java-25-openjdk/NEWS

Key:

JDK-X  - https://bugs.openjdk.java.net/browse/JDK-X
CVE-XXXX-YYYY: https://cve.mitre.org/cgi-bin/cvename.cgi?name=XXXX-YYYY

New in release OpenJDK 25.0.1 (2025-10-21):
===========================================

* CVEs
  - CVE-2025-53057
  - CVE-2025-53066
  - CVE-2025-61748
* Changes
  - JDK-8315131: Clarify VarHandle set/get access on 32-bit platforms
  - JDK-8352637: Enhance bytecode verification
  - JDK-8356294: Enhance Path Factories
  - JDK-8356587: Missing object ID X in pool jdk.types.Method
  - JDK-8357826: Avoid running some jtreg tests when asan is configured
  - JDK-8358452: JNI exception pending in Java_sun_awt_screencast_ScreencastHelper_remoteDesktopKeyImpl of screencast_pipewire.c:1214 (ID: 51119)
  - JDK-8358577: Test serviceability/jvmti/thread/GetCurrentContendedMonitor/contmon01/contmon01.java failed: unexpexcted monitor object
  - JDK-8358819: The first year is not displayed correctly in Japanese Calendar
  - JDK-8359059: Bump version numbers for 25.0.1
  - JDK-8359218: RISC-V: Only enable CRC32 intrinsic when AvoidUnalignedAccess == false
  - JDK-8359270: C2: alignment check should consider base offset when emitting arraycopy runtime call
  - JDK-8359454: Enhance String handling
  - JDK-8359596: Behavior change when both -Xlint:options and -Xlint:-options flags are given
  - JDK-8360179: RISC-V: Only enable BigInteger intrinsics when AvoidUnalignedAccess == false
  - JDK-8360533: ContainerRuntimeVersionTestUtils fromVersionString fails with some docker versions
  - JDK-8360647: [XWayland] [OL10] NumPad keys are not triggered
  - JDK-8360679: Shenandoah: AOT saved adapter calls into broken GC barrier stub
  - JDK-8360937: Enhance certificate handling
  - JDK-8361212: Remove AffirmTrust root CAs
  - JDK-8361532: RISC-V: Several vector tests fail after JDK-8354383
  - JDK-8361829: [TESTBUG] RISC-V: compiler/vectorization/runner/BasicIntOpTest.java fails with RVV but not Zvbb
  - JDK-8362109: Change milestone to fcs for all releases
  - JDK-8362882: Update SubmissionPublisher() specification to reflect use of ForkJoinPool.asyncCommonPool()
  - JDK-8366223: ZGC: ZPageAllocator::cleanup_failed_commit_multi_partition is broken
  - JDK-8367031: [backout] Change java.time month/day field types to 'byte'
  - JDK-8368308: ISO 4217 Amendment 180 Update

Notes on individual issues:
===========================

core-libs/java.io:serialization:

JDK-8367031: [backout] Change java.time month/day field types to 'byte'
=======================================================================
In the initial release of OpenJDK 25, attempting to read serialised
Class objects created by earlier versions of OpenJDK for several of
the `java.time` classes would fail with a
`InvalidClassException`. Similarly, `java.time` Class objects
serialised with OpenJDK 25 could not be read by older OpenJDK
versions.  This was due to the type of the day and month fields in
these classes being changed to `byte`. This change has now been
reverted and compatibility between OpenJDK 25 and older versions
restored.

Note that this incompatibility occurred with the `Class` object and
not an instance of the object i.e. `writeObject(LocalDate.class)`
would produce incompatible serialised data, but
`writeObject(LocalDate.now())` would not.

security-libs/java.security:

JDK-8361212: Remove AffirmTrust root CAs
========================================
The following root certificates from AffirmTrust, which were
deactivated in the 21.0.5 release of October 2024, have been removed
from the `cacerts` keystore:

Alias name: affirmtrustcommercialca [jdk]
CN=AffirmTrust Commercial
O=AffirmTrust
C=US
SHA256: 03:76:AB:1D:54:C5:F9:80:3C:E4:B2:E2:01:A0:EE:7E:EF:7B:57:B6:36:E8:A9:3C:9B:8D:48:60:C9:6F:5F:A7

Alias name: affirmtrustnetworkingca [jdk]
CN=AffirmTrust Networking
O=AffirmTrust
C=US
SHA256: 0A:81:EC:5A:92:97:77:F1:45:90:4A:F3:8D:5D:50:9F:66:B5:E2:C5:8F:CD:B5:31:05:8B:0E:17:F3:F0B4:1B

