diff -r a1bee305515d -r c62d2e8b2728 hotspot/src/share/vm/classfile/systemDictionary.hpp --- a/hotspot/src/share/vm/classfile/systemDictionary.hpp Thu Jul 27 17:47:57 2017 -0700 +++ b/hotspot/src/share/vm/classfile/systemDictionary.hpp Fri Jul 28 10:48:35 2017 -0400 @@ -35,31 +35,34 @@ #include "utilities/hashtable.hpp" #include "utilities/hashtable.inline.hpp" -// The system dictionary stores all loaded classes and maps: +// The dictionary in each ClassLoaderData stores all loaded classes, either +// initiatied by its class loader or defined by its class loader: // -// [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* +// class loader -> ClassLoaderData -> [class, protection domain set] // // Classes are loaded lazily. The default VM class loader is // represented as NULL. -// The underlying data structure is an open hash table with a fixed number -// of buckets. During loading the loader object is locked, (for the VM loader -// a private lock object is used). Class loading can thus be done concurrently, -// but only by different loaders. +// The underlying data structure is an open hash table (Dictionary) per +// ClassLoaderData with a fixed number of buckets. During loading the +// class loader object is locked, (for the VM loader a private lock object is used). +// The global SystemDictionary_lock is held for all additions into the ClassLoaderData +// dictionaries. TODO: fix lock granularity so that class loading can +// be done concurrently, but only by different loaders. // // During loading a placeholder (name, loader) is temporarily placed in // a side data structure, and is used to detect ClassCircularityErrors // and to perform verification during GC. A GC can occur in the midst // of class loading, as we call out to Java, have to take locks, etc. // -// When class loading is finished, a new entry is added to the system -// dictionary and the place holder is removed. Note that the protection -// domain field of the system dictionary has not yet been filled in when -// the "real" system dictionary entry is created. +// When class loading is finished, a new entry is added to the dictionary +// of the class loader and the placeholder is removed. Note that the protection +// domain field of the dictionary entry has not yet been filled in when +// the "real" dictionary entry is created. // // Clients of this class who are interested in finding if a class has // been completely loaded -- not classes in the process of being loaded -- -// can read the SystemDictionary unlocked. This is safe because +// can read the dictionary unlocked. This is safe because // - entries are only deleted at safepoints // - readers cannot come to a safepoint while actively examining // an entry (an entry cannot be deleted from under a reader) @@ -78,6 +81,8 @@ template class HashtableBucket; class ResolutionErrorTable; class SymbolPropertyTable; +class ProtectionDomainCacheTable; +class ProtectionDomainCacheEntry; class GCTimer; // Certain classes are preloaded, such as java.lang.Object and java.lang.String. @@ -281,7 +286,7 @@ bool is_superclass, TRAPS); - // Parse new stream. This won't update the system dictionary or + // Parse new stream. This won't update the dictionary or // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. // Also used by Unsafe_DefineAnonymousClass static InstanceKlass* parse_stream(Symbol* class_name, @@ -348,14 +353,6 @@ Handle class_loader, TRAPS); - // Iterate over all klasses in dictionary - // Just the classes from defining class loaders - static void classes_do(void f(Klass*)); - // Added for initialize_itable_for_klass to handle exceptions - static void classes_do(void f(Klass*, TRAPS), TRAPS); - // All classes, and their class loaders, including initiating class loaders - static void classes_do(void f(Klass*, ClassLoaderData*)); - // Iterate over all methods in all klasses static void methods_do(void f(Method*)); @@ -394,11 +391,6 @@ static void print(bool details = true); static void print_shared(bool details = true); - // Number of contained klasses - // This is both fully loaded classes and classes in the process - // of being loaded - static int number_of_classes(); - // Monotonically increasing counter which grows as classes are // loaded or modifications such as hot-swapping or setting/removing // of breakpoints are performed @@ -558,28 +550,21 @@ static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, Symbol** message); + + static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); + protected: enum Constants { _loader_constraint_size = 107, // number of entries in constraint table _resolution_error_size = 107, // number of entries in resolution error table _invoke_method_size = 139, // number of entries in invoke method table - _nof_buckets = 1009, // number of buckets in hash table for placeholders - _old_default_sdsize = 1009, // backward compat for system dictionary size - _prime_array_size = 8, // array of primes for system dictionary size - _average_depth_goal = 3 // goal for lookup length + _shared_dictionary_size = 1009, // number of entries in shared dictionary + _placeholder_table_size = 1009 // number of entries in hash table for placeholders }; - // Static variables - - // hashtable sizes for system dictionary to allow growth - // prime numbers for system dictionary size - static int _sdgeneration; - static const int _primelist[_prime_array_size]; - - // Hashtable holding loaded classes. - static Dictionary* _dictionary; + // Static tables owned by the SystemDictionary // Hashtable holding placeholders for classes being loaded. static PlaceholderTable* _placeholders; @@ -588,7 +573,7 @@ static Dictionary* _shared_dictionary; // Monotonically increasing counter which grows with - // _number_of_classes as well as hot-swapping and breakpoint setting + // loading classes as well as hot-swapping and breakpoint setting // and removal. static int _number_of_modifications; @@ -604,10 +589,8 @@ // Invoke methods (JSR 292) static SymbolPropertyTable* _invoke_method_table; -public: - // for VM_CounterDecay iteration support - friend class CounterDecay; - static Klass* try_get_next_class(); + // ProtectionDomain cache + static ProtectionDomainCacheTable* _pd_cache_table; protected: static void validate_protection_domain(InstanceKlass* klass, @@ -616,7 +599,6 @@ friend class VM_PopulateDumpSharedSpace; friend class TraversePlaceholdersClosure; - static Dictionary* dictionary() { return _dictionary; } static Dictionary* shared_dictionary() { return _shared_dictionary; } static PlaceholderTable* placeholders() { return _placeholders; } static LoaderConstraintTable* constraints() { return _loader_constraints; } @@ -666,7 +648,7 @@ // Basic find on loaded classes static InstanceKlass* find_class(int index, unsigned int hash, - Symbol* name, ClassLoaderData* loader_data); + Symbol* name, Dictionary* dictionary); static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); // Basic find on classes in the midst of being loaded