/*

 * Copyright (c) 1997, 2017, 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_VM_MEMORY_UNIVERSE_HPP

#define SHARE_VM_MEMORY_UNIVERSE_HPP

#include "oops/array.hpp"

#include "runtime/handles.hpp"

#include "utilities/growableArray.hpp"

// Universe is a name space holding known system classes and objects in the VM.

//

// Loaded classes are accessible through the SystemDictionary.

//

// The object heap is allocated and accessed through Universe, and various allocation

// support is provided. Allocation by the interpreter and compiled code is done inline

// and bails out to Scavenge::invoke_and_allocate.

class CollectedHeap;

class DeferredObjAllocEvent;

// A helper class for caching a Method* when the user of the cache

// only cares about the latest version of the Method*.  This cache safely

// interacts with the RedefineClasses API.

class LatestMethodCache : public CHeapObj<mtClass> {

  // We save the Klass* and the idnum of Method* in order to get

  // the current cached Method*.

 private:

  Klass*                _klass;

  int                   _method_idnum;

 public:

  LatestMethodCache()   { _klass = NULL; _method_idnum = -1; }

  ~LatestMethodCache()  { _klass = NULL; _method_idnum = -1; }

  void   init(Klass* k, Method* m);

  Klass* klass() const           { return _klass; }

  int    method_idnum() const    { return _method_idnum; }

  Method* get_method();

  // CDS support.  Replace the klass in this with the archive version

  // could use this for Enhanced Class Redefinition also.

  void serialize(SerializeClosure* f) {

    f->do_ptr((void**)&_klass);

  }

  void metaspace_pointers_do(MetaspaceClosure* it);

};

// For UseCompressedOops.

struct NarrowPtrStruct {

  // Base address for oop-within-java-object materialization.

  // NULL if using wide oops or zero based narrow oops.

  address _base;

  // Number of shift bits for encoding/decoding narrow ptrs.

  // 0 if using wide ptrs or zero based unscaled narrow ptrs,

  // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.

  int     _shift;

  // Generate code with implicit null checks for narrow ptrs.

  bool    _use_implicit_null_checks;

};

enum VerifyOption {

      VerifyOption_Default = 0,

      // G1

      VerifyOption_G1UsePrevMarking = VerifyOption_Default,

      VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,

      VerifyOption_G1UseMarkWord    = VerifyOption_G1UseNextMarking + 1

};

class Universe: AllStatic {

  // Ugh.  Universe is much too friendly.

  friend class MarkSweep;

  friend class oopDesc;

  friend class ClassLoader;

  friend class SystemDictionary;

  friend class ReservedHeapSpace;

  friend class VMStructs;

  friend class VM_PopulateDumpSharedSpace;

  friend class Metaspace;

  friend class MetaspaceShared;

  friend jint  universe_init();

  friend void  universe2_init();

  friend bool  universe_post_init();

  friend void  universe_post_module_init();

 private:

  // Known classes in the VM

  static Klass* _boolArrayKlassObj;

  static Klass* _byteArrayKlassObj;

  static Klass* _charArrayKlassObj;

  static Klass* _intArrayKlassObj;

  static Klass* _shortArrayKlassObj;

  static Klass* _longArrayKlassObj;

  static Klass* _singleArrayKlassObj;

  static Klass* _doubleArrayKlassObj;

  static Klass* _typeArrayKlassObjs[T_VOID+1];

  static Klass* _objectArrayKlassObj;

  // Known objects in the VM

  // Primitive objects

  static oop _int_mirror;

  static oop _float_mirror;

  static oop _double_mirror;

  static oop _byte_mirror;

  static oop _bool_mirror;

  static oop _char_mirror;

  static oop _long_mirror;

  static oop _short_mirror;

  static oop _void_mirror;

  static oop          _main_thread_group;             // Reference to the main thread group object

  static oop          _system_thread_group;           // Reference to the system thread group object

  static objArrayOop  _the_empty_class_klass_array;   // Canonicalized obj array of type java.lang.Class

  static oop          _the_null_string;               // A cache of "null" as a Java string

  static oop          _the_min_jint_string;          // A cache of "-2147483648" as a Java string

  static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects

  static LatestMethodCache* _loader_addClass_cache;    // method for registering loaded classes in class loader vector

  static LatestMethodCache* _pd_implies_cache;         // method for checking protection domain attributes

  static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method

  static LatestMethodCache* _do_stack_walk_cache;      // method for stack walker callback

