/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * 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.

 *

 */

#ifndef SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP

#define SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP

#include "classfile/classLoaderData.hpp"

#include "oops/objArrayOop.hpp"

#include "oops/symbol.hpp"

#include "runtime/java.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/reflectionUtils.hpp"

#include "runtime/signature.hpp"

#include "utilities/hashtable.hpp"

// The dictionary in each ClassLoaderData stores all loaded classes, either

// initiatied by its class loader or defined by its class loader:

//

//   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 (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 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 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)

//    - 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 BootstrapInfo;

class ClassFileStream;

class Dictionary;

class PlaceholderTable;

class LoaderConstraintTable;

template <MEMFLAGS F> class HashtableBucket;

class ResolutionErrorTable;

class SymbolPropertyTable;

class ProtectionDomainCacheTable;

class ProtectionDomainCacheEntry;

class GCTimer;

#define WK_KLASS_ENUM_NAME(kname)    kname##_knum

// Certain classes, such as java.lang.Object and java.lang.String,

// are "well-known", in the sense that no class loader is allowed

// to provide a different definition.

//

// Each well-known class has a short klass name (like object_klass),

// and a vmSymbol name (like java_lang_Object).

//

// The order of these definitions is significant: the classes are

// resolved during early VM start-up by resolve_well_known_classes

// in this order. Changing the order may require careful restructuring

// of the VM start-up sequence.

//

#define WK_KLASSES_DO(do_klass)                                                                                 \

  /* well-known classes */                                                                                      \

  do_klass(Object_klass,                                java_lang_Object                                      ) \

  do_klass(String_klass,                                java_lang_String                                      ) \

  do_klass(Class_klass,                                 java_lang_Class                                       ) \

  do_klass(Cloneable_klass,                             java_lang_Cloneable                                   ) \

  do_klass(ClassLoader_klass,                           java_lang_ClassLoader                                 ) \

  do_klass(Serializable_klass,                          java_io_Serializable                                  ) \

  do_klass(System_klass,                                java_lang_System                                      ) \

  do_klass(Throwable_klass,                             java_lang_Throwable                                   ) \

  do_klass(Error_klass,                                 java_lang_Error                                       ) \

  do_klass(ThreadDeath_klass,                           java_lang_ThreadDeath                                 ) \

  do_klass(Exception_klass,                             java_lang_Exception                                   ) \

  do_klass(RuntimeException_klass,                      java_lang_RuntimeException                            ) \

  do_klass(SecurityManager_klass,                       java_lang_SecurityManager                             ) \

  do_klass(ProtectionDomain_klass,                      java_security_ProtectionDomain                        ) \

  do_klass(AccessControlContext_klass,                  java_security_AccessControlContext                    ) \

  do_klass(AccessController_klass,                      java_security_AccessController                        ) \

  do_klass(SecureClassLoader_klass,                     java_security_SecureClassLoader                       ) \

  do_klass(ClassNotFoundException_klass,                java_lang_ClassNotFoundException                      ) \

  do_klass(NoClassDefFoundError_klass,                  java_lang_NoClassDefFoundError                        ) \

  do_klass(LinkageError_klass,                          java_lang_LinkageError                                ) \

  do_klass(ClassCastException_klass,                    java_lang_ClassCastException                          ) \

  do_klass(ArrayStoreException_klass,                   java_lang_ArrayStoreException                         ) \

  do_klass(VirtualMachineError_klass,                   java_lang_VirtualMachineError                         ) \

  do_klass(OutOfMemoryError_klass,                      java_lang_OutOfMemoryError                            ) \

  do_klass(StackOverflowError_klass,                    java_lang_StackOverflowError                          ) \

  do_klass(IllegalMonitorStateException_klass,          java_lang_IllegalMonitorStateException                ) \

  do_klass(Reference_klass,                             java_lang_ref_Reference                               ) \

                                                                                                                \

  /* ref klasses and set reference types */                                                                     \

  do_klass(SoftReference_klass,                         java_lang_ref_SoftReference                           ) \

  do_klass(WeakReference_klass,                         java_lang_ref_WeakReference                           ) \

  do_klass(FinalReference_klass,                        java_lang_ref_FinalReference                          ) \

  do_klass(PhantomReference_klass,                      java_lang_ref_PhantomReference                        ) \

  do_klass(Finalizer_klass,                             java_lang_ref_Finalizer                               ) \

                                                                                                                \

  do_klass(Thread_klass,                                java_lang_Thread                                      ) \

  do_klass(ThreadGroup_klass,                           java_lang_ThreadGroup                                 ) \

  do_klass(Properties_klass,                            java_util_Properties                                  ) \

  do_klass(Module_klass,                                java_lang_Module                                      ) \

  do_klass(reflect_AccessibleObject_klass,              java_lang_reflect_AccessibleObject                    ) \

  do_klass(reflect_Field_klass,                         java_lang_reflect_Field                               ) \

  do_klass(reflect_Parameter_klass,                     java_lang_reflect_Parameter                           ) \

  do_klass(reflect_Method_klass,                        java_lang_reflect_Method                              ) \

  do_klass(reflect_Constructor_klass,                   java_lang_reflect_Constructor                         ) \

