Java代理DeadLock启动时，锁定ClassLoader和[I？

Question

具有两个javaagent的应用程序陷入死锁(在执行main之前)。

为什么有一个线程试图获得[I**？的锁为什么会有一个死掉的家伙？**

J堆栈的死锁输出：

Found one Java-level deadlock:
=============================
"com.taobao.diamond.client.Worker.longPullingdefault":
  waiting to lock monitor 0x00007fb6341d0ec8 (object 0x000000073e8efe20, a [I),
  which is held by "oneagent plugin Bsnt-agent start"
"oneagent plugin Bsnt-agent start":
  waiting to lock monitor 0x00007fb6940038d8 (object 0x0000000766224ec8, a com.bilibili.ntib.agent.starter.SandboxClassLoader),
  which is held by "oneagent plugin msha-java-agent start"
"oneagent plugin msha-java-agent start":
  waiting to lock monitor 0x00007fb6341d0ec8 (object 0x000000073e8efe20, a [I),
  which is held by "oneagent plugin Bsnt-agent start"

Java stack information for the threads listed above:
===================================================
"com.taobao.diamond.client.Worker.longPullingdefault":
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureFactory.createClassStructure(ClassStructureFactory.java:57)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.getClassStructure(SandboxClassFileTransformer.java:64)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer._transform(SandboxClassFileTransformer.java:117)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.transform(SandboxClassFileTransformer.java:84)
    at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
    at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:428)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    - locked <0x00000007435e1620> (a java.lang.Object)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at com.taobao.diamond.client.impl.CacheData.safeNotifyListener(CacheData.java:145)
    at com.taobao.diamond.client.impl.CacheData.checkListenerMd5(CacheData.java:136)
    at com.taobao.diamond.client.impl.ClientWorker$LongPullingRunnable.run(ClientWorker.java:451)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
"oneagent plugin Bsnt-agent start":
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureFactory.createClassStructure(ClassStructureFactory.java:57)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.getClassStructure(SandboxClassFileTransformer.java:64)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer._transform(SandboxClassFileTransformer.java:117)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.transform(SandboxClassFileTransformer.java:84)
    at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
    at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:428)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    - locked <0x000000073e463248> (a com.navercorp.pinpoint.common.plugin.PluginLoaderClassLoader)
    at com.navercorp.pinpoint.common.plugin.PluginLoaderClassLoader.loadClass(PluginLoaderClassLoader.java:45)
    - locked <0x000000073e463248> (a com.navercorp.pinpoint.common.plugin.PluginLoaderClassLoader)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at com.navercorp.pinpoint.plugin.jdbc.ppas.PPASPlugin.<init>(PPASPlugin.java:29)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at java.lang.Class.newInstance(Class.java:442)
    at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380)
    at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
    at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
    at com.navercorp.pinpoint.common.plugin.PluginLoader.load(PluginLoader.java:66)
    at com.navercorp.pinpoint.common.plugin.PluginLoader.load(PluginLoader.java:47)
    at com.navercorp.pinpoint.profiler.plugin.ProfilerPluginLoader.load(ProfilerPluginLoader.java:84)
    at com.navercorp.pinpoint.profiler.plugin.DefaultPluginContextLoadResult.load(DefaultPluginContextLoadResult.java:80)
    at com.navercorp.pinpoint.profiler.plugin.DefaultPluginContextLoadResult.<init>(DefaultPluginContextLoadResult.java:70)
    at com.navercorp.pinpoint.profiler.context.provider.PluginContextLoadResultProvider.get(PluginContextLoadResultProvider.java:68)
    at com.navercorp.pinpoint.profiler.context.provider.PluginContextLoadResultProvider.get(PluginContextLoadResultProvider.java:34)
    at com.google.inject.internal.ProviderInternalFactory.provision(ProviderInternalFactory.java:81)
    at com.google.inject.internal.BoundProviderFactory.provision(BoundProviderFactory.java:72)
