/*

 * Copyright (c) 2011, 2019, 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

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 */

#include "precompiled.hpp"

#include "gc/g1/g1CollectedHeap.inline.hpp"

#include "gc/g1/g1MonitoringSupport.hpp"

#include "gc/g1/g1Policy.hpp"

#include "gc/g1/g1MemoryPool.hpp"

#include "gc/shared/hSpaceCounters.hpp"

#include "memory/metaspaceCounters.hpp"

#include "services/memoryPool.hpp"

class G1GenerationCounters : public GenerationCounters {

protected:

  G1MonitoringSupport* _g1mm;

public:

  G1GenerationCounters(G1MonitoringSupport* g1mm,

                       const char* name, int ordinal, int spaces,

                       size_t min_capacity, size_t max_capacity,

                       size_t curr_capacity)

  : GenerationCounters(name, ordinal, spaces, min_capacity,

                       max_capacity, curr_capacity), _g1mm(g1mm) { }

};

class G1YoungGenerationCounters : public G1GenerationCounters {

public:

  // We pad the capacity three times given that the young generation

  // contains three spaces (eden and two survivors).

  G1YoungGenerationCounters(G1MonitoringSupport* g1mm, const char* name, size_t max_size)

  : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,

                         G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,

                         G1MonitoringSupport::pad_capacity(max_size, 3),

                         G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {

    if (UsePerfData) {

      update_all();

    }

  }

  virtual void update_all() {

    size_t committed =

              G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);

    _current_size->set_value(committed);

  }

};

class G1OldGenerationCounters : public G1GenerationCounters {

public:

  G1OldGenerationCounters(G1MonitoringSupport* g1mm, const char* name, size_t max_size)

  : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,

                         G1MonitoringSupport::pad_capacity(0) /* min_capacity */,

                         G1MonitoringSupport::pad_capacity(max_size),

                         G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {

    if (UsePerfData) {

      update_all();

    }

  }

  virtual void update_all() {

    size_t committed =

              G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());

    _current_size->set_value(committed);

  }

};

G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :

  _g1h(g1h),

  _incremental_memory_manager("G1 Young Generation", "end of minor GC"),

  _full_gc_memory_manager("G1 Old Generation", "end of major GC"),

  _eden_space_pool(NULL),

  _survivor_space_pool(NULL),

  _old_gen_pool(NULL),

  _incremental_collection_counters(NULL),

  _full_collection_counters(NULL),

  _conc_collection_counters(NULL),

  _young_gen_counters(NULL),

  _old_gen_counters(NULL),

  _old_space_counters(NULL),

  _eden_space_counters(NULL),

  _from_space_counters(NULL),

  _to_space_counters(NULL),

  _overall_committed(0),

  _overall_used(0),

  _young_gen_committed(0),

  _old_gen_committed(0),

  _eden_space_committed(0),

  _eden_space_used(0),

  _survivor_space_committed(0),

  _survivor_space_used(0),

  _old_gen_used(0) {

  recalculate_sizes();

  // Counters for garbage collections

  //

  //  name "collector.0".  In a generational collector this would be the

  // young generation collection.

  _incremental_collection_counters =

    new CollectorCounters("G1 young collection pauses", 0);

  //   name "collector.1".  In a generational collector this would be the

  // old generation collection.

  _full_collection_counters =

    new CollectorCounters("G1 full collection pauses", 1);

  //   name "collector.2".  In a generational collector this would be the

  // STW phases in concurrent collection.

  _conc_collection_counters =

    new CollectorCounters("G1 concurrent cycle pauses", 2);

  // "Generation" and "Space" counters.

  //

  //  name "generation.1" This is logically the old generation in

  // generational GC terms.  The "1, 1" parameters are for

  // the n-th generation (=1) with 1 space.

  // Counters are created from minCapacity, maxCapacity, and capacity

  _old_gen_counters = new G1OldGenerationCounters(this, "old", _g1h->max_capacity());

  //  name  "generation.1.space.0"

  // Counters are created from maxCapacity, capacity, initCapacity,

  // and used.

  _old_space_counters = new HSpaceCounters(_old_gen_counters->name_space(),

    "space", 0 /* ordinal */,

    pad_capacity(g1h->max_capacity()) /* max_capacity */,

    pad_capacity(_old_gen_committed) /* init_capacity */);

  //   Young collection set

  //  name "generation.0".  This is logically the young generation.

  //  The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.

