JDK-8337331 : crash: pinned virtual thread will lead to jvm crash when running with the javaagent option
  • Type: Bug
  • Component: hotspot
  • Sub-Component: jvmti
  • Affected Version: 21.0.5,23
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • OS: linux
  • CPU: x86
  • Submitted: 2024-07-29
  • Updated: 2024-09-07
  • Resolved: 2024-08-09
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
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JDK 21 JDK 23 JDK 24
21.0.6Fixed 23.0.2Fixed 24 b11Fixed
Related Reports
Relates :  
JDK-8339701 - Test TestPinCaseWithCFLH.java fails with -Xcomp
Relates :  
JDK-8330146 - assert(!_thread->is_in_any_VTMS_transition()) failed
Description
JDK HEAD commit: 476d2ae69d6

Testcase:
1. Add javaagent which will change the class file (CFLH will be touched)
2. A virtual thread need to be pinned
3. Add the option `-Djdk.tracePinnedThreads=full`
I add the testcase in the attachment.
I think this and JDK-8330146  should be backport for JDK21. JDK21 will run into deadlock now.
Update: I pull some new commits and now HEAD is 657c0bddf90. The release version will run into deadlock instead of causing jvm crash. The slowdebug version will run into jvm crash.

Cause:
When the virtual thread is pinned, it will use the class `PinnedThreadPrinter` to report. When loading this class, javaagent will change its content and post the CFLH. However, JvmtiClassFileLoadHookPoster should not call `post` for vthreads which are in VTMS transition.

Solution:
Add condition judegement for `JvmtiClassFileLoadHookPoster::post`

The crash log:

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007f861178c8b1, pid=41748, tid=41772
#
# JRE version: OpenJDK Runtime Environment (24.0) (build 24-internal-adhoc.tjw378335.jdk)
# Java VM: OpenJDK 64-Bit Server VM (24-internal-adhoc.tjw378335.jdk, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0x2f58b1]  AccessInternal::PostRuntimeDispatch<G1BarrierSet::AccessBarrier<548964ul, G1BarrierSet>, (AccessInternal::BarrierType)2, 548964ul>::oop_access_barrier(void*)+0x1
#
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# If you would like to submit a bug report, please visit:
#   https://bugreport.java.com/bugreport/crash.jsp
#

---------------  S U M M A R Y ------------


Host: Intel(R) Xeon(R) Platinum 8163 CPU @ 2.50GHz, 96 cores, 503G, Alibaba Group Enterprise Linux Server release 7.2 (Paladin)
Time: Mon Jul 29 15:08:54 2024 CST elapsed time: 0.128565 seconds (0d 0h 0m 0s)

---------------  T H R E A D  ---------------

Current thread (0x00007f8528061400):  JavaThread "pool-1-thread-1"        [_thread_in_vm, id=41772, stack(0x00007f85ab13a000,0x00007f85ab23b000) (1028K)]

