Project Panama: Interconnecting JVM and native code

We are improving and enriching the connections between the Java ^TM virtual machine and well-defined but “foreign” (non-Java) APIs, including many interfaces commonly used by C programmers.

To this end, Project Panama will include most or all of these components:

• native function calling from JVM (C, C++), specifically per JEP 191
• native data access from JVM or inside JVM heap
• new data layouts in JVM heap
• native metadata definition for JVM
• header file API extraction tools (see below)
• native library management APIs
• native-oriented interpreter and runtime “hooks”
• class and method resolution “hooks”
• native-oriented JIT optimizations
• tooling or wrapper interposition for safety
• exploratory work with difficult-to-integrate native libraries

Community

This Project is sponsored by the Hotspot Group.

• Mailing lists
  • panama-dev — the usual developer list
  • panama-spec-experts — moderated, restricted to specification discussions only
• Bloggers
  • Charles Nutter
  • John Rose
• Links
  • new project CFV for Panama
  • JEP 191: Foreign Function Interface
  • example code: Java Native Runtime
  • problem space overview: the isthmus in the VM

Workflow

Project Panama is designed to incubate a series of components for eventual inclusion in the JDK, via curated merge. Following the experience of Project Lambda, we have our own tree of repositories that parallel the structure of JDK 9. Although this process is local and subject to change, we expect that typical moves will be as follows:

• Commit rough changesets to JDK and/or JVM code, with ad hoc review, change set format, and testing. (Rough changeset example from Project Lambda)
• Frequently (goal is nightly), perform private regression tests.
• Periodically (goal is weekly), resync from JDK 9 master and rebase pending (incubated) changes. (Resync example from Project Lambda)
• Periodically (goal is weekly), make private builds, marking with distinguished tags like panama-b9042.
• Create and update JIRA sub-issues to informally manage features by parts, using labels like 9-repo-panama as needed to mark private changes to incubated code.
• Infrequently, create a “curated” change set targeted at JDK; properly review, test, integrate. (Curated changeset example from Project Lambda)