  // See  _old_collection_counters for additional counters

  _young_gen_counters = new G1YoungGenerationCounters(this, "young", _g1h->max_capacity());

  const char* young_collection_name_space = _young_gen_counters->name_space();

  //  name "generation.0.space.0"

  // See _old_space_counters for additional counters

  _eden_space_counters = new HSpaceCounters(young_collection_name_space,

    "eden", 0 /* ordinal */,

    pad_capacity(g1h->max_capacity()) /* max_capacity */,

    pad_capacity(_eden_space_committed) /* init_capacity */);

  //  name "generation.0.space.1"

  // See _old_space_counters for additional counters

  // Set the arguments to indicate that this survivor space is not used.

  _from_space_counters = new HSpaceCounters(young_collection_name_space,

    "s0", 1 /* ordinal */,

    pad_capacity(0) /* max_capacity */,

    pad_capacity(0) /* init_capacity */);

  // Given that this survivor space is not used, we update it here

  // once to reflect that its used space is 0 so that we don't have to

  // worry about updating it again later.

  if (UsePerfData) {

    _from_space_counters->update_used(0);

  }

  //  name "generation.0.space.2"

  // See _old_space_counters for additional counters

  _to_space_counters = new HSpaceCounters(young_collection_name_space,

    "s1", 2 /* ordinal */,

    pad_capacity(g1h->max_capacity()) /* max_capacity */,

    pad_capacity(_survivor_space_committed) /* init_capacity */);

}

G1MonitoringSupport::~G1MonitoringSupport() {

  delete _eden_space_pool;

  delete _survivor_space_pool;

  delete _old_gen_pool;

}

void G1MonitoringSupport::initialize_serviceability() {

  _eden_space_pool = new G1EdenPool(_g1h, _eden_space_committed);

  _survivor_space_pool = new G1SurvivorPool(_g1h, _survivor_space_committed);

  _old_gen_pool = new G1OldGenPool(_g1h, _old_gen_committed, _g1h->max_capacity());

  _full_gc_memory_manager.add_pool(_eden_space_pool);

  _full_gc_memory_manager.add_pool(_survivor_space_pool);

  _full_gc_memory_manager.add_pool(_old_gen_pool);

  _incremental_memory_manager.add_pool(_eden_space_pool);

  _incremental_memory_manager.add_pool(_survivor_space_pool);

  _incremental_memory_manager.add_pool(_old_gen_pool, false /* always_affected_by_gc */);

}

MemoryUsage G1MonitoringSupport::memory_usage() {

  MutexLocker x(MonitoringSupport_lock, Mutex::_no_safepoint_check_flag);

  return MemoryUsage(InitialHeapSize, _overall_used, _overall_committed, _g1h->max_capacity());

}

GrowableArray<GCMemoryManager*> G1MonitoringSupport::memory_managers() {

  GrowableArray<GCMemoryManager*> memory_managers(2);

  memory_managers.append(&_incremental_memory_manager);

  memory_managers.append(&_full_gc_memory_manager);

  return memory_managers;

}

GrowableArray<MemoryPool*> G1MonitoringSupport::memory_pools() {

  GrowableArray<MemoryPool*> memory_pools(3);

  memory_pools.append(_eden_space_pool);

  memory_pools.append(_survivor_space_pool);

  memory_pools.append(_old_gen_pool);

  return memory_pools;

}

void G1MonitoringSupport::recalculate_sizes() {

  assert_heap_locked_or_at_safepoint(true);

  MutexLocker x(MonitoringSupport_lock, Mutex::_no_safepoint_check_flag);

  // Recalculate all the sizes from scratch.

  // This never includes used bytes of current allocating heap region.

  _overall_used = _g1h->used_unlocked();

  _eden_space_used = _g1h->eden_regions_used_bytes();

  _survivor_space_used = _g1h->survivor_regions_used_bytes();

  // _overall_used and _eden_space_used are obtained concurrently so

  // may be inconsistent with each other. To prevent _old_gen_used going negative,

  // use smaller value to substract.

  _old_gen_used = _overall_used - MIN2(_overall_used, _eden_space_used + _survivor_space_used);

  uint survivor_list_length = _g1h->survivor_regions_count();

  // Max length includes any potential extensions to the young gen

  // we'll do when the GC locker is active.

  uint young_list_max_length = _g1h->policy()->young_list_max_length();

  assert(young_list_max_length >= survivor_list_length, "invariant");

  uint eden_list_max_length = young_list_max_length - survivor_list_length;

  // First calculate the committed sizes that can be calculated independently.

  _survivor_space_committed = survivor_list_length * HeapRegion::GrainBytes;

  _old_gen_committed = HeapRegion::align_up_to_region_byte_size(_old_gen_used);

  // Next, start with the overall committed size.

  _overall_committed = _g1h->capacity();

  size_t committed = _overall_committed;

  // Remove the committed size we have calculated so far (for the

  // survivor and old space).

  assert(committed >= (_survivor_space_committed + _old_gen_committed), "sanity");

  committed -= _survivor_space_committed + _old_gen_committed;

  // Next, calculate and remove the committed size for the eden.

  _eden_space_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;

  // Somewhat defensive: be robust in case there are inaccuracies in

  // the calculations

  _eden_space_committed = MIN2(_eden_space_committed, committed);

  committed -= _eden_space_committed;

  // Finally, give the rest to the old space...

  _old_gen_committed += committed;

  // ..and calculate the young gen committed.

  _young_gen_committed = _eden_space_committed + _survivor_space_committed;

  assert(_overall_committed ==

         (_eden_space_committed + _survivor_space_committed + _old_gen_committed),

         "the committed sizes should add up");

  // Somewhat defensive: cap the eden used size to make sure it

  // never exceeds the committed size.

  _eden_space_used = MIN2(_eden_space_used, _eden_space_committed);

  // _survivor_space_used is calculated during a safepoint and _survivor_space_committed

  // is calculated from survivor region count * heap region size.

  assert(_survivor_space_used <= _survivor_space_committed, "Survivor used bytes(" SIZE_FORMAT

         ") should be less than or equal to survivor committed(" SIZE_FORMAT ")",

         _survivor_space_used, _survivor_space_committed);

  // _old_gen_committed is calculated in terms of _old_gen_used value.

  assert(_old_gen_used <= _old_gen_committed, "Old gen used bytes(" SIZE_FORMAT

         ") should be less than or equal to old gen committed(" SIZE_FORMAT ")",

         _old_gen_used, _old_gen_committed);

}

void G1MonitoringSupport::update_sizes() {

  recalculate_sizes();

  if (UsePerfData) {

    _eden_space_counters->update_capacity(pad_capacity(_eden_space_committed));

    _eden_space_counters->update_used(_eden_space_used);

   // only the "to" survivor space is active, so we don't need to

    // update the counters for the "from" survivor space

    _to_space_counters->update_capacity(pad_capacity(_survivor_space_committed));

    _to_space_counters->update_used(_survivor_space_used);

    _old_space_counters->update_capacity(pad_capacity(_old_gen_committed));

    _old_space_counters->update_used(_old_gen_used);

    _young_gen_counters->update_all();

    _old_gen_counters->update_all();

    MetaspaceCounters::update_performance_counters();

    CompressedClassSpaceCounters::update_performance_counters();

  }

}

void G1MonitoringSupport::update_eden_size() {

  // Recalculate everything - this should be fast enough and we are sure that we do not

  // miss anything.

  recalculate_sizes();

  if (UsePerfData) {

    _eden_space_counters->update_used(_eden_space_used);

  }

}

MemoryUsage G1MonitoringSupport::eden_space_memory_usage(size_t initial_size, size_t max_size) {

  MutexLocker x(MonitoringSupport_lock, Mutex::_no_safepoint_check_flag);

  return MemoryUsage(initial_size,

                     _eden_space_used,

                     _eden_space_committed,

                     max_size);

}

MemoryUsage G1MonitoringSupport::survivor_space_memory_usage(size_t initial_size, size_t max_size) {

  MutexLocker x(MonitoringSupport_lock, Mutex::_no_safepoint_check_flag);

  return MemoryUsage(initial_size,

                     _survivor_space_used,

                     _survivor_space_committed,

                     max_size);

}

MemoryUsage G1MonitoringSupport::old_gen_memory_usage(size_t initial_size, size_t max_size) {

  MutexLocker x(MonitoringSupport_lock, Mutex::_no_safepoint_check_flag);

  return MemoryUsage(initial_size,

                     _old_gen_used,

                     _old_gen_committed,

                     max_size);

}

G1MonitoringScope::G1MonitoringScope(G1MonitoringSupport* g1mm, bool full_gc, bool all_memory_pools_affected) :

  _tcs(full_gc ? g1mm->_full_collection_counters : g1mm->_incremental_collection_counters),

  _tms(full_gc ? &g1mm->_full_gc_memory_manager : &g1mm->_incremental_memory_manager,

       G1CollectedHeap::heap()->gc_cause(), all_memory_pools_affected) {

}