RELEASE NOTES FOR: 21.0.12
====================================================================================================

Notes generated: Fri Mar 20 06:13:14 CET 2026

Hint: Prefix bug IDs with https://bugs.openjdk.org/browse/ to reach the relevant JIRA entry.

JAVA ENHANCEMENT PROPOSALS (JEP):

  None.

RELEASE NOTES:

  None.

ALL FIXED ISSUES, BY COMPONENT AND PRIORITY:

client-libs/2d:
  (P4) JDK-8358058: sun/java2d/OpenGL/DrawImageBg.java Test fails intermittently
  (P4) JDK-8369335: Two  sun/java2d/OpenGL tests fail on Windows after JDK-8358058

client-libs/java.awt:
  (P3) JDK-8376233: Clean up code in Desktop native peer

client-libs/javax.swing:
  (P3) JDK-8365625: Can't change accelerator colors in Windows L&F
  (P3) JDK-8374506: Incorrect positioning of arrow icon in parent JMenu in Windows L&F
  (P3) JDK-8373650: Test "javax/swing/JMenuItem/6458123/ManualBug6458123.java" fails because the check icons are not aligned properly as expected
  (P4) JDK-8365379: SU3.applyInsets may produce wrong results

core-libs/java.lang:
  (P4) JDK-8298783: java/lang/ref/FinalizerHistogramTest.java failed with "RuntimeException: MyObject is not found in test output"

core-libs/java.lang.invoke:
  (P4) JDK-8373832: Test java/lang/invoke/TestVHInvokerCaching.java tests nothing

core-libs/java.lang.module:
  (P4) JDK-8183336: Better cleanup for jdk/test/java/lang/module/customfs/ModulesInCustomFileSystem.java

core-libs/java.net:
  (P4) JDK-8368625: com/sun/net/httpserver/ServerStopTerminationTest.java fails intermittently
  (P4) JDK-8373704: Improve "SocketException: Protocol family unavailable" message
  (P4) JDK-8366031: Mark com/sun/nio/sctp/SctpChannel/CloseDescriptors.java as intermittent

core-libs/java.nio:
  (P4) JDK-8357280: (bf) Remove @requires tags from java/nio/Buffer/LimitDirectMemory[NegativeTest].java

hotspot/compiler:
  (P3) JDK-8378353: [PPC64] StringCoding.countPositives causes errors when the length is not a proper 32 bit int
  (P4) JDK-8368866: compiler/codecache/stress/UnexpectedDeoptimizationTest.java intermittent timed out
  (P4) JDK-8286865: vmTestbase/vm/mlvm/meth/stress/jni/nativeAndMH/Test.java fails with Out of space in CodeCache

hotspot/gc:
  (P4) JDK-8378561: Mark gc/shenandoah/compiler/TestLinkToNativeRBP.java as /native

hotspot/jfr:
  (P2) JDK-8368670: Deadlock in JFR on event register + class load
  (P2) JDK-8341427: JFR: Adjust object sampler span handling
  (P2) JDK-8364190: JFR: RemoteRecordingStream withers don't work

hotspot/jvmti:
  (P4) JDK-8277444: Data race between JvmtiClassFileReconstituter::copy_bytecodes and class linking

hotspot/runtime:
  (P4) JDK-8370492: [Linux] Update cpu shares to cpu.weight mapping function
  (P4) JDK-8374711: Hotspot runtime/CommandLine/OptionsValidation/TestOptionsWithRanges fails without printing the option name
  (P4) JDK-8367485: os::physical_memory is broken in 32-bit JVMs when running on 64-bit OSes
  (P4) JDK-8357086: os::xxx functions returning memory size should return size_t
  (P4) JDK-8371503: RETAIN_IMAGE_AFTER_TEST do not work for some tests
  (P4) JDK-8338883: Show warning when CreateCoredumpOnCrash set, but core dump will not happen

hotspot/svc:
  (P3) JDK-8359472: JVM crashes when attaching a dynamic agent before JVMTI_PHASE_LIVE

infrastructure:
  (P4) JDK-8378775: Bump update version for OpenJDK: jdk-21.0.12

security-libs/java.security:
  (P4) JDK-8360882: Tests throw SkippedException when they should fail

security-libs/javax.net.ssl:
  (P4) JDK-8366182: Some PKCS11Tests are being skipped when they shouldn't

security-libs/jdk.security:
  (P4) JDK-8371262: sun/security/pkcs11/Cipher/KeyWrap tests may silently skip
  (P4) JDK-8365861: test/jdk/sun/security/pkcs11/Provider/ tests skipped without SkippedException

tools/javac:
  (P4) JDK-8369851: Remove darcy author tags from langtools tests

tools/jpackage:
  (P4) JDK-8378802: [21u] backport changes to TKit.java by JDK-8352419
  (P4) JDK-8375080: The tools/jpackage/windows/Win8365790Test.java may fail with ClassNotFoundException: jtreg.SkippedException

tools/jshell:
  (P4) JDK-8350749: Upgrade JLine to 3.29.0