8027146: Class loading verification failure if GC occurs in Universe::flush_dependents_on
Summary: Remove search in system dictionary and hacks, replace with verifying in CLD::_klasses list.
Reviewed-by: dcubed, acorn
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
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*/
#ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
#define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
#include "classfile/classFileStream.hpp"
#include "classfile/classLoader.hpp"
#include "oops/objArrayOop.hpp"
#include "oops/symbol.hpp"
#include "runtime/java.hpp"
#include "runtime/reflectionUtils.hpp"
#include "utilities/hashtable.hpp"
#include "utilities/hashtable.inline.hpp"
// The system dictionary stores all loaded classes and maps:
//
// [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
//
// 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.
//
// 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.
//
// 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
// - 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)
// - entries must be fully formed before they are available to concurrent
// readers (we must ensure write ordering)
//
// Note that placeholders are deleted at any time, as they are removed
// when a class is completely loaded. Therefore, readers as well as writers
// of placeholders must hold the SystemDictionary_lock.
//
class Dictionary;
class PlaceholderTable;
class LoaderConstraintTable;
template <MEMFLAGS F> class HashtableBucket;
class ResolutionErrorTable;
class SymbolPropertyTable;
class Ticks;
// Certain classes are preloaded, such as java.lang.Object and java.lang.String.
// They are all "well-known", in the sense that no class loader is allowed
// to provide a different definition.
//
// These klasses must all have names defined in vmSymbols.
#define WK_KLASS_ENUM_NAME(kname) kname##_knum
// Each well-known class has a short klass name (like object_klass),
// a vmSymbol name (like java_lang_Object), and a flag word
// that makes some minor distinctions, like whether the klass
// is preloaded, optional, release-specific, etc.
// The order of these definitions is significant; it is the order in which
// preloading is actually performed by initialize_preloaded_classes.
#define WK_KLASSES_DO(do_klass) \
/* well-known classes */ \
do_klass(Object_klass, java_lang_Object, Pre ) \
do_klass(String_klass, java_lang_String, Pre ) \
do_klass(Class_klass, java_lang_Class, Pre ) \
do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
do_klass(Serializable_klass, java_io_Serializable, Pre ) \
do_klass(System_klass, java_lang_System, Pre ) \
do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
do_klass(Error_klass, java_lang_Error, Pre ) \
do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
do_klass(Exception_klass, java_lang_Exception, Pre ) \
do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
\
/* Preload ref klasses and set reference types */ \
do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
\
do_klass(Thread_klass, java_lang_Thread, Pre ) \
do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
do_klass(Properties_klass, java_util_Properties, Pre ) \
do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
\
/* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
/* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
/* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15 ) \
do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15 ) \
do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
\
/* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292 ) \
do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292 ) \
do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292 ) \
do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292 ) \
do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292 ) \
do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292 ) \
do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292 ) \
do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292 ) \
do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292 ) \
/* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
\
do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \
\
/* It's NULL in non-1.4 JDKs. */ \
do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
/* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
/* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
\
/* Preload boxing klasses */ \
do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
do_klass(Character_klass, java_lang_Character, Pre ) \
do_klass(Float_klass, java_lang_Float, Pre ) \
do_klass(Double_klass, java_lang_Double, Pre ) \
do_klass(Byte_klass, java_lang_Byte, Pre ) \
do_klass(Short_klass, java_lang_Short, Pre ) \
do_klass(Integer_klass, java_lang_Integer, Pre ) \
do_klass(Long_klass, java_lang_Long, Pre ) \
/*end*/
class SystemDictionary : AllStatic {
friend class VMStructs;
friend class SystemDictionaryHandles;
public:
enum WKID {
NO_WKID = 0,
#define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
WK_KLASSES_DO(WK_KLASS_ENUM)
#undef WK_KLASS_ENUM
WKID_LIMIT,
FIRST_WKID = NO_WKID + 1
};
enum InitOption {
Pre, // preloaded; error if not present
Pre_JSR292, // preloaded if EnableInvokeDynamic
// Order is significant. Options before this point require resolve_or_fail.