  // preallocated error objects (no backtrace)

  static oop          _out_of_memory_error_java_heap;

  static oop          _out_of_memory_error_metaspace;

  static oop          _out_of_memory_error_class_metaspace;

  static oop          _out_of_memory_error_array_size;

  static oop          _out_of_memory_error_gc_overhead_limit;

  static oop          _out_of_memory_error_realloc_objects;

  // preallocated cause message for delayed StackOverflowError

  static oop          _delayed_stack_overflow_error_message;

  static Array<int>*       _the_empty_int_array;    // Canonicalized int array

  static Array<u2>*        _the_empty_short_array;  // Canonicalized short array

  static Array<Klass*>*  _the_empty_klass_array;  // Canonicalized klass obj array

  static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array

  static Array<Klass*>*  _the_array_interfaces_array;

  // array of preallocated error objects with backtrace

  static objArrayOop   _preallocated_out_of_memory_error_array;

  // number of preallocated error objects available for use

  static volatile jint _preallocated_out_of_memory_error_avail_count;

  static oop          _null_ptr_exception_instance;   // preallocated exception object

  static oop          _arithmetic_exception_instance; // preallocated exception object

  static oop          _virtual_machine_error_instance; // preallocated exception object

  // The object used as an exception dummy when exceptions are thrown for

  // the vm thread.

  static oop          _vm_exception;

  static oop          _allocation_context_notification_obj;

  // References waiting to be transferred to the ReferenceHandler

  static oop          _reference_pending_list;

  // The particular choice of collected heap.

  static CollectedHeap* _collectedHeap;

  static intptr_t _non_oop_bits;

  // For UseCompressedOops.

  static struct NarrowPtrStruct _narrow_oop;

  // For UseCompressedClassPointers.

  static struct NarrowPtrStruct _narrow_klass;

  static address _narrow_ptrs_base;

  // array of dummy objects used with +FullGCAlot

  debug_only(static objArrayOop _fullgc_alot_dummy_array;)

  // index of next entry to clear

  debug_only(static int         _fullgc_alot_dummy_next;)

  // Compiler/dispatch support

  static int  _base_vtable_size;                      // Java vtbl size of klass Object (in words)

  // Initialization

  static bool _bootstrapping;                         // true during genesis

  static bool _module_initialized;                    // true after call_initPhase2 called

  static bool _fully_initialized;                     // true after universe_init and initialize_vtables called

  // the array of preallocated errors with backtraces

  static objArrayOop  preallocated_out_of_memory_errors()     { return _preallocated_out_of_memory_error_array; }

  // generate an out of memory error; if possible using an error with preallocated backtrace;

  // otherwise return the given default error.

  static oop        gen_out_of_memory_error(oop default_err);

  // Historic gc information

  static size_t _heap_capacity_at_last_gc;

  static size_t _heap_used_at_last_gc;

  template <class Heap, class Policy> static CollectedHeap* create_heap_with_policy();

  static CollectedHeap* create_heap();

  static CollectedHeap* create_heap_ext();

  static jint initialize_heap();

  static void initialize_basic_type_mirrors(TRAPS);

  static void fixup_mirrors(TRAPS);

  static void reinitialize_vtable_of(Klass* k, TRAPS);

  static void reinitialize_itables(TRAPS);

  static void compute_base_vtable_size();             // compute vtable size of class Object

  static void genesis(TRAPS);                         // Create the initial world

  // Mirrors for primitive classes (created eagerly)

  static oop check_mirror(oop m) {

    assert(m != NULL, "mirror not initialized");

    return m;

  }

  static void     set_narrow_oop_base(address base) {

    assert(UseCompressedOops, "no compressed oops?");

