/*

 * Copyright (c) 2013, 2016, 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 "runtime/os.hpp"

#include "runtime/threadCritical.hpp"

#include "services/memTracker.hpp"

#include "services/virtualMemoryTracker.hpp"

size_t VirtualMemorySummary::_snapshot[CALC_OBJ_SIZE_IN_TYPE(VirtualMemorySnapshot, size_t)];

void VirtualMemorySummary::initialize() {

  assert(sizeof(_snapshot) >= sizeof(VirtualMemorySnapshot), "Sanity Check");

  // Use placement operator new to initialize static data area.

  ::new ((void*)_snapshot) VirtualMemorySnapshot();

}

SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>* VirtualMemoryTracker::_reserved_regions;

int compare_committed_region(const CommittedMemoryRegion& r1, const CommittedMemoryRegion& r2) {

  return r1.compare(r2);

}

int compare_reserved_region_base(const ReservedMemoryRegion& r1, const ReservedMemoryRegion& r2) {

  return r1.compare(r2);

}

bool ReservedMemoryRegion::add_committed_region(address addr, size_t size, const NativeCallStack& stack) {

  assert(addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  assert(contain_region(addr, size), "Not contain this region");

  if (all_committed()) return true;

  CommittedMemoryRegion committed_rgn(addr, size, stack);

  LinkedListNode<CommittedMemoryRegion>* node = _committed_regions.head();

  while (node != NULL) {

    CommittedMemoryRegion* rgn = node->data();

    if (rgn->same_region(addr, size)) {

      return true;

    }

    if (rgn->adjacent_to(addr, size)) {

      // special case to expand prior region if there is no next region

      LinkedListNode<CommittedMemoryRegion>* next = node->next();

      if (next == NULL && rgn->call_stack()->equals(stack)) {

        VirtualMemorySummary::record_uncommitted_memory(rgn->size(), flag());

        // the two adjacent regions have the same call stack, merge them

        rgn->expand_region(addr, size);

        VirtualMemorySummary::record_committed_memory(rgn->size(), flag());

        return true;

      }

      }

    if (rgn->overlap_region(addr, size)) {

      // Clear a space for this region in the case it overlaps with any regions.

      remove_uncommitted_region(addr, size);

      break;  // commit below

    }

    if (rgn->end() >= addr + size){

      break;

    }

    node = node->next();

  }

    // New committed region

    VirtualMemorySummary::record_committed_memory(size, flag());

    return add_committed_region(committed_rgn);

  }

void ReservedMemoryRegion::set_all_committed(bool b) {

  if (all_committed() != b) {

    _all_committed = b;

    if (b) {

      VirtualMemorySummary::record_committed_memory(size(), flag());

    }

  }

}

bool ReservedMemoryRegion::remove_uncommitted_region(LinkedListNode<CommittedMemoryRegion>* node,

  address addr, size_t size) {

  assert(addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  CommittedMemoryRegion* rgn = node->data();

  assert(rgn->contain_region(addr, size), "Has to be contained");

  assert(!rgn->same_region(addr, size), "Can not be the same region");

  if (rgn->base() == addr ||

      rgn->end() == addr + size) {

    rgn->exclude_region(addr, size);

    return true;

  } else {

    // split this region

    address top =rgn->end();

    // use this region for lower part

    size_t exclude_size = rgn->end() - addr;

    rgn->exclude_region(addr, exclude_size);

    // higher part

    address high_base = addr + size;

    size_t  high_size = top - high_base;

    CommittedMemoryRegion high_rgn(high_base, high_size, *rgn->call_stack());

    LinkedListNode<CommittedMemoryRegion>* high_node = _committed_regions.add(high_rgn);

    assert(high_node == NULL || node->next() == high_node, "Should be right after");

    return (high_node != NULL);

  }

  return false;

}

bool ReservedMemoryRegion::remove_uncommitted_region(address addr, size_t sz) {

  // uncommit stack guard pages

  if (flag() == mtThreadStack && !same_region(addr, sz)) {

    return true;

