On Mon, 20 Jul 2026 18:28:07 GMT, Igor Veresov <[email protected]> wrote:
>> Before this PR, you cannot use -XX:AOTCache in the training run: >> >> >> $ java -XX:AOTCache=foo.aot -cp HelloWorld.jar \ >> -XX:AOTMode=record -XX:AOTConfiguration=hw.aotconfig \ >> HelloWorld >> [...] AOTCache must not be specified when using -XX:AOTMode=record >> >> >> However, in some cases, it may be desirable to train the AOT cache in two or >> more steps. For example: >> >> ## Separate Training for Framework and Application: >> >> - First perform a training run to exercise commonly-used areas of the >> framework. >> - Second, perform a training run of a specific application. >> >> The idea is that important parts of the framework may not be covered by a >> single application training run, but they may still be used in the >> production run due to runtime-specific input. >> >> >> # Train the framework >> java -XX:AOTCacheOutput=first.aot -cp FrameWork.jar FrameWorkTraningHelper >> >> # Train the app >> java -XX:AOTCache=first.aot -XX:AOTCacheOutput=second.aot -cp >> FrameWork.jar:App.jar MyApp >> >> # Production run using second.aot, which contains artifacts from >> # the first and second training runs >> java -XX:AOTCache=second.aot -cp FrameWork.jar:App.jar MyApp >> >> Note that the classpaths of the training runs must be compatible. I.e., the >> classpath of an earlier training run must be the same as, or the prefix of, >> the classpath of a later training run. >> >> ## Train the Same Application in Multiple Runs: >> >> An application may perform 3 different operations. It's not easy to perform >> all 3 operations in a single training run, as the 3 operations are >> represented by 3 separate main classes (`WalkDog`, `FeedCat`, and >> `WaterPlants`). So, we perform 3 separate training runs and combine the >> results into a single AOT cache. >> >> >> # Training >> java -XX:AOTCacheOutput=tmp1.aot -cp MyApp.jar WalkDog >> java -XX:AOTCache=tmp1.aot -XX:AOTCacheOutput=tmp2.aot -cp MyApp.jar FeedCat >> java -XX:AOTCache=tmp2.aot -XX:AOTCacheOutput=final.aot -cp MyApp.jar >> WaterPlants >> >> # Production: final.aot contains artifacts for optimizing all 3 operations: >> java -XX:AOTCache=final.aot -cp MyApp.jar WalkDog >> java -XX:AOTCache=final.aot -cp MyApp.jar FeedCat >> java -XX:AOTCache=final.aot -cp MyApp.jar WaterPlants >> >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > src/hotspot/share/cds/aotMetaspace.cpp line 768: > >> 766: >> 767: if (!CDSConfig::is_dumping_final_static_archive()) { >> 768: //guarantee(!CDSConfig::is_using_archive(), "We should not be using >> an archive when we dump"); > > Should this be removed? This is temporary. I need to fix it properly. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/31344#discussion_r3616842946