Alias name: affirmtrustpremiumca [jdk]
CN=AffirmTrust Premium
O=AffirmTrust
C=US
SHA256: 70:A7:3F:7F:37:6B:60:07:42:48:90:45:34:B1:14:82:D5:BF:0E:69:8E:CC:49:8D:F5:25:77:EB:F2:E9:3B:9A

Alias name: affirmtrustpremiumeccca [jdk]
CN=AffirmTrust Premium ECC
O=AffirmTrust
C=US
SHA256: BD:71:FD:F6:DA:97:E4:CF:62:D1:64:7A:DD:25:81:B0:7D:79:AD:F8:39:7E:B4:EC:BA:9C:5E:84:88:82:14:23

New in release OpenJDK 25.0.0 (2025-09-16):
===========================================
Major changes are listed below.  Some changes may have been backported
to earlier releases following their first appearance in OpenJDK 22
through to 25.

NEW FEATURES
============

Language Features
=================

Flexible Constructor Bodies
============================
https://openjdk.org/jeps/447
https://openjdk.org/jeps/482
https://openjdk.org/jeps/492
https://openjdk.org/jeps/513

In constructors in the Java programming language, allow statements to
appear before an explicit constructor invocation, i.e., super(..) or
this(..). The statements cannot reference the instance under
construction, but they can initialize its fields. Initializing fields
before invoking another constructor makes a class more reliable when
methods are overridden.

This language feature is now finalised (JEP 513). It was first
introduced as a preview language feature
(http://openjdk.java.net/jeps/12) in OpenJDK 22 (JEP 447) under the
name "Statements before super(...)".  It reached a second preview in
OpenJDK 23 (JEP 482) with the addition of allowing fields to be
initialized before invoking another constructor. It reached a third
preview in OpenJDK 24 (JEP 492).

Unnamed Patterns and Variables
==============================
https://openjdk.org/jeps/443
https://openjdk.org/jeps/456

Enhance the Java language with unnamed patterns, which match a record
component without stating the component's name or type, and unnamed
variables, which can be initialized but not used. Both are denoted by
an underscore character, _.

This feature is now finalised (JEP 456). It was a preview feature
(http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 443).

Primitive Types in Patterns, instanceof, and switch
===================================================
https://openjdk.org/jeps/455
https://openjdk.org/jeps/488
https://openjdk.org/jeps/507

Enhance pattern matching by allowing primitive type patterns in all
pattern contexts, and extend instanceof and switch to work with all
primitive types.

This is a preview language feature (http://openjdk.java.net/jeps/12)
introduced in OpenJDK 23 (JEP 455) with a second preview in OpenJDK 24
(JEP 488) and reaching a third in OpenJDK 25 (JEP 507).

Module Import Declarations
==========================
https://openjdk.org/jeps/476
https://openjdk.org/jeps/494
https://openjdk.org/jeps/511

Enhance the Java programming language with the ability to succinctly
import all of the packages exported by a module. This simplifies the
reuse of modular libraries, but does not require the importing code to
be in a module itself.

This language feature is now finalised (JEP 511). It was introduced as
a preview language feature (http://openjdk.java.net/jeps/12) in
OpenJDK 23 (JEP 476) and had a second preview in OpenJDK 24 (JEP 494).

Library Features
================

Foreign Function & Memory API
=============================
https://openjdk.org/jeps/412
https://openjdk.org/jeps/419
https://openjdk.org/jeps/424
https://openjdk.org/jeps/434
https://openjdk.org/jeps/442
https://openjdk.org/jeps/454

Introduce an API by which Java programs can interoperate with code and
data outside of the Java runtime. By efficiently invoking foreign
functions (i.e., code outside the JVM), and by safely accessing
foreign memory (i.e., memory not managed by the JVM), the API enables
Java programs to call native libraries and process native data without
the brittleness and danger of JNI.

This API is now finalised (JEP 454). It was first introduced in
incubation (https://openjdk.java.net/jeps/11) in OpenJDK 17 (JEP 412),
and is an evolution of the Foreign Memory Access API (OpenJDK 14
through 16) and Foreign Linker API (OpenJDK 16) (see release notes for
java-17-openjdk). OpenJDK 18 saw a second round of incubation (JEP
419) before its inclusion as a preview feature
(http://openjdk.java.net/jeps/12) in OpenJDK 19 (JEP 424). A second
preview took place in OpenJDK 20 (JEP 434) and a third and final
preview in OpenJDK 21 (JEP 442).