    _narrow_oop._base    = base;

  }

  static void     set_narrow_klass_base(address base) {

    assert(UseCompressedClassPointers, "no compressed klass ptrs?");

    _narrow_klass._base   = base;

  }

  static void     set_narrow_oop_use_implicit_null_checks(bool use) {

    assert(UseCompressedOops, "no compressed ptrs?");

    _narrow_oop._use_implicit_null_checks   = use;

  }

  // Debugging

  static int _verify_count;                           // number of verifies done

  // True during call to verify().  Should only be set/cleared in verify().

  static bool _verify_in_progress;

  static long verify_flags;

  static uintptr_t _verify_oop_mask;

  static uintptr_t _verify_oop_bits;

  static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;

  static void compute_verify_oop_data();

 public:

  // Known classes in the VM

  static Klass* boolArrayKlassObj()                 { return _boolArrayKlassObj;   }

  static Klass* byteArrayKlassObj()                 { return _byteArrayKlassObj;   }

  static Klass* charArrayKlassObj()                 { return _charArrayKlassObj;   }

  static Klass* intArrayKlassObj()                  { return _intArrayKlassObj;    }

  static Klass* shortArrayKlassObj()                { return _shortArrayKlassObj;  }

  static Klass* longArrayKlassObj()                 { return _longArrayKlassObj;   }

  static Klass* singleArrayKlassObj()               { return _singleArrayKlassObj; }

  static Klass* doubleArrayKlassObj()               { return _doubleArrayKlassObj; }

  static Klass* objectArrayKlassObj() {

    return _objectArrayKlassObj;

  }

  static Klass* typeArrayKlassObj(BasicType t) {

    assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t));

    assert(_typeArrayKlassObjs[t] != NULL, "domain check");

    return _typeArrayKlassObjs[t];

  }

  // Known objects in the VM

  static oop int_mirror()                   { return check_mirror(_int_mirror); }

  static oop float_mirror()                 { return check_mirror(_float_mirror); }

  static oop double_mirror()                { return check_mirror(_double_mirror); }

  static oop byte_mirror()                  { return check_mirror(_byte_mirror); }

  static oop bool_mirror()                  { return check_mirror(_bool_mirror); }

  static oop char_mirror()                  { return check_mirror(_char_mirror); }

  static oop long_mirror()                  { return check_mirror(_long_mirror); }

  static oop short_mirror()                 { return check_mirror(_short_mirror); }

  static oop void_mirror()                  { return check_mirror(_void_mirror); }

  // table of same

  static oop _mirrors[T_VOID+1];

  static oop java_mirror(BasicType t) {

    assert((uint)t < T_VOID+1, "range check");

    return check_mirror(_mirrors[t]);

  }

  static oop      main_thread_group()                 { return _main_thread_group; }

  static void set_main_thread_group(oop group)        { _main_thread_group = group;}

  static oop      system_thread_group()               { return _system_thread_group; }

  static void set_system_thread_group(oop group)      { _system_thread_group = group;}

  static objArrayOop  the_empty_class_klass_array ()  { return _the_empty_class_klass_array;   }

  static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array;   }

  static oop          the_null_string()               { return _the_null_string;               }

  static oop          the_min_jint_string()          { return _the_min_jint_string;          }

  static Method*      finalizer_register_method()     { return _finalizer_register_cache->get_method(); }

  static Method*      loader_addClass_method()        { return _loader_addClass_cache->get_method(); }

  static Method*      protection_domain_implies_method() { return _pd_implies_cache->get_method(); }

  static Method*      throw_illegal_access_error()    { return _throw_illegal_access_error_cache->get_method(); }

  static Method*      do_stack_walk_method()          { return _do_stack_walk_cache->get_method(); }

  // Function to initialize these

  static void initialize_known_methods(TRAPS);

  static oop          null_ptr_exception_instance()   { return _null_ptr_exception_instance;   }

  static oop          arithmetic_exception_instance() { return _arithmetic_exception_instance; }

  static oop          virtual_machine_error_instance() { return _virtual_machine_error_instance; }

  static oop          vm_exception()                  { return _vm_exception; }

  static inline oop   allocation_context_notification_obj();

  static inline void  set_allocation_context_notification_obj(oop obj);

