On Fri, 25 Oct 2024 16:29:52 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 five > additional commits since the last revision: > > - Better handle patched modules > > Also add a test which ensures that module patching (if present), will > get an appropriate error message. > - Add /othervm to some langtools tier1 tests > > Those tests are using module patches from JTREG. Since the run-time > image based link uses ModuleFinder.ofSystem(), which will see the extra > classes comming from the module patch. Then the size look-up using the > JRT FS provider fails, since that only looks in the module image > (lib/modules) and NOT also in the patch. Thus, we get a > NoSuchFileException and the link fails. > > Run the tests with othervm so that the JTREG patch'ed module isn't > visible to the test. > - Fix tests for builds with --enable-linable-runtime > > Those builds don't include the packaged modules, `jmods` directory. > However, some tests assume that they're there. Add appropriate requires > tag. > - Fix provider verification when some JMODs are present > > In some configurations, e.g. when java.base is missing from the packaged > modules, but another JDK module is present as JMOD that is linked into > an image, then provider verification can fail. Thus, the run-time image > link fails. Verify that this doesn't happen. > > The fix is to return Platform.runtime() for run-time image based links > as well. Otherwise this code would return the wrong result. > - Show run-time image based capability in help > > Also add a test for it when it's turned on and off. Changes requested by mr (Lead). src/jdk.jlink/share/classes/jdk/tools/jlink/resources/jlink.properties line 119: > 117: warn.prefix=Warning: > 118: > 119: err.runtime.link.not.linkable.runtime=The current run-time image does > not support run-time linking. Please remove the trailing periods from the new messages. The existing messages don’t use them, and JDK command-line tools in general don’t use them. ------------- PR Review: https://git.openjdk.org/jdk/pull/14787#pullrequestreview-2399260041 PR Review Comment: https://git.openjdk.org/jdk/pull/14787#discussion_r1819168717
