I was playing with .NET 2.0 unmanaged hosting API. I am trying to customize assembly loading and “fix” some assemblies on the fly. I found an interesting gotcha, that I want to write down.<\/p>\n
In one line: if you return a non-null value from <\/p>\n The CLR hosting API is very well structured. You start with Naturally, I was interested in the assembly manager that implements What it does not describe, is that if you return a non-NULL for “non host store assemblies list”, an internal variable In particular, Note, that all that matters is a non-null value of the “non host store assemblies list”. If you call I was playing with .NET 2.0 unmanaged hosting API. I am trying to customize assembly loading and “fix” some assemblies on the fly. I found an interesting gotcha, that I […]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"Layout":"","footnotes":""},"categories":[3,7,4],"tags":[],"class_list":["entry","author-ikriv","has-more-link","post-16","post","type-post","status-publish","format-standard","category-dotnet","category-cpp","category-hack"],"_links":{"self":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/16","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=16"}],"version-history":[{"count":0,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/16\/revisions"}],"wp:attachment":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=16"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=16"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=16"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}IHostAssemblyManager::GetNonHostStoreAssemblies<\/code>, then ICLRRuntimeHost::ExecuteInDefaultAppDomain<\/code> returns error code 0x80131051 or FUSION_E_LOADFROM_BLOCKED<\/code>, without ever consulting your assembly store, or the non-host store assemblies list.<\/p>\nCorBindToRuntimeEx<\/code> call, followed by ICLRRuntimeHost::SetHostControl<\/code>, and then CLR will ask your host to provide a number of “managers”, such as memory manager, assembly manager, etc. All managers are optional: you may return E_NOINTERFACE to let CLR do the default thing.<\/p>\nIHostAssemblyManager<\/code> interface. This interface returns two objects to the CLR: the assembly store, that knows how to get assemblies, and the list of “non host store assemblies” that the CLR should be able to load by itself. The documentation<\/a> says that the CLR behaves differently depending on whether non host store assemblies list is NULL or not, but it describes only the differences in assembly loading order.<\/p>\ng_bFusionHosted<\/code> is set to true<\/code>, and the method CorHost2::IsLoadFromBlocked<\/code> returns true<\/code>. This means that whenever you try to load an assembly from a particular path, you will get return code FUSION_E_LOADFROM_BLOCKED<\/code>, or 0x80131051.<\/p>\nExecuteInDefaultAppDomain<\/code> will fail with this error code, because it loads assembly from a path. Even if you don’t specify the path, and don’t specify the extension, it still fails.<\/p>\nExecuteInDefaultAppDomain<\/code> the CLR never actually consults this list. You may even pass any garbage value instead of the real list, the result will still be the same.<\/p>\n","protected":false},"excerpt":{"rendered":"