Stack: [0x00007f85ab13a000,0x00007f85ab23b000],  sp=0x00007f85ab237c10,  free space=1015k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x2f58b1]  AccessInternal::PostRuntimeDispatch<G1BarrierSet::AccessBarrier<548964ul, G1BarrierSet>, (AccessInternal::BarrierType)2, 548964ul>::oop_access_barrier(void*)+0x1  (access.inline.hpp:81)
V  [libjvm.so+0xb2e933]  JvmtiClassFileLoadHookPoster::post_to_env(JvmtiEnv*, bool)+0x163  (jvmtiExport.cpp:270)
V  [libjvm.so+0xb23ce5]  JvmtiExport::post_class_file_load_hook(Symbol*, Handle, Handle, unsigned char**, unsigned char**, JvmtiCachedClassFileData**)+0x1d5  (jvmtiExport.cpp:987)
V  [libjvm.so+0xb53c26]  KlassFactory::create_from_stream(ClassFileStream*, Symbol*, ClassLoaderData*, ClassLoadInfo const&, JavaThread*)+0x176  (klassFactory.cpp:148)
V  [libjvm.so+0x62e33e]  ClassLoader::load_class(Symbol*, PackageEntry*, bool, JavaThread*)+0x24e  (classLoader.cpp:1205)
V  [libjvm.so+0xf707f5]  SystemDictionary::load_instance_class_impl(Symbol*, Handle, JavaThread*)+0x235  (systemDictionary.cpp:1279)
V  [libjvm.so+0xf6f148]  SystemDictionary::load_instance_class(Symbol*, Handle, JavaThread*)+0x18  (systemDictionary.cpp:1343)
V  [libjvm.so+0xf6f80f]  SystemDictionary::resolve_instance_class_or_null(Symbol*, Handle, Handle, JavaThread*)+0x5ef  (systemDictionary.cpp:702)
V  [libjvm.so+0xf6fc50]  SystemDictionary::resolve_or_null(Symbol*, Handle, Handle, JavaThread*)+0x40  (systemDictionary.cpp:343)
V  [libjvm.so+0xf6fdae]  SystemDictionary::resolve_or_fail(Symbol*, Handle, Handle, bool, JavaThread*)+0x1e  (systemDictionary.cpp:321)
V  [libjvm.so+0x6b2616]  ConstantPool::klass_ref_at(int, Bytecodes::Code, JavaThread*)+0x296  (constantPool.cpp:599)
V  [libjvm.so+0xb83726]  LinkInfo::LinkInfo(constantPoolHandle const&, int, Bytecodes::Code, JavaThread*)+0x46  (linkResolver.cpp:278)
V  [libjvm.so+0xb8fcaa]  LinkResolver::resolve_invoke(CallInfo&, Handle, constantPoolHandle const&, int, Bytecodes::Code, JavaThread*)+0x28a  (linkResolver.cpp:1745)
V  [libjvm.so+0x9155e6]  InterpreterRuntime::resolve_invoke(JavaThread*, Bytecodes::Code)+0x1c6  (interpreterRuntime.cpp:842)
V  [libjvm.so+0x915ab5]  InterpreterRuntime::resolve_from_cache(JavaThread*, Bytecodes::Code)+0xd5  (interpreterRuntime.cpp:1004)
j  java.lang.VirtualThread$VThreadContinuation.onPinned(Ljdk/internal/vm/Continuation$Pinned;)V+42 java.base@24-internal
j  jdk.internal.vm.Continuation.onPinned0(I)V+5 java.base@24-internal
j  jdk.internal.vm.Continuation.yield0(Ljdk/internal/vm/ContinuationScope;Ljdk/internal/vm/Continuation;)Z+325 java.base@24-internal
j  jdk.internal.vm.Continuation.yield(Ljdk/internal/vm/ContinuationScope;)Z+69 java.base@24-internal
j  java.lang.VirtualThread.yieldContinuation()Z+8 java.base@24-internal
j  java.lang.VirtualThread.parkNanos(J)V+64 java.base@24-internal
j  java.lang.VirtualThread.sleepNanos(J)V+70 java.base@24-internal
j  java.lang.Thread.sleepNanos(J)V+26 java.base@24-internal
j  java.lang.Thread.sleep(J)V+25 java.base@24-internal
j  TestPinCaseWithTrace.native2Java(I)I+11
v  ~StubRoutines::call_stub 0x00007f85fb9b5c86
V  [libjvm.so+0x91e014]  JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, JavaThread*)+0x2f4  (javaCalls.cpp:415)
V  [libjvm.so+0x9d3241]  jni_invoke_static(JNIEnv_*, JavaValue*, _jobject*, JNICallType, _jmethodID*, JNI_ArgumentPusher*, JavaThread*) [clone .isra.148] [clone .constprop.253]+0x161  (jni.cpp:888)
V  [libjvm.so+0x9d3d5f]  jni_CallStaticIntMethod+0x14f  (jni.cpp:1580)
C  [libPinJNI.so+0x677]  Java_TestPinCaseWithTrace_nativeFuncPin+0x47  (libPinJNI.c:29)
j  TestPinCaseWithTrace.nativeFuncPin(I)I+0
j  TestPinCaseWithTrace.lambda$main$0()V+4
j  TestPinCaseWithTrace$$Lambda+0x00007f856b003438.run()V+0
j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5 java.base@24-internal
j  java.lang.VirtualThread.run(Ljava/lang/Runnable;)V+66 java.base@24-internal