  // Reference pending list manipulation.  Access is protected by

  // Heap_lock.  The getter, setter and predicate require the caller

  // owns the lock.  Swap is used by parallel non-concurrent reference

  // processing threads, where some higher level controller owns

  // Heap_lock, so requires the lock is locked, but not necessarily by

  // the current thread.

  static oop          reference_pending_list();

  static void         set_reference_pending_list(oop list);

  static bool         has_reference_pending_list();

  static oop          swap_reference_pending_list(oop list);

  static Array<int>*       the_empty_int_array()    { return _the_empty_int_array; }

  static Array<u2>*        the_empty_short_array()  { return _the_empty_short_array; }

  static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }

  static Array<Klass*>*  the_empty_klass_array()  { return _the_empty_klass_array; }

  // OutOfMemoryError support. Returns an error with the required message. The returned error

  // may or may not have a backtrace. If error has a backtrace then the stack trace is already

  // filled in.

  static oop out_of_memory_error_java_heap()          { return gen_out_of_memory_error(_out_of_memory_error_java_heap);  }

  static oop out_of_memory_error_metaspace()          { return gen_out_of_memory_error(_out_of_memory_error_metaspace);   }

  static oop out_of_memory_error_class_metaspace()    { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace);   }

  static oop out_of_memory_error_array_size()         { return gen_out_of_memory_error(_out_of_memory_error_array_size); }

  static oop out_of_memory_error_gc_overhead_limit()  { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit);  }

  static oop out_of_memory_error_realloc_objects()    { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects);  }

  static oop delayed_stack_overflow_error_message()   { return _delayed_stack_overflow_error_message; }

  // Accessors needed for fast allocation

  static Klass** boolArrayKlassObj_addr()           { return &_boolArrayKlassObj;   }

  static Klass** byteArrayKlassObj_addr()           { return &_byteArrayKlassObj;   }

  static Klass** charArrayKlassObj_addr()           { return &_charArrayKlassObj;   }

  static Klass** intArrayKlassObj_addr()            { return &_intArrayKlassObj;    }

  static Klass** shortArrayKlassObj_addr()          { return &_shortArrayKlassObj;  }

  static Klass** longArrayKlassObj_addr()           { return &_longArrayKlassObj;   }

  static Klass** singleArrayKlassObj_addr()         { return &_singleArrayKlassObj; }

  static Klass** doubleArrayKlassObj_addr()         { return &_doubleArrayKlassObj; }

  static Klass** objectArrayKlassObj_addr()         { return &_objectArrayKlassObj; }

  // The particular choice of collected heap.

  static CollectedHeap* heap() { return _collectedHeap; }

  // For UseCompressedOops

  // Narrow Oop encoding mode:

  // 0 - Use 32-bits oops without encoding when

  //     NarrowOopHeapBaseMin + heap_size < 4Gb

  // 1 - Use zero based compressed oops with encoding when

  //     NarrowOopHeapBaseMin + heap_size < 32Gb

  // 2 - Use compressed oops with disjoint heap base if

  //     base is 32G-aligned and base > 0. This allows certain

  //     optimizations in encoding/decoding.

  //     Disjoint: Bits used in base are disjoint from bits used

  //     for oops ==> oop = (cOop << 3) | base.  One can disjoint

  //     the bits of an oop into base and compressed oop.

  // 3 - Use compressed oops with heap base + encoding.

  enum NARROW_OOP_MODE {

    UnscaledNarrowOop  = 0,

    ZeroBasedNarrowOop = 1,

    DisjointBaseNarrowOop = 2,

    HeapBasedNarrowOop = 3,

    AnyNarrowOopMode = 4

  };

  static NARROW_OOP_MODE narrow_oop_mode();

  static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);

  static char*    preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);

  static char*    preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);

  static address  narrow_oop_base()                  { return  _narrow_oop._base; }

  // Test whether bits of addr and possible offsets into the heap overlap.

  static bool     is_disjoint_heap_base_address(address addr) {

    return (((uint64_t)(intptr_t)addr) &

            (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;

  }

  // Check for disjoint base compressed oops.

  static bool     narrow_oop_base_disjoint()        {

    return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);

  }

  // Check for real heapbased compressed oops.