  }

  assert(addr != NULL, "Invalid address");

  assert(sz > 0, "Invalid size");

  if (all_committed()) {

    assert(_committed_regions.is_empty(), "Sanity check");

    assert(contain_region(addr, sz), "Reserved region does not contain this region");

    set_all_committed(false);

    VirtualMemorySummary::record_uncommitted_memory(sz, flag());

    if (same_region(addr, sz)) {

      return true;

    } else {

      CommittedMemoryRegion rgn(base(), size(), *call_stack());

      if (rgn.base() == addr || rgn.end() == (addr + sz)) {

        rgn.exclude_region(addr, sz);

        return add_committed_region(rgn);

      } else {

        // split this region

        // top of the whole region

        address top =rgn.end();

        // use this region for lower part

        size_t exclude_size = rgn.end() - addr;

        rgn.exclude_region(addr, exclude_size);

        if (add_committed_region(rgn)) {

          // higher part

          address high_base = addr + sz;

          size_t  high_size = top - high_base;

          CommittedMemoryRegion high_rgn(high_base, high_size, NativeCallStack::EMPTY_STACK);

          return add_committed_region(high_rgn);

        } else {

          return false;

        }

      }

    }

  } else {

    CommittedMemoryRegion del_rgn(addr, sz, *call_stack());

    address end = addr + sz;

    LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();

    LinkedListNode<CommittedMemoryRegion>* prev = NULL;

    CommittedMemoryRegion* crgn;

    while (head != NULL) {

      crgn = head->data();

      if (crgn->same_region(addr, sz)) {

        VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());

          _committed_regions.remove_after(prev);

          return true;

      }

      // del_rgn contains crgn

      if (del_rgn.contain_region(crgn->base(), crgn->size())) {

          VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());

          head = head->next();

          _committed_regions.remove_after(prev);

        continue;  // don't update head or prev

        }

      // Found addr in the current crgn. There are 2 subcases:

      if (crgn->contain_address(addr)) {

        // (1) Found addr+size in current crgn as well. (del_rgn is contained in crgn)

        if (crgn->contain_address(end - 1)) {

          VirtualMemorySummary::record_uncommitted_memory(sz, flag());

          return remove_uncommitted_region(head, addr, sz); // done!

        } else {

          // (2) Did not find del_rgn's end in crgn.

          size_t size = crgn->end() - del_rgn.base();

          crgn->exclude_region(addr, size);

          VirtualMemorySummary::record_uncommitted_memory(size, flag());

      }

      } else if (crgn->contain_address(end - 1)) {

      // Found del_rgn's end, but not its base addr.

        size_t size = del_rgn.end() - crgn->base();

        crgn->exclude_region(crgn->base(), size);

        VirtualMemorySummary::record_uncommitted_memory(size, flag());

        return true;  // should be done if the list is sorted properly!

      }

      prev = head;

      head = head->next();

    }

  }

  return true;

}

void ReservedMemoryRegion::move_committed_regions(address addr, ReservedMemoryRegion& rgn) {

  assert(addr != NULL, "Invalid address");

  // split committed regions

  LinkedListNode<CommittedMemoryRegion>* head =

    _committed_regions.head();

  LinkedListNode<CommittedMemoryRegion>* prev = NULL;

  while (head != NULL) {

    if (head->data()->base() >= addr) {

      break;

    }

    prev = head;

    head = head->next();

  }

  if (head != NULL) {

    if (prev != NULL) {

      prev->set_next(head->next());

    } else {

      _committed_regions.set_head(NULL);

    }

  }

  rgn._committed_regions.set_head(head);

}

size_t ReservedMemoryRegion::committed_size() const {

  if (all_committed()) {

    return size();

  } else {

    size_t committed = 0;

    LinkedListNode<CommittedMemoryRegion>* head =

      _committed_regions.head();

    while (head != NULL) {

      committed += head->data()->size();

      head = head->next();

    }

    return committed;