Prepare to Restrict the Use of JNI
==================================
https://openjdk.org/jeps/472

Issue warnings about uses of the Java Native Interface (JNI) and
adjust the Foreign Function & Memory (FFM) API to issue warnings in a
consistent manner. All such warnings aim to prepare developers for a
future release that ensures integrity by default by uniformly
restricting JNI and the FFM API. Application developers can avoid both
current warnings and future restrictions by selectively enabling these
interfaces where essential using the --enable-native-access
command-line option.

Class-File API
==============
https://openjdk.org/jeps/457
https://openjdk.org/jeps/466
https://openjdk.org/jeps/484

Provide a standard API for parsing, generating, and transforming Java
class files.

This API is now finalised (JEP 484). It was introduced as a preview
library feature (http://openjdk.java.net/jeps/12) in OpenJDK 22 (JEP
457) with a second preview in OpenJDK 23 (JEP 466).

Vector API
==========
https://openjdk.org/jeps/338
https://openjdk.org/jeps/414
https://openjdk.org/jeps/417
https://openjdk.org/jeps/426
https://openjdk.org/jeps/438
https://openjdk.org/jeps/448
https://openjdk.org/jeps/460
https://openjdk.org/jeps/469
https://openjdk.org/jeps/489
https://openjdk.org/jeps/508

Introduce an API to express vector computations that reliably compile
at runtime to optimal vector hardware instructions on supported CPU
architectures and thus achieve superior performance to equivalent
scalar computations.

This is an incubation feature (https://openjdk.java.net/jeps/11)
introduced in OpenJDK 16 (JEP 338). A second round of incubation took
place in OpenJDK 17 (JEP 414), OpenJDK 18 (JEP 417) saw a third,
OpenJDK 19 a fourth (JEP 426), OpenJDK 20 (JEP 438) a fifth, OpenJDK
21 a sixth (JEP 448), OpenJDK 22 a seventh (JEP 460), OpenJDK 23 an
eighth (JEP 469), OpenJDK 24 a ninth (JEP 489) and it reaches its
tenth in OpenJDK 25 (JEP 508).

Stream Gatherers
================
https://openjdk.org/jeps/461
https://openjdk.org/jeps/473
https://openjdk.org/jeps/485

Enhance the Stream API to support custom intermediate operations. This
will allow stream pipelines to transform data in ways that are not
easily achievable with the existing built-in intermediate operations.

This API is now finalised (JEP 485). It was introduced as a preview
library feature (http://openjdk.java.net/jeps/12) in OpenJDK 22 (JEP
461) with a second preview in OpenJDK 23 (JEP 473).

Structured Concurrency
======================
https://openjdk.org/jeps/428
https://openjdk.org/jeps/437
https://openjdk.org/jeps/453
https://openjdk.org/jeps/462
https://openjdk.org/jeps/480
https://openjdk.org/jeps/499
https://openjdk.org/jeps/505

Simplify multithreaded programming by introducing an API for
structured concurrency. Structured concurrency treats multiple tasks
running in different threads as a single unit of work, thereby
streamlining error handling and cancellation, improving reliability,
and enhancing observability.

This API was first introduced in incubation
(https://openjdk.java.net/jeps/11) in OpenJDK 19 (JEP 428) and had a
second round of incubation in OpenJDK 20 (JEP 437). It became a
preview feature (http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP
453), reached its second preview in OpenJDK 22 (JEP 462), had a third
preview in OpenJDK 23 (JEP 480), a fourth in OpenJDK 24 (JEP 499) and
reaches its fifth in OpenJDK 25 (JEP 505).

Compact Source Files and Instance Main Methods
==============================================
https://openjdk.org/jeps/445
https://openjdk.org/jeps/463
https://openjdk.org/jeps/477
https://openjdk.org/jeps/495
https://openjdk.org/jeps/512

Evolve the Java programming language so that beginners can write their
first programs without needing to understand language features
designed for large programs. Far from using a separate dialect of the
language, beginners can write streamlined declarations for
single-class programs and then seamlessly expand their programs to use
more advanced features as their skills grow. Experienced developers
can likewise enjoy writing small programs succinctly, without the need
for constructs intended for programming in the large.