j  java.lang.VirtualThread$VThreadContinuation$1.run()V+8 java.base@24-internal
j  jdk.internal.vm.Continuation.enter0()V+4 java.base@24-internal
j  jdk.internal.vm.Continuation.enter(Ljdk/internal/vm/Continuation;Z)V+1 java.base@24-internal
J 240  jdk.internal.vm.Continuation.enterSpecial(Ljdk/internal/vm/Continuation;ZZ)V java.base@24-internal (0 bytes) @ 0x00007f85fc22445c [0x00007f85fc224320+0x000000000000013c]
j  jdk.internal.vm.Continuation.run()V+122 java.base@24-internal
j  java.lang.VirtualThread.runContinuation()V+72 java.base@24-internal
j  java.lang.VirtualThread$$Lambda+0x00007f856b064cb8.run()V+4 java.base@24-internal
j  java.util.concurrent.ThreadPoolExecutor.runWorker(Ljava/util/concurrent/ThreadPoolExecutor$Worker;)V+92 java.base@24-internal
j  java.util.concurrent.ThreadPoolExecutor$Worker.run()V+5 java.base@24-internal
j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5 java.base@24-internal
j  java.lang.Thread.run()V+19 java.base@24-internal
v  ~StubRoutines::call_stub 0x00007f85fb9b5c86
V  [libjvm.so+0x91e014]  JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, JavaThread*)+0x2f4  (javaCalls.cpp:415)
V  [libjvm.so+0x91fc43]  JavaCalls::call_virtual(JavaValue*, Handle, Klass*, Symbol*, Symbol*, JavaThread*)+0x223  (javaCalls.cpp:329)
V  [libjvm.so+0x9fa5d3]  thread_entry(JavaThread*, JavaThread*)+0x73  (jvm.cpp:2910)
V  [libjvm.so+0x937c0c]  JavaThread::run()+0x15c  (javaThread.cpp:757)
V  [libjvm.so+0xfbd18f]  Thread::call_run()+0x9f  (thread.cpp:225)
V  [libjvm.so+0xd160aa]  thread_native_entry(Thread*)+0xda  (os_linux.cpp:858)
Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
j  java.lang.VirtualThread$VThreadContinuation.onPinned(Ljdk/internal/vm/Continuation$Pinned;)V+42 java.base@24-internal
j  jdk.internal.vm.Continuation.onPinned0(I)V+5 java.base@24-internal
j  jdk.internal.vm.Continuation.yield0(Ljdk/internal/vm/ContinuationScope;Ljdk/internal/vm/Continuation;)Z+325 java.base@24-internal
j  jdk.internal.vm.Continuation.yield(Ljdk/internal/vm/ContinuationScope;)Z+69 java.base@24-internal
j  java.lang.VirtualThread.yieldContinuation()Z+8 java.base@24-internal
j  java.lang.VirtualThread.parkNanos(J)V+64 java.base@24-internal
j  java.lang.VirtualThread.sleepNanos(J)V+70 java.base@24-internal
j  java.lang.Thread.sleepNanos(J)V+26 java.base@24-internal
j  java.lang.Thread.sleep(J)V+25 java.base@24-internal
j  TestPinCaseWithTrace.native2Java(I)I+11
v  ~StubRoutines::call_stub 0x00007f85fb9b5c86
j  TestPinCaseWithTrace.nativeFuncPin(I)I+0
j  TestPinCaseWithTrace.lambda$main$0()V+4
j  TestPinCaseWithTrace$$Lambda+0x00007f856b003438.run()V+0
j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5 java.base@24-internal
j  java.lang.VirtualThread.run(Ljava/lang/Runnable;)V+66 java.base@24-internal
j  java.lang.VirtualThread$VThreadContinuation$1.run()V+8 java.base@24-internal
j  jdk.internal.vm.Continuation.enter0()V+4 java.base@24-internal
j  jdk.internal.vm.Continuation.enter(Ljdk/internal/vm/Continuation;Z)V+1 java.base@24-internal
J 240  jdk.internal.vm.Continuation.enterSpecial(Ljdk/internal/vm/Continuation;ZZ)V java.base@24-internal (0 bytes) @ 0x00007f85fc22445c [0x00007f85fc224320+0x000000000000013c]
j  jdk.internal.vm.Continuation.run()V+122 java.base@24-internal
j  java.lang.VirtualThread.runContinuation()V+72 java.base@24-internal
j  java.lang.VirtualThread$$Lambda+0x00007f856b064cb8.run()V+4 java.base@24-internal
j  java.util.concurrent.ThreadPoolExecutor.runWorker(Ljava/util/concurrent/ThreadPoolExecutor$Worker;)V+92 java.base@24-internal
j  java.util.concurrent.ThreadPoolExecutor$Worker.run()V+5 java.base@24-internal
j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5 java.base@24-internal
j  java.lang.Thread.run()V+19 java.base@24-internal
v  ~StubRoutines::call_stub 0x00007f85fb9b5c86

