--- 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 <MEMFLAGS F> 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