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Diffstat (limited to 'src/vm/classloadlevel.h')
| -rw-r--r-- | src/vm/classloadlevel.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/src/vm/classloadlevel.h b/src/vm/classloadlevel.h new file mode 100644 index 0000000000..1cf388fbdc --- /dev/null +++ b/src/vm/classloadlevel.h @@ -0,0 +1,88 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. +// +// classloadlevel.h + + +#ifndef _H_CLASSLOADLEVEL +#define _H_CLASSLOADLEVEL + +// Class loading is split into phases in order to handle recursion +// through field types and generic instantiations in the presence of +// multiple threads and the possibility of load failures. +// +// This enum represents the level to which a class has been loaded. +// (See GetLoadLevel() on TypeHandle, MethodTable and TypeDesc). +// +// CLASS_LOAD_BEGIN +// +// Placeholder level used before type has been created or located in ngen image +// +// +// CLASS_LOAD_UNRESTOREDTYPEKEY +// +// Type lives in an ngen image and components of its type key need restoring: +// for methodtables: generic arguments, EEClass pointer, Module pointer in EEClass +// for typedescs: param type, template methodtable +// +// +// CLASS_LOAD_UNRESTORED +// +// Type lives in an ngen image and contains fields that need restoring +// (e.g. parent, interfaces, param type) +// +// +// CLASS_LOAD_APPROXPARENTS +// +// Type has been created, or loaded from an ngen image and fields +// have been restored, but some fields have been filled in with only +// "approximate" information for generic type arguments. In +// particular, the parent class is approximate, and interfaces are +// generic (instantiation at formal type parameters). Other +// information (vtable and dictionary) may be based on these +// approximate type arguments. +// +// +// CLASS_LOAD_EXACTPARENTS +// +// The generic arguments to parent class and interfaces are exact +// types, and the whole hierarchy (parent and interfaces) is loaded +// to this level. However, other dependent types (such as generic arguments) +// may still be loaded at a lower level. +// +// +// CLASS_DEPENDENCIES_LOADED +// +// The type is fully loaded, as are all dependents (hierarchy, generic args, +// canonical MT, etc). For generic instantiations, the constraints +// have not yet been verified. +// +// +// CLASS_LOADED +// +// This is a "read-only" verification phase that changes no state other than +// to flip the IsFullyLoaded() bit. We use this phase to do conformity +// checks (which can't be done in an earlier phase) on the class in a +// recursion-proof manner. +// For eg, we check constraints on generic types, and access checks for +// the type of (valuetype) fields. +// + +enum ClassLoadLevel +{ + CLASS_LOAD_BEGIN, + CLASS_LOAD_UNRESTOREDTYPEKEY, + CLASS_LOAD_UNRESTORED, + CLASS_LOAD_APPROXPARENTS, + CLASS_LOAD_EXACTPARENTS, + CLASS_DEPENDENCIES_LOADED, + CLASS_LOADED, + + CLASS_LOAD_LEVEL_FINAL = CLASS_LOADED, +}; + + +extern const char * const classLoadLevelName[]; + +#endif // _H_CLASSLOADLEVEL |