---------------  Dead Lock Stack Trace (the other condition)  ------------
The deadlock related stacktrace:

Thread 24 "pool-1-thread-1" hit Breakpoint 5, JvmtiVTMSTransitionDisabler::JvmtiVTMSTransitionDisabler (this=0x7fff8fde5940, thread=0x0) at src/hotspot/share/prims/jvmtiThreadState.cpp:256
256     JvmtiVTMSTransitionDisabler::JvmtiVTMSTransitionDisabler(jthread thread)
(gdb) bt
#0  JvmtiVTMSTransitionDisabler::JvmtiVTMSTransitionDisabler (this=0x7fff8fde5940, thread=0x0) at src/hotspot/share/prims/jvmtiThreadState.cpp:256
#1  0x00007ffff64c691d in JvmtiEnv::SetThreadLocalStorage (this=this@entry=0x7ffff001a2a0, thread=thread@entry=0x0, data=data@entry=0x7effc0bb) at src/hotspot/share/prims/jvmtiEnv.cpp:152
#2  0x00007ffff6479b8e in jvmti_SetThreadLocalStorage (env=0x7ffff001a2a0, thread=0x0, data=0x7effc0bb) at build/linux-x86_64-server-release/hotspot/variant-server/gensrc/jvmtifiles/jvmtiEnter.cpp:1049
#3  0x00007ffff508ab0f in confirmingTLSSet (jvmtienv=jvmtienv@entry=0x7ffff001a2a0, thread=thread@entry=0x0, newValue=newValue@entry=0x7effc0bb) at src/java.instrument/share/native/libinstrument/Reentrancy.c:73
#4  0x00007ffff508abbc in tryToAcquireReentrancyToken (jvmtienv=0x7ffff001a2a0, thread=thread@entry=0x0) at src/java.instrument/share/native/libinstrument/Reentrancy.c:130
#5  0x00007ffff50883c2 in transformClassFile (agent=0x7ffff001a8e0, jnienv=jnienv@entry=0x7ffff02a89a0, loaderObject=loaderObject@entry=0x0, name=name@entry=0x7fff24105478 "java/lang/PinnedThreadPrinter", 
    classBeingRedefined=classBeingRedefined@entry=0x0, protectionDomain=protectionDomain@entry=0x0, class_data_len=8100, class_data=0x7fff241034a0 "\312\376\272\276", new_class_data_len=0x7fff8fde5c64, new_class_data=0x7fff8fde5c68, 
    is_retransformer=0 '\000') at src/java.instrument/share/native/libinstrument/JPLISAgent.c:829
#6  0x00007ffff50872ef in eventHandlerClassFileLoadHook (jvmtienv=<optimized out>, jnienv=0x7ffff02a89a0, class_being_redefined=0x0, loader=0x0, name=0x7fff24105478 "java/lang/PinnedThreadPrinter", protectionDomain=0x0, 
    class_data_len=8100, class_data=0x7fff241034a0 "\312\376\272\276", new_class_data_len=0x7fff8fde5c64, new_class_data=0x7fff8fde5c68) at src/java.instrument/share/native/libinstrument/InvocationAdapter.c:650
#7  0x00007ffff64ec742 in JvmtiClassFileLoadHookPoster::post_to_env (this=0x7fff8fde5d80, env=0x7ffff001a2a0, caching_needed=<optimized out>) at src/hotspot/share/prims/jvmtiExport.cpp:1014
#8  0x00007ffff64e1965 in JvmtiClassFileLoadHookPoster::post_all_envs (this=0x7fff8fde5d80) at src/hotspot/share/prims/jvmtiExport.cpp:987
#9  JvmtiClassFileLoadHookPoster::post (this=0x7fff8fde5d80) at src/hotspot/share/prims/jvmtiExport.cpp:971
#10 JvmtiExport::post_class_file_load_hook (h_name=h_name@entry=0x7fffac09c2d8, class_loader=..., h_protection_domain=..., data_ptr=data_ptr@entry=0x7fff8fde5e90, end_ptr=end_ptr@entry=0x7fff8fde5e98, 
    cache_ptr=cache_ptr@entry=0x7fff8fde5e88) at src/hotspot/share/prims/jvmtiExport.cpp:1105
#11 0x00007ffff65119d6 in check_class_file_load_hook (__the_thread__=0x7ffff02a85e0, cached_class_file=0x7fff8fde5e88, protection_domain=..., loader_data=0x7ffff0205b60, name=0x7fffac09c2d8, stream=0x7fff24105448)
    at src/hotspot/share/classfile/klassFactory.cpp:148
