Linux x64 binding exception

[jsorel]

Hello,

I am trying to use java bindings on linux x64 (fedora 40). but the .so fails to load in java with a good old exception :

Exception in thread "main" java.lang.UnsatisfiedLinkError: /tmp/jni-1601019841721826404/libpdaljni.2.8.so: libpdalcpp.so.18: Ne peut ouvrir le fichier d'objet partagé: Aucun fichier ou dossier de ce type
	at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
	at java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:331)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:197)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:139)
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2399)
	at java.base/java.lang.Runtime.load0(Runtime.java:852)
	at java.base/java.lang.System.load(System.java:2030)

The file does exist, and is a valid x64 elf,

(base) jsorel@pc10:/tmp/jni-1601019841721826404$ readelf -h libpdaljni.2.8.so 
En-tête ELF:
  Magique:   7f 45 4c 46 02 01 01 03 00 00 00 00 00 00 00 00 
  Classe:                            ELF64
  Données:                          complément à 2, système à octets de poids faible d'abord (little endian)
  Version:                           1 (actuelle)
  OS/ABI:                            UNIX - GNU
  Version ABI:                       0
  Type:                              DYN (fichier objet partagé)
  Machine:                           Advanced Micro Devices X86-64
  Version:                           0x1
  Adresse du point d'entrée:         0x0
  Début des en-têtes de programme :  64 (octets dans le fichier)
  Début des en-têtes de section :    176120 (octets dans le fichier)
  Fanions:                           0x0
  Taille de cet en-tête:             64 (octets)
  Taille de l'en-tête du programme:  56 (octets)
  Nombre d'en-tête du programme:     11
  Taille des en-têtes de section:    64 (octets)
  Nombre d'en-têtes de section:      32
  Table d'index des chaînes d'en-tête de section: 31

But it's a dynamic lib, not a static one.

When listing the native links in the .so we have :

(base) jsorel@pc10:/tmp/jni-1601019841721826404$ ldd libpdaljni.2.8.so
ldd: attention : vous n'avez pas la permission d'exécution pour `./libpdaljni.2.8.so'
	linux-vdso.so.1 (0x00007fd4c780c000)
	libpdalcpp.so.18 => not found
	libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007fd4c7400000)
	libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007fd4c779b000)
	libc.so.6 => /lib64/libc.so.6 (0x00007fd4c721e000)
	libm.so.6 => /lib64/libm.so.6 (0x00007fd4c76ba000)
	/lib64/ld-linux-x86-64.so.2 (0x00007fd4c780e000)

libpdalcpp.so.18 => not found

I believe this is why the so is not loaded, because a required lib is not available.

I tried installing PDAL on my machine, so I got pdal 2.5.6 (the latest one available on fedora 40) and downgraded the java binding to the closest version which is 2.5.1.

This time it loads but crashed a bit later :

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007f5a7bb8238f, pid=28993, tid=28994
#
# JRE version: OpenJDK Runtime Environment Temurin-22.0.2+9 (22.0.2+9) (build 22.0.2+9)
# Java VM: OpenJDK 64-Bit Server VM Temurin-22.0.2+9 (22.0.2+9, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# C  [libpdal_base.so.15+0x38238f]  pdal::PipelineManager::validateStageOptions() const+0x1f
#

In it's current state the portable binding only works if you have the exact same version of PDAL already installed.

Would it be possible to have a release with a static build of PDAL java bindings for linux x64 ?

thank you

Johann

[pomadchin]

Hi! Thanks for reporting. That's a good question, should be not hard to do, most likely a flag. But I thought / think it's still treated as the 'x86' platform.

[pomadchin]

I believe this is why the so is not loaded, because a required lib is not available.

That is correct, PDAL-JNI is just PDAL bindings. Reading through the issue one more time.

But it's a dynamic lib, not a static one.

This is also true, we rely on the PDAL version and dynamically link. 👍

• Could you try the latest PDAL / bindings versions?
• What is the code that is running? Mb it's a bug of the older bindings overlapped with smth else.
  • 2.6.1 release had a couple of bug fixes around pipeline execution and stages validation: https://github.com/PDAL/java/releases/tag/v2.6.1 I would still recommend using the most up to date bindings.