  // We must subtract the base as the bits overlap.

  // If we negate above function, we also get unscaled and zerobased.

  static bool     narrow_oop_base_overlaps()          {

    return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);

  }

  static bool  is_narrow_oop_base(void* addr)             { return (narrow_oop_base() == (address)addr); }

  static int      narrow_oop_shift()                      { return  _narrow_oop._shift; }

  static bool     narrow_oop_use_implicit_null_checks()   { return  _narrow_oop._use_implicit_null_checks; }

  // For UseCompressedClassPointers

  static address  narrow_klass_base()                     { return  _narrow_klass._base; }

  static bool  is_narrow_klass_base(void* addr)           { return (narrow_klass_base() == (address)addr); }

  static int      narrow_klass_shift()                    { return  _narrow_klass._shift; }

  static bool     narrow_klass_use_implicit_null_checks() { return  _narrow_klass._use_implicit_null_checks; }

  static address* narrow_ptrs_base_addr()                 { return &_narrow_ptrs_base; }

  static void     set_narrow_ptrs_base(address a)         { _narrow_ptrs_base = a; }

  static address  narrow_ptrs_base()                      { return _narrow_ptrs_base; }

  static void     print_compressed_oops_mode(outputStream* st);

  // this is set in vm_version on sparc (and then reset in universe afaict)

  static void     set_narrow_oop_shift(int shift)         {

    _narrow_oop._shift   = shift;

  }

  static void     set_narrow_klass_shift(int shift)       {

    assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");

    _narrow_klass._shift   = shift;

  }

  // Reserve Java heap and determine CompressedOops mode

  static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);

  // Historic gc information

  static size_t get_heap_capacity_at_last_gc()         { return _heap_capacity_at_last_gc; }

  static size_t get_heap_free_at_last_gc()             { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }

  static size_t get_heap_used_at_last_gc()             { return _heap_used_at_last_gc; }

  static void update_heap_info_at_gc();

  // Testers

  static bool is_bootstrapping()                      { return _bootstrapping; }

  static bool is_module_initialized()                 { return _module_initialized; }

  static bool is_fully_initialized()                  { return _fully_initialized; }

  static inline bool element_type_should_be_aligned(BasicType type);

  static inline bool field_type_should_be_aligned(BasicType type);

  static bool        on_page_boundary(void* addr);

  static bool        should_fill_in_stack_trace(Handle throwable);

  static void check_alignment(uintx size, uintx alignment, const char* name);

  // Finalizer support.

  static void run_finalizers_on_exit();

  // Iteration

  // Apply "f" to the addresses of all the direct heap pointers maintained

  // as static fields of "Universe".

  static void oops_do(OopClosure* f, bool do_all = false);

  // CDS support

  static void serialize(SerializeClosure* f, bool do_all = false);

  // Apply "f" to all klasses for basic types (classes not present in

  // SystemDictionary).

  static void basic_type_classes_do(void f(Klass*));

  static void metaspace_pointers_do(MetaspaceClosure* it);

  // Debugging

  enum VERIFY_FLAGS {

    Verify_Threads = 1,

    Verify_Heap = 2,

    Verify_SymbolTable = 4,

    Verify_StringTable = 8,

    Verify_CodeCache = 16,

    Verify_SystemDictionary = 32,

    Verify_ClassLoaderDataGraph = 64,

    Verify_MetaspaceAux = 128,

    Verify_JNIHandles = 256,

    Verify_CodeCacheOops = 512,

    Verify_All = -1

  };

  static void initialize_verify_flags();

  static bool should_verify_subset(uint subset);

  static bool verify_in_progress() { return _verify_in_progress; }

  static void verify(VerifyOption option, const char* prefix);

  static void verify(const char* prefix) {

    verify(VerifyOption_Default, prefix);