/*

 * Copyright 1998-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_cpCacheOop.cpp.incl"

// Implememtation of ConstantPoolCacheEntry

void ConstantPoolCacheEntry::set_initial_state(int index) {

  _indices = index;

}

int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final,

                    bool is_vfinal, bool is_volatile,

                    bool is_method_interface, bool is_method) {

  int f = state;

  assert( state < number_of_states, "Invalid state in as_flags");

  f <<= 1;

  if (is_final) f |= 1;

  f <<= 1;

  if (is_vfinal) f |= 1;

  f <<= 1;

  if (is_volatile) f |= 1;

  f <<= 1;

  if (is_method_interface) f |= 1;

  f <<= 1;

  if (is_method) f |= 1;

  f <<= ConstantPoolCacheEntry::hotSwapBit;

  // Preserve existing flag bit values

#ifdef ASSERT

  int old_state = ((_flags >> tosBits) & 0x0F);

  assert(old_state == 0 || old_state == state,

         "inconsistent cpCache flags state");

#endif

  return (_flags | f) ;

}

void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {

#ifdef ASSERT

  // Read once.

  volatile Bytecodes::Code c = bytecode_1();

  assert(c == 0 || c == code || code == 0, "update must be consistent");

#endif

  // Need to flush pending stores here before bytecode is written.

  OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 16));

}

void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {

#ifdef ASSERT

  // Read once.

  volatile Bytecodes::Code c = bytecode_2();

  assert(c == 0 || c == code || code == 0, "update must be consistent");

#endif

  // Need to flush pending stores here before bytecode is written.

  OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 24));

}

#ifdef ASSERT

// It is possible to have two different dummy methodOops created

// when the resolve code for invoke interface executes concurrently

// Hence the assertion below is weakened a bit for the invokeinterface

// case.

bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {

  return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==

         ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==

         ((methodOop)f1)->signature());

}

#endif

// Note that concurrent update of both bytecodes can leave one of them

// reset to zero.  This is harmless; the interpreter will simply re-resolve

// the damaged entry.  More seriously, the memory synchronization is needed

// to flush other fields (f1, f2) completely to memory before the bytecodes

// are updated, lest other processors see a non-zero bytecode but zero f1/f2.

void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,

                                       Bytecodes::Code put_code,

                                       KlassHandle field_holder,

                                       int orig_field_index,

                                       int field_offset,

                                       TosState field_type,

                                       bool is_final,

                                       bool is_volatile) {

  set_f1(field_holder());

  set_f2(field_offset);

  // The field index is used by jvm/ti and is the index into fields() array

  // in holder instanceKlass.  This is scaled by instanceKlass::next_offset.

  assert((orig_field_index % instanceKlass::next_offset) == 0, "wierd index");

  const int field_index = orig_field_index / instanceKlass::next_offset;

  assert(field_index <= field_index_mask,

         "field index does not fit in low flag bits");

  set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |

            (field_index & field_index_mask));

  set_bytecode_1(get_code);

  set_bytecode_2(put_code);

  NOT_PRODUCT(verify(tty));

}

int  ConstantPoolCacheEntry::field_index() const {

  return (_flags & field_index_mask) * instanceKlass::next_offset;

}

void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,

                                        methodHandle method,

                                        int vtable_index) {

  assert(method->interpreter_entry() != NULL, "should have been set at this point");

  assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");

  bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface);

  int byte_no = -1;

  bool needs_vfinal_flag = false;

  switch (invoke_code) {

    case Bytecodes::_invokevirtual:

    case Bytecodes::_invokeinterface: {

        if (method->can_be_statically_bound()) {

          set_f2((intptr_t)method());

          needs_vfinal_flag = true;

        } else {

          assert(vtable_index >= 0, "valid index");

          set_f2(vtable_index);

        }

        byte_no = 2;

        break;

    }

    case Bytecodes::_invokespecial:

      // Preserve the value of the vfinal flag on invokevirtual bytecode

      // which may be shared with this constant pool cache entry.

      needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal();

      // fall through

    case Bytecodes::_invokestatic:

      set_f1(method());

      byte_no = 1;

      break;

    default:

      ShouldNotReachHere();

      break;

  }

  set_flags(as_flags(as_TosState(method->result_type()),

                     method->is_final_method(),

                     needs_vfinal_flag,

                     false,

                     change_to_virtual,

                     true)|

            method()->size_of_parameters());

  // Note:  byte_no also appears in TemplateTable::resolve.

  if (byte_no == 1) {

    set_bytecode_1(invoke_code);

  } else if (byte_no == 2)  {

    if (change_to_virtual) {

      // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!