  }

}

void ReservedMemoryRegion::set_flag(MEMFLAGS f) {

  assert((flag() == mtNone || flag() == f), "Overwrite memory type");

  if (flag() != f) {

    VirtualMemorySummary::move_reserved_memory(flag(), f, size());

    VirtualMemorySummary::move_committed_memory(flag(), f, committed_size());

    _flag = f;

  }

}

bool VirtualMemoryTracker::initialize(NMT_TrackingLevel level) {

  if (level >= NMT_summary) {

    VirtualMemorySummary::initialize();

  }

  return true;

}

bool VirtualMemoryTracker::late_initialize(NMT_TrackingLevel level) {

  if (level >= NMT_summary) {

    _reserved_regions = new (std::nothrow, ResourceObj::C_HEAP, mtNMT)

      SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>();

    return (_reserved_regions != NULL);

  }

  return true;

}

bool VirtualMemoryTracker::add_reserved_region(address base_addr, size_t size,

   const NativeCallStack& stack, MEMFLAGS flag, bool all_committed) {

  assert(base_addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  assert(_reserved_regions != NULL, "Sanity check");

  ReservedMemoryRegion  rgn(base_addr, size, stack, flag);

  ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);

  LinkedListNode<ReservedMemoryRegion>* node;

  if (reserved_rgn == NULL) {

    VirtualMemorySummary::record_reserved_memory(size, flag);

    node = _reserved_regions->add(rgn);

    if (node != NULL) {

      node->data()->set_all_committed(all_committed);

      return true;

    } else {

      return false;

    }

  } else {

    if (reserved_rgn->same_region(base_addr, size)) {

      reserved_rgn->set_call_stack(stack);

      reserved_rgn->set_flag(flag);

      return true;

    } else if (reserved_rgn->adjacent_to(base_addr, size)) {

      VirtualMemorySummary::record_reserved_memory(size, flag);

      reserved_rgn->expand_region(base_addr, size);

      reserved_rgn->set_call_stack(stack);

      return true;

    } else {

      // Overlapped reservation.

      // It can happen when the regions are thread stacks, as JNI

      // thread does not detach from VM before exits, and leads to

      // leak JavaThread object

      if (reserved_rgn->flag() == mtThreadStack) {

        guarantee(!CheckJNICalls, "Attached JNI thread exited without being detached");

        // Overwrite with new region

        // Release old region

        VirtualMemorySummary::record_uncommitted_memory(reserved_rgn->committed_size(), reserved_rgn->flag());

        VirtualMemorySummary::record_released_memory(reserved_rgn->size(), reserved_rgn->flag());

        // Add new region

        VirtualMemorySummary::record_reserved_memory(rgn.size(), flag);

        *reserved_rgn = rgn;

        return true;

      }

      // CDS mapping region.

      // CDS reserves the whole region for mapping CDS archive, then maps each section into the region.

      // NMT reports CDS as a whole.

      if (reserved_rgn->flag() == mtClassShared) {

        assert(reserved_rgn->contain_region(base_addr, size), "Reserved CDS region should contain this mapping region");

        return true;

      }

      // Mapped CDS string region.

      // The string region(s) is part of the java heap.

      if (reserved_rgn->flag() == mtJavaHeap) {

        assert(reserved_rgn->contain_region(base_addr, size), "Reserved heap region should contain this mapping region");

        return true;

      }

      ShouldNotReachHere();

      return false;

    }

  }

}

void VirtualMemoryTracker::set_reserved_region_type(address addr, MEMFLAGS flag) {

  assert(addr != NULL, "Invalid address");

  assert(_reserved_regions != NULL, "Sanity check");

  ReservedMemoryRegion   rgn(addr, 1);

  ReservedMemoryRegion*  reserved_rgn = _reserved_regions->find(rgn);

  if (reserved_rgn != NULL) {

    assert(reserved_rgn->contain_address(addr), "Containment");

    if (reserved_rgn->flag() != flag) {

      assert(reserved_rgn->flag() == mtNone, "Overwrite memory type");

      reserved_rgn->set_flag(flag);

