/*

 * Copyright (c) 2015, 2018, 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 "gc/shared/oopStorage.hpp"

#include "gc/z/zAddress.hpp"

#include "gc/z/zGlobals.hpp"

#include "gc/z/zHeap.inline.hpp"

#include "gc/z/zHeapIterator.hpp"

#include "gc/z/zList.inline.hpp"

#include "gc/z/zLock.inline.hpp"

#include "gc/z/zMark.inline.hpp"

#include "gc/z/zOopClosures.inline.hpp"

#include "gc/z/zPage.inline.hpp"

#include "gc/z/zPageTable.inline.hpp"

#include "gc/z/zRelocationSet.inline.hpp"

#include "gc/z/zResurrection.hpp"

#include "gc/z/zRootsIterator.hpp"

#include "gc/z/zStat.hpp"

#include "gc/z/zTask.hpp"

#include "gc/z/zThread.hpp"

#include "gc/z/zTracer.inline.hpp"

#include "gc/z/zVirtualMemory.inline.hpp"

#include "gc/z/zWorkers.inline.hpp"

#include "logging/log.hpp"

#include "memory/resourceArea.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/safepoint.hpp"

#include "runtime/thread.hpp"

#include "utilities/align.hpp"

#include "utilities/debug.hpp"

static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes);

static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes);

static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes);

static const ZStatSampler ZSamplerHeapUsedAfterRelocation("Memory", "Heap Used After Relocation", ZStatUnitBytes);

static const ZStatCounter ZCounterUndoPageAllocation("Memory", "Undo Page Allocation", ZStatUnitOpsPerSecond);

static const ZStatCounter ZCounterOutOfMemory("Memory", "Out Of Memory", ZStatUnitOpsPerSecond);

ZHeap* ZHeap::_heap = NULL;

ZHeap::ZHeap() :

    _workers(),

    _object_allocator(_workers.nworkers()),

    _page_allocator(heap_min_size(), heap_max_size(), heap_max_reserve_size()),

    _pagetable(),

    _mark(&_workers, &_pagetable),

    _reference_processor(&_workers),

    _weak_roots_processor(&_workers),

    _relocate(&_workers),

    _relocation_set(),

    _serviceability(heap_min_size(), heap_max_size()) {

  // Install global heap instance

  assert(_heap == NULL, "Already initialized");

  _heap = this;

  // Update statistics

  ZStatHeap::set_at_initialize(heap_max_size(), heap_max_reserve_size());

}

size_t ZHeap::heap_min_size() const {

  const size_t aligned_min_size = align_up(InitialHeapSize, ZPageSizeMin);

  return MIN2(aligned_min_size, heap_max_size());

}

size_t ZHeap::heap_max_size() const {

  const size_t aligned_max_size = align_up(MaxHeapSize, ZPageSizeMin);

  return MIN2(aligned_max_size, ZAddressOffsetMax);

}

size_t ZHeap::heap_max_reserve_size() const {

  // Reserve one small page per worker plus one shared medium page. This is still just

  // an estimate and doesn't guarantee that we can't run out of memory during relocation.

  const size_t max_reserve_size = (_workers.nworkers() * ZPageSizeSmall) + ZPageSizeMedium;

  return MIN2(max_reserve_size, heap_max_size());

}

bool ZHeap::is_initialized() const {

  return _page_allocator.is_initialized() && _mark.is_initialized();

}

size_t ZHeap::min_capacity() const {

  return heap_min_size();

}

size_t ZHeap::max_capacity() const {

  return _page_allocator.max_capacity();

}

size_t ZHeap::current_max_capacity() const {

  return _page_allocator.current_max_capacity();

}

size_t ZHeap::capacity() const {

  return _page_allocator.capacity();

}

size_t ZHeap::max_reserve() const {

  return _page_allocator.max_reserve();

}

size_t ZHeap::used_high() const {

  return _page_allocator.used_high();

}

size_t ZHeap::used_low() const {

  return _page_allocator.used_low();

}

size_t ZHeap::used() const {

  return _page_allocator.used();

}

size_t ZHeap::allocated() const {

  return _page_allocator.allocated();

}

size_t ZHeap::reclaimed() const {

  return _page_allocator.reclaimed();

}

size_t ZHeap::tlab_capacity() const {

  return capacity();

}

size_t ZHeap::tlab_used() const {

  return _object_allocator.used();

}

size_t ZHeap::max_tlab_size() const {

  return ZObjectSizeLimitSmall;

}

size_t ZHeap::unsafe_max_tlab_alloc() const {

  size_t size = _object_allocator.remaining();

  if (size < MinTLABSize) {

    // The remaining space in the allocator is not enough to

    // fit the smallest possible TLAB. This means that the next

    // TLAB allocation will force the allocator to get a new

    // backing page anyway, which in turn means that we can then

    // fit the largest possible TLAB.

