentrantlock,下面的代码允许我们运行作业,同时通过使用ReentrantLock确保一次只能运行一个作业 是否有任何方法可以修改此代码以异步运行job.call(),并在启动线程之前将MyConcurrentJobException返回给客户端 我们尝试将try/catch/finally块包装在一个新的线程中,但是解锁和锁定必须发生在同一个线程中,因此我们得到了一个非法监视异常 ? 您可以使用Semaphore而不是ReentrantLock,它的许可证不绑定到线程 类似这样的情况(不确定在异步情况下如何处
作业
,同时通过使用ReentrantLock
确保一次只能运行一个作业
是否有任何方法可以修改此代码以异步运行job.call()
,并在启动线程之前将MyConcurrentJobException
返回给客户端
我们尝试将try/catch/finally块包装在一个新的线程中
,但是解锁
和锁定
必须发生在同一个线程中,因此我们得到了一个非法监视异常
?
您可以使用
Semaphore
而不是ReentrantLock
,它的许可证不绑定到线程
类似这样的情况(不确定在异步情况下如何处理job.call()
的结果):
我认为我完全误解了这一点,因为在异步执行某些操作时阻塞和等待对我来说没有太大意义,除非在调用线程上取得一些进展 你能这样做吗:
final static Lock lock = new ReentrantLock();
final static ExecutorService service = Executors.newThreadPoolExecutor();
public Object runJob(String desc, Callable job, boolean wait) {
logger.info("Acquiring lock");
if (!lock.tryLock()) {
throw new MyConcurrentJobException();
}
activeJob = new JobStatus(desc);
logger.info("Lock acquired");
try {
Future<?> future = service.submit(job);
// This next line will block until the job is finished
// and also will hold onto the lock.
boolean finished = false;
Object o = null;
while(!finished) {
try {
o = future.get(300, TimeUnit.MILLISECONDS);
finished = true;
catch(TimeOutException e) {
// Do some periodic task while waiting
// foot.tapLots();
}
}
if (o instanceof MarginServiceAssertionException) {
throw ((MargineServiceAssertionException)o);
} else if (o instanceof MargineServiceSystemException) {
throw ((MarginServiceSystemException)o);
} else if (o instanceof Exception) {
throw new MarginServiceSystemException(e);
}
} catch (... InterruptedException e) { /// catch whatever exceptions throws as part of this
/// Whatever needs to be done.
} finally {
activeJob = null;
logger.info("Releasing lock");
lock.unlock();
logger.info("Lock released");
}
}
final static Lock=new ReentrantLock();
final static ExecutorService service=Executors.newThreadPoolExecutor();
公共对象运行作业(字符串描述、可调用作业、布尔等待){
logger.info(“获取锁”);
如果(!lock.tryLock()){
抛出新的MyConcurrentJobException();
}
activeJob=新作业状态(desc);
logger.info(“锁定已获取”);
试一试{
未来=服务。提交(作业);
//下一行将阻塞,直到作业完成
//也会抓住锁。
布尔完成=假;
对象o=null;
当(!完成){
试一试{
o=future.get(300,时间单位为毫秒);
完成=正确;
捕获(超时异常e){
//在等待时做一些定期任务
//脚。塔普洛特();
}
}
if(o MarginServiceAssertionException实例){
抛出((MargineServiceAssertionException)o);
}else if(o MargineServiceSystemException实例){
抛出((MarginServiceSystemException)o);
}else if(o实例异常){
抛出新的MarginServiceSystemException(e);
}
}catch(…InterruptedException e){///捕获作为此过程的一部分抛出的任何异常
///无论需要做什么。
}最后{
activeJob=null;
logger.info(“释放锁”);
lock.unlock();
logger.info(“锁已释放”);
}
}
我们希望使用gui启动作业。我们希望立即通过“您的作业已启动”消息将控制权返回gui。但我们希望防止并发作业发生。因此,如果用户试图在另一个作业正在进行时启动作业,他们会出错。啊,好的,那么我会使用axtavt的解决方案。
final static Semaphore lock = new Semaphore(1);
public void runJob(String desc, Callable job, boolean wait) {
logger.info("Acquiring lock");
if (!lock.tryAcquire()) {
throw new MyConcurrentJobException();
}
startThread(new Runnable() {
public void run() {
try {
job.call();
} finally {
lock.release();
}
}
});
}
final static Lock lock = new ReentrantLock();
final static ExecutorService service = Executors.newThreadPoolExecutor();
public Object runJob(String desc, Callable job, boolean wait) {
logger.info("Acquiring lock");
if (!lock.tryLock()) {
throw new MyConcurrentJobException();
}
activeJob = new JobStatus(desc);
logger.info("Lock acquired");
try {
Future<?> future = service.submit(job);
// This next line will block until the job is finished
// and also will hold onto the lock.
boolean finished = false;
Object o = null;
while(!finished) {
try {
o = future.get(300, TimeUnit.MILLISECONDS);
finished = true;
catch(TimeOutException e) {
// Do some periodic task while waiting
// foot.tapLots();
}
}
if (o instanceof MarginServiceAssertionException) {
throw ((MargineServiceAssertionException)o);
} else if (o instanceof MargineServiceSystemException) {
throw ((MarginServiceSystemException)o);
} else if (o instanceof Exception) {
throw new MarginServiceSystemException(e);
}
} catch (... InterruptedException e) { /// catch whatever exceptions throws as part of this
/// Whatever needs to be done.
} finally {
activeJob = null;
logger.info("Releasing lock");
lock.unlock();
logger.info("Lock released");
}
}