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# Eclipse OpenJ9 version 0.32.0 release notes

These release notes support the [Eclipse OpenJ9 0.32.0 release plan](https://projects.eclipse.org/projects/technology.openj9/releases/0.32.0/plan).

## Supported environments

OpenJ9 release 0.32.0 supports OpenJDK 8, 11, 17, 18.

All releases are tested against the OpenJ9 functional verification (FV) test suite, the OpenJDK test suites, and additional tests provided by Adoptium.

To learn more about support for OpenJ9 releases, including OpenJDK levels and platform support, see [Supported environments](https://eclipse.org/openj9/docs/openj9_support/index.html).

## Notable changes in this release

The following table covers notable changes in v0.32.0. Further information about these changes can be found in the [user documentation](https://www.eclipse.org/openj9/docs/version0.32/).

<table cellpadding="4" cellspacing="0" summary="" width="100%" rules="all" frame="border" border="1"><thead align="left">
<tr>
<th valign="bottom">Issue number</th>
<th valign="bottom">Description</th>
<th valign="bottom">Version / Platform</th>
<th valign="bottom">Impact</th>
</tr>
</thead>
<tbody>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/pull/3627">#3267</a></td>
<td valign="top">New <tt>-XX:[+|-]ShowHiddenFrames</tt> option added</td>
<td valign="top">All versions</td>
<td valign="top">This option controls if hidden method frames generated for MethodHandles are displayed in a stacktrace. This option is disabled by default and can be enabled for debugging purposes.</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/pull/13925">#13925</a></td>
<td valign="top">New <tt>SharedClassStatistics</tt> API added</td>
<td valign="top">All versions</td>
<td valign="top">New shared classes API is added in <tt>SharedClassStatistics</tt> for <tt>cacheDir()</tt>, <tt>cacheName()</tt>, <tt>cachePath()</tt>, <tt>numberAttached()</tt>.
For more details see the API documentation. Only the OpenJDK 18 API documentation is updated in this release, API documentation for the other versions will be updated in the next release.</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/pull/14623">#14623</a></td>
<td valign="top">Modified default for <tt>-XX:MaxDirectMemorySize</tt></td>
<td valign="top">OpenJDK 11 and later</td>
<td valign="top">In builds with OpenJDK 11 and later, <tt>-XX:MaxDirectMemorySize</tt> is no longer set by default and the class library limits the amount of heap memory used for
Direct Byte Buffers to the same value as the maximum heap size. Previously the limit was 87.5% of the maximum heap size.</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/ibmruntimes/openj9-openjdk-jdk11/pull/484">ibmruntimes/openj9-openjdk-jdk11#484</a></td>
<td valign="top">libfreetype.so native library is bundled on AIX</td>
<td valign="top">OpenJDK 11 on AIX only</td>
<td valign="top">The libfreetype.so native library is bundled with OpenJDK 11 for AIX, similarly to builds with OpenJDK 17 and later. This removes the requirement of having to install this prerequisite when using the java.desktop module.</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/11164">#11164</a></td>
<td valign="top">Early access release for Apple Silicon macOS</td>
<td valign="top">OpenJDK 11 and later / Apple Silicon macOS</td>
<td valign="top">Build for Apple Silicon (AArch64) macOS is available as an early access release.  It is stable enough for evaluation but not suitable for production yet.</td>
</tr>

<tr><td valign="top"><a href="https://github.com/eclipse-openj9/openj9/pull/14424">#14424</a></td>
<td valign="top">JITServer technology is now a supported feature for Linux on IBM Z systems (Linux on x86-64 and Linux on Power are supported since version 0.29.0)</td>
<td valign="top">OpenJDK 8, 11 and 17 (64-bit only)</td>
<td valign="top">JITServer decouples the JIT compiler from the OpenJ9 VM, freeing up CPU and memory for an application. JITServer then runs in its own process, either locally or on a remote machine, where resources can be separately managed.</td>
</tr>

</tbody>
</table>

## Known issues

The v0.32.0 release contains the following known issues and limitations:

<table cellpadding="4" cellspacing="0" summary="" width="100%" rules="all" frame="border" border="1">
<thead align="left">
<tr>
<th valign="bottom">Issue number</th>
<th valign="bottom">Description</th>
<th valign="bottom">Platform</th>
<th valign="bottom">Impact</th>
<th valign="bottom">Workaround</th>
</tr>
</thead>

<tbody>
<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/15011">#15011</a></td>
<td valign="top">The default stack size is modified for the main thread</td>
<td valign="top">All</td>
<td valign="top">The main thread stack size was 1MB in previous releases. In this release it's modified to a smaller platform dependent value,
which may result in a <tt>java.lang.StackOverflowError: operating system stack overflow</tt></td>
<td valign="top">Use <tt>-Xmso</tt> to set the default stack size. See the default value by using <tt>-verbose:sizes</tt>.</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/13767">#13767</a></td>
<td valign="top">Compressed references mode is not available</td>
<td valign="top">Apple Silicon macOS (early access)</td>
<td valign="top">You can use only the large heap (non-compressed references) mode.</td>
<td valign="top">None</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/14387">#14387</a></td>
<td valign="top">DDR is not enabled</td>
<td valign="top">Apple Silicon macOS (early access)</td>
<td valign="top">You cannot use DDR (Direct Dump Reader) functionalities.</td>
<td valign="top">None</td>
</tr>

<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/14502">#14502</a></td>
<td valign="top">JIT field watch fails to work</td>
<td valign="top">Apple Silicon macOS (early access)</td>
<td valign="top">Enabling JIT field watch may cause bus errors.</td>
<td valign="top">Avoid using the <tt>-XX:+JITInlineWatches</tt> option.</td>
</tr>
<tr>
<td valign="top"><a href="https://github.com/eclipse-openj9/openj9/issues/14803">#14803</a></td>
<td valign="top">Using the <tt>-XX:+ShowHiddenFrames</tt> option in an OpenJ9 release built with OpenJDK 18 causes errors due to underlying problems in OpenJDK</td>
<td valign="top">All platforms</td>
<td valign="top">Wrong exception may be thrown when using the Reflection API.</td>
<td valign="top">Avoid using the <tt>-XX:+ShowHiddenFrames</tt> option with OpenJDK 18</td>
</tr>

</tbody>
</table>

## Other changes

A full commit history for this release is available at [Eclipse OpenJ9 v0.32.0](https://github.com/eclipse-openj9/openj9/releases/tag/openj9-0.32.0).
