{ "runtimeTarget": { "name": ".NETCoreApp,Version=v3.1", "signature": "" }, "compilationOptions": {}, "targets": { ".NETCoreApp,Version=v3.1": { "PluginSample/1.0.0": { "dependencies": { "Microsoft.Extensions.Hosting.Abstractions": "5.0.0-rc.2.20475.5" }, "runtime": { "PluginSample.dll": {} } }, "Microsoft.Extensions.Configuration.Abstractions/5.0.0-rc.2.20475.5": { "dependencies": { "Microsoft.Extensions.Primitives": "5.0.0-rc.2.20475.5" }, "runtime": { "lib/netstandard2.0/Microsoft.Extensions.Configuration.Abstractions.dll": { "assemblyVersion": "5.0.0.0", "fileVersion": "5.0.20.47505" } } ...
using (var dependencyFileStream = File.OpenRead("Sample.deps.json")) { using (DependencyContextJsonReader dependencyContextJsonReader = new DependencyContextJsonReader()) { //获得对应的实体文件 var dependencyContext = dependencyContextJsonReader.Read(dependencyFileStream); //定义的运行环境,没有,则为全平台运行. string currentRuntimeIdentifier= dependencyContext.Target.Runtime; //运行时所须要的dll文件 var assemblyNames= dependencyContext.RuntimeLibraries; } }
{ "runtimes": { "win-arm64": { "#import": [ "win" ] }, "win-arm64-aot": { "#import": [ "win-aot", "win-arm64" ] }, "win-x64": { "#import": [ "win" ] }, "win-x64-aot": { "#import": [ "win-aot", "win-x64" ] }, }
win7-x64 win7-x86 | \ / | | win7 | | | | win-x64 | win-x86 \ | / win | any
linux (linux)linux
linux-armgit
1. .net core的runtime.json文件由微软提供:查看runtime.json.github
2. runtime.json的runeims节点下,定义了全部的RID字典表以及RID树关系.macos
3. 根据*.deps.json依赖文件中的程序集定义RID标识,就能够判断出依赖文件中指向的dll是否能在某一平台运行.json
4. 当程序发布为兼容模式时,咱们出能够使用runtime.json文件选择性的加载平台dll并运行.windows
public class PluginLoadContext : AssemblyLoadContext { private AssemblyDependencyResolver _resolver; public PluginLoadContext(string pluginFolder, params string[] commonAssemblyFolders) : base(isCollectible: true) { this.ResolvingUnmanagedDll += PluginLoadContext_ResolvingUnmanagedDll; this.Resolving += PluginLoadContext_Resolving; //第1步,解析des.json文件,并调用Load和LoadUnmanagedDll函数 _resolver = new AssemblyDependencyResolver(pluginFolder); //第6步,经过第4,5步,解析仍失败的dll会自动尝试调用主程序中的程序集, //若是失败,则直接抛出程序集没法加载的错误 } private Assembly PluginLoadContext_Resolving(AssemblyLoadContext assemblyLoadContext, AssemblyName assemblyName) { //第4步,Load函数加载程序集失败后,执行的事件 } private IntPtr PluginLoadContext_ResolvingUnmanagedDll(Assembly assembly, string unmanagedDllName) { //第5步,LoadUnmanagedDll加载native dll失败后执行的事件 } protected override Assembly Load(AssemblyName assemblyName) { //第2步,先执行程序集的加载函数 } protected override IntPtr LoadUnmanagedDll(string unmanagedDllName) { //第3步,先执行的native dll加载逻辑 } }
class PluginLoadContext : AssemblyLoadContext { private AssemblyDependencyResolver _resolver; public PluginLoadContext(string pluginPath) { _resolver = new AssemblyDependencyResolver(pluginPath); } protected override Assembly Load(AssemblyName assemblyName) { string assemblyPath = _resolver.ResolveAssemblyToPath(assemblyName); if (assemblyPath != null) { //加载程序集 return LoadFromAssemblyPath(assemblyPath); } //返回null,则直接加载主项目程序集 return null; } protected override IntPtr LoadUnmanagedDll(string unmanagedDllName) { string libraryPath = _resolver.ResolveUnmanagedDllToPath(unmanagedDllName); if (libraryPath != null) { //加载native dll文件 return LoadUnmanagedDllFromPath(libraryPath); } //返回IntPtr.Zero,即null指针.将会加载主项中runtimes文件夹下的dll return IntPtr.Zero; } }
1. 官方这个示例是有问题的.LoadFromAssemblyPath()函数有bug,
该函数并不会加载依赖的程序集.正确用法是LoadFormStream() api
2. Load和LoadUnmanagedDll函数其实是给开发者手动加载程序集使用的,
自动加载应放到Resolving和ResolvingUnmanagedDll事件中
缘由是,这样的加载顺序不会致使项目的程序集覆盖插件的程序集,形成程序集加载失败. app
3. 手动加载时能够根据deps.json文件定义的runtime加载当前平台下的unmanaged dll文件. 异步
这些平台相关的dll文件,通常位于发布目录中的runtimes文件夹中.async
当你调用AssemblyLoadContext.UnLoad()卸载完插件觉得相关程序集已经释放,那你可能就错了. 官方文档代表卸载执行失败会抛出InvalidOperationException,不容许卸载官方说明。
但实际测试中,卸载失败,但并未报错.
