On Wed, 14 May 2025 21:03:35 GMT, Ioi Lam <ik...@openjdk.org> wrote: >> https://openjdk.org/jeps/483 mentions: >> >>> To enjoy the benefits of the AOT cache generated during a training run, the >>> training run and all subsequent runs must be essentially similar. [...] All >>> runs must not use JVMTI agents that can arbitrarily rewrite classfiles >>> using ClassFileLoadHook. >> >> However, when *any* java agent is specified in the training run, the JVM >> fails at start-up. E.g., >> >> >> $ java -XX:AOTMode=record -javaagent:agent.jar -cp app.jar App >> Error occurred during CDS dumping >> Must enable AllowArchivingWithJavaAgent in order to run Java agent during >> CDS dumping >> >> >> With the AOT cache, the main concern for JVMTI agents is that they can >> modify the contents of loaded Java classes. If we store such modified >> classes into the AOT cache, their contents will no longer match the original >> class files (from application JAR files, etc). As a result, when using the >> AOT cache in production runs, the application may have unexpected behavior. >> >> With this PR, we allow JVMTI agents in the AOT workflow. To address the >> above concern, we ensure that JVMTI agents cannot affect the contents of AOT >> cache: >> >> - In training runs (`java -XX:AOTMode=record`), JVMTI agents are allowed, >> but the AOT configuration file should filter out classes that are >> transformed by the agents. This can be checking >> `InstanceKlass::has_been_redefined()` and >> `ClassFileStream::from_class_file_load_hook()`. >> >> - In the assembly phase (`java -XX:AOTMode=record`), agents can be specified >> in the command-line. However, since the assembly phase doesn't execute any >> application logic, we will also not load any of the specified agents. >> Therefore, the agents cannot affect the contents of the AOT cache created in >> the assembly phase. > > Ioi Lam has updated the pull request with a new target base due to a merge or > a rebase. The incremental webrev excludes the unrelated changes brought in by > the merge/rebase. The pull request contains five additional commits since the > last revision: > > - Merge branch 'master' into 8356693-aot-assembly-phase-fails-with-java-agent > - @ashu-mehra comments > - fixed whitespace > - 8356693: AOT assembly phase fails with -javaagent > - step1
Looks good. ------------- Marked as reviewed by ccheung (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/25170#pullrequestreview-2841595350