    at com.google.inject.internal.ProviderInternalFactory.circularGet(ProviderInternalFactory.java:61)
    at com.google.inject.internal.BoundProviderFactory.get(BoundProviderFactory.java:62)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1092)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.internal.SingletonScope$1.get(SingletonScope.java:194)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:41)
    at com.google.inject.internal.InjectorImpl$2$1.call(InjectorImpl.java:1019)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1092)
    at com.google.inject.internal.InjectorImpl$2.get(InjectorImpl.java:1015)
    at com.navercorp.pinpoint.profiler.context.provider.ApplicationServerTypeProvider.get(ApplicationServerTypeProvider.java:62)
    at com.navercorp.pinpoint.profiler.context.provider.ApplicationServerTypeProvider.get(ApplicationServerTypeProvider.java:36)
    at com.google.inject.internal.ProviderInternalFactory.provision(ProviderInternalFactory.java:81)
    at com.google.inject.internal.BoundProviderFactory.provision(BoundProviderFactory.java:72)
    at com.google.inject.internal.ProviderInternalFactory.circularGet(ProviderInternalFactory.java:61)
    at com.google.inject.internal.BoundProviderFactory.get(BoundProviderFactory.java:62)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1092)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.internal.SingletonScope$1.get(SingletonScope.java:194)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:41)
    at com.google.inject.internal.InternalInjectorCreator$1.call(InternalInjectorCreator.java:205)
    at com.google.inject.internal.InternalInjectorCreator$1.call(InternalInjectorCreator.java:199)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1085)
    at com.google.inject.internal.InternalInjectorCreator.loadEagerSingletons(InternalInjectorCreator.java:199)
    at com.google.inject.internal.InternalInjectorCreator.injectDynamically(InternalInjectorCreator.java:180)
    at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:110)
    at com.google.inject.Guice.createInjector(Guice.java:99)
    at com.google.inject.Guice.createInjector(Guice.java:84)
    at com.navercorp.pinpoint.profiler.context.module.DefaultApplicationContext.<init>(DefaultApplicationContext.java:145)
    at com.navercorp.pinpoint.profiler.DefaultAgent.newApplicationContext(DefaultAgent.java:127)
    at com.navercorp.pinpoint.profiler.DefaultAgent.<init>(DefaultAgent.java:107)
    at com.navercorp.pinpoint.profiler.DefaultAgent.<init>(DefaultAgent.java:70)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.navercorp.pinpoint.bootstrap.AgentClassLoader$2.call(AgentClassLoader.java:78)
    at com.navercorp.pinpoint.bootstrap.ContextClassLoaderExecuteTemplate.execute(ContextClassLoaderExecuteTemplate.java:42)
    at com.navercorp.pinpoint.bootstrap.AgentClassLoader.boot(AgentClassLoader.java:73)
    at com.navercorp.pinpoint.bootstrap.PinpointStarter.run(PinpointStarter.java:111)
    at com.navercorp.pinpoint.bootstrap.PinpointBootStrap.bootstrap(PinpointBootStrap.java:255)
    at com.navercorp.pinpoint.bootstrap.PinpointBootStrap.premain(PinpointBootStrap.java:40)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.alibaba.oneagent.plugin.TraditionalPlugin.start(TraditionalPlugin.java:109)
    at com.alibaba.oneagent.plugin.PluginManagerImpl.startOnePlugin(PluginManagerImpl.java:302)
    at com.alibaba.oneagent.plugin.PluginManagerImpl.access$200(PluginManagerImpl.java:31)
    at com.alibaba.oneagent.plugin.PluginManagerImpl$2.run(PluginManagerImpl.java:333)
    at java.lang.Thread.run(Thread.java:748)
"oneagent plugin msha-java-agent start":
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureFactory.createClassStructure(ClassStructureFactory.java:57)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.getClassStructure(SandboxClassFileTransformer.java:64)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer._transform(SandboxClassFileTransformer.java:117)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.SandboxClassFileTransformer.transform(SandboxClassFileTransformer.java:84)
    at sun.instrument.TransformerManager.transform(TransformerManager.java:188)
    at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:428)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    - locked <0x000000073e0a65f8> (a java.lang.Object)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:411)
