The following test timed out in the JDK20 CI:

java/lang/Thread/virtual/stress/Skynet.java#id0

Here's a snippet from the log file:

#section:main
----------messages:(8/284)----------
command: main Skynet
reason: User specified action: run main/othervm/timeout=300 Skynet
started: Mon Dec 12 08:17:19 GMT 2022
Mode: othervm [/othervm specified]
Timeout information:
--- Timeout information end.
finished: Mon Dec 12 09:12:45 GMT 2022
elapsed time (seconds): 3325.458
----------configuration:(0/0)----------
----------System.out:(1108/69603)----------
Result: 499999500000 in 43750 ms
Timeout refired 3000 times
Exception in VM (AttachListener::init) :
java.lang.OutOfMemoryError: Java heap space
Exception in VM (AttachListener::init) :
java.lang.OutOfMemoryError: Java heap space
Exception in VM (AttachListener::init) :
java.lang.OutOfMemoryError: Java heap space
Exception in VM (AttachListener::init) :
java.lang.OutOfMemoryError: Java heap space
2022-12-12 09:07:47
Full thread dump Java HotSpot(TM) 64-Bit Server VM (20-ea+27-2213 compiled mode, sharing):

Threads class SMR info:
_java_thread_list=0x00007fbcf8ecc730, length=10, elements={
0x00007fbcfa008e10, 0x00007fbcf900f010, 0x00007fbcf901a810, 0x00007fbcfa025c10,
0x00007fbcf9820810, 0x00007fbcf9829210, 0x00007fbcf9829a10, 0x00007fbcfa026a10,
0x00007fbcfa733410, 0x00007fbcfa79d810
}
_java_thread_list_alloc_cnt=19, _java_thread_list_free_cnt=17, _java_thread_list_max=14, _nested_thread_list_max=0
_tlh_cnt=37426, _tlh_times=97, avg_tlh_time=0.00, _tlh_time_max=10
_deleted_thread_cnt=4, _deleted_thread_times=0, avg_deleted_thread_time=0.00, _deleted_thread_time_max=0
_delete_lock_wait_cnt=0, _delete_lock_wait_max=1
_to_delete_list_cnt=0, _to_delete_list_max=2

"main" #1 [9219] prio=5 os_prio=31 cpu=803.13ms elapsed=3027.52s tid=0x00007fbcfa008e10 nid=9219 in Object.wait() [0x0000700003098000]
   java.lang.Thread.State: WAITING (on object monitor)
Thread: 0x00007fbcfa008e10 [0x2403] State: _at_safepoint _at_poll_safepoint 0
   JavaThread state: _thread_blocked
at java.lang.Object.wait0(java.base@20-ea/Native Method)
- waiting on <no object reference available>
at java.lang.Object.wait(java.base@20-ea/Object.java:366)
at java.lang.Thread.join(java.base@20-ea/Thread.java:2115)
- locked <0x000008002ce01b20> (a java.lang.Thread)
at java.lang.Thread.join(java.base@20-ea/Thread.java:2191)
at com.sun.javatest.regtest.agent.MainWrapper.main(MainWrapper.java:72)

<snip>

"RuntimeWorker#1" os_prio=31 cpu=30.75ms elapsed=3279.26s tid=0x00007fbcf8d0dd20 nid=17667 runnable

"RuntimeWorker#2" os_prio=31 cpu=30.38ms elapsed=3279.26s tid=0x00007fbcf8d0e880 nid=17411 runnable

"VM Periodic Task Thread" os_prio=31 cpu=584.99ms elapsed=3273.08s tid=0x00007fbcfaf72e20 nid=40707 waiting on condition

JNI global refs: 9, weak refs: 0

Heap
 ZHeap used 768M, capacity 768M, max capacity 768M
 Metaspace used 2906K, committed 3072K, reserved 1114112K
  class space used 90K, committed 192K, reserved 1048576K

----------System.err:(0/0)----------
----------rerun:(42/6400)*----------

<snip>

result: Error. Program `/System/Volumes/Data/mesos/work_dir/jib-master/install/jdk-20+27-2213/macosx-x64-debug.jdk/jdk-20/fastdebug/bin/java' timed out (timeout set to 3000000ms, elapsed time including timeout handling was 3325444ms).