/*

 * Copyright (c) 2012, 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.

 *

 */

#include "precompiled.hpp"

#include "classfile/classListParser.hpp"

#include "classfile/classLoaderExt.hpp"

#include "classfile/dictionary.hpp"

#include "classfile/loaderConstraints.hpp"

#include "classfile/placeholders.hpp"

#include "classfile/sharedClassUtil.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/systemDictionaryShared.hpp"

#include "code/codeCache.hpp"

#include "gc/shared/gcLocker.hpp"

#include "interpreter/bytecodeStream.hpp"

#include "interpreter/bytecodes.hpp"

#include "logging/log.hpp"

#include "logging/logMessage.hpp"

#include "memory/filemap.hpp"

#include "memory/metaspace.hpp"

#include "memory/metaspaceShared.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceClassLoaderKlass.hpp"

#include "oops/instanceMirrorKlass.hpp"

#include "oops/instanceRefKlass.hpp"

#include "oops/objArrayKlass.hpp"

#include "oops/objArrayOop.hpp"

#include "oops/oop.inline.hpp"

#include "oops/typeArrayKlass.hpp"

#include "prims/jvm.h"

#include "prims/jvmtiRedefineClasses.hpp"

#include "runtime/timerTrace.hpp"

#include "runtime/os.hpp"

#include "runtime/signature.hpp"

#include "runtime/vmThread.hpp"

#include "runtime/vm_operations.hpp"

#include "utilities/align.hpp"

#include "utilities/defaultStream.hpp"

#include "utilities/hashtable.inline.hpp"

#include "memory/metaspaceClosure.hpp"

ReservedSpace MetaspaceShared::_shared_rs;

VirtualSpace MetaspaceShared::_shared_vs;

MetaspaceSharedStats MetaspaceShared::_stats;

bool MetaspaceShared::_has_error_classes;

bool MetaspaceShared::_archive_loading_failed = false;

bool MetaspaceShared::_remapped_readwrite = false;

address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;

size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;

size_t MetaspaceShared::_core_spaces_size = 0;

// The CDS archive is divided into the following regions:

//

//

// SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions

// are page-aligned, and there's no gap between any consecutive regions.

//

// These 5 regions are populated in the following steps:

// [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are

//     temporarily allocated outside of the shared regions. Only the method entry

//     trampolines are written into the mc region.

// [2] ArchiveCompactor copies RW metadata into the rw region.

// [3] ArchiveCompactor copies RO metadata into the ro region.

// [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data

//     are copied into the ro region as read-only tables.

// [5] C++ vtables are copied into the md region.

// [6] Original class files are copied into the od region.

//

class DumpRegion {

private:

  const char* _name;

  char* _base;

  char* _top;

  char* _end;

  bool _is_packed;

  char* expand_top_to(char* newtop) {

    assert(is_allocatable(), "must be initialized and not packed");

    assert(newtop >= _top, "must not grow backwards");

    if (newtop > _end) {

      MetaspaceShared::report_out_of_space(_name, newtop - _top);

      ShouldNotReachHere();

    }

    MetaspaceShared::commit_shared_space_to(newtop);

    _top = newtop;

    return _top;

  }

public:

  DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}

  char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {

    char* p = (char*)align_up(_top, alignment);

    char* newtop = p + align_up(num_bytes, alignment);

    expand_top_to(newtop);

    memset(p, 0, newtop - p);

    return p;

  }

  void append_intptr_t(intptr_t n) {

    assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");

    intptr_t *p = (intptr_t*)_top;

    char* newtop = _top + sizeof(intptr_t);

    expand_top_to(newtop);

    *p = n;

  }

  char* base()      const { return _base;        }

  char* top()       const { return _top;         }

  char* end()       const { return _end;         }

  size_t reserved() const { return _end - _base; }

  size_t used()     const { return _top - _base; }

  bool is_packed()  const { return _is_packed;   }

  bool is_allocatable() const {

    return !is_packed() && _base != NULL;

  }

  double perc(size_t used, size_t total) const {

    if (total == 0) {

      total = 1;

    }

    return used / double(total) * 100.0;

  }

  void print(size_t total_bytes) const {

    tty->print_cr("%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,

                  _name, used(), perc(used(), total_bytes), reserved(), perc(used(), reserved()), p2i(_base));

  }

  void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {

    tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",

               _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));

    if (strcmp(_name, failing_region) == 0) {

      tty->print_cr(" required = %d", int(needed_bytes));

    } else {

      tty->cr();

    }

  }

  void init(const ReservedSpace* rs) {

    _base = _top = rs->base();

    _end = rs->end();

  }

  void init(char* b, char* t, char* e) {

    _base = b;

    _top = t;

    _end = e;

  }

  void pack(DumpRegion* next = NULL) {

    assert(!is_packed(), "sanity");