This library feature is now finalised (JEP 512) with some minor
changes from the last release. It was first introduced as a preview
(http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 445) under the
name "Unnamed Classes and Instance Main Methods". It reached a second
preview in OpenJDK 22 (JEP 463) and a third in OpenJDK 23 (JEP 477)
under the new name, "Implicitly Declared Classes and Instance Main
Methods", due to the move away from unnamed classes to an implicitly
declared name chosen by the host system. It had a fourth preview in
OpenJDK 24 (JEP 495) with new terminology and a revised title ("Simple
Source Files and Instance Main Methods"), but otherwise unchanged.

Scoped Values
=============
https://openjdk.org/jeps/429
https://openjdk.org/jeps/446
https://openjdk.org/jeps/464
https://openjdk.org/jeps/481
https://openjdk.org/jeps/487
https://openjdk.org/jeps/506

Introduce scoped values, which enable the sharing of immutable data
within and across threads. They are preferred to thread-local
variables, especially when using large numbers of virtual threads.

This API is now finalised (JEP 506). This API was first introduced in
incubation (https://openjdk.java.net/jeps/11) in OpenJDK 20 (JEP
429). It became a preview feature (http://openjdk.java.net/jeps/12) in
OpenJDK 21 (JEP 446), had a second preview in OpenJDK 22 (JEP 464), a
third in OpenJDK 23 (JEP 481) and a fourth in OpenJDK 24 (JEP 487).

Key Derivation Function API
===========================
https://openjdk.org/jeps/478
https://openjdk.org/jeps/510

Introduce an API for Key Derivation Functions (KDFs), which are
cryptographic algorithms for deriving additional keys from a secret
key and other data.

This API is now finalised (JEP 510). It was first introduced as a
preview library feature (http://openjdk.java.net/jeps/12) in OpenJDK
24 (JEP 478).

Quantum-Resistant Module-Lattice-Based Key Encapsulation Mechanism
==================================================================
https://openjdk.org/jeps/496

Enhance the security of Java applications by providing an
implementation of the quantum-resistant Module-Lattice-Based
Key-Encapsulation Mechanism (ML-KEM). Key encapsulation mechanisms
(KEMs) are used to secure symmetric keys over insecure communication
channels using public key cryptography. ML-KEM is designed to be
secure against future quantum computing attacks. It has been
standardized by the United States National Institute of Standards and
Technology (NIST) in FIPS 203 [0].

[0] https://csrc.nist.gov/pubs/fips/203/final

Quantum-Resistant Module-Lattice-Based Digital Signature Algorithm
==================================================================
https://openjdk.org/jeps/497

Enhance the security of Java applications by providing an
implementation of the quantum-resistant Module-Lattice-Based Digital
Signature Algorithm (ML-DSA). Digital signatures are used to detect
unauthorized modifications to data and to authenticate the identity of
signatories. ML-DSA is designed to be secure against future quantum
computing attacks. It has been standardized by the United States
National Institute of Standards and Technology (NIST) in FIPS 204 [0].

[0] https://csrc.nist.gov/pubs/fips/204/final

PEM Encodings of Cryptographic Objects
======================================
https://openjdk.org/jeps/470

Introduce an API for encoding objects that represent cryptographic
keys, certificates, and certificate revocation lists into the
widely-used Privacy-Enhanced Mail (PEM) transport format, and for
decoding from that format back into objects.

This is a preview library feature (http://openjdk.java.net/jeps/12)
introduced in OpenJDK 25 (JEP 470).

Stable Values
=============
https://openjdk.org/jeps/502

Introduce an API for stable values, which are objects that hold
immutable data. Stable values are treated as constants by the JVM,
enabling the same performance optimizations that are enabled by
declaring a field final. Compared to final fields, however, stable
values offer greater flexibility as to the timing of their
initialization.

This is a preview library feature (http://openjdk.java.net/jeps/12)
introduced in OpenJDK 25 (JEP 502).

Virtual Machine Enhancements
============================

Region Pinning for G1
=====================
https://openjdk.org/jeps/423

Reduce latency by implementing region pinning in G1, so that garbage
collection need not be disabled during Java Native Interface (JNI)
critical regions.

ZGC: Generational Mode by Default
=================================
https://openjdk.org/jeps/439
https://openjdk.org/jeps/474

Switch the default mode of the Z Garbage Collector (ZGC) to the
generational mode. Deprecate the non-generational mode, with the
intent to remove it in a future release.