    - locked <0x0000000766224ec8> (a com.bilibili.ntib.agent.starter.SandboxClassLoader)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.classloader.RoutingURLClassLoader$1.loadClass(RoutingURLClassLoader.java:74)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.classloader.ClassLoadingLock.loadingInLock(ClassLoadingLock.java:55)
    - locked <0x000000073e0a5610> (a java.lang.Object)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.classloader.RoutingURLClassLoader.loadClass(RoutingURLClassLoader.java:63)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at com.bilibili.ntib.agent.sandbox.module.SandboxFilter.doClassFilter(SandboxFilter.java:97)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.ExtFilterMatcher.matchingClassStructure(ExtFilterMatcher.java:59)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.ExtFilterMatcher._matching(ExtFilterMatcher.java:113)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.ExtFilterMatcher.matching(ExtFilterMatcher.java:79)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.GroupMatcher$And.matching(GroupMatcher.java:52)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreLoadedClassDataSource.find(DefaultCoreLoadedClassDataSource.java:106)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreLoadedClassDataSource.findForReTransform(DefaultCoreLoadedClassDataSource.java:73)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultModuleEventWatcher.watch(DefaultModuleEventWatcher.java:186)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultModuleEventWatcher.watch(DefaultModuleEventWatcher.java:158)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultModuleEventWatcher.watch(DefaultModuleEventWatcher.java:150)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.SandboxProtector$2.invoke(SandboxProtector.java:91)
    at com.sun.proxy.$Proxy56.watch(Unknown Source)
    at com.bilibili.ntib.agent.sandbox.module.MshaSandboxModule.registerAspectPlugins(MshaSandboxModule.java:123)
    at com.bilibili.ntib.agent.sandbox.module.MshaSandboxModule.loadAspectPlugins(MshaSandboxModule.java:55)
    at com.bilibili.ntib.agent.sandbox.module.MshaSandboxModule.onActive(MshaSandboxModule.java:44)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.callAndFireModuleLifeCycle(DefaultCoreModuleManager.java:120)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.active(DefaultCoreModuleManager.java:433)
    - locked <0x0000000737424d18> (a com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.markActiveOnLoadIfNecessary(DefaultCoreModuleManager.java:338)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.load(DefaultCoreModuleManager.java:193)
    - locked <0x0000000737424d18> (a com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.access$300(DefaultCoreModuleManager.java:38)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager$InnerModuleLoadCallback.onLoad(DefaultCoreModuleManager.java:580)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.ModuleJarLoader.loadingModules(ModuleJarLoader.java:93)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.ModuleJarLoader.load(ModuleJarLoader.java:129)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.ModuleLibLoader.load(ModuleLibLoader.java:77)
    at com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager.reset(DefaultCoreModuleManager.java:607)
    - locked <0x0000000737424d18> (a com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.manager.impl.DefaultCoreModuleManager)
    at com.bilibili.ntib.agent.boot.sandbox.AgentModuleManager.initManager(AgentModuleManager.java:120)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.bilibili.ntib.agent.starter.initializer.SandboxAgentInitializer.init(SandboxAgentInitializer.java:18)
    at com.bilibili.ntib.agent.starter.AgentLauncher.launch(AgentLauncher.java:53)
    at com.bilibili.ntib.agent.starter.AgentMain.premain(AgentMain.java:24)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.alibaba.oneagent.plugin.TraditionalPlugin.start(TraditionalPlugin.java:109)
    at com.alibaba.oneagent.plugin.PluginManagerImpl.startOnePlugin(PluginManagerImpl.java:302)
    at com.alibaba.oneagent.plugin.PluginManagerImpl.access$200(PluginManagerImpl.java:31)
    at com.alibaba.oneagent.plugin.PluginManagerImpl$2.run(PluginManagerImpl.java:333)
    at java.lang.Thread.run(Thread.java:748)