    _end = (char*)align_up(_top, Metaspace::reserve_alignment());

    _is_packed = true;

    if (next != NULL) {

      next->_base = next->_top = this->_end;

      next->_end = MetaspaceShared::shared_rs()->end();

    }

  }

  bool contains(char* p) {

    return base() <= p && p < top();

  }

};

DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");

char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {

  return _mc_region.allocate(num_bytes);

}

char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {

  return _ro_region.allocate(num_bytes);

}

void MetaspaceShared::initialize_shared_rs() {

  const size_t reserve_alignment = Metaspace::reserve_alignment();

  bool large_pages = false; // No large pages when dumping the CDS archive.

  char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);

#ifdef _LP64

  // On 64-bit VM, the heap and class space layout will be the same as if

  // you're running in -Xshare:on mode:

  //

  //                         +-- SharedBaseAddress (default = 0x800000000)

  //                         v

  // +-..---------+----+ ... +----+----+----+----+----+---------------+

  // |    Heap    | ST |     | MC | RW | RO | MD | OD | class space   |

  // +-..---------+----+ ... +----+----+----+----+----+---------------+

  // |<--MaxHeapSize->|     |<-- UnscaledClassSpaceMax = 4GB ------->|

  //

  const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);

  const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);

#else

  // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.

  size_t cds_total = align_down(256*M, reserve_alignment);

#endif

  // First try to reserve the space at the specified SharedBaseAddress.

  _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);

  if (_shared_rs.is_reserved()) {

    assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");

  } else {

    // Get a mmap region anywhere if the SharedBaseAddress fails.

    _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);

  }

  if (!_shared_rs.is_reserved()) {

    vm_exit_during_initialization("Unable to reserve memory for shared space",

                                  err_msg(SIZE_FORMAT " bytes.", cds_total));

  }

#ifdef _LP64

  // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:

  // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()

  //   will store Klasses into this space.

  // + The lower 3 GB is used for the archive -- when preload_classes() is done,

  //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,

  //   then the RO parts.

  assert(UseCompressedOops && UseCompressedClassPointers,

      "UseCompressedOops and UseCompressedClassPointers must be set");

  size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);

  ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);

  CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);

  _shared_rs = _shared_rs.first_part(max_archive_size);

  // Set up compress class pointers.

  Universe::set_narrow_klass_base((address)_shared_rs.base());

  if (UseAOT || cds_total > UnscaledClassSpaceMax) {

    // AOT forces narrow_klass_shift=LogKlassAlignmentInBytes

    Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);

  } else {

    Universe::set_narrow_klass_shift(0);

  }

  Metaspace::initialize_class_space(tmp_class_space);

  tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",

                p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());

  tty->print_cr("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,

                CompressedClassSpaceSize, p2i(tmp_class_space.base()));

#endif

  // Start with 0 committed bytes. The memory will be committed as needed by

  // MetaspaceShared::commit_shared_space_to().

  if (!_shared_vs.initialize(_shared_rs, 0)) {

    vm_exit_during_initialization("Unable to allocate memory for shared space");

  }

  _mc_region.init(&_shared_rs);

  tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,

                _shared_rs.size(), p2i(_shared_rs.base()));

}

void MetaspaceShared::commit_shared_space_to(char* newtop) {

  assert(DumpSharedSpaces, "dump-time only");

  char* base = _shared_rs.base();

  size_t need_committed_size = newtop - base;

  size_t has_committed_size = _shared_vs.committed_size();

  if (need_committed_size < has_committed_size) {

    return;

  }

  size_t min_bytes = need_committed_size - has_committed_size;

  size_t preferred_bytes = 1 * M;

  size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;

  size_t commit = MAX2(min_bytes, preferred_bytes);

  assert(commit <= uncommitted, "sanity");

  bool result = _shared_vs.expand_by(commit, false);

  if (!result) {

    vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",

                                          need_committed_size));

  }

  log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",

                commit, _shared_vs.actual_committed_size(), _shared_vs.high());

}

// Read/write a data stream for restoring/preserving metadata pointers and

// miscellaneous data from/to the shared archive file.

void MetaspaceShared::serialize(SerializeClosure* soc) {

  int tag = 0;

  soc->do_tag(--tag);

  // Verify the sizes of various metadata in the system.

  soc->do_tag(sizeof(Method));

  soc->do_tag(sizeof(ConstMethod));

  soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));

  soc->do_tag(sizeof(ConstantPool));

  soc->do_tag(sizeof(ConstantPoolCache));

  soc->do_tag(objArrayOopDesc::base_offset_in_bytes());

  soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));

  soc->do_tag(sizeof(Symbol));

  // Dump/restore miscellaneous metadata.