Late Barrier Expansion for G1
=============================
https://openjdk.org/jeps/475

Simplify the implementation of the G1 garbage collector's barriers,
which record information about application memory accesses, by
shifting their expansion from early in the C2 JIT's compilation
pipeline to later.

Ahead-of-Time Class Loading & Linking
=====================================
https://openjdk.org/jeps/483
https://openjdk.org/jeps/514

Improve startup time by making the classes of an application instantly
available, in a loaded and linked state, when the HotSpot Java Virtual
Machine starts. Achieve this by monitoring the application during one
run and storing the loaded and linked forms of all classes in a cache
for use in subsequent runs. Lay a foundation for future improvements
to both startup and warmup time.

Using this feature requires a two stage process:

1. Create the Ahead-of-Time cache from a training run of the
application using the option `--XX:AOTCacheOutput=<cache name>` where
`<cache name>` is the cache reference to use in later runs.

2. When running the application in testing or production, use the
option `-XX:AOTCache=<cache name>` to run the application with the
cache generated in #2.

Previously, in OpenJDK 24 (JEP 483), the training run and cache
creation were handled by two separate steps:

1. Populate the Ahead-of-Time configuration data with a training run
of the application using the options `-XX:AOTMode=record
-XX:AOTConfiguration=<config name>` where `<config name>` is the
configuration reference to use in #2.

2. Create the Ahead-of-Time cache using the options
`-XX:AOTMode=create -XX:AOTConfiguration=<config name>
-XX:AOTCache=<cache name>` where `<config name>` is the configuration
reference from #1 and `<cache name>` is the cache reference to use in
later runs.

JEP 514 ("Ahead-of-Time Command-Line Ergonomics") in OpenJDK 25 adds
the option `--XX:AOTCacheOutput` which performs both the above steps
from a single command-line invocation using a temporary configuration
file.  A new environment variable, `JDK_AOT_VM_OPTIONS`, can be used
to pass options to the cache creation step without affecting the
training run step.

Ahead-of-Time Method Profiling
==============================
https://openjdk.org/jeps/515

Improve warmup time by making method-execution profiles from a
previous run of an application instantly available, when the HotSpot
Java Virtual Machine starts. This will enable the JIT compiler to
generate native code immediately upon application startup, rather than
having to wait for profiles to be collected.

Synchronize Virtual Threads without Pinning
===========================================
https://openjdk.org/jeps/491

Improve the scalability of Java code that uses synchronized methods
and statements by arranging for virtual threads that block in such
constructs to release their underlying platform threads for use by
other virtual threads. This will eliminate nearly all cases of virtual
threads being pinned to platform threads, which severely restricts the
number of virtual threads available to handle an application's
workload.

Compact Object Headers
======================
https://openjdk.org/jeps/450
https://openjdk.org/jeps/519

Reduce the size of object headers in the HotSpot JVM from between 96
and 128 bits down to 64 bits on 64-bit architectures. This will reduce
heap size, improve deployment density, and increase data locality.

This is now a production feature in OpenJDK 25 (JEP 519) enabled using
`-XX:+UseCompactObjectHeaders`. It was first introduced as an
experimental feature (JEP 450) that also required the use of
`-XX:+UnlockExperimentalVMOptions`.

Generational Shenandoah
=======================
https://openjdk.org/jeps/404
https://openjdk.org/jeps/521

Enhance the Shenandoah garbage collector with experimental
generational collection capabilities to improve sustainable
throughput, load-spike resilience, and memory utilization.

This is now a production feature in OpenJDK 25 (JEP 521) enabled using
`-XX:ShenandoahGCMode=generational`. It was first introduced as an
experimental feature (JEP 404) that also required the use of
`-XX:+UnlockExperimentalVMOptions`.

JFR Cooperative Sampling
========================
https://openjdk.org/jeps/518

Improve the stability of the JDK Flight Recorder (JFR) when it
asynchronously samples Java thread stacks. Achieve this by walking
call stacks only at safepoints, while minimizing safepoint bias.

JFR Method Timing & Tracing
===========================
https://openjdk.org/jeps/520

Extend the JDK Flight Recorder (JFR) with facilities for method timing
and tracing via bytecode instrumentation.

JFR CPU-Time Profiling
======================
https://openjdk.org/jeps/509

Enhance the JDK Flight Recorder (JFR) to capture more accurate
CPU-time profiling information on Linux.

