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Diffstat (limited to 'src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs')
| -rw-r--r-- | src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs new file mode 100644 index 0000000000..e614cab6ab --- /dev/null +++ b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs @@ -0,0 +1,158 @@ +#region Copyright notice and license + +// Copyright 2015-2016, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#endregion + +using System; +using System.Collections.Concurrent; +using System.Diagnostics; +using System.IO; +using System.Reflection; +using System.Runtime.InteropServices; +using System.Threading; + +using Grpc.Core.Logging; +using Grpc.Core.Utils; + +namespace Grpc.Core.Internal +{ + /// <summary> + /// Represents a dynamically loaded unmanaged library in a (partially) platform independent manner. + /// An important difference in library loading semantics is that on Windows, once we load a dynamic library using LoadLibrary, + /// that library becomes instantly available for <c>DllImport</c> P/Invoke calls referring to the same library name. + /// On Unix systems, dlopen has somewhat different semantics, so we need to use dlsym and <c>Marshal.GetDelegateForFunctionPointer</c> + /// to obtain delegates to native methods. + /// See http://stackoverflow.com/questions/13461989/p-invoke-to-dynamically-loaded-library-on-mono. + /// </summary> + internal class UnmanagedLibrary + { + static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<UnmanagedLibrary>(); + + // flags for dlopen + const int RTLD_LAZY = 1; + const int RTLD_GLOBAL = 8; + + readonly string libraryPath; + readonly IntPtr handle; + + public UnmanagedLibrary(string libraryPath) + { + this.libraryPath = Preconditions.CheckNotNull(libraryPath); + + if (!File.Exists(this.libraryPath)) + { + throw new FileNotFoundException("Error loading native library. File does not exist.", this.libraryPath); + } + + Logger.Debug("Attempting to load native library \"{0}\"", this.libraryPath); + + this.handle = PlatformSpecificLoadLibrary(this.libraryPath); + + if (this.handle == IntPtr.Zero) + { + throw new IOException(string.Format("Error loading native library \"{0}\"", this.libraryPath)); + } + } + + /// <summary> + /// Loads symbol in a platform specific way. + /// </summary> + /// <param name="symbolName"></param> + /// <returns></returns> + public IntPtr LoadSymbol(string symbolName) + { + if (PlatformApis.IsLinux) + { + return Linux.dlsym(this.handle, symbolName); + } + if (PlatformApis.IsMacOSX) + { + return MacOSX.dlsym(this.handle, symbolName); + } + throw new InvalidOperationException("Unsupported platform."); + } + + public T GetNativeMethodDelegate<T>(string methodName) + where T : class + { + var ptr = LoadSymbol(methodName); + if (ptr == IntPtr.Zero) + { + throw new MissingMethodException(string.Format("The native method \"{0}\" does not exist", methodName)); + } + return Marshal.GetDelegateForFunctionPointer(ptr, typeof(T)) as T; + } + + /// <summary> + /// Loads library in a platform specific way. + /// </summary> + private static IntPtr PlatformSpecificLoadLibrary(string libraryPath) + { + if (PlatformApis.IsWindows) + { + return Windows.LoadLibrary(libraryPath); + } + if (PlatformApis.IsLinux) + { + return Linux.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY); + } + if (PlatformApis.IsMacOSX) + { + return MacOSX.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY); + } + throw new InvalidOperationException("Unsupported platform."); + } + + private static class Windows + { + [DllImport("kernel32.dll")] + internal static extern IntPtr LoadLibrary(string filename); + } + + private static class Linux + { + [DllImport("libdl.so")] + internal static extern IntPtr dlopen(string filename, int flags); + + [DllImport("libdl.so")] + internal static extern IntPtr dlsym(IntPtr handle, string symbol); + } + + private static class MacOSX + { + [DllImport("libSystem.dylib")] + internal static extern IntPtr dlopen(string filename, int flags); + + [DllImport("libSystem.dylib")] + internal static extern IntPtr dlsym(IntPtr handle, string symbol); + } + } +} |