/// <summary>
/// When overridden in a derived class, executes the code required to free the handle.
/// </summary>
/// <returns><see langword="true"/> if the handle is released successfully; otherwise, in the event of a catastrophic failure, <see langword="false"/>.</returns>
protected override bool ReleaseHandle()
{
bool released;
try
{
if (handle == IntPtr.Zero)
{
throw new InvalidHandleException();
}
switch (PlatformHelper.CurrentPlatform)
{
case PlatformHelper.Platform.Windows:
Kernel32.FreeLibrary(handle);
break;
case PlatformHelper.Platform.Linux:
case PlatformHelper.Platform.MacOS:
case PlatformHelper.Platform.FreeBSD:
Libdl.dlclose(handle);
break;
default:
break;
}
handle = IntPtr.Zero;
released = true;
}
catch
{
released = false;
}
return(released);
}
public IntPtr Resolve(string entryPoint)
{
#if !MONO
return(Win32.GetProcAddress(_p, entryPoint));
#else
return(Libdl.dlsym(_p, entryPoint));
#endif
}
private void Free()
{
if (_p != IntPtr.Zero)
{
#if !MONO
Win32.FreeLibrary(_p);
#else
Libdl.dlclose(_p);
#endif
_p = IntPtr.Zero;
}
}
public DynamicLibraryImportResolver(string dllName)
{
#if !MONO
_p = Win32.LoadLibrary(dllName);
#else
// TODO: how can we read name remaps out of app.confg <dllmap> ?
_p = Libdl.dlopen(dllName, Libdl.RTLD_NOW);
#endif
if (_p == IntPtr.Zero)
{
throw new InvalidOperationException("LoadLibrary returned NULL");
}
}
public static void FreeDL(IntPtr DLHandle)
{
switch (SystemType)
{
case System.Linux:
Libdl.DLclose(DLHandle);
break;
case System.Windows:
Kernel32.FreeLibrary(DLHandle);
break;
}
}
/// <summary>
/// Loads a function pointer with the given name.
/// </summary>
/// <param name="name">The name of the native function.</param>
/// <returns>A function pointer for the given name, or <see cref="IntPtr.Zero"/> if no function with the specified name was found.</returns>
public IntPtr LoadFunction(string name)
{
if (string.IsNullOrEmpty(name))
{
throw new ArgumentNullException(nameof(name));
}
switch (PlatformHelper.CurrentPlatform)
{
case PlatformHelper.Platform.Windows:
return(Kernel32.GetProcAddress(Handle, name));
case PlatformHelper.Platform.Linux:
case PlatformHelper.Platform.MacOS:
case PlatformHelper.Platform.FreeBSD:
return(Libdl.dlsym(Handle, name));
default:
return(IntPtr.Zero);
}
}
private static IntPtr GetHandle(NativeAssemblyResolver resolver, params string[] names)
{
if (names == null || names.Length == 0)
{
throw new ArgumentNullException(nameof(names));
}
IntPtr value = IntPtr.Zero;
foreach (string name in names)
{
if (Path.IsPathRooted(name))
{
switch (PlatformHelper.CurrentPlatform)
{
case PlatformHelper.Platform.Windows:
value = Kernel32.LoadLibrary(name);
break;
case PlatformHelper.Platform.Linux:
case PlatformHelper.Platform.MacOS:
case PlatformHelper.Platform.FreeBSD:
value = Libdl.dlopen(name, 0x002);
break;
default:
break;
}
}
else
{
foreach (string loadTarget in resolver.EnumerateLoadTargets(name))
{
if (!Path.IsPathRooted(loadTarget) || File.Exists(loadTarget))
{
IntPtr v = IntPtr.Zero;
switch (PlatformHelper.CurrentPlatform)
{
case PlatformHelper.Platform.Windows:
v = Kernel32.LoadLibrary(loadTarget);
break;
case PlatformHelper.Platform.Linux:
case PlatformHelper.Platform.MacOS:
case PlatformHelper.Platform.FreeBSD:
v = Libdl.dlopen(loadTarget, 0x002);
break;
default:
break;
}
if (v != IntPtr.Zero)
{
value = v;
}
}
}
}
if (value != IntPtr.Zero)
{
break;
}
}
if (value == IntPtr.Zero)
{
throw new FileNotFoundException($"Could not load a library with the specified name(s): [ {string.Join(", ", names)} ]");
}
return(value);
}