// Options after this point will use resolve_or_null instead.
Opt, // preload tried; NULL if not present
Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
Opt_Only_JDK15, // preload tried; use only with JDK1.5+
OPTION_LIMIT,
CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
};
// Returns a class with a given class name and class loader. Loads the
// class if needed. If not found a NoClassDefFoundError or a
// ClassNotFoundException is thrown, depending on the value on the
// throw_error flag. For most uses the throw_error argument should be set
// to true.
static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
// Convenient call for null loader and protection domain.
static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
private:
// handle error translation for resolve_or_null results
static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
public:
// Returns a class with a given class name and class loader.
// Loads the class if needed. If not found NULL is returned.
static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
// Version with null loader and protection domain
static Klass* resolve_or_null(Symbol* class_name, TRAPS);
// Resolve a superclass or superinterface. Called from ClassFileParser,
// parse_interfaces, resolve_instance_class_or_null, load_shared_class
// "child_name" is the class whose super class or interface is being resolved.
static Klass* resolve_super_or_fail(Symbol* child_name,
Symbol* class_name,
Handle class_loader,
Handle protection_domain,
bool is_superclass,
TRAPS);
// Parse new stream. This won't update the system dictionary or
// class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
static Klass* parse_stream(Symbol* class_name,
Handle class_loader,
Handle protection_domain,
ClassFileStream* st,
TRAPS) {
KlassHandle nullHandle;
return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
}
static Klass* parse_stream(Symbol* class_name,
Handle class_loader,
Handle protection_domain,
ClassFileStream* st,
KlassHandle host_klass,
GrowableArray<Handle>* cp_patches,
TRAPS);
// Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
Handle protection_domain,
ClassFileStream* st, bool verify, TRAPS);
// Lookup an already loaded class. If not found NULL is returned.
static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
// Lookup an already loaded instance or array class.
// Do not make any queries to class loaders; consult only the cache.
// If not found NULL is returned.
static Klass* find_instance_or_array_klass(Symbol* class_name,
Handle class_loader,
Handle protection_domain,
TRAPS);
// Lookup an instance or array class that has already been loaded
// either into the given class loader, or else into another class
// loader that is constrained (via loader constraints) to produce
// a consistent class. Do not take protection domains into account.
// Do not make any queries to class loaders; consult only the cache.
// Return NULL if the class is not found.
//
// This function is a strict superset of find_instance_or_array_klass.
// This function (the unchecked version) makes a conservative prediction
// of the result of the checked version, assuming successful lookup.
// If both functions return non-null, they must return the same value.
// Also, the unchecked version may sometimes be non-null where the
// checked version is null. This can occur in several ways:
// 1. No query has yet been made to the class loader.
// 2. The class loader was queried, but chose not to delegate.
// 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
// 4. Loading was attempted, but there was a linkage error of some sort.
// In all of these cases, the loader constraints on this type are
// satisfied, and it is safe for classes in the given class loader
// to manipulate strongly-typed values of the found class, subject
// to local linkage and access checks.
static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
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
static void classes_do(void f(Klass*, ClassLoaderData*));
static void placeholders_do(void f(Symbol*));
// Iterate over all methods in all klasses in dictionary
static void methods_do(void f(Method*));
// Garbage collection support
// This method applies "blk->do_oop" to all the pointers to "system"
// classes and loaders.
static void always_strong_oops_do(OopClosure* blk);
static void always_strong_classes_do(KlassClosure* closure);
// Unload (that is, break root links to) all unmarked classes and
// loaders. Returns "true" iff something was unloaded.
static bool do_unloading(BoolObjectClosure* is_alive);
static int calculate_systemdictionary_size(int loadedclasses);
// Applies "f->do_oop" to all root oops in the system dictionary.
static void oops_do(OopClosure* f);
// System loader lock
static oop system_loader_lock() { return _system_loader_lock_obj; }
private:
// Extended Redefine classes support (tbi)
static void preloaded_classes_do(KlassClosure* f);
static void lazily_loaded_classes_do(KlassClosure* f);
public:
// Sharing support.
