/*

 * Copyright (c) 1997, 2011, 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 "compiler/compileBroker.hpp"

#include "gc_implementation/shared/markSweep.inline.hpp"

#include "gc_interface/collectedHeap.inline.hpp"

#include "oops/methodDataOop.hpp"

#include "oops/objArrayKlass.inline.hpp"

#include "oops/oop.inline.hpp"

size_t                  MarkSweep::_preserved_count = 0;

size_t                  MarkSweep::_preserved_count_max = 0;

PreservedMark*          MarkSweep::_preserved_marks = NULL;

ReferenceProcessor*     MarkSweep::_ref_processor   = NULL;

#ifdef VALIDATE_MARK_SWEEP

GrowableArray<void*>*   MarkSweep::_root_refs_stack = NULL;

GrowableArray<oop> *    MarkSweep::_live_oops = NULL;

GrowableArray<oop> *    MarkSweep::_live_oops_moved_to = NULL;

GrowableArray<size_t>*  MarkSweep::_live_oops_size = NULL;

size_t                  MarkSweep::_live_oops_index = 0;

size_t                  MarkSweep::_live_oops_index_at_perm = 0;

GrowableArray<void*>*   MarkSweep::_other_refs_stack = NULL;

GrowableArray<void*>*   MarkSweep::_adjusted_pointers = NULL;

bool                         MarkSweep::_pointer_tracking = false;

bool                         MarkSweep::_root_tracking = true;

GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops = NULL;

GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops_moved_to = NULL;

GrowableArray<size_t>   * MarkSweep::_cur_gc_live_oops_size = NULL;

GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops = NULL;

GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops_moved_to = NULL;

GrowableArray<size_t>   * MarkSweep::_last_gc_live_oops_size = NULL;

#endif

void MarkSweep::revisit_weak_klass_link(Klass* k) {

  _revisit_klass_stack.push(k);

}

void MarkSweep::follow_weak_klass_links() {

  // All klasses on the revisit stack are marked at this point.

  // Update and follow all subklass, sibling and implementor links.

  if (PrintRevisitStats) {

    gclog_or_tty->print_cr("#classes in system dictionary = %d",

                           SystemDictionary::number_of_classes());

    gclog_or_tty->print_cr("Revisit klass stack size = " SIZE_FORMAT,

                           _revisit_klass_stack.size());

  }

  while (!_revisit_klass_stack.is_empty()) {

    Klass* const k = _revisit_klass_stack.pop();

    k->follow_weak_klass_links(&is_alive, &keep_alive);

  }

  follow_stack();

}

void MarkSweep::revisit_mdo(DataLayout* p) {

  _revisit_mdo_stack.push(p);

}

void MarkSweep::follow_mdo_weak_refs() {

  // All strongly reachable oops have been marked at this point;

  // we can visit and clear any weak references from MDO's which

  // we memoized during the strong marking phase.

  assert(_marking_stack.is_empty(), "Marking stack should be empty");

  if (PrintRevisitStats) {

    gclog_or_tty->print_cr("#classes in system dictionary = %d",

                           SystemDictionary::number_of_classes());

    gclog_or_tty->print_cr("Revisit MDO stack size = " SIZE_FORMAT,

                           _revisit_mdo_stack.size());

  }

  while (!_revisit_mdo_stack.is_empty()) {

    _revisit_mdo_stack.pop()->follow_weak_refs(&is_alive);

  }

  follow_stack();

}

MarkSweep::FollowRootClosure  MarkSweep::follow_root_closure;

CodeBlobToOopClosure MarkSweep::follow_code_root_closure(&MarkSweep::follow_root_closure, /*do_marking=*/ true);

void MarkSweep::FollowRootClosure::do_oop(oop* p)       { follow_root(p); }

void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }

MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;

void MarkSweep::MarkAndPushClosure::do_oop(oop* p)       { assert(*p == NULL || (*p)->is_oop(), ""); mark_and_push(p); }

void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }

void MarkSweep::follow_stack() {

  do {

    while (!_marking_stack.is_empty()) {

      oop obj = _marking_stack.pop();

      assert (obj->is_gc_marked(), "p must be marked");

      obj->follow_contents();

    }

    // Process ObjArrays one at a time to avoid marking stack bloat.

    if (!_objarray_stack.is_empty()) {

      ObjArrayTask task = _objarray_stack.pop();

      objArrayKlass* const k = (objArrayKlass*)task.obj()->blueprint();

      k->oop_follow_contents(task.obj(), task.index());

    }

  } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());

}

MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;

void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }

// We preserve the mark which should be replaced at the end and the location

// that it will go.  Note that the object that this markOop belongs to isn't

// currently at that address but it will be after phase4

void MarkSweep::preserve_mark(oop obj, markOop mark) {

  // We try to store preserved marks in the to space of the new generation since

  // this is storage which should be available.  Most of the time this should be

  // sufficient space for the marks we need to preserve but if it isn't we fall

  // back to using Stacks to keep track of the overflow.

  if (_preserved_count < _preserved_count_max) {

    _preserved_marks[_preserved_count++].init(obj, mark);

  } else {

    _preserved_mark_stack.push(mark);

    _preserved_oop_stack.push(obj);

  }

}

MarkSweep::AdjustPointerClosure MarkSweep::adjust_root_pointer_closure(true);

MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure(false);

void MarkSweep::AdjustPointerClosure::do_oop(oop* p)       { adjust_pointer(p, _is_root); }

void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p, _is_root); }

void MarkSweep::adjust_marks() {

  assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),

         "inconsistent preserved oop stacks");

  // adjust the oops we saved earlier

  for (size_t i = 0; i < _preserved_count; i++) {

    _preserved_marks[i].adjust_pointer();

