On Mon, 16 Sep 2024 01:08:19 GMT, David Holmes <dhol...@openjdk.org> wrote:
>> Jaikiran Pai has updated the pull request incrementally with one additional >> commit since the last revision: >> >> typos > > src/java.base/share/native/libjli/java.c line 38: > >> 36: * One job of the launcher is to remove command line options which the >> 37: * vm does not understand and will not process. These options include >> 38: * options which select which style of vm is run (e.g. -client and > > Aren't these the only options now? Right now, in mainline, the launcher code in `CheckJvmType` function additionally also checks for the presence of `-XXaltjvm` launcher option. Just like for `-server`, `-client` options, this `CheckJvmType` function also strips the `-XXaltjvm` option from the options that are passed along to the JVM. Specifically, in mainline, right now the following appears to be functional: <JDK_24>/bin/java -XXaltjvm=<JDK_22>/lib/server/ -version will load and print the Java 22 VM output: openjdk version "22" 2024-03-19 OpenJDK Runtime Environment (build 22+36-2370) OpenJDK 64-Bit Server VM (build 22+36-2370, mixed mode, sharing) i.e. the launcher from mainline JDK launches the altjvm from JDK 22. `CheckJvmType` in the launcher code, is where this parsing and stripping of `-XXaltjvm` is currently happening. (There's also some hotspot VM side code which appears to be parsing a `-Dsun.java.launcher.is_altjvm=` option to detect this `-XXaltjvm` usage, but as far as I can see the launcher no where sets this `-Dsun.java.launcher.is_altjvm=` when `-XXaltjvm` is used. So, I think, this needs a separate investigation of its own) ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20997#discussion_r1760584301