This is an experimental feature so its JFR events are tagged with the
`@Experimental` annotation. Unlike other experimental virtual machine
features, it does not need to be explicitly enabled with
`-XX:+UnlockExperimentalVMOptions`.

Tools
=====

Launch Multi-File Source-Code Programs
======================================
https://openjdk.org/jeps/458

Enhance the java application launcher to be able to run a program
supplied as multiple files of Java source code. This will make the
transition from small programs to larger ones more gradual, enabling
developers to choose whether and when to go to the trouble of
configuring a build tool.

Markdown Documentation Comments
===============================
https://openjdk.org/jeps/467

Enable JavaDoc documentation comments to be written in Markdown rather
than solely in a mixture of HTML and JavaDoc @-tags.

Linking Run-Time Images without JMODs
=====================================
https://openjdk.org/jeps/493

Reduce the size of the JDK by approximately 25% by enabling the jlink
tool to create custom run-time images without using the JDK's JMOD
files.

This feature must be enabled when the JDK is built using the
--enable-linkable-runtime option.  It will not be enabled by default,
and some JDK vendors may choose not to enable it.

DEPRECATIONS
============

Deprecate the Memory-Access Methods in sun.misc.Unsafe for Removal
==================================================================
https://openjdk.org/jeps/471

Deprecate the memory-access methods in sun.misc.Unsafe for removal in
a future release. These unsupported methods have been superseded by
standard APIs, namely the VarHandle API (JEP 193, OpenJDK 9) and the
Foreign Function & Memory API (JEP 454, OpenJDK 22). We strongly
encourage library developers to migrate from sun.misc.Unsafe to
supported replacements, so that applications can migrate smoothly to
modern JDK releases.

Warn upon Use of Memory-Access Methods in sun.misc.Unsafe
=========================================================
https://openjdk.org/jeps/498

Issue a warning at run time on the first occasion that any
memory-access method in sun.misc.Unsafe is invoked. All of these
unsupported methods were terminally deprecated in JDK 23 (see JEP 471
above). They have been superseded by standard APIs, namely the
VarHandle API (JEP 193, OpenJDK 9) and the Foreign Function & Memory
API (JEP 454, OpenJDK 22). We strongly encourage library developers to
migrate from sun.misc.Unsafe to supported replacements, so that
applications can migrate smoothly to modern JDK releases.

Permanently Disable the Security Manager
========================================
https://openjdk.org/jeps/486

The Security Manager has not been the primary means of securing
client-side Java code for many years, it has rarely been used to
secure server-side code, and it is costly to maintain. We therefore
deprecated it for removal in OpenJDK 17 via JEP 411 (2021). As the
next step toward removing the Security Manager, we will revise the
Java Platform specification so that developers cannot enable it and
other Platform classes do not refer to it. This change will have no
impact on the vast majority of applications, libraries, and tools. We
will remove the Security Manager API in a future release.

REMOVALS
========

String Templates
================
https://openjdk.org/jeps/430
https://openjdk.org/jeps/459
https://openjdk.org/jeps/465

This was a preview feature (http://openjdk.java.net/jeps/12)
introduced in OpenJDK 21 (JEP 430) with a second preview in OpenJDK 22
(JEP 459).  A third preview was proposed but ultimately withdrawn for
OpenJDK 23 (JEP 465) and the feature is no longer present.  See [0]
for further explanation.

[0] https://mail.openjdk.org/pipermail/amber-spec-experts/2024-April/004106.html

Remove the Windows & Linux 32-bit x86 Ports
===========================================
https://openjdk.org/jeps/449
https://openjdk.org/jeps/479
https://openjdk.org/jeps/501
https://openjdk.org/jeps/503

Remove the source code and build support for the Windows (JEP 479) &
Linux (JEP 503) 32-bit x86 ports. The Windows port was deprecated for
removal in JDK 21 by JEP 449 and the Linux port was deprecated for
removal in JDK 24 by JEP 501. Both deprecations took place with the
express intent to remove the ports in a future release.

Following this removal of these 32-bit x86 ports, the
architecture-agnostic Zero port is the only way to run Java programs
on 32-bit x86 processors.

ZGC: Remove the Non-Generational Mode
=====================================
https://openjdk.org/jeps/439
https://openjdk.org/jeps/474
https://openjdk.org/jeps/490

Remove the non-generational mode of the Z Garbage Collector (ZGC),
keeping the generational mode as the default for ZGC (see JEP 439 &
474).