| #region Copyright notice and license |
| |
| // Copyright 2015, 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.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. |
| /// First, the native library is loaded using dlopen (on Unix systems) or using LoadLibrary (on Windows). |
| /// dlsym or GetProcAddress are then used to obtain symbol addresses. <c>Marshal.GetDelegateForFunctionPointer</c> |
| /// transforms the addresses into 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[] libraryPathAlternatives) |
| { |
| this.libraryPath = FirstValidLibraryPath(libraryPathAlternatives); |
| |
| 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.IsWindows) |
| { |
| // See http://stackoverflow.com/questions/10473310 for background on this. |
| if (PlatformApis.Is64Bit) |
| { |
| return Windows.GetProcAddress(this.handle, symbolName); |
| } |
| else |
| { |
| // Yes, we could potentially predict the size... but it's a lot simpler to just try |
| // all the candidates. Most functions have a suffix of @0, @4 or @8 so we won't be trying |
| // many options - and if it takes a little bit longer to fail if we've really got the wrong |
| // library, that's not a big problem. This is only called once per function in the native library. |
| symbolName = "_" + symbolName + "@"; |
| for (int stackSize = 0; stackSize < 128; stackSize += 4) |
| { |
| IntPtr candidate = Windows.GetProcAddress(this.handle, symbolName + stackSize); |
| if (candidate != IntPtr.Zero) |
| { |
| return candidate; |
| } |
| } |
| // Fail. |
| return IntPtr.Zero; |
| } |
| } |
| if (PlatformApis.IsLinux) |
| { |
| if (PlatformApis.IsMono) |
| { |
| return Mono.dlsym(this.handle, symbolName); |
| } |
| if (PlatformApis.IsNetCore) |
| { |
| return CoreCLR.dlsym(this.handle, symbolName); |
| } |
| 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) |
| { |
| if (PlatformApis.IsMono) |
| { |
| return Mono.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY); |
| } |
| if (PlatformApis.IsNetCore) |
| { |
| return CoreCLR.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY); |
| } |
| 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 string FirstValidLibraryPath(string[] libraryPathAlternatives) |
| { |
| GrpcPreconditions.CheckArgument(libraryPathAlternatives.Length > 0, "libraryPathAlternatives cannot be empty."); |
| foreach (var path in libraryPathAlternatives) |
| { |
| if (File.Exists(path)) |
| { |
| return path; |
| } |
| } |
| throw new FileNotFoundException( |
| String.Format("Error loading native library. Not found in any of the possible locations: {0}", |
| string.Join(",", libraryPathAlternatives))); |
| } |
| |
| private static class Windows |
| { |
| [DllImport("kernel32.dll")] |
| internal static extern IntPtr LoadLibrary(string filename); |
| |
| [DllImport("kernel32.dll")] |
| internal static extern IntPtr GetProcAddress(IntPtr hModule, string procName); |
| } |
| |
| 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); |
| } |
| |
| /// <summary> |
| /// On Linux systems, using using dlopen and dlsym results in |
| /// DllNotFoundException("libdl.so not found") if libc6-dev |
| /// is not installed. As a workaround, we load symbols for |
| /// dlopen and dlsym from the current process as on Linux |
| /// Mono sure is linked against these symbols. |
| /// </summary> |
| private static class Mono |
| { |
| [DllImport("__Internal")] |
| internal static extern IntPtr dlopen(string filename, int flags); |
| |
| [DllImport("__Internal")] |
| internal static extern IntPtr dlsym(IntPtr handle, string symbol); |
| } |
| |
| /// <summary> |
| /// Similarly as for Mono on Linux, we load symbols for |
| /// dlopen and dlsym from the "libcoreclr.so", |
| /// to avoid the dependency on libc-dev Linux. |
| /// </summary> |
| private static class CoreCLR |
| { |
| [DllImport("libcoreclr.so")] |
| internal static extern IntPtr dlopen(string filename, int flags); |
| |
| [DllImport("libcoreclr.so")] |
| internal static extern IntPtr dlsym(IntPtr handle, string symbol); |
| } |
| } |
| } |