On Tue, 8 Jun 2021 01:39:12 GMT, Serguei Spitsyn <[email protected]> wrote:
> The JVM TI Heap functions 1.0 were superseded by newer functions in JVM TI > 1.2 (Java 6) and should be deprecated so they can be removed in a future > release. > > We need to replace this sentence: > "These functions and data types were introduced in the original JVM TI > version 1.0 and have been superseded by more powerful and flexible > versions which:" > with: > "These functions and data types were introduced in the original JVM TI > version 1.0. They are deprecated and will be changed to return an error > in a future release. They were superseded in JVM TI version 1.2 (Java 6) by > more powerful and flexible versions which:" > > The CSR has been approved: > https://bugs.openjdk.java.net/browse/JDK-8268242 > > The JVM TI Heap functions reflect the requirements of tool vendors during > JSR-163. They pre-date concurrent collectors, the built-in heap dump support, > and JFR. They are a maintenance burden and there is little evidence that they > are used by modern tools (they involve stop-the-world operations and so are > not suitable for production systems). > > The JVM TI functions to deprecate are: > IterateOverObjectsReachableFromObject > IterateOverReachableObjects > IterateOverHeap > IterateOverInstancesOfClass > > The "Heap 1.0" section of the JVM TI spec has existing wording in bold to say > that the functions have been superseded. The proposal is to change this to > say that the functions are deprecated and will be degraded in a future > release. > A release note is planned. The release note will detail how to use > -Xlog:jvmti=trace and -XX:TraceJVMTI= to identify any residual usages of > these functions. > > A future CSR will likely degrade these functions so that they return an error > to indicate that they are no longer implemented/supported. We also plan to > re-examine the newer Heap functions with a view to deprecate them in the > future too (this requires a bit more work to understand if there is any real > usage, also some adjustments to the JDWP and JDI specs). This pull request has now been integrated. Changeset: 07108c91 Author: Serguei Spitsyn <[email protected]> URL: https://git.openjdk.java.net/jdk/commit/07108c916263896fa6c5dbacfedf5b4c2f5bf97a Stats: 7 lines in 1 file changed: 5 ins; 0 del; 2 mod 8268241: deprecate JVM TI Heap functions 1.0 Reviewed-by: alanb, iris, kevinw ------------- PR: https://git.openjdk.java.net/jdk/pull/4406