    size = max_tlab_size();

  }

  return MIN2(size, max_tlab_size());

}

bool ZHeap::is_in(uintptr_t addr) const {

  if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) {

    return false;

  }

  const ZPage* const page = _pagetable.get(addr);

  if (page != NULL) {

    return page->is_in(addr);

  }

  return false;

}

uintptr_t ZHeap::block_start(uintptr_t addr) const {

  const ZPage* const page = _pagetable.get(addr);

  return page->block_start(addr);

}

size_t ZHeap::block_size(uintptr_t addr) const {

  const ZPage* const page = _pagetable.get(addr);

  return page->block_size(addr);

}

bool ZHeap::block_is_obj(uintptr_t addr) const {

  const ZPage* const page = _pagetable.get(addr);

  return page->block_is_obj(addr);

}

uint ZHeap::nconcurrent_worker_threads() const {

  return _workers.nconcurrent();

}

uint ZHeap::nconcurrent_no_boost_worker_threads() const {

  return _workers.nconcurrent_no_boost();

}

void ZHeap::set_boost_worker_threads(bool boost) {

  _workers.set_boost(boost);

}

void ZHeap::worker_threads_do(ThreadClosure* tc) const {

  _workers.threads_do(tc);

}

void ZHeap::print_worker_threads_on(outputStream* st) const {

  _workers.print_threads_on(st);

}

void ZHeap::out_of_memory() {

  ResourceMark rm;

  ZStatInc(ZCounterOutOfMemory);

  log_info(gc)("Out Of Memory (%s)", Thread::current()->name());

}

ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {

  ZPage* const page = _page_allocator.alloc_page(type, size, flags);

  if (page != NULL) {

    // Update pagetable

    _pagetable.insert(page);

  }

  return page;

}

void ZHeap::undo_alloc_page(ZPage* page) {

  assert(page->is_allocating(), "Invalid page state");

  ZStatInc(ZCounterUndoPageAllocation);

  log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT,

                ZThread::id(), ZThread::name(), p2i(page), page->size());

  release_page(page, false /* reclaimed */);

}

bool ZHeap::retain_page(ZPage* page) {

  return page->inc_refcount();

}

void ZHeap::release_page(ZPage* page, bool reclaimed) {

  if (page->dec_refcount()) {

    _page_allocator.free_page(page, reclaimed);

  }

}

void ZHeap::flip_views() {

  // For debugging only

  if (ZUnmapBadViews) {

    // Flip pages

    ZPageTableIterator iter(&_pagetable);

    for (ZPage* page; iter.next(&page);) {

      if (!page->is_detached()) {

        _page_allocator.flip_page(page);

      }

    }

    // Flip pre-mapped memory

    _page_allocator.flip_pre_mapped();

  }

}

void ZHeap::mark_start() {

  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");

  // Update statistics

  ZStatSample(ZSamplerHeapUsedBeforeMark, used());

  // Flip address view

  ZAddressMasks::flip_to_marked();

  flip_views();

  // Retire allocating pages

  _object_allocator.retire_pages();

  // Reset allocated/reclaimed/used statistics

  _page_allocator.reset_statistics();

  // Reset encountered/dropped/enqueued statistics

  _reference_processor.reset_statistics();

  // Enter mark phase

  ZGlobalPhase = ZPhaseMark;

  // Reset marking information and mark roots

  _mark.start();

  // Update statistics

  ZStatHeap::set_at_mark_start(capacity(), used());

}

}

void ZHeap::mark_flush_and_free(Thread* thread) {

  _mark.flush_and_free(thread);

}

class ZFixupPartialLoadsClosure : public ZRootsIteratorClosure {

public:

  virtual void do_oop(oop* p) {

    ZBarrier::mark_barrier_on_root_oop_field(p);

  }

  virtual void do_oop(narrowOop* p) {

    ShouldNotReachHere();

  }

};

class ZFixupPartialLoadsTask : public ZTask {

private:

  ZThreadRootsIterator _thread_roots;

public:

  ZFixupPartialLoadsTask() :

      ZTask("ZFixupPartialLoadsTask"),

      _thread_roots() {}

  virtual void work() {

    ZFixupPartialLoadsClosure cl;

    _thread_roots.oops_do(&cl);

  }

};

void ZHeap::fixup_partial_loads() {

  ZFixupPartialLoadsTask task;

  _workers.run_parallel(&task);

}

bool ZHeap::mark_end() {

  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");

  // C2 can generate code where a safepoint poll is inserted

  // between a load and the associated load barrier. To handle

  // this case we need to rescan the thread stack here to make

  // sure such oops are marked.

  fixup_partial_loads();

