/usr/lib64/libdl.so.2, but no libdl.so

[zcsizmadia]

In CentOS 7 /usr/lib64/libdl.so.2 exists, but not libdl.so. To resolve the issue, I created a symlink to /usr/lib64/libdl.so.2 as /usr/lib64/libdl.so.

Is there a better way to solve this, maybe addig libdl.so.2 to the Posix NativeMethods module?

Thanks!

[ied206]

Thanks for trying my library and testing it out. As a quick fix, I will separate Linux code and macOS.

The issue turns out quite complicated due to the fragmentation of linux userspace library location and naming. Originally I have used libdl.so.2, but it was changed to libdl to support Linux and macOS with one code (macOS offers only libdl.dylib).

Solutions

(Fastest) Separate Linux/macOS from shared POSIX code

Copy and paste DllImported libdl function definitions into two. One for Linux (libdl.so.2), and the other for macOS (libdl.dylib).

Pros: Fastest way to solve.
**Cons: ** We have to do similar things per target platform.

Use .Net Core's NativeLibrary class

.Net Core 3.0 offers the new class, NativeLibrary, which solves this problem entirely. I have considered using it but was unable to. The API does not exist in .Net Standard, and shipping .Net Core assembly directly and keeping its forward-compatibility is hard.

Zstandard.Net have similar pull request. I will review their code.

Pros: Now the .Net Core runtime is responsible for exposing native library loading functionality. We can expect that Microsoft will take care of such fragmentation things.
Cons: Only available after .Net Core 3.0. .Net Core does not 100% guarantee the behavior compatibility of APIs over major update, unlike .Net Standard.

Study how .Net Core runtime solved it

.Net Core team must have faced similar problems while implementing DllImport for Linux. I will review the code of CoreFX in the long run.

[ied206]

I patched the libdl DllImport code in commit b26e4ca.

If you would, please clone the develop branch and run the test (dotnet test) on CentOS.

[ied206]

The updated package was uploaded to NuGet. It should work on CentOS, please try it.

[zcsizmadia]

Thanks for the update!

Compression.XZ is still referencing DynLoader 1.2.0, so I had to force to use the latest 1.2.1. After adding the PackageReference DybLoader 1.2.1 to the Compression.XZ.Test the test passed on CentOS 7.

[ied206]

Yes, I also am working on other libraries which depends on Joveler.DynLoader.

[ied206]

Joveler.Compression.XZ and its siblings were updated to reference Joveler.DynLoader 1.2,1. Please have a look.