#12 KlassFactory::create_from_stream (stream=0x7fff24105448, name=name@entry=0x7fffac09c2d8, loader_data=0x7ffff0205b60, cl_info=..., __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/classfile/klassFactory.cpp:189
#13 0x00007ffff5fea6de in ClassLoader::load_class (name=name@entry=0x7fffac09c2d8, pkg_entry=pkg_entry@entry=0x7ffff02128e0, search_append_only=search_append_only@entry=false, __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/classfile/classLoader.cpp:1205
#14 0x00007ffff6928a35 in SystemDictionary::load_instance_class_impl (class_name=class_name@entry=0x7fffac09c2d8, class_loader=..., __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/classfile/systemDictionary.cpp:1279
#15 0x00007ffff6927388 in SystemDictionary::load_instance_class (name=name@entry=0x7fffac09c2d8, class_loader=class_loader@entry=..., __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/classfile/systemDictionary.cpp:1343
#16 0x00007ffff6927a4f in SystemDictionary::resolve_instance_class_or_null (name=name@entry=0x7fffac09c2d8, class_loader=..., class_loader@entry=..., protection_domain=..., __the_thread__=0x7ffff02a85e0)
    at src/hotspot/share/classfile/systemDictionary.cpp:702
#17 0x00007ffff6927e90 in SystemDictionary::resolve_or_null (class_name=class_name@entry=0x7fffac09c2d8, class_loader=..., protection_domain=..., __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/classfile/systemDictionary.cpp:343
#18 0x00007ffff6927fee in SystemDictionary::resolve_or_fail (class_name=class_name@entry=0x7fffac09c2d8, class_loader=..., class_loader@entry=..., protection_domain=..., throw_error=throw_error@entry=true, 
    __the_thread__=__the_thread__@entry=0x7ffff02a85e0) at src/hotspot/share/classfile/systemDictionary.cpp:321
#19 0x00007ffff606e526 in ConstantPool::klass_at_impl (__the_thread__=0x7ffff02a85e0, cp_index=44, this_cp=...) at src/hotspot/share/oops/constantPool.cpp:599
#20 ConstantPool::klass_at (__the_thread__=0x7ffff02a85e0, cp_index=44, this=<optimized out>) at src/hotspot/share/oops/constantPool.hpp:381
#21 ConstantPool::klass_ref_at (this=<optimized out>, which=which@entry=5, code=code@entry=Bytecodes::_invokestatic, __the_thread__=__the_thread__@entry=0x7ffff02a85e0) at src/hotspot/share/oops/constantPool.cpp:840
#22 0x00007ffff6541216 in LinkInfo::LinkInfo (this=0x7fff8fde6830, pool=..., index=5, code=Bytecodes::_invokestatic, __the_thread__=0x7ffff02a85e0) at src/hotspot/share/interpreter/linkResolver.cpp:278
#23 0x00007ffff654d79a in LinkResolver::resolve_invokestatic (__the_thread__=0x7ffff02a85e0, index=-1881247760, pool=..., result=...) at src/hotspot/share/interpreter/linkResolver.cpp:1745
#24 LinkResolver::resolve_invoke (result=..., recv=recv@entry=..., pool=..., index=index@entry=5, byte=byte@entry=Bytecodes::_invokestatic, __the_thread__=__the_thread__@entry=0x7ffff02a85e0)
    at src/hotspot/share/interpreter/linkResolver.cpp:1705
#25 0x00007ffff62d2556 in InterpreterRuntime::resolve_invoke (current=0x7ffff02a85e0, bytecode=Bytecodes::_invokestatic) at src/hotspot/share/interpreter/interpreterRuntime.cpp:842
#26 0x00007ffff62d2a25 in InterpreterRuntime::resolve_from_cache (current=0x7ffff02a85e0, bytecode=<optimized out>) at src/hotspot/share/interpreter/interpreterRuntime.cpp:1004