  Universe::serialize(soc, true);

  soc->do_tag(--tag);

  // Dump/restore references to commonly used names and signatures.

  vmSymbols::serialize(soc);

  soc->do_tag(--tag);

  // Dump/restore the symbol and string tables

  SymbolTable::serialize(soc);

  StringTable::serialize(soc);

  soc->do_tag(--tag);

  soc->do_tag(666);

}

address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {

  if (DumpSharedSpaces) {

    if (_cds_i2i_entry_code_buffers == NULL) {

      _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);

      _cds_i2i_entry_code_buffers_size = total_size;

    }

  } else if (UseSharedSpaces) {

    assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");

  } else {

    return NULL;

  }

  assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");

  return _cds_i2i_entry_code_buffers;

}

// CDS code for dumping shared archive.

// Global object for holding classes that have been loaded.  Since this

// is run at a safepoint just before exit, this is the entire set of classes.

static GrowableArray<Klass*>* _global_klass_objects;

class CollectClassesClosure : public KlassClosure {

  void do_klass(Klass* k) {

    if (!(k->is_instance_klass() && InstanceKlass::cast(k)->is_in_error_state())) {

      _global_klass_objects->append_if_missing(k);

    }

  }

};

static void remove_unshareable_in_classes() {

  for (int i = 0; i < _global_klass_objects->length(); i++) {

    Klass* k = _global_klass_objects->at(i);

    k->remove_unshareable_info();

  }

}

static void rewrite_nofast_bytecode(Method* method) {

  RawBytecodeStream bcs(method);

  while (!bcs.is_last_bytecode()) {

    Bytecodes::Code opcode = bcs.raw_next();

    switch (opcode) {

    case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;

    case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;

    case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;

    case Bytecodes::_iload: {

      if (!bcs.is_wide()) {

        *bcs.bcp() = Bytecodes::_nofast_iload;

      }

      break;

    }

    default: break;

    }

  }

}

// Walk all methods in the class list to ensure that they won't be modified at

// run time. This includes:

// [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified

//     at run time by RewriteBytecodes/RewriteFrequentPairs

// [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.

static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {

  for (int i = 0; i < _global_klass_objects->length(); i++) {

    Klass* k = _global_klass_objects->at(i);

    if (k->is_instance_klass()) {

      InstanceKlass* ik = InstanceKlass::cast(k);

      for (int i = 0; i < ik->methods()->length(); i++) {

        Method* m = ik->methods()->at(i);

        rewrite_nofast_bytecode(m);

        Fingerprinter fp(m);

        // The side effect of this call sets method's fingerprint field.

        fp.fingerprint();

      }

    }

  }

}

static void relocate_cached_class_file() {

  for (int i = 0; i < _global_klass_objects->length(); i++) {

    Klass* k = _global_klass_objects->at(i);

    if (k->is_instance_klass()) {

      InstanceKlass* ik = InstanceKlass::cast(k);

      JvmtiCachedClassFileData* p = ik->get_archived_class_data();

      if (p != NULL) {

        int size = offset_of(JvmtiCachedClassFileData, data) + p->length;

        JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);

        q->length = p->length;

        memcpy(q->data, p->data, p->length);

        ik->set_archived_class_data(q);

      }

    }

  }

}

// Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.

// (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)

//

// Addresses of the vtables and the methods may be different across JVM runs,

// if libjvm.so is dynamically loaded at a different base address.

//

// To ensure that the Metadata objects in the CDS archive always have the correct vtable:

//

// + at dump time:  we redirect the _vptr to point to our own vtables inside

//                  the CDS image

// + at run time:   we clone the actual contents of the vtables from libjvm.so

//                  into our own tables.

// Currently, the archive contain ONLY the following types of objects that have C++ vtables.

#define CPP_VTABLE_PATCH_TYPES_DO(f) \

  f(ConstantPool) \

  f(InstanceKlass) \

  f(InstanceClassLoaderKlass) \

  f(InstanceMirrorKlass) \

  f(InstanceRefKlass) \

  f(Method) \

  f(ObjArrayKlass) \

  f(TypeArrayKlass)

class CppVtableInfo {

  intptr_t _vtable_size;

  intptr_t _cloned_vtable[1];

public:

  static int num_slots(int vtable_size) {

    return 1 + vtable_size; // Need to add the space occupied by _vtable_size;

  }

  int vtable_size()           { return int(uintx(_vtable_size)); }

  void set_vtable_size(int n) { _vtable_size = intptr_t(n); }

  intptr_t* cloned_vtable()   { return &_cloned_vtable[0]; }

  void zero()                 { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }

  // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo

  static size_t byte_size(int vtable_size) {

    CppVtableInfo i;

    return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));

  }

};

template <class T> class CppVtableCloner : public T {

  static intptr_t* vtable_of(Metadata& m) {

    return *((intptr_t**)&m);

  }

  static CppVtableInfo* _info;