為什么阿里不允許用Executors創(chuàng)建線程池

FixedThreadPool SingleThreadPool允許請(qǐng)求隊(duì)列長度為Integer.MAX_VALUE可能會(huì)堆積大量請(qǐng)求從而導(dǎo)致OOM
CachedThreadPool ScheduledThreadPool允許創(chuàng)建線程數(shù)量為Integer.MAX_VALUE可能會(huì)創(chuàng)建大量線程從而導(dǎo)致OOM

# FixedThreadPool SingleThreadPoolpublic static ExecutorService newFixedThreadPool(int nThreads) { return new ThreadPoolExecutor(nThreads, nThreads, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());}
public static ExecutorService newSingleThreadExecutor() { return new FinalizableDelegatedExecutorService (new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>()));}

# CachedThreadPool ScheduledThreadPoolpublic static ExecutorService newCachedThreadPool() { return new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>());}
public static ScheduledExecutorService newSingleThreadScheduledExecutor() { return new DelegatedScheduledExecutorService (new ScheduledThreadPoolExecutor(1));}
public ScheduledThreadPoolExecutor(int corePoolSize) { super(corePoolSize, Integer.MAX_VALUE, 0, NANOSECONDS, new DelayedWorkQueue());}

public void testThread() throws Exception { ExecutorService fixedExecutor = Executors.newFixedThreadPool(10); for (int i = 0; i < 1000; i++) { fixedExecutor.execute(new Runnable() { @Override public void run() { System.out.println("公眾號(hào)互聯(lián)網(wǎng)公園"); } }); }}

"pool-1-thread-2" #525 prio=5 os_prio=0 tid=0x00006f6561039100 nid=0xdaa waiting on condition [0x00006f64e646d000]java.lang.Thread.State: WAITING (parking)at sun.misc.Unsafe.park(Native Method)parking to wait for <0x00000006e6f3e230> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)at java.util.concurrent.locks.LockSupport.park(LockSupport.java:165)at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1066)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1126)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:616)at java.lang.Thread.run(Thread.java:645)

public class FixedThreadPool implements ThreadPool {
 @Override public Executor getExecutor(URL url) {
 // 線程名稱 String name = url.getParameter(Constants.THREAD_NAME_KEY, Constants.DEFAULT_THREAD_NAME);
 // 線程個(gè)數(shù)默認(rèn)200 int threads = url.getParameter(Constants.THREADS_KEY, Constants.DEFAULT_THREADS);
 // 隊(duì)列容量默認(rèn)0 int queues = url.getParameter(Constants.QUEUES_KEY, Constants.DEFAULT_QUEUES);
 // 隊(duì)列容量等于0使用阻塞隊(duì)列SynchronousQueue // 隊(duì)列容量小于0使用無界阻塞隊(duì)列LinkedBlockingQueue // 隊(duì)列容量大于0使用有界阻塞隊(duì)列LinkedBlockingQueue // NamedInternalThreadFactory為線程命名 return new ThreadPoolExecutor(threads, threads, 0, TimeUnit.MILLISECONDS, queues == 0 ? new SynchronousQueue<Runnable>() : (queues < 0 ? new LinkedBlockingQueue<Runnable>() : new LinkedBlockingQueue<Runnable>(queues)), new NamedInternalThreadFactory(name, true), new AbortPolicyWithReport(name, url)); }}

public abstract class AbstractServer extends AbstractEndpoint implements Server { protected static final String SERVER_THREAD_POOL_NAME = "DubboServerHandler";}

"DubboServerHandler-1.1.1.1:20881-thread-20" #511 daemon prio = 5 os_prio = 0 tid = 0x00001f153121f200 nid = 0xd1a waiting on condition [0x00001f14edcdf000]java.lang.Thread.State: WAITING (parking)at sun.misc.Unsafe.park(Native Method)- parking to wait for <0x00000001e1f3abc0> (a java.util.concurrent.SynchronousQueue$TransferStack)at java.util.concurrent.locks.LockSupport.park(LockSupport.java : 115)at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java : 452)at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java : 312)at java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java : 924)at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java : 1011)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java : 1121)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java : 111)

public abstract class AbstractClient extends AbstractEndpoint implements Client { protected static final String CLIENT_THREAD_POOL_NAME = "DubboClientHandler";}