namespace PluginSample { public class SimpleService { public void Run(string name) { Console.WriteLine($"Hello World!"); } } }
namespace Test { public class PluginLoader { pubilc AssemblyLoadContext assemblyLoadContext; public Assembly assembly; public Type type; public MethodInfo method; public void Load() { assemblyLoadContext = new PluginLoadContext("插件文件夹"); assembly = alc.Load(new AssemblyName("PluginSample")); type = assembly.GetType("PluginSample.SimpleService"); method=type.GetMethod() } } }
1. 在主项目程序中.AssemblyLoadContext,Assembly,Type,MethodInfo等不能直接定义在任何类中.
不然在插件卸载时会失败.当时为了测试是否卸载成功,采用手动加载,执行,卸载了1000次,
发现内存一直上涨,则表示卸载失败.
2. 参照官方文档后了解了WeakReferece类.使用该类与AssemblyLoadContext关联,当手动GC清理时,
AssemblyLoadContext就会变为null值,若是没有变为null值则表示卸载失败.
3. 使用WeakReference关联AssemblyLoadContext并判断是否卸载成功
public void Load(out WeakReference weakReference) { var assemblyLoadContext = new PluginLoadContext("插件文件夹"); weakReference = new WeakReference(pluginLoadContext, true); assemblyLoadContext.UnLoad(); } public void Check() { WeakReference weakReference=null; Load(out weakReference); //通常第二次,IsAlive就会变为False,即AssemblyLoadContext卸载失败. for (int i = 0; weakReference.IsAlive && (i < 10); i++) { GC.Collect(); GC.WaitForPendingFinalizers(); } }
4. 为了解决以上问题.能够把须要的变量放到静态字典中.在Unload以前把对应的Key值删除掉,便可.
public class SimpleService { //同步执行,插件卸载成功 public void Run(string name) { Console.WriteLine($"Hello {name}!"); } //异步执行,卸载成功 public Task RunAsync(string name) { Console.WriteLine($"Hello {name}!"); return Task.CompletedTask; } //异步执行,卸载成功 public Task RunTask(string name) { return Task.Run(() => { Console.WriteLine($"Hello {name}!"); }); } //异步执行,卸载成功 public Task RunWaitTask(string name) { return Task.Run( async ()=> { while (true) { if (CancellationTokenSource.IsCancellationRequested) { break; } await Task.Delay(1000); Console.WriteLine($"Hello {name}!"); } }); } //异步执行,卸载成功 public Task RunWaitTaskForCancel(string name, CancellationToken cancellation) { return Task.Run(async () => { while (true) { if (cancellation.IsCancellationRequested) { break; } await Task.Delay(1000); Console.WriteLine($"Hello {name}!"); } }); } //异步执行,卸载失败 public async Task RunWait(string name) { while (true) { if (CancellationTokenSource.IsCancellationRequested) { break; } await Task.Delay(1000); Console.WriteLine($"Hello {name}!"); } } //异步执行,卸载失败 public Task RunWaitNewTask(string name) { return Task.Factory.StartNew(async ()=> { while (true) { if (CancellationTokenSource.IsCancellationRequested) { break; } await Task.Delay(1000); Console.WriteLine($"Hello {name}!"); } },TaskCreationOptions.DenyChildAttach); } }
1. 以上测试能够看出,若是插件调用的是一个常规带wait的async异步函数,则插件必定会卸载失败.
缘由推测是返回的结果是编译器自动生成的状态机实现的,而状态机是在插件中定义的.
2. 若是在插件中使用Task.Factory.StartNew函数也会调用失败,缘由不明.
官方文档说和Task.Run函数是Task.Factory.StartNew的简单形式,只是参数不一样.官方说明
按照官方提供的默认参数测试,卸载仍然失败.说明这两种方式实现底层应该是不一样的.