/*

 * Copyright (c) 1997, 2014, 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 "memory/allocation.inline.hpp"

#include "oops/constantPool.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/atomic.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/thread.inline.hpp"

PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

#ifdef ASSERT

oop* HandleArea::allocate_handle(oop obj) {

  assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");

  assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");

  assert(obj->is_oop(), err_msg("not an oop: " INTPTR_FORMAT, (intptr_t*) obj));

  return real_allocate_handle(obj);

}

Handle::Handle(Thread* thread, oop obj) {

  assert(thread == Thread::current(), "sanity check");

  if (obj == NULL) {

    _handle = NULL;

  } else {

    _handle = thread->handle_area()->allocate_handle(obj);

  }

}

#endif

static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {

  oop* bottom = (oop*) chunk->bottom();

  oop* top    = (oop*) chunk_top;

  uintx handles_visited = top - bottom;

  assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");

  // during GC phase 3, a handle may be a forward pointer that

  // is not yet valid, so loosen the assertion

  while (bottom < top) {

    // This test can be moved up but for now check every oop.

    assert((*bottom)->is_oop(), "handle should point to oop");

    f->do_oop(bottom++);

  }

  return handles_visited;

}

// Used for debugging handle allocation.

NOT_PRODUCT(jint _nof_handlemarks  = 0;)

void HandleArea::oops_do(OopClosure* f) {

  uintx handles_visited = 0;

  // First handle the current chunk. It is filled to the high water mark.

  handles_visited += chunk_oops_do(f, _chunk, _hwm);

  // Then handle all previous chunks. They are completely filled.

  Chunk* k = _first;

  while(k != _chunk) {

    handles_visited += chunk_oops_do(f, k, k->top());

    k = k->next();

  }

  // The thread local handle areas should not get very large

  if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {

#ifdef ASSERT

    warning("%d: Visited in HandleMark : %d",

      _nof_handlemarks, handles_visited);

#else

    warning("Visited in HandleMark : %d", handles_visited);

#endif

  }

  if (_prev != NULL) _prev->oops_do(f);

}

void HandleMark::initialize(Thread* thread) {

  _thread = thread;

  // Save area

  _area  = thread->handle_area();

  // Save current top

  _chunk = _area->_chunk;

  _hwm   = _area->_hwm;

  _max   = _area->_max;

  _size_in_bytes = _area->_size_in_bytes;

  debug_only(_area->_handle_mark_nesting++);

  assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");

  debug_only(Atomic::inc(&_nof_handlemarks);)

  // Link this in the thread

  set_previous_handle_mark(thread->last_handle_mark());

  thread->set_last_handle_mark(this);

}

HandleMark::~HandleMark() {

  HandleArea* area = _area;   // help compilers with poor alias analysis

  assert(area == _thread->handle_area(), "sanity check");

  assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );

  debug_only(area->_handle_mark_nesting--);

  // Debug code to trace the number of handles allocated per mark/

#ifdef ASSERT

  if (TraceHandleAllocation) {

    size_t handles = 0;

    Chunk *c = _chunk->next();

    if (c == NULL) {

      handles = area->_hwm - _hwm; // no new chunk allocated

    } else {

      handles = _max - _hwm;      // add rest in first chunk

      while(c != NULL) {

        handles += c->length();

        c = c->next();

      }

      handles -= area->_max - area->_hwm; // adjust for last trunk not full

    }

    handles /= sizeof(void *); // Adjust for size of a handle

    if (handles > HandleAllocationLimit) {

      // Note: _nof_handlemarks is only set in debug mode

      warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);

    }

    tty->print_cr("Handles %d", handles);

  }

#endif

  // Delete later chunks

  if( _chunk->next() ) {

    // reset arena size before delete chunks. Otherwise, the total

    // arena size could exceed total chunk size

    assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");

    area->set_size_in_bytes(size_in_bytes());

    _chunk->next_chop();

  } else {

    assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");

  }

  // Roll back arena to saved top markers

  area->_chunk = _chunk;

  area->_hwm = _hwm;

  area->_max = _max;

#ifdef ASSERT

  // clear out first chunk (to detect allocation bugs)

  if (ZapVMHandleArea) {

    memset(_hwm, badHandleValue, _max - _hwm);

  }

  Atomic::dec(&_nof_handlemarks);

#endif

  // Unlink this from the thread

  _thread->set_last_handle_mark(previous_handle_mark());

}

void* HandleMark::operator new(size_t size) throw() {

  return AllocateHeap(size, mtThread);

}

void* HandleMark::operator new [] (size_t size) throw() {

  return AllocateHeap(size, mtThread);

}

void HandleMark::operator delete(void* p) {

  FreeHeap(p);

}

void HandleMark::operator delete[](void* p) {

  FreeHeap(p);

}

#ifdef ASSERT

NoHandleMark::NoHandleMark() {

  HandleArea* area = Thread::current()->handle_area();

  area->_no_handle_mark_nesting++;

  assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );

}

NoHandleMark::~NoHandleMark() {

  HandleArea* area = Thread::current()->handle_area();

  assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );

  area->_no_handle_mark_nesting--;

}

ResetNoHandleMark::ResetNoHandleMark() {

  HandleArea* area = Thread::current()->handle_area();

  _no_handle_mark_nesting = area->_no_handle_mark_nesting;

  area->_no_handle_mark_nesting = 0;

}

ResetNoHandleMark::~ResetNoHandleMark() {

  HandleArea* area = Thread::current()->handle_area();

  area->_no_handle_mark_nesting = _no_handle_mark_nesting;

}

#endif