Advanced Code Hot Swapping in JDK 8?
hotswap, java, jvm-hotspot
Solution
JEPs coming in JDK 8 and JDK 9 are listed in this page. JEP-159 is not among them. From jep index you can see that JEP-159 is not yet targeted to any JDK release, not even jdk 10.
JEP-159 status is currently "Submitted". The process is described as follows:
A successful JEP passes through the following states:
- Draft — In circulation by the author for initial review and consensus-building
- Posted — Entered into the JEP Archive by the author for wider review
- Submitted — Declared by the author to be ready for evaluation
- Candidate — Accepted for inclusion in the Roadmap by the OpenJDK Lead
- Funded — Judged by a Group or Area Lead to be fully funded
- Completed — Finished and delivered
So it's not yet accepted for any roadmap.
Problem
I am looking for better HotSwapping in the JavaVM. Being able to only apply method body changes is okay but quite limiting. The options available is JRebel and a discontinued project called Dynamic Code Evolution Virtual Machine (DCEVM). There is a JEP 159 out there that was written by the core developper of DCEVM. A blog post from 2011 mentioned that the developers of DCEVM now work for Oracle to integrate this into the JDK. Do we have this kind of support for JDK 8 beta already or was it postponed to JDK 9? I need hot swapping for adding and removing and renaming private methods mostly. This would help alot. Is there a product allowing me to do so (beside JRebel which PR-campaigns got me upset). The last supported version of DCEVM is for 1.6u24 and it only provides 32-bit linux binaries. Since I use 1.7 and 64bit Linux this is both a show stopper for me. There is also another project available on github called Fakereplace. Can this be easily used for my purpose or should I not investigate into this?