The following test failed in the JDK26 CI:

applications/jcstress/coherence.java

Here's a snippet from the log file:

#section:driver
----------messages:(9/432)*----------
command: driver applications.jcstress.JcstressRunner -v -t org.openjdk.jcstress.tests.coherence\\.
reason: User specified action: run driver/timeout=21600 applications.jcstress.JcstressRunner -v -t org.openjdk.jcstress.tests.coherence\\.
exclusiveAccess wait time (seconds): 0.0
started: Fri Jul 11 13:45:47 BST 2025
Mode: agentvm
Agent id: 2
Process id: 5218
finished: Fri Jul 11 13:52:25 BST 2025
elapsed time (seconds): 398.297
----------configuration:(16/2436)----------

<snip>

Exception in thread "main" java.lang.AssertionError: TEST FAILURES:
org.openjdk.jcstress.tests.coherence.varHandles.byteBuffer.direct.little.volatiles.CharTest [-Djava.io.tmpdir=/System/Volumes/Data/mesos/work_dir/slaves/d2398cde-9325-49c3-b030-8961a4f0a253-S577412/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/08ca9cc2-48ca-4349-8f18-10965ef30656/runs/c820cfee-458d-41fa-b4b0-4c4b45808a99/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -Djava.io.tmpdir=/System/Volumes/Data/mesos/work_dir/slaves/d2398cde-9325-49c3-b030-8961a4f0a253-S577412/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/08ca9cc2-48ca-4349-8f18-10965ef30656/runs/c820cfee-458d-41fa-b4b0-4c4b45808a99/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -XX:MaxRAMPercentage=25, -Dtest.boot.jdk=/System/Volumes/Data/mesos/work_dir/jib-master/install/jdk/24/36/bundles/macos-aarch64/jdk-24_macos-aarch64_bin.tar.gz/jdk-24.jdk/Contents/Home, -Djava.io.tmpdir=/System/Volumes/Data/mesos/work_dir/slaves/d2398cde-9325-49c3-b030-8961a4f0a253-S577412/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/08ca9cc2-48ca-4349-8f18-10965ef30656/runs/c820cfee-458d-41fa-b4b0-4c4b45808a99/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/tmp, -XX:-UseCompressedOops, -XX:+HeapDumpOnOutOfMemoryError, -XX:+CrashOnOutOfMemoryError] had failed with the VM error.

at org.openjdk.jcstress.infra.grading.ExceptionReportPrinter.work(ExceptionReportPrinter.java:63)
at org.openjdk.jcstress.JCStress.parseResults(JCStress.java:162)
at org.openjdk.jcstress.JCStress.run(JCStress.java:85)
at org.openjdk.jcstress.Main.main(Main.java:57)
]cout/cerr
java.lang.Error: jctress test finished with nonzero exitcode 1
at applications.jcstress.JcstressRunner.main(JcstressRunner.java:89)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:565)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:335)
at java.base/java.lang.Thread.run(Thread.java:1474)

JavaTest Message: Test threw exception: java.lang.Error
JavaTest Message: shutting down test

result: Failed. Execution failed: `main' threw exception: java.lang.Error: jctress test finished with nonzero exitcode 1


test result: Failed. Execution failed: `main' threw exception: java.lang.Error: jctress test finished with nonzero exitcode 1


Here's snippets from the hs_err_pid file:

# Internal Error (/System/Volumes/Data/mesos/work_dir/slaves/d2398cde-9325-49c3-b030-8961a4f0a253-S577086/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/1f3cfa0a-4572-4136-b5f2-98913154b9e8/runs/c26e9a91-2751-4097-8f37-d3ee1ba2714d/workspace/open/src/hotspot/share/utilities/debug.cpp:281), pid=7210, tid=26439
# fatal error: OutOfMemory encountered: Java heap space
#
# JRE version: Java(TM) SE Runtime Environment (26.0+6) (fastdebug build 26-ea+6-582)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 26-ea+6-582, mixed mode, sharing, tiered, compressed class ptrs, g1 gc, bsd-aarch64)
# Core dump will be written. Default location: core.7210

<snip>


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

Current thread (0x000000012e82e210): JavaThread "JcstressThread_actor2" daemon [_thread_in_vm, id=26439, stack(0x000000016f978000,0x000000016fb7b000) (2060K)]

Stack: [0x000000016f978000,0x000000016fb7b000], sp=0x000000016fb7a450, free space=2057k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x121dc24] VMError::report(outputStream*, bool)+0x1b00 (debug.cpp:281)
V [libjvm.dylib+0x12214c4] VMError::report_and_die(int, char const*, char const*, char*, Thread*, unsigned char*, void const*, void const*, char const*, int, unsigned long)+0x55c
V [libjvm.dylib+0x5a954c] DebuggingContext::~DebuggingContext()+0x0
V [libjvm.dylib+0x5a99fc] report_java_out_of_memory(char const*)+0xf8
V [libjvm.dylib+0xdb4c00] MemAllocator::Allocation::check_out_of_memory()+0x134
V [libjvm.dylib+0xdb5eb0] MemAllocator::allocate() const+0xd4
V [libjvm.dylib+0x87dd68] InstanceKlass::allocate_instance(JavaThread*)+0x9c
V [libjvm.dylib+0xfc5238] OptoRuntime::new_instance_C(Klass*, JavaThread*)+0x448
Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
v ~RuntimeStub::C2 Runtime new_instance_blob 0x000000011648d78c
J 681 c2 org.openjdk.jcstress.tests.coherence.varHandles.byteBuffer.direct.little.volatiles.CharTest_jcstress.jcstress_consume_reinit(Lorg/openjdk/jcstress/util/Counter;[Lorg/openjdk/jcstress/tests/coherence/varHandles/byteBuffer/direct/little/volatiles/CharTest;[Lorg/openjdk/jcstress/infra/results/CC_Result;Lorg/openjdk/jcstress/tests/coherence/varHandles/byteBuffer/direct/little/volatiles/CharTest;II)V (80 bytes) @ 0x00000001169ffa50 [0x00000001169ff740+0x0000000000000310]
j org.openjdk.jcstress.tests.coherence.varHandles.byteBuffer.direct.little.volatiles.CharTest_jcstress$JcstressThread_actor2.jcstress_iteration_actor2()Lorg/openjdk/jcstress/util/Counter;+156
j org.openjdk.jcstress.tests.coherence.varHandles.byteBuffer.direct.little.volatiles.CharTest_jcstress$JcstressThread_actor2.internalRun()Lorg/openjdk/jcstress/util/Counter;+1
j org.openjdk.jcstress.infra.runners.CounterThread.run()V+2
v ~StubRoutines::Stub Generator call_stub_stub 0x000000011644048c
Lock stack of current Java thread (top to bottom):

I'm starting this issue in hotspot/compiler for initial triage since it
looks like the compiler was requesting memory when we ran out.