Java线程挂起没有死锁

我目前在处理悬挂的过程时遇到了一些麻烦。

首先，下面的线程转储显示没有死锁。 另一个有趣的事情是该进程挂在java.lang.System.identityHashCode方法中。 该进程的当前CPU使用率为0％，有时高峰为1％…通常该进程使用100％。 它使用1.7GB的RAM（这个过程是正常的）。 该机器有足够的CPU，磁盘空间和RAM可用。

 Attaching to process ID 4146, please wait... Debugger attached successfully. Server compiler detected. JVM version is 23.7-b01 Deadlock Detection: No deadlocks found. Thread 12761: (state = BLOCKED) Thread 4159: (state = BLOCKED) Thread 4158: (state = BLOCKED) - java.lang.Object.wait(long) @bci=0 (Interpreted frame) - java.lang.ref.ReferenceQueue.remove(long) @bci=44, line=135 (Interpreted frame) - java.lang.ref.ReferenceQueue.remove() @bci=2, line=151 (Interpreted frame) - java.lang.ref.Finalizer$FinalizerThread.run() @bci=3, line=177 (Interpreted frame) Thread 4157: (state = BLOCKED) - java.lang.Object.wait(long) @bci=0 (Interpreted frame) - java.lang.Object.wait() @bci=2, line=503 (Interpreted frame) - java.lang.ref.Reference$ReferenceHandler.run() @bci=46, line=133 (Interpreted frame) Thread 4147: (state = IN_VM) - java.lang.System.identityHashCode(java.lang.Object) @bci=0 (Compiled frame; information may be imprecise) - java.util.IdentityHashMap.hash(java.lang.Object, int) @bci=1, line=301 (Compiled frame) - java.util.IdentityHashMap.containsKey(java.lang.Object) @bci=17, line=358 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=18, line=346 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.FastClonerArrayList.clone(java.lang.Object, com.rits.cloning.Cloner, java.util.Map) @bci=47, line=23 (Compiled frame) - com.rits.cloning.Cloner.fastClone(java.lang.Object, java.util.Map) @bci=30, line=96 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=100, line=355 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.FastClonerArrayList.clone(java.lang.Object, com.rits.cloning.Cloner, java.util.Map) @bci=47, line=23 (Compiled frame) - com.rits.cloning.Cloner.fastClone(java.lang.Object, java.util.Map) @bci=30, line=96 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=100, line=355 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.FastClonerArrayList.clone(java.lang.Object, com.rits.cloning.Cloner, java.util.Map) @bci=47, line=23 (Compiled frame) - com.rits.cloning.Cloner.fastClone(java.lang.Object, java.util.Map) @bci=30, line=96 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=100, line=355 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.FastClonerArrayList.clone(java.lang.Object, com.rits.cloning.Cloner, java.util.Map) @bci=47, line=23 (Compiled frame) - com.rits.cloning.Cloner.fastClone(java.lang.Object, java.util.Map) @bci=30, line=96 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=100, line=355 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.FastClonerArrayList.clone(java.lang.Object, com.rits.cloning.Cloner, java.util.Map) @bci=47, line=23 (Compiled frame) - com.rits.cloning.Cloner.fastClone(java.lang.Object, java.util.Map) @bci=30, line=96 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=100, line=355 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.cloneInternal(java.lang.Object, java.util.Map) @bci=368, line=404 (Compiled frame) - com.rits.cloning.Cloner.deepClone(java.lang.Object) @bci=61, line=309 (Compiled frame) - arquitetura.representation.Architecture.deepClone() @bci=23, line=497 (Compiled frame) - jmetal.operators.mutation.PLAFeatureMutation.execute(java.lang.Object) @bci=109, line=862 (Compiled frame) - jmetal.metaheuristics.nsgaII.NSGAII.execute() @bci=321, line=129 (Compiled frame) - br.ufpr.inf.opla.patterns.main.NSGAII_OPLA.main(java.lang.String[]) @bci=1116, line=179 (Interpreted frame) 

我现在用不同的参数执行相同的过程（超过一周）。 我正在使用进化算法，因此耗费时间对我的问题来说是正常的。 我执行了120次相同的过程（使用不同的参数），这是第一个挂起的时间。 目前有4个进程同时运行（计算被吊死的进程），有些甚至更多的进程需要花费更多时间。 他们正在完成，我的程序通常使用ProcessBuilder启动其他进程。 我确实阅读了每一个的输出。 被绞死的过程在不到一半的时间内输出正常的日志。 没有错误。 另一个重要的事情是，进程被冻结的方法不会产生输出，因此我假设输出消耗没有问题。

我的问题是：我不想杀死这个过程，所以有没有办法unhang这个过程？ 另外，为什么它处于IN_VM状态（在VirtualMachine中运行）并且仍然处于冻结状态？ 进程在java.lang.System.identityHashCode方法中冻结是否正常？ 为什么我的CPU使用0％（极少1％）？

如果我可以提供任何其他信息，请发出询问，我很乐意在此发布。

提前致谢。

编辑：虽然我使用multithreading，但每个线程使用ProcessBuilder启动一个Process对象。 因此，挂起进程是一个独立的JVM实例，只执行一个主线程。 我将输出重定向到一个文件，但如前所述，该进程挂起了一个不产生输出的方法，因此我假设输出消耗没有问题。

编辑2：杀死了这个过程。 后续流程已启动并且运行顺利。

Answer 1

这个过程并没有停止，你只是碰巧在上面发布的状态中发现了它。 你可以告诉，因为有问题的线程没有像其他人那样说BLOCKED，所以它正常执行。

为什么进程不再执行可能有不同的原因，但我可以向您保证，它们都不与identityHashCode相关联，因为这是一个经过良好测试的内部Java函数。

继续：

• 比较几个挂断的JVM状态。 如果它始终与上面相同，则问题可能与哈希生成相关联。 如果不：

• 发布更相关的代码，以便我们查看它。 如果问题不在这行代码中，那么它必须在其他地方（ com.rits.cloning.Cloner听起来像是一个开始寻找的合理点）。

• 告诉我们您要归档的内容，有人可能会发现错误或更好的方法，这完全可以避免导致问题的原因。