Found 1 deadlock.

jstack：https://pastebin.com/z1frQepX的全部输出

jstack -m：https://pastebin.com/t6aWE6K7的全部输出

一些已实现的源代码：

• com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.util.matcher.structure.ClassStructureImplByAsm
• com.bilibili.ntib.third.com.alibaba.jvm.sandbox.core.classloader.RoutingURLClassLoader
• com.navercorp.pinpoint.common.plugin.PluginLoaderClassLoader
• com.bilibili.ntib.agent.starter.SandboxClassLoader：

class SandboxClassLoader extends URLClassLoader {

    SandboxClassLoader(final String namespace) throws Throwable {
        super(getServiceJar());
    }

    private static URL[] getServiceJar() throws IOException {
        // ...
        return urls;
    }

    @Override
    public URL getResource(String name) {
        URL url = super.getResource(name);
        return url;
    }

    @Override
    public Enumeration<URL> getResources(String name) throws IOException {
        Enumeration<URL> urls = super.getResources(name);
        return urls;
    }
}

• com.alibaba.oneagent

Java版本：Java HotSpot(TM) 64-Bit Server VM; 1.8.0_172; 25.172-b11; mixed mode

Answer 1

查看jstack输出，我们看到以下内容：

1. com.taobao.diamond.client.Worker.longPullingdefault调用堆栈

- `ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)`: The `<init>` tells you that something happens while executing a constructor or otherwise initialising the instance of an object under construction, i.e. while assigning default values to fields. the latter is the case here, because line 400 assigns a value to `ClassStructureImplByAsm.annotationTypeClassStructuresLazyGet` of type `LazyGet`. More precisely, an instance of an anonymous `LazyGet<List<ClassStructure>>` subclass is being created and assigned.

- Looking forther down the first call stack, we see that `CacheData.safeNotifyListener` tries to call `ClassLoader.loadClass`. At the beginning of that method in the JDK source code you see `synchronized (getClassLoadingLock(name))` and in `getClassLoadingLock` you see that by default (non-parallel-capable classloader) it simply synchronises on `this`, i.e. on the classloader instance.

1. oneagent plugin Bsnt-agent start调用堆栈

- Again, the top of the call stack is `ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)`, just like before.

- Again, `ClassLoader.loadClass` gets triggered and synchronises on the classloader, this time called by `PluginLoaderClassLoader.loadClass(PluginLoaderClassLoader.java:45)`.

1. oneagent plugin msha-java-agent start调用堆栈

- Again, the top of the call stack is `ClassStructureImplByAsm.<init>(ClassStructureImplByAsm.java:400)`, just like before.

- Again, `ClassLoader.loadClass` gets triggered and synchronises on the classloader, this time indirectly called by `SandboxFilter.doClassFilter(SandboxFilter.java:97)`, further up the stack by `RoutingURLClassLoader$1.loadClass(RoutingURLClassLoader.java:74)`. A `SandboxClassLoader` also seems to be involved.

我不确定，但看起来死锁似乎发生在ClassLoader基类中，而三个单独的线程试图同时对它进行同步。

也许推迟在延迟的getter方法中分配ClassStructureImplByAsm.annotationTypeClassStructuresLazyGet会有帮助，例如，当第一次需要成员而仍然需要null时，getter会创建匿名子类实例。否则，它只返回已经分配的成员。我不知道您是否是ClassStructureImplByAsm的维护者，并且可以更改它，但即使不是，您至少可以在本地对修改进行分叉和测试，然后再为上游项目创建一个拉请求。

对不起，我不能说更具体的话，因为我不能编译和运行jstack协议来重现您的问题。复制者示例项目(即MCVE )会更好。