Loader.loadNativeLibraries() taking much longer to run in v9.12 MacOS M1

[ClaudioConsolmagno]

What version of OR-Tools and what language are you using?
Version: v9.12
Language: Java

Which solver are you using (e.g. CP-SAT, Routing Solver, GLOP, BOP, Gurobi)
Not relevant I think but I use ModelBuilder with SCIP

What operating system (Linux, Windows, ...) and version?
MacOS M1
Java corretto 21.0.6 aarch64 (same results on Java 8 and 17)
Have tested on linux and that works fine.

What did you do?
Steps to reproduce the behavior:

plugins {
    id 'java'
}

group = 'dev.claudio'
version = '1.0-SNAPSHOT'

repositories {
    mavenCentral()
}

dependencies {
    implementation('com.google.ortools:ortools-java:9.12.4544')
//    implementation('com.google.ortools:ortools-java:9.11.4210')
}

package dev.claudio;

import com.google.ortools.Loader;

public class Main {
    public static void main(String[] args) {
        long start = System.currentTimeMillis();
        System.out.println("Started");
        Loader.loadNativeLibraries();
        long timeMs = System.currentTimeMillis() - start;
        System.out.printf("Time taken: %.3f seconds%n", timeMs / 1000.0);
    }
}

• On v9.12: Time taken: 13.387 seconds
• On v9.11: Time taken: 0.948 seconds

Anything else we should know about your project / environment
It doesn't seem like there's a lot of CPU usage. I'm not sure how to analyse profiler data:

[lperron]

does it happen the second time ? I have the same with python binary. The first run is very slow, the second is not.

[ClaudioConsolmagno]

Once loaded for the first time, Loader.java will immediatelly return. It's not much of a problem in production for us but it is a problem for unit tests and running tests quickly during development.

  /** Unpack and Load the native libraries needed for using ortools-java. */
  private static boolean loaded = false;

  public static synchronized void loadNativeLibraries() {
    // prints the name of the Operating System
    // System.out.println("OS: " + System.getProperty("os.name"));
    if (loaded) {
      return;
    }
   ...
}

[Mizux]

we migrate from static libs for deps (with ODR violation) to dynamic libraries...

[lperron]

I meant what happens if you run the program twice ? On my python tests, it is very slow the first time, and fast after that.

[lperron]

maybe an explanation: https://developer.apple.com/forums/thread/655773

[ClaudioConsolmagno]

On my python tests, it is very slow the first time, and fast after that.

I see. No for me, at least with java with gradle build system, running and re-running have the same effect of ~15s init time.