  }

  // deal with the overflow stack

  while (!iter.is_empty()) {

    oop* p = iter.next_addr();

    adjust_pointer(p);

  }

}

void MarkSweep::restore_marks() {

  assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),

         "inconsistent preserved oop stacks");

  if (PrintGC && Verbose) {

    gclog_or_tty->print_cr("Restoring %d marks",

                           _preserved_count + _preserved_oop_stack.size());

  }

  // restore the marks we saved earlier

  for (size_t i = 0; i < _preserved_count; i++) {

    _preserved_marks[i].restore();

  }

  // deal with the overflow

  while (!_preserved_oop_stack.is_empty()) {

    oop obj       = _preserved_oop_stack.pop();

    markOop mark  = _preserved_mark_stack.pop();

    obj->set_mark(mark);

  }

}

#ifdef VALIDATE_MARK_SWEEP

void MarkSweep::track_adjusted_pointer(void* p, bool isroot) {

  if (!ValidateMarkSweep)

    return;

  if (!isroot) {

    if (_pointer_tracking) {

      guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");

      _adjusted_pointers->remove(p);

    }

  } else {

    ptrdiff_t index = _root_refs_stack->find(p);

    if (index != -1) {

      int l = _root_refs_stack->length();

      if (l > 0 && l - 1 != index) {

        void* last = _root_refs_stack->pop();

        assert(last != p, "should be different");

        _root_refs_stack->at_put(index, last);

      } else {

        _root_refs_stack->remove(p);

      }

    }

  }

}

void MarkSweep::check_adjust_pointer(void* p) {

  _adjusted_pointers->push(p);

}

class AdjusterTracker: public OopClosure {

 public:

  AdjusterTracker() {}

  void do_oop(oop* o)       { MarkSweep::check_adjust_pointer(o); }

  void do_oop(narrowOop* o) { MarkSweep::check_adjust_pointer(o); }

};

void MarkSweep::track_interior_pointers(oop obj) {

  if (ValidateMarkSweep) {

    _adjusted_pointers->clear();

    _pointer_tracking = true;

    AdjusterTracker checker;

    obj->oop_iterate(&checker);

  }

}

void MarkSweep::check_interior_pointers() {

  if (ValidateMarkSweep) {

    _pointer_tracking = false;

    guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");

  }

}

void MarkSweep::reset_live_oop_tracking(bool at_perm) {

  if (ValidateMarkSweep) {

    guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");

    _live_oops_index = at_perm ? _live_oops_index_at_perm : 0;

  }

}

void MarkSweep::register_live_oop(oop p, size_t size) {

  if (ValidateMarkSweep) {

    _live_oops->push(p);

    _live_oops_size->push(size);

    _live_oops_index++;

  }

}

void MarkSweep::validate_live_oop(oop p, size_t size) {

  if (ValidateMarkSweep) {

    oop obj = _live_oops->at((int)_live_oops_index);

    guarantee(obj == p, "should be the same object");

    guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");

    _live_oops_index++;

  }

}

void MarkSweep::live_oop_moved_to(HeapWord* q, size_t size,

                                  HeapWord* compaction_top) {

  assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),

         "should be moved to forwarded location");

  if (ValidateMarkSweep) {

    MarkSweep::validate_live_oop(oop(q), size);

    _live_oops_moved_to->push(oop(compaction_top));

  }

  if (RecordMarkSweepCompaction) {

    _cur_gc_live_oops->push(q);

    _cur_gc_live_oops_moved_to->push(compaction_top);

    _cur_gc_live_oops_size->push(size);

  }

}

void MarkSweep::compaction_complete() {

  if (RecordMarkSweepCompaction) {

    GrowableArray<HeapWord*>* _tmp_live_oops          = _cur_gc_live_oops;

    GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;

    GrowableArray<size_t>   * _tmp_live_oops_size     = _cur_gc_live_oops_size;

    _cur_gc_live_oops           = _last_gc_live_oops;

    _cur_gc_live_oops_moved_to  = _last_gc_live_oops_moved_to;

    _cur_gc_live_oops_size      = _last_gc_live_oops_size;

    _last_gc_live_oops          = _tmp_live_oops;

    _last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;

    _last_gc_live_oops_size     = _tmp_live_oops_size;

  }

}

void MarkSweep::print_new_location_of_heap_address(HeapWord* q) {

  if (!RecordMarkSweepCompaction) {

    tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");

    return;

  }

  if (_last_gc_live_oops == NULL) {

    tty->print_cr("No compaction information gathered yet");

    return;

  }

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

    HeapWord* old_oop = _last_gc_live_oops->at(i);

    size_t    sz      = _last_gc_live_oops_size->at(i);

    if (old_oop <= q && q < (old_oop + sz)) {

      HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);

      size_t offset = (q - old_oop);

      tty->print_cr("Address " PTR_FORMAT, q);

      tty->print_cr(" Was in oop " PTR_FORMAT ", size " SIZE_FORMAT ", at offset " SIZE_FORMAT, old_oop, sz, offset);

      tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);

      return;

    }

  }

  tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);

}

#endif //VALIDATE_MARK_SWEEP

MarkSweep::IsAliveClosure   MarkSweep::is_alive;

void MarkSweep::IsAliveClosure::do_object(oop p)   { ShouldNotReachHere(); }

bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }

MarkSweep::KeepAliveClosure MarkSweep::keep_alive;

void MarkSweep::KeepAliveClosure::do_oop(oop* p)       { MarkSweep::KeepAliveClosure::do_oop_work(p); }

void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }

void marksweep_init() { /* empty */ }

#ifndef PRODUCT

void MarkSweep::trace(const char* msg) {

  if (TraceMarkSweep)

    gclog_or_tty->print("%s", msg);

}

#endif