  // Try end marking

  if (!_mark.end()) {

    // Marking not completed, continue concurrent mark

    return false;

  }

  // Enter mark completed phase

  ZGlobalPhase = ZPhaseMarkCompleted;

  // Resize metaspace

  MetaspaceGC::compute_new_size();

  // Update statistics

  ZStatSample(ZSamplerHeapUsedAfterMark, used());

  ZStatHeap::set_at_mark_end(capacity(), allocated(), used());

  // Block resurrection of weak/phantom references

  ZResurrection::block();

  // Process weak roots

  _weak_roots_processor.process_weak_roots();

  // Verification

  if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {

    Universe::verify();

  }

  return true;

}

void ZHeap::set_soft_reference_policy(bool clear) {

  _reference_processor.set_soft_reference_policy(clear);

}

void ZHeap::process_non_strong_references() {

  // Process Soft/Weak/Final/PhantomReferences

  _reference_processor.process_references();

  // Process concurrent weak roots

  _weak_roots_processor.process_concurrent_weak_roots();

  // Unblock resurrection of weak/phantom references

  ZResurrection::unblock();

  // Enqueue Soft/Weak/Final/PhantomReferences. Note that this

  // must be done after unblocking resurrection. Otherwise the

  // Finalizer thread could call Reference.get() on the Finalizers

  // that were just enqueued, which would incorrectly return null

  // during the resurrection block window, since such referents

  // are only Finalizable marked.

  _reference_processor.enqueue_references();

}

void ZHeap::destroy_detached_pages() {

  ZList<ZPage> list;

  _page_allocator.flush_detached_pages(&list);

  for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {

    // Remove pagetable entry

    _pagetable.remove(page);

    // Delete the page

    _page_allocator.destroy_page(page);

  }

}

void ZHeap::select_relocation_set() {

  // Register relocatable pages with selector

  ZRelocationSetSelector selector;

  ZPageTableIterator iter(&_pagetable);

  for (ZPage* page; iter.next(&page);) {

    if (!page->is_relocatable()) {

      // Not relocatable, don't register

      continue;

    }

    if (page->is_marked()) {

      // Register live page

      selector.register_live_page(page);

    } else {

      // Register garbage page

      selector.register_garbage_page(page);

      // Reclaim page immediately

      release_page(page, true /* reclaimed */);

    }

  }

  // Select pages to relocate

  selector.select(&_relocation_set);

  // Update statistics

  ZStatRelocation::set_at_select_relocation_set(selector.relocating());

  ZStatHeap::set_at_select_relocation_set(selector.live(),

                                          selector.garbage(),

                                          reclaimed());

}

void ZHeap::prepare_relocation_set() {

  ZRelocationSetIterator iter(&_relocation_set);

  for (ZPage* page; iter.next(&page);) {

    // Prepare for relocation

    page->set_forwarding();

    // Update pagetable

    _pagetable.set_relocating(page);

  }

}

void ZHeap::reset_relocation_set() {

  ZRelocationSetIterator iter(&_relocation_set);

  for (ZPage* page; iter.next(&page);) {

    // Reset relocation information

    page->reset_forwarding();

    // Update pagetable

    _pagetable.clear_relocating(page);

  }

}

void ZHeap::relocate_start() {

  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");

  // Update statistics

  ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());

  // Flip address view

  ZAddressMasks::flip_to_remapped();

  flip_views();

  // Enter relocate phase

  ZGlobalPhase = ZPhaseRelocate;

  // Update statistics

  ZStatHeap::set_at_relocate_start(capacity(), allocated(), used());

  // Remap/Relocate roots

  _relocate.start();

}

uintptr_t ZHeap::relocate_object(uintptr_t addr) {

  assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed");

  ZPage* const page = _pagetable.get(addr);

  const bool retained = retain_page(page);

  const uintptr_t new_addr = page->relocate_object(addr);

  if (retained) {

    release_page(page, true /* reclaimed */);

  }

  return new_addr;

}

uintptr_t ZHeap::forward_object(uintptr_t addr) {

  assert(ZGlobalPhase == ZPhaseMark ||

         ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed");

  ZPage* const page = _pagetable.get(addr);

  return page->forward_object(addr);

}

void ZHeap::relocate() {

  // Relocate relocation set

  const bool success = _relocate.relocate(&_relocation_set);

  // Update statistics

  ZStatSample(ZSamplerHeapUsedAfterRelocation, used());

  ZStatRelocation::set_at_relocate_end(success);

  ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(),

                                 used(), used_high(), used_low());

}

void ZHeap::object_iterate(ObjectClosure* cl, bool visit_referents) {

  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");

  ZHeapIterator iter(visit_referents);

  iter.objects_do(cl);

}

void ZHeap::serviceability_initialize() {