Difference between revisions of "Tensorflow JNI development"

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How to:
 
How to:
* Build TF JNI - '''libtensorflow.jar, libtensorflow_jni.so'''
+
* '''Build TF JNI - libtensorflow.jar, libtensorflow_jni.so'''
* Add '''libtensorflow.jar''' to local Maven repository which will override the [https://mvnrepository.com/artifact/org.tensorflow/tensorflow Central Maven Repository]
+
* '''Add libtensorflow.jar to local Maven repository''' which will override the [https://mvnrepository.com/artifact/org.tensorflow/tensorflow Central Maven Repository]
* Modify TF JNI functions
+
* '''Modify TF JNI functions'''
* Create a Maven project and use modified TF JNI
+
* '''Create a Maven project and use modified TF JNI'''
  
There's [https://github.com/bytedeco/javacpp-presets JavaCPP Presets] project. But they fail to clearly explain what it does.
+
There's [https://github.com/bytedeco/javacpp-presets JavaCPP Presets] project. Useful?
  
 
==Install==
 
==Install==

Revision as of 17:31, 4 March 2020

About

Based on Build TensorFlow 2.0 for Java on Windows article. Also this one - tensorflow/java/README.md.

These instructions are for Linux and old TensorFlow 1.15.0.

How to:

  • Build TF JNI - libtensorflow.jar, libtensorflow_jni.so
  • Add libtensorflow.jar to local Maven repository which will override the Central Maven Repository
  • Modify TF JNI functions
  • Create a Maven project and use modified TF JNI

There's JavaCPP Presets project. Useful?

Install

  • In Kubuntu
  • Get TF 1.15.0 - git or archive
  • Install bazel 0.25.2 - see *.deb in releases

Build

cd ~/git/tensorflow-1.15.0
./configure # do not forget CUDA
bazel build -c opt //tensorflow/java:tensorflow //tensorflow/java:libtensorflow_jni //tensorflow/java:pom

With tensorflow bazel (when restarted?) tends to rebuild everything from scratch which takes a ton of time. Bazel starts its server which, to prevent it, add to ~/.bazelrc:

startup --max_idle_secs=0

Artifacts of interest in bazel-bin/tensorflow/java/:

libtensorflow_jni.so
libtensorflow.jar
pom.xml
  • xml and jar are taken care of.
  • so will have to be in the library path - set LD_LIBRARY_PATH or PATH or go "java -Djava.library.path"

Install TF to local maven repo

mvn install:install-file -Dfile=bazel-bin/tensorflow/java/libtensorflow.jar -DpomFile=bazel-bin/tensorflow/java/pom.xml

How to uninstall maven local repo - and switch back to official versions form Central:

https://stackoverflow.com/questions/15358851/how-to-remove-jar-file-from-local-maven-repository-which-was-added-with-install

Modify TF JNI

For example, one wants to create a new function in org.tensorflow.TensorFlow package. Then, see:

tensorflow/java/src/main/java/org/tensorflow/
tensorflow/java/src/main/native/
  • add native method to tensorflow/java/src/main/java/org/tensorflow/TensorFlow.java
  • add to header file tensorflow/java/src/main/native/tensorflow_jni.h
  • add to c file tensorflow/java/src/main/native/tensorflow_jni.cc
  • rebuild and reinstall to mvn

Java maven project in Eclipse

  • Create a new maven project
  • Edit pom.xml:
<project>
  ...
  <dependencies>
    ...
    <dependency>
      <groupId>org.tensorflow</groupId>
      <artifactId>libtensorflow</artifactId>
      <version>1.15.0</version>
    </dependency>
    ...
  </dependencies>
  ...
</project>

Basic example code

tfhello.java:

import org.tensorflow.TensorFlow;

public class tfhello{
	public static void main(String[] args){
		System.out.println(TensorFlow.version());
	}
}