"DubboClientHandler-1.1.1.1:20881-thread-10" #688 daemon prio=1 os_prio=0 tid=0x00001f6114004800 nid=0x14d8 waiting on condition [0x00001f63e131a000]java.lang.Thread.State: TIMED_WAITING (parking)at sun.misc.Unsafe.park(Native Method)- parking to wait for <0x00000006e21df0d0> (a java.util.concurrent.SynchronousQueue$TransferStack)at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:111)at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:460)at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:361)at java.util.concurrent.SynchronousQueue.poll(SynchronousQueue.java:141)at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1066)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1111)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:611)at java.lang.Thread.run(Thread.java:141)

public class NamedInternalThreadFactory extends NamedThreadFactory { public NamedInternalThreadFactory() { super(); }
 public NamedInternalThreadFactory(String prefix) { super(prefix, false); }
 public NamedInternalThreadFactory(String prefix, boolean daemon) { super(prefix, daemon); }
 @Override public Thread newThread(Runnable runnable) { String name = mPrefix + mThreadNum.getAndIncrement(); InternalThread ret = new InternalThread(mGroup, runnable, name, 0); ret.setDaemon(mDaemon); return ret; }}
public class NamedThreadFactory implements ThreadFactory { protected static final AtomicInteger POOL_SEQ = new AtomicInteger(1); protected final AtomicInteger mThreadNum = new AtomicInteger(1); protected final String mPrefix; protected final boolean mDaemon; protected final ThreadGroup mGroup;
 public NamedThreadFactory() { this("pool-" + POOL_SEQ.getAndIncrement(), false); }
 public NamedThreadFactory(String prefix) { this(prefix, false); }
 public NamedThreadFactory(String prefix, boolean daemon) { mPrefix = prefix + "-thread-"; mDaemon = daemon; SecurityManager s = System.getSecurityManager(); mGroup = (s == null) ? Thread.currentThread().getThreadGroup() : s.getThreadGroup(); }
 @Override public Thread newThread(Runnable runnable) { String name = mPrefix + mThreadNum.getAndIncrement(); Thread ret = new Thread(mGroup, runnable, name, 0); ret.setDaemon(mDaemon); return ret; }
 public ThreadGroup getThreadGroup() { return mGroup; }}

public class ThreadPoolStarter { public static ThreadPoolExecutor getExecutor(String threadName) { if (executor == null) { synchronized (ThreadPoolStarter.class) { if (executor == null) { int coreSize = Runtime.getRuntime().availableProcessors(); BlockingQueue<Runnable> queueToUse = new LinkedBlockingQueue<Runnable>(QUEUE_SIZE); executor = new ThreadPoolExecutor(coreSize, POOL_CORE_SIZE, MAX_SIZE, TimeUnit.SECONDS, queueToUse, new NamedInternalThreadFactory(threadName, true), new AbortPolicyDoReport(threadName)); } } } return executor; }}
public class ThreadExecutor { public static void execute(String bizName, Runnable job) { ThreadPoolStarter.getExecutor(bizName).execute(job); }
 public static Future<?> sumbit(String bizName, Runnable job) { return ThreadPoolStarter.getExecutor(bizName).submit(job); }}

public void testThread() throws Exception { for (int i = 0; i < 10000; i++) { ThreadExecutor.execute("BizName", new Runnable() { @Override public void run() { System.out.println("公眾號(hào)互聯(lián)網(wǎng)公園"); } }); Thread.sleep(1000L); } }}

"BizName-thread-8" #262 daemon prio=5 os_prio=0 tid=0x0000000023b5c000 nid=0x31d4 waiting on condition [0x000000003c0be000]java.lang.Thread.State: WAITING (parking)at sun.misc.Unsafe.park(Native Method)- parking to wait for <0x00000006c35781f0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)at java.lang.Thread.run(Thread.java:748)