static void reorder_dictionary();
static void copy_buckets(char** top, char* end);
static void copy_table(char** top, char* end);
static void reverse();
static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
int number_of_entries);
// Printing
static void print() PRODUCT_RETURN;
static void print_class_statistics() PRODUCT_RETURN;
static void print_method_statistics() PRODUCT_RETURN;
// 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
static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
// Needed by evolution and breakpoint code
static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
// Verification
static void verify();
#ifdef ASSERT
static bool is_internal_format(Symbol* class_name);
#endif
// Initialization
static void initialize(TRAPS);
// Fast access to commonly used classes (preloaded)
static Klass* check_klass(Klass* k) {
assert(k != NULL, "preloaded klass not initialized");
return k;
}
static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
static Klass* check_klass_Opt( Klass* k) { return k; }
static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
return k;
}
static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
// despite the optional loading, if you use this it must be present:
return check_klass(k);
}
static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
int limit = (int)end_id + 1;
initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
}
public:
#define WK_KLASS_DECLARE(name, symbol, option) \
static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
static Klass** name##_addr() { \
return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
}
WK_KLASSES_DO(WK_KLASS_DECLARE);
#undef WK_KLASS_DECLARE
static Klass* well_known_klass(WKID id) {
assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
return _well_known_klasses[id];
}
static Klass** well_known_klass_addr(WKID id) {
assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
return &_well_known_klasses[id];
}
// Local definition for direct access to the private array:
#define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
static Klass* box_klass(BasicType t) {
assert((uint)t < T_VOID+1, "range check");
return check_klass(_box_klasses[t]);
}
static BasicType box_klass_type(Klass* k); // inverse of box_klass
// methods returning lazily loaded klasses
// The corresponding method to load the class must be called before calling them.
static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
static void load_abstract_ownable_synchronizer_klass(TRAPS);
private:
// Tells whether ClassLoader.loadClassInternal is present
static bool has_loadClassInternal() { return _has_loadClassInternal; }
// Returns the class loader data to be used when looking up/updating the
// system dictionary.
static ClassLoaderData *class_loader_data(Handle class_loader) {
return ClassLoaderData::class_loader_data(class_loader());
}
public:
// Tells whether ClassLoader.checkPackageAccess is present
static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
// Returns default system loader
static oop java_system_loader();
// Compute the default system loader
static void compute_java_system_loader(TRAPS);
// Register a new class loader
static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
private:
// Mirrors for primitive classes (created eagerly)
static oop check_mirror(oop m) {
assert(m != NULL, "mirror not initialized");
return m;
}
public:
// Note: java_lang_Class::primitive_type is the inverse of java_mirror
// Check class loader constraints
static bool add_loader_constraint(Symbol* name, Handle loader1,
Handle loader2, TRAPS);
static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
Handle loader2, bool is_method, TRAPS);
// JSR 292
// find a java.lang.invoke.MethodHandle.invoke* method for a given signature
// (asks Java to compute it if necessary, except in a compiler thread)
static methodHandle find_method_handle_invoker(Symbol* name,
Symbol* signature,
KlassHandle accessing_klass,
Handle *appendix_result,
Handle *method_type_result,
TRAPS);
// for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
// (does not ask Java, since this is a low-level intrinsic defined by the JVM)
static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
Symbol* signature,
TRAPS);
// find a java.lang.invoke.MethodType object for a given signature
// (asks Java to compute it if necessary, except in a compiler thread)
static Handle find_method_handle_type(Symbol* signature,
KlassHandle accessing_klass,
TRAPS);
// ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
static Handle link_method_handle_constant(KlassHandle caller,
int ref_kind, //e.g., JVM_REF_invokeVirtual
KlassHandle callee,
Symbol* name,
Symbol* signature,
TRAPS);
// ask Java to create a dynamic call site, while linking an invokedynamic op
static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
Handle bootstrap_method,
Symbol* name,
Symbol* type,
Handle *appendix_result,
Handle *method_type_result,
TRAPS);
// Utility for printing loader "name" as part of tracing constraints
static const char* loader_name(oop loader) {
return ((loader) == NULL ? "<bootloader>" :
InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
}
static const char* loader_name(ClassLoaderData* loader_data) {
return (loader_data->class_loader() == NULL ? "<bootloader>" :
InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
}
// Record the error when the first attempt to resolve a reference from a constant
// pool entry to a class fails.