The `JvmtiVTMSTransitionDisabler::JvmtiVTMSTransitionDisabler` cannot jump out the loop since the vthread-1 itself is in VTMS Transition. (VTMS_transition_mark is true)
Comments
Hi, I backported it to JDK23, may I get the approval? I want to backport it to JDK21 after that.
19-08-2024
[jdk23u-fix-request] Approval Request from Jiawei Tang fix the jvm crash / dead lock problem. It's a clean backport.
15-08-2024
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk23u/pull/73 Date: 2024-08-15 01:54:31 +0000
15-08-2024
JDK 21u maintainer comment. This is a very recent change and should get first backported to JDK 23u. Once it has had some soak time in mainline and JDK 23 it can maybe reconsidered for 21u. But not at this point. Therefore, removed the label.
13-08-2024
[jdk21u-fix-request] Approval Request from Jiawei Tang fix the jvm crash / dead lock problem. It's a clean backport.
12-08-2024
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk21u-dev/pull/910 Date: 2024-08-12 08:26:00 +0000
12-08-2024
Changeset: 55c50970 Branch: master Author: Jiawei Tang <jwtang@openjdk.org> Date: 2024-08-09 02:29:15 +0000 URL: https://git.openjdk.org/jdk/commit/55c509708e9b89a7609fd41b6e5a271f250bbacd
09-08-2024
[~jwtang] Thank you for filing this issue. In fact, my fix of JDK-8330146 was not not correct for CFLH. The fix had to be in the post_class_file_load_hook() instead of `JvmtiClassFileLoadHookPoster()` constructor.
29-07-2024
I have read the code in loom and this issue can be resolved by using JFR event instead. But I hope this could be fixed since using javaagent is very common in java application. The root cause is that no new class should be use after the vthread is pinned, since a agent can change the class bytecode and need to use `JvmtiVTMSTransitionDisabler` when transforming class. However, this vthread is in VTMS, it cannot jump out the loop. Using `-Djdk.tracePinnedThreads=full` will use the class `PinnedThreadPrinter` so we end in a deadlock.
29-07-2024
-Djdk.tracePinnedThreads has been very problematic, it has been removed in the loom repo as part of the object monitor changes planned for (hopefully) JDK 24. In its place, the JFR event jdk.VirutalThreadPinned is now recorded in several more cases, and with additional information. This doesn't take from the JVMTI issue reported here, just pointing out that execution of code in "onPinned" when pinned in critical code has been very problematic.
29-07-2024
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/20373 Date: 2024-07-29 09:36:47 +0000
29-07-2024