dingmingcheng

@oldratlee 有出现过。但只有当时dump下来的线程栈信息，有两个线程都卡在了下面的代码。Java版本是1.8.0_192。 ```java "http-nio-127.0.0.1-8300-exec-97" #195 daemon prio=5 os_prio=0 tid=0x00007f03513a6000 nid=0x4e6 runnable [0x00007f02eab59000] java.lang.Thread.State: RUNNABLE at java.util.WeakHashMap.getEntry(WeakHashMap.java:431) at java.util.WeakHashMap.containsKey(WeakHashMap.java:417) at com.alibaba.ttl.threadpool.agent.TtlExtensionTransformletManager.collectExtensionTransformlet(TtlExtensionTransformletManager.java:67) at com.alibaba.ttl.threadpool.agent.TtlTransformer.transform(TtlTransformer.java:68) at sun.instrument.TransformerManager.transform(TransformerManager.java:188) at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:428) at sun.misc.Unsafe.defineClass(Native Method) at...