pityka / aten-scala

jni bindings to aten from libtorch

Version Matrix


Build documentation

The JNI bindings are built with clang++ for Mac and for Linux. The build runs on a Mac and uses Docker for cross compilation. The docker image used for building (and possible at runtime) is defined in docker-runtime/Dockerfile. This image is pushed to the Docker Hub (https://hub.docker.com/r/pityka/base-ubuntu-libtorch/tags?page=1&ordering=last_updated), and by default the build will pull it.


  • needs a mac with clang++ installed
  • needs docker on the mac
  • on the mac needs libtorch in /usr/local/lib/. There are multiple methods to install libtorch. One is to copy the *.dylib files from the libtorch distribution of the appropriate pytorch version (e.g. https://download.pytorch.org/libtorch/cpu/libtorch-macos-1.9.0.zip) to /usr/local/lib/ .
  • needs bloop (https://scalacenter.github.io/bloop/) and sbt (https://www.scala-sbt.org/).
  • Needs CUDA header files. You can download an older (e.g. version 10) mac CUDA Toolkit archive from Nvidia. The installer contains a tarball with the header files, place them to /usr/local/cuda/include/.


  1. make prepare - this creates bloop build definitions from sbt the sbt build definition
  2. make test - builds the binding for mac, and runs tests. Tests pass if the suite does not crash or throws exception.
  3. make test-linux - builds for linux and runs tests in a linux container (needs docker for mac, will pull pityka/base-ubuntu-libtorch from docker hub)
  4. make test-cuda - runs tests in a cuda enabled remote docker context


  • make publishLocal - publishes artifacts locally
  • make publish - publishes artifacts to github packages.
  • bash publish.sh - publishes the artifacts to Maven Central

How this works

The Makefile will generate Java and C++ sources and create a JNI native library.

parser/ holds a parser for parseable.h which is a subset of the libtorch/include/ATen/Functions.h. This parser generates cpp (./wrapper.cpp) and java JNI code (./aten-scala/core/src/main/java/ATen.java). The cpp code is compiled to ./aten-scala/jni-osx/src/main/resources/libatenscalajni.dylib.

aten-scala/ holds an sbt project with two subprojects. aten-scala/core is the Java counterpart of the binding. It depends on Scala because std::tuple is translated into Scala tuples. aten-scala/jni-osx contains no source code but its Maven artifact contains the native library.

Libtorch runtime dependency

Libtorch is linked dynamically during runtime. On OSX you can brew install libtorch, or by copying the .dylib files from the libtorch distribution archive to /usr/local/lib/. On Linux you can install torch with pip then add the relevant folders to the ld search path. See the docker-runtime/Dockerfiles on how to do this.

Docker image for Linux with libtorch and CUDA

See docker-runtime/Dockerfile. This image is pushed to the Docker Hub (https://hub.docker.com/r/pityka/base-ubuntu-libtorch/tags?page=1&ordering=last_updated).

The image also has Java 8 and sbt. It is ready to make use of this library on Linux.


See LICENSE file.