    }

  }

}

bool VirtualMemoryTracker::add_committed_region(address addr, size_t size,

  const NativeCallStack& stack) {

  assert(addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  assert(_reserved_regions != NULL, "Sanity check");

  ReservedMemoryRegion  rgn(addr, size);

  ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);

  assert(reserved_rgn != NULL, "No reserved region");

  assert(reserved_rgn->contain_region(addr, size), "Not completely contained");

  bool result = reserved_rgn->add_committed_region(addr, size, stack);

  return result;

}

bool VirtualMemoryTracker::remove_uncommitted_region(address addr, size_t size) {

  assert(addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  assert(_reserved_regions != NULL, "Sanity check");

  ReservedMemoryRegion  rgn(addr, size);

  ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);

  assert(reserved_rgn != NULL, "No reserved region");

  assert(reserved_rgn->contain_region(addr, size), "Not completely contained");

  bool result = reserved_rgn->remove_uncommitted_region(addr, size);

  return result;

}

bool VirtualMemoryTracker::remove_released_region(address addr, size_t size) {

  assert(addr != NULL, "Invalid address");

  assert(size > 0, "Invalid size");

  assert(_reserved_regions != NULL, "Sanity check");

  ReservedMemoryRegion  rgn(addr, size);

  ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);

  assert(reserved_rgn != NULL, "No reserved region");

  // uncommit regions within the released region

  if (!reserved_rgn->remove_uncommitted_region(addr, size)) {

    return false;

  }

  if (reserved_rgn->flag() == mtClassShared &&

      reserved_rgn->contain_region(addr, size) &&

      !reserved_rgn->same_region(addr, size)) {

    // This is an unmapped CDS region, which is part of the reserved shared

    // memory region.

    // See special handling in VirtualMemoryTracker::add_reserved_region also.

    return true;

  }

  VirtualMemorySummary::record_released_memory(size, reserved_rgn->flag());

  if (reserved_rgn->same_region(addr, size)) {

    return _reserved_regions->remove(rgn);

  } else {

    assert(reserved_rgn->contain_region(addr, size), "Not completely contained");

    if (reserved_rgn->base() == addr ||

        reserved_rgn->end() == addr + size) {

        reserved_rgn->exclude_region(addr, size);

      return true;

    } else {

      address top = reserved_rgn->end();

      address high_base = addr + size;

      ReservedMemoryRegion high_rgn(high_base, top - high_base,

        *reserved_rgn->call_stack(), reserved_rgn->flag());

      // use original region for lower region

      reserved_rgn->exclude_region(addr, top - addr);

      LinkedListNode<ReservedMemoryRegion>* new_rgn = _reserved_regions->add(high_rgn);

      if (new_rgn == NULL) {

        return false;

      } else {

        reserved_rgn->move_committed_regions(addr, *new_rgn->data());

        return true;

      }

    }

  }

}

bool VirtualMemoryTracker::walk_virtual_memory(VirtualMemoryWalker* walker) {

  assert(_reserved_regions != NULL, "Sanity check");

  ThreadCritical tc;

  // Check that the _reserved_regions haven't been deleted.

  if (_reserved_regions != NULL) {

    LinkedListNode<ReservedMemoryRegion>* head = _reserved_regions->head();

    while (head != NULL) {

      const ReservedMemoryRegion* rgn = head->peek();

      if (!walker->do_allocation_site(rgn)) {

        return false;

      }

      head = head->next();

    }

   }

  return true;

}

// Transition virtual memory tracking level.

bool VirtualMemoryTracker::transition(NMT_TrackingLevel from, NMT_TrackingLevel to) {

  assert (from != NMT_minimal, "cannot convert from the lowest tracking level to anything");

  if (to == NMT_minimal) {

    assert(from == NMT_summary || from == NMT_detail, "Just check");

    // Clean up virtual memory tracking data structures.

    ThreadCritical tc;

    // Check for potential race with other thread calling transition

    if (_reserved_regions != NULL) {

      delete _reserved_regions;

      _reserved_regions = NULL;

    }

  }

  return true;

}