Opentk/Source/OpenTK/Platform/MacOS/NS.cs
2014-04-24 13:45:04 +02:00

114 lines
4 KiB
C#

#region License
//
// NS.cs
//
// Author:
// Stefanos A. <stapostol@gmail.com>
//
// Copyright (c) 2006-2013 Stefanos Apostolopoulos
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
#endregion
using System;
using System.Runtime.InteropServices;
namespace OpenTK.Platform.MacOS
{
internal class NS
{
const string Library = "libdl.dylib";
[DllImport(Library, EntryPoint = "NSIsSymbolNameDefined")]
static extern bool NSIsSymbolNameDefined(string s);
[DllImport(Library, EntryPoint = "NSIsSymbolNameDefined")]
static extern bool NSIsSymbolNameDefined(IntPtr s);
[DllImport(Library, EntryPoint = "NSLookupAndBindSymbol")]
static extern IntPtr NSLookupAndBindSymbol(string s);
[DllImport(Library, EntryPoint = "NSLookupAndBindSymbol")]
static extern IntPtr NSLookupAndBindSymbol(IntPtr s);
[DllImport(Library, EntryPoint = "NSAddressOfSymbol")]
static extern IntPtr NSAddressOfSymbol(IntPtr symbol);
[DllImport(Library)]
private static extern IntPtr dlopen(String fileName, int flags);
[DllImport(Library)]
private static extern int dlclose(IntPtr handle);
[DllImport (Library)]
private static extern IntPtr dlsym (IntPtr handle, string symbol);
public static IntPtr GetAddress(string function)
{
// Instead of allocating and combining strings in managed memory
// we do that directly in unmanaged memory. This way, we avoid
// 2 string allocations every time this function is called.
// must add a '_' prefix and null-terminate the function name,
// hence we allocate +2 bytes
IntPtr ptr = Marshal.AllocHGlobal(function.Length + 2);
try
{
Marshal.WriteByte(ptr, (byte)'_');
for (int i = 0; i < function.Length; i++)
{
Marshal.WriteByte(ptr, i + 1, (byte)function[i]);
}
Marshal.WriteByte(ptr, function.Length + 1, 0); // null-terminate
IntPtr symbol = GetAddress(ptr);
return symbol;
}
finally
{
Marshal.FreeHGlobal(ptr);
}
}
public static IntPtr GetAddress(IntPtr function)
{
IntPtr symbol = IntPtr.Zero;
if (NSIsSymbolNameDefined(function))
{
symbol = NSLookupAndBindSymbol(function);
if (symbol != IntPtr.Zero)
symbol = NSAddressOfSymbol(symbol);
}
return symbol;
}
public static IntPtr GetSymbol(IntPtr handle, string symbol)
{
return dlsym(handle, symbol);
}
public static IntPtr LoadLibrary(string fileName)
{
const int RTLD_NOW = 2;
return dlopen(fileName, RTLD_NOW);
}
public static void FreeLibrary(IntPtr handle)
{
dlclose(handle);
}
}
}