      //

      // Workaround for the case where we encounter an invokeinterface, but we

      // should really have an _invokevirtual since the resolved method is a

      // virtual method in java.lang.Object. This is a corner case in the spec

      // but is presumably legal. javac does not generate this code.

      //

      // We set bytecode_1() to _invokeinterface, because that is the

      // bytecode # used by the interpreter to see if it is resolved.

      // We set bytecode_2() to _invokevirtual.

      // See also interpreterRuntime.cpp. (8/25/2000)

      // Only set resolved for the invokeinterface case if method is public.

      // Otherwise, the method needs to be reresolved with caller for each

      // interface call.

      if (method->is_public()) set_bytecode_1(invoke_code);

      set_bytecode_2(Bytecodes::_invokevirtual);

    } else {

      set_bytecode_2(invoke_code);

    }

  } else {

    ShouldNotReachHere();

  }

  NOT_PRODUCT(verify(tty));

}

void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {

  klassOop interf = method->method_holder();

  assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");

  set_f1(interf);

  set_f2(index);

  set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());

  set_bytecode_1(Bytecodes::_invokeinterface);

}

class LocalOopClosure: public OopClosure {

 private:

  void (*_f)(oop*);

 public:

  LocalOopClosure(void f(oop*))        { _f = f; }

  virtual void do_oop(oop* o)          { _f(o); }

  virtual void do_oop(narrowOop *o)    { ShouldNotReachHere(); }

};

void ConstantPoolCacheEntry::oops_do(void f(oop*)) {

  LocalOopClosure blk(f);

  oop_iterate(&blk);

}

void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  blk->do_oop((oop*)&_f1);

  if (is_vfinal()) {

    blk->do_oop((oop*)&_f2);

  }

}

void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);

  if (is_vfinal()) {

    if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);

  }

}

void ConstantPoolCacheEntry::follow_contents() {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  MarkSweep::mark_and_push((oop*)&_f1);

  if (is_vfinal()) {

    MarkSweep::mark_and_push((oop*)&_f2);

  }

}

#ifndef SERIALGC

void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  PSParallelCompact::mark_and_push(cm, (oop*)&_f1);

  if (is_vfinal()) {

    PSParallelCompact::mark_and_push(cm, (oop*)&_f2);

  }

}

#endif // SERIALGC

void ConstantPoolCacheEntry::adjust_pointers() {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  MarkSweep::adjust_pointer((oop*)&_f1);

  if (is_vfinal()) {

    MarkSweep::adjust_pointer((oop*)&_f2);

  }

}

#ifndef SERIALGC

void ConstantPoolCacheEntry::update_pointers() {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  PSParallelCompact::adjust_pointer((oop*)&_f1);

  if (is_vfinal()) {

    PSParallelCompact::adjust_pointer((oop*)&_f2);

  }

}

void ConstantPoolCacheEntry::update_pointers(HeapWord* beg_addr,

                                             HeapWord* end_addr) {

  assert(in_words(size()) == 4, "check code below - may need adjustment");

  // field[1] is always oop or NULL

  PSParallelCompact::adjust_pointer((oop*)&_f1, beg_addr, end_addr);

  if (is_vfinal()) {

    PSParallelCompact::adjust_pointer((oop*)&_f2, beg_addr, end_addr);

  }

}

#endif // SERIALGC

// RedefineClasses() API support:

// If this constantPoolCacheEntry refers to old_method then update it

// to refer to new_method.

bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,

       methodOop new_method, bool * trace_name_printed) {

  if (is_vfinal()) {

    // virtual and final so f2() contains method ptr instead of vtable index

    if (f2() == (intptr_t)old_method) {

      // match old_method so need an update

      _f2 = (intptr_t)new_method;

      if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

        if (!(*trace_name_printed)) {

          // RC_TRACE_MESG macro has an embedded ResourceMark

          RC_TRACE_MESG(("adjust: name=%s",

            Klass::cast(old_method->method_holder())->external_name()));

          *trace_name_printed = true;

        }

        // RC_TRACE macro has an embedded ResourceMark

        RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",

          new_method->name()->as_C_string(),

          new_method->signature()->as_C_string()));

      }

      return true;

    }

    // f1() is not used with virtual entries so bail out

    return false;

  }

  if ((oop)_f1 == NULL) {

    // NULL f1() means this is a virtual entry so bail out

    // We are assuming that the vtable index does not need change.

    return false;

  }

  if ((oop)_f1 == old_method) {

    _f1 = new_method;

    if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

      if (!(*trace_name_printed)) {

        // RC_TRACE_MESG macro has an embedded ResourceMark

        RC_TRACE_MESG(("adjust: name=%s",

          Klass::cast(old_method->method_holder())->external_name()));

        *trace_name_printed = true;

      }

      // RC_TRACE macro has an embedded ResourceMark

      RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",

        new_method->name()->as_C_string(),

        new_method->signature()->as_C_string()));

    }

    return true;

  }

  return false;

}

bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {

  if (!is_method_entry()) {

    // not a method entry so not interesting by default

    return false;

  }

  methodOop m = NULL;

  if (is_vfinal()) {

    // virtual and final so _f2 contains method ptr instead of vtable index

    m = (methodOop)_f2;

  } else if ((oop)_f1 == NULL) {

    // NULL _f1 means this is a virtual entry so also not interesting

    return false;

  } else {

    if (!((oop)_f1)->is_method()) {

      // _f1 can also contain a klassOop for an interface

      return false;

    }

    m = (methodOop)_f1;

  }

  assert(m != NULL && m->is_method(), "sanity check");

  if (m == NULL || !m->is_method() || m->method_holder() != k) {

    // robustness for above sanity checks or method is not in

    // the interesting class

    return false;

  }

  // the method is in the interesting class so the entry is interesting

  return true;

}

void ConstantPoolCacheEntry::print(outputStream* st, int index) const {

  // print separator

  if (index == 0) tty->print_cr("                 -------------");

  // print entry

  tty->print_cr("                 [   %08x]", (address)(oop)_f1);

  tty->print_cr("                 [   %08x]", _f2);

  tty->print_cr("                 [   %08x]", _flags);

  tty->print_cr("                 -------------");

}

void ConstantPoolCacheEntry::verify(outputStream* st) const {

  // not implemented yet

}

// Implementation of ConstantPoolCache

void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {

  assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");

  for (int i = 0; i < length(); i++) entry_at(i)->set_initial_state(inverse_index_map[i]);

}

// RedefineClasses() API support:

// If any entry of this constantPoolCache points to any of

// old_methods, replace it with the corresponding new_method.

void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,

                                                     int methods_length, bool * trace_name_printed) {

  if (methods_length == 0) {

    // nothing to do if there are no methods

    return;

  }

  // get shorthand for the interesting class

  klassOop old_holder = old_methods[0]->method_holder();

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

    if (!entry_at(i)->is_interesting_method_entry(old_holder)) {

      // skip uninteresting methods

      continue;

    }

    // The constantPoolCache contains entries for several different

    // things, but we only care about methods. In fact, we only care

    // about methods in the same class as the one that contains the

    // old_methods. At this point, we have an interesting entry.

    for (int j = 0; j < methods_length; j++) {

      methodOop old_method = old_methods[j];

      methodOop new_method = new_methods[j];

      if (entry_at(i)->adjust_method_entry(old_method, new_method,

          trace_name_printed)) {

        // current old_method matched this entry and we updated it so

        // break out and get to the next interesting entry if there one

        break;

      }

    }

  }

}