                                                                                                                \

  /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */                     \

  /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                 \

  do_klass(reflect_MagicAccessorImpl_klass,             reflect_MagicAccessorImpl                             ) \

  do_klass(reflect_MethodAccessorImpl_klass,            reflect_MethodAccessorImpl                            ) \

  do_klass(reflect_ConstructorAccessorImpl_klass,       reflect_ConstructorAccessorImpl                       ) \

  do_klass(reflect_DelegatingClassLoader_klass,         reflect_DelegatingClassLoader                         ) \

  do_klass(reflect_ConstantPool_klass,                  reflect_ConstantPool                                  ) \

  do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl                 ) \

  do_klass(reflect_CallerSensitive_klass,               reflect_CallerSensitive                               ) \

  do_klass(reflect_NativeConstructorAccessorImpl_klass, reflect_NativeConstructorAccessorImpl                 ) \

                                                                                                                \

  /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */                                   \

  do_klass(DirectMethodHandle_klass,                    java_lang_invoke_DirectMethodHandle                   ) \

  do_klass(MethodHandle_klass,                          java_lang_invoke_MethodHandle                         ) \

  do_klass(VarHandle_klass,                             java_lang_invoke_VarHandle                            ) \

  do_klass(MemberName_klass,                            java_lang_invoke_MemberName                           ) \

  do_klass(ResolvedMethodName_klass,                    java_lang_invoke_ResolvedMethodName                   ) \

  do_klass(MethodHandleNatives_klass,                   java_lang_invoke_MethodHandleNatives                  ) \

  do_klass(LambdaForm_klass,                            java_lang_invoke_LambdaForm                           ) \

  do_klass(MethodType_klass,                            java_lang_invoke_MethodType                           ) \

  do_klass(BootstrapMethodError_klass,                  java_lang_BootstrapMethodError                        ) \

  do_klass(CallSite_klass,                              java_lang_invoke_CallSite                             ) \

  do_klass(Context_klass,                               java_lang_invoke_MethodHandleNatives_CallSiteContext  ) \

  do_klass(ConstantCallSite_klass,                      java_lang_invoke_ConstantCallSite                     ) \

  do_klass(MutableCallSite_klass,                       java_lang_invoke_MutableCallSite                      ) \

  do_klass(VolatileCallSite_klass,                      java_lang_invoke_VolatileCallSite                     ) \

  /* Note: MethodHandle must be first, and VolatileCallSite last in group */                                    \

                                                                                                                \

  do_klass(AssertionStatusDirectives_klass,             java_lang_AssertionStatusDirectives                   ) \

  do_klass(StringBuffer_klass,                          java_lang_StringBuffer                                ) \

  do_klass(StringBuilder_klass,                         java_lang_StringBuilder                               ) \

  do_klass(UnsafeConstants_klass,                       jdk_internal_misc_UnsafeConstants                     ) \

  do_klass(internal_Unsafe_klass,                       jdk_internal_misc_Unsafe                              ) \

  do_klass(module_Modules_klass,                        jdk_internal_module_Modules                           ) \

                                                                                                                \

  /* support for CDS */                                                                                         \

  do_klass(ByteArrayInputStream_klass,                  java_io_ByteArrayInputStream                          ) \

  do_klass(URL_klass,                                   java_net_URL                                          ) \

  do_klass(Jar_Manifest_klass,                          java_util_jar_Manifest                                ) \

  do_klass(jdk_internal_loader_ClassLoaders_klass,      jdk_internal_loader_ClassLoaders                      ) \

  do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass,      jdk_internal_loader_ClassLoaders_AppClassLoader) \

  do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader) \

  do_klass(CodeSource_klass,                            java_security_CodeSource                              ) \

                                                                                                                \

  do_klass(StackTraceElement_klass,                     java_lang_StackTraceElement                           ) \

                                                                                                                \

  /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                 \

  do_klass(nio_Buffer_klass,                            java_nio_Buffer                                       ) \

                                                                                                                \

  /* Stack Walking */                                                                                           \

  do_klass(StackWalker_klass,                           java_lang_StackWalker                                 ) \

  do_klass(AbstractStackWalker_klass,                   java_lang_StackStreamFactory_AbstractStackWalker      ) \

  do_klass(StackFrameInfo_klass,                        java_lang_StackFrameInfo                              ) \

  do_klass(LiveStackFrameInfo_klass,                    java_lang_LiveStackFrameInfo                          ) \

                                                                                                                \

  /* support for stack dump lock analysis */                                                                    \

  do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer) \

                                                                                                                \

  /* boxing klasses */                                                                                          \

  do_klass(Boolean_klass,                               java_lang_Boolean                                     ) \

  do_klass(Character_klass,                             java_lang_Character                                   ) \

  do_klass(Float_klass,                                 java_lang_Float                                       ) \

  do_klass(Double_klass,                                java_lang_Double                                      ) \

  do_klass(Byte_klass,                                  java_lang_Byte                                        ) \

  do_klass(Short_klass,                                 java_lang_Short                                       ) \

  do_klass(Integer_klass,                               java_lang_Integer                                     ) \

  do_klass(Long_klass,                                  java_lang_Long                                        ) \

                                                                                                                \

  /* force inline of iterators */                                                                               \

  do_klass(Iterator_klass,                              java_util_Iterator                                    ) \

                                                                                                                \

  /*end*/

class SystemDictionary : AllStatic {

  friend class BootstrapInfo;

  friend class VMStructs;

  friend class SystemDictionaryHandles;

 public:

  enum WKID {

    NO_WKID = 0,

    #define WK_KLASS_ENUM(name, symbol) 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

  };

  // 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);

protected:

  // handle error translation for resolve_or_null results

  static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, 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 InstanceKlass* 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 dictionary or

  // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.

