On Tue, 19 Mar 2024 16:55:14 GMT, Severin Gehwolf <sgehw...@openjdk.org> wrote:
>> Please review this patch which adds a jlink mode to the JDK which doesn't >> need the packaged modules being present. A.k.a run-time image based jlink. >> Fundamentally this patch adds an option to use `jlink` even though your JDK >> install might not come with the packaged modules (directory `jmods`). This >> is particularly useful to further reduce the size of a jlinked runtime. >> After the removal of the concept of a JRE, a common distribution mechanism >> is still the full JDK with all modules and packaged modules. However, >> packaged modules can incur an additional size tax. For example in a >> container scenario it could be useful to have a base JDK container including >> all modules, but without also delivering the packaged modules. This comes at >> a size advantage of `~25%`. Such a base JDK container could then be used to >> `jlink` application specific runtimes, further reducing the size of the >> application runtime image (App + JDK runtime; as a single image *or* >> separate bundles, depending on the app being modularized). >> >> The basic design of this approach is to add a jlink plugin for tracking >> non-class and non-resource files of a JDK install. I.e. files which aren't >> present in the jimage (`lib/modules`). This enables producing a `JRTArchive` >> class which has all the info of what constitutes the final jlinked runtime. >> >> Basic usage example: >> >> $ diff -u <(./bin/java --list-modules --limit-modules java.se) >> <(../linux-x86_64-server-release/images/jdk/bin/java --list-modules >> --limit-modules java.se) >> $ diff -u <(./bin/java --list-modules --limit-modules jdk.jlink) >> <(../linux-x86_64-server-release/images/jdk/bin/java --list-modules >> --limit-modules jdk.jlink) >> $ ls ../linux-x86_64-server-release/images/jdk/jmods >> java.base.jmod java.net.http.jmod java.sql.rowset.jmod >> jdk.crypto.ec.jmod jdk.internal.opt.jmod >> jdk.jdi.jmod jdk.management.agent.jmod jdk.security.auth.jmod >> java.compiler.jmod java.prefs.jmod java.transaction.xa.jmod >> jdk.dynalink.jmod jdk.internal.vm.ci.jmod >> jdk.jdwp.agent.jmod jdk.management.jfr.jmod jdk.security.jgss.jmod >> java.datatransfer.jmod java.rmi.jmod java.xml.crypto.jmod >> jdk.editpad.jmod jdk.internal.vm.compiler.jmod >> jdk.jfr.jmod jdk.management.jmod jdk.unsupported.desktop.jmod >> java.desktop.jmod java.scripting.jmod java.xml.jmod >> jdk.hotspot.agent.jmod jdk.i... > > Severin Gehwolf has updated the pull request incrementally with one > additional commit since the last revision: > > Move CreateLinkableRuntimePlugin to build folder > > Keep runtime link supporting classes in package > jdk.tools.jlink.internal.runtimelink make/jdk/src/jdk.unsupported_jlink_runtime/share/classes/build/tools/runtimelink/CreateLinkableRuntimePlugin.java line 1: > 1: /* This file does not at all fit in with the pattern of other build tools, which are not module-based but instead live in packages `build.tools.*` in the `make/jdk/src/classes` directory. We will need to find a better arrangement for this. First question, do this class really need to be in a separate module? (I'm afraid the answer is "yes" but I need to ask it anyway). ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/14787#discussion_r1534094775
