Fixed libdl.so.2 issue

Whisper.net/LibraryLoader/LibdlLibraryLoader.cs

@@ -6,6 +6,10 @@ namespace Whisper.net.LibraryLoader;
 
 internal class LibdlLibraryLoader : ILibraryLoader
 {
+    // We need to use the libdl.so.2 library on some systems
+    // We use this flag to remember which one to use, so we don't have to check every time
+    private bool? useLibdl2;
+
     [DllImport("libdl", CharSet = CharSet.Auto, EntryPoint = "dlopen")]
     public static extern IntPtr NativeOpenLibraryLibdl(string? filename, int flags);
 
@@ -15,18 +19,65 @@ internal class LibdlLibraryLoader : ILibraryLoader
     [DllImport("libdl", CharSet = CharSet.Auto, EntryPoint = "dlclose")]
     public static extern int NativeCloseLibraryLibdl(IntPtr handle);
 
+    [DllImport("libdl.so.2", CharSet = CharSet.Auto, EntryPoint = "dlopen")]
+    public static extern IntPtr NativeOpenLibraryLibdl2(string? filename, int flags);
+
+    [DllImport("libdl.so.2", CharSet = CharSet.Auto, EntryPoint = "dlerror")]
+    public static extern IntPtr GetLoadError2();
+
+    [DllImport("libdl.so.2", CharSet = CharSet.Auto, EntryPoint = "dlclose")]
+    public static extern int NativeCloseLibraryLibdl2(IntPtr handle);
+
     public void CloseLibrary(IntPtr handle)
     {
-        NativeCloseLibraryLibdl(handle);
+        if (useLibdl2.HasValue)
+        {
+            if (useLibdl2.Value)
+            {
+                NativeCloseLibraryLibdl2(handle);
+                return;
+            }
+            NativeCloseLibraryLibdl(handle);
+            return;
+        }
+
+        // We don't know which one can be used, so we try both
+        try
+        {
+            NativeCloseLibraryLibdl(handle);
+            useLibdl2 = false;
+        }
+        catch (DllNotFoundException)
+        {
+            NativeCloseLibraryLibdl2(handle);
+            useLibdl2 = true;
+        }
     }
 
     public bool TryOpenLibrary(string fileName, out IntPtr libHandle)
     {
         try
         {
             // open with rtld now + global
-            libHandle = NativeOpenLibraryLibdl(fileName, 0x00102);
-            return libHandle != IntPtr.Zero;
+            if (useLibdl2.HasValue)
+            {
+                libHandle = useLibdl2.Value ? NativeOpenLibraryLibdl2(fileName, 0x00102) : NativeOpenLibraryLibdl(fileName, 0x00102);
+                return libHandle != IntPtr.Zero;
+            }
+
+            // We don't know which one can be used, so we try both
+            try
+            {
+                libHandle = NativeOpenLibraryLibdl(fileName, 0x00102);
+                useLibdl2 = false;
+                return libHandle != IntPtr.Zero;
+            }
+            catch (DllNotFoundException)
+            {
+                libHandle = NativeOpenLibraryLibdl2(fileName, 0x00102);
+                useLibdl2 = true;
+                return libHandle != IntPtr.Zero;
+            }
         }
         catch (DllNotFoundException)
         {
@@ -37,7 +88,30 @@ public bool TryOpenLibrary(string fileName, out IntPtr libHandle)
 
     public string GetLastError()
     {
-        return Marshal.PtrToStringAnsi(GetLoadError()) ?? "Unknown error";
+        if (useLibdl2.HasValue)
+        {
+            var error = useLibdl2.Value ? GetLoadError2() : GetLoadError();
+            return GetError(error);
+        }
+
+        // We don't know which one can be used, so we try both
+        try
+        {
+            var error = GetLoadError();
+            useLibdl2 = false;
+            return GetError(error);
+        }
+        catch (DllNotFoundException)
+        {
+            var error = GetLoadError2();
+            useLibdl2 = true;
+            return GetError(error);
+        }
+    }
+
+    private string GetError(IntPtr error)
+    {
+        return Marshal.PtrToStringAnsi(error) ?? "Unknown error";
     }
 }
 #endif