  // Also used by Unsafe_DefineAnonymousClass

  static InstanceKlass* parse_stream(Symbol* class_name,

                                     Handle class_loader,

                                     Handle protection_domain,

                                     ClassFileStream* st,

                                     TRAPS) {

    return parse_stream(class_name,

                        class_loader,

                        protection_domain,

                        st,

                        NULL, // unsafe_anonymous_host

                        NULL, // cp_patches

                        THREAD);

  }

  static InstanceKlass* parse_stream(Symbol* class_name,

                                     Handle class_loader,

                                     Handle protection_domain,

                                     ClassFileStream* st,

                                     const InstanceKlass* unsafe_anonymous_host,

                                     GrowableArray<Handle>* cp_patches,

                                     TRAPS);

  // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)

  static InstanceKlass* resolve_from_stream(Symbol* class_name,

                                            Handle class_loader,

                                            Handle protection_domain,

                                            ClassFileStream* st,

                                            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);

  static void classes_do(MetaspaceClosure* it);

  // Iterate over all methods in all klasses

  static void methods_do(void f(Method*));

  // Garbage collection support

  // Unload (that is, break root links to) all unmarked classes and

  // loaders.  Returns "true" iff something was unloaded.

  static bool do_unloading(GCTimer* gc_timer);

  // Applies "f->do_oop" to all root oops in the system dictionary.

  // If include_handles is true (the default), then the handles in the

  // vm_global OopStorage object are included.

  static void oops_do(OopClosure* f, bool include_handles = true);

  // System loader lock

  static oop system_loader_lock()           { return _system_loader_lock_obj; }

  // Protection Domain Table

  static ProtectionDomainCacheTable* pd_cache_table() { return _pd_cache_table; }

public:

  // Printing

  static void print();

  static void print_on(outputStream* st);

  static void dump(outputStream* st, bool verbose);

  // Verification

  static void verify();

  // Initialization

  static void initialize(TRAPS);

  // Checked fast access to the well-known classes -- so that you don't try to use them

  // before they are resolved.

  static InstanceKlass* check_klass(InstanceKlass* k) {

    assert(k != NULL, "klass not loaded");

    return k;

  }

  static bool resolve_wk_klass(WKID id, TRAPS);

  static void resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);

  static void resolve_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {

    int limit = (int)end_id + 1;

    resolve_wk_klasses_until((WKID) limit, start_id, THREAD);

  }

public:

  #define WK_KLASS_DECLARE(name, symbol) \

    static InstanceKlass* name() { return check_klass(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \

    static InstanceKlass** name##_addr() {                                                              \

      return &_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];                          \

    }                                                                                                   \

    static bool name##_is_loaded() {                                                                    \

      return _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] != NULL;                   \

    }

  WK_KLASSES_DO(WK_KLASS_DECLARE);

  #undef WK_KLASS_DECLARE

  static InstanceKlass* well_known_klass(WKID id) {

    assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");

    return _well_known_klasses[id];

  }

  static InstanceKlass** well_known_klass_addr(WKID id) {

    assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");

    return &_well_known_klasses[id];

  }

  static void well_known_klasses_do(MetaspaceClosure* it);

  // Local definition for direct access to the private array:

  #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]

  static InstanceKlass* 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

#ifdef ASSERT

  static bool is_well_known_klass(Klass* k) {

    return is_well_known_klass(k->name());

  }

  static bool is_well_known_klass(Symbol* class_name);

#endif

protected:

  // 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:

  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 java system loader

  static oop java_system_loader();

  // Returns java platform loader

  static oop java_platform_loader();

  // Compute the java system and platform loaders

  static void compute_java_loaders(TRAPS);

  // Register a new class loader

  static ClassLoaderData* register_loader(Handle class_loader);

protected:

  // 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)

  // 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)

  // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.)

  // Either the accessing_klass or the CL/PD can be non-null, but not both.

  static Handle    find_java_mirror_for_type(Symbol* signature,

                                             Klass* accessing_klass,

                                             Handle class_loader,

                                             Handle protection_domain,

                                             SignatureStream::FailureMode failure_mode,

                                             TRAPS);

  static Handle    find_java_mirror_for_type(Symbol* signature,

                                             Klass* accessing_klass,

                                             SignatureStream::FailureMode failure_mode,

                                             TRAPS) {

    // callee will fill in CL/PD from AK, if they are needed

    return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(),

                                     failure_mode, THREAD);

  }