static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
static void delete_resolution_error(ConstantPool* pool);
static Symbol* find_resolution_error(constantPoolHandle pool, int which);
private:
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
};
// 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;
// Hashtable holding placeholders for classes being loaded.
static PlaceholderTable* _placeholders;
// Hashtable holding classes from the shared archive.
static Dictionary* _shared_dictionary;
// Monotonically increasing counter which grows with
// _number_of_classes as well as hot-swapping and breakpoint setting
// and removal.
static int _number_of_modifications;
// Lock object for system class loader
static oop _system_loader_lock_obj;
// Constraints on class loaders
static LoaderConstraintTable* _loader_constraints;
// Resolution errors
static ResolutionErrorTable* _resolution_errors;
// Invoke methods (JSR 292)
static SymbolPropertyTable* _invoke_method_table;
public:
// for VM_CounterDecay iteration support
friend class CounterDecay;
static Klass* try_get_next_class();
private:
static void validate_protection_domain(instanceKlassHandle klass,
Handle class_loader,
Handle protection_domain, TRAPS);
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; }
static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
// Basic loading operations
static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
// Wait on SystemDictionary_lock; unlocks lockObject before
// waiting; relocks lockObject with correct recursion count
// after waiting, but before reentering SystemDictionary_lock
// to preserve lock order semantics.
static void double_lock_wait(Handle lockObject, TRAPS);
static void define_instance_class(instanceKlassHandle k, TRAPS);
static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
Handle class_loader,
instanceKlassHandle k, TRAPS);
static instanceKlassHandle load_shared_class(Symbol* class_name,
Handle class_loader, TRAPS);
static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
Handle class_loader, TRAPS);
static void clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS);
static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
static void check_loader_lock_contention(Handle loader_lock, TRAPS);
static bool is_parallelCapable(Handle class_loader);
static bool is_parallelDefine(Handle class_loader);
public:
static bool is_ext_class_loader(Handle class_loader);
private:
static Klass* find_shared_class(Symbol* class_name);
// Setup link to hierarchy
static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
// event based tracing
static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
Handle initiating_loader);
// We pass in the hashtable index so we can calculate it outside of
// the SystemDictionary_lock.
// Basic find on loaded classes
static Klass* find_class(int index, unsigned int hash,
Symbol* name, ClassLoaderData* loader_data);
static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
// Basic find on classes in the midst of being loaded
static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
// Updating entry in dictionary
// Add a completely loaded class
static void add_klass(int index, Symbol* class_name,
ClassLoaderData* loader_data, KlassHandle obj);
// Add a placeholder for a class being loaded
static void add_placeholder(int index,
Symbol* class_name,
ClassLoaderData* loader_data);
static void remove_placeholder(int index,
Symbol* class_name,
ClassLoaderData* loader_data);
// Performs cleanups after resolve_super_or_fail. This typically needs
// to be called on failure.
// Won't throw, but can block.
static void resolution_cleanups(Symbol* class_name,
ClassLoaderData* loader_data,
TRAPS);
// Initialization
static void initialize_preloaded_classes(TRAPS);
// Class loader constraints
static void check_constraints(int index, unsigned int hash,
instanceKlassHandle k, Handle loader,
bool defining, TRAPS);
static void update_dictionary(int d_index, unsigned int d_hash,
int p_index, unsigned int p_hash,
instanceKlassHandle k, Handle loader,
TRAPS);
// Variables holding commonly used klasses (preloaded)
static Klass* _well_known_klasses[];
// Lazily loaded klasses
static Klass* volatile _abstract_ownable_synchronizer_klass;
// table of box klasses (int_klass, etc.)
static Klass* _box_klasses[T_VOID+1];
static oop _java_system_loader;
static bool _has_loadClassInternal;
static bool _has_checkPackageAccess;
};
#endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP