Ziele Untersuchung
mit Columbo Integrität von
Datenbanken Interaktion und
Portierbarkeit Ergonomie der
Schnittstellen

Angebot Produkte Projekt Beratung

Mittel Analytik Modellierung Sprachen Algebra Logik Hardware Denken Kreativität

Zusammenhänge Gesellschaft Wirtschaft Branche Firma


products/sources/formale Sprachen/Java/Openjdk/src/hotspot/share/gc/parallel/ (Sun/Oracle ^©) Datei vom 13.11.2022 mit Größe 11 kB

Quelle psPromotionManager.cpp Sprache: C

/*
* Copyright (c) 2002, 2022, 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 "classfile/javaClasses.inline.hpp"
#include "gc/parallel/mutableSpace.hpp"
#include "gc/parallel/parallelScavengeHeap.hpp"
#include "gc/parallel/psOldGen.hpp"
#include "gc/parallel/psPromotionManager.inline.hpp"
#include "gc/parallel/psScavenge.inline.hpp"
#include "gc/shared/continuationGCSupport.inline.hpp"
#include "gc/shared/gcTrace.hpp"
#include "gc/shared/preservedMarks.inline.hpp"
#include "gc/shared/taskqueue.inline.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/iterator.inline.hpp"
#include "memory/memRegion.hpp"
#include "memory/padded.inline.hpp"
#include "memory/resourceArea.hpp"
#include "oops/access.inline.hpp"
#include "oops/compressedOops.inline.hpp"

PaddedEnd<PSPromotionManager>* PSPromotionManager::_manager_array = NULL;
PSPromotionManager::PSScannerTasksQueueSet* PSPromotionManager::_stack_array_depth = NULL;
PreservedMarksSet*             PSPromotionManager::_preserved_marks_set = NULL;
PSOldGen*                      PSPromotionManager::_old_gen = NULL;
MutableSpace*                  PSPromotionManager::_young_space = NULL;

void PSPromotionManager::initialize() {
  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  _old_gen = heap->old_gen();
  _young_space = heap->young_gen()->to_space();

  const uint promotion_manager_num = ParallelGCThreads;

  // To prevent false sharing, we pad the PSPromotionManagers
  // and make sure that the first instance starts at a cache line.
  assert(_manager_array == NULL, "Attempt to initialize twice");
  _manager_array = PaddedArray<PSPromotionManager, mtGC>::create_unfreeable(promotion_manager_num);

  _stack_array_depth = new PSScannerTasksQueueSet(ParallelGCThreads);

  // Create and register the PSPromotionManager(s) for the worker threads.
  for(uint i=0; i<ParallelGCThreads; i++) {
    stack_array_depth()->register_queue(i, _manager_array[i].claimed_stack_depth());
  }
  // The VMThread gets its own PSPromotionManager, which is not available
  // for work stealing.

  assert(_preserved_marks_set == NULL, "Attempt to initialize twice");
  _preserved_marks_set = new PreservedMarksSet(true /* in_c_heap */);
  _preserved_marks_set->init(promotion_manager_num);
  for (uint i = 0; i < promotion_manager_num; i += 1) {
    _manager_array[i].register_preserved_marks(_preserved_marks_set->get(i));
  }
}

// Helper functions to get around the circular dependency between
// psScavenge.inline.hpp and psPromotionManager.inline.hpp.
bool PSPromotionManager::should_scavenge(oop* p, bool check_to_space) {
  return PSScavenge::should_scavenge(p, check_to_space);
}
bool PSPromotionManager::should_scavenge(narrowOop* p, bool check_to_space) {
  return PSScavenge::should_scavenge(p, check_to_space);
}

PSPromotionManager* PSPromotionManager::gc_thread_promotion_manager(uint index) {
  assert(index < ParallelGCThreads, "index out of range");
  assert(_manager_array != NULL, "Sanity");
  return &_manager_array[index];
}

PSPromotionManager* PSPromotionManager::vm_thread_promotion_manager() {
  assert(_manager_array != NULL, "Sanity");
  return &_manager_array[0];
}

void PSPromotionManager::pre_scavenge() {
  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  _preserved_marks_set->assert_empty();
  _young_space = heap->young_gen()->to_space();

  for(uint i=0; i<ParallelGCThreads; i++) {
    manager_array(i)->reset();
  }
}

bool PSPromotionManager::post_scavenge(YoungGCTracer& gc_tracer) {
  bool promotion_failure_occurred = false;

  TASKQUEUE_STATS_ONLY(print_taskqueue_stats());
  for (uint i = 0; i < ParallelGCThreads; i++) {
    PSPromotionManager* manager = manager_array(i);
    assert(manager->claimed_stack_depth()->is_empty(), "should be empty");
    if (manager->_promotion_failed_info.has_failed()) {
      gc_tracer.report_promotion_failed(manager->_promotion_failed_info);
      promotion_failure_occurred = true;
    }
    manager->flush_labs();
    manager->flush_string_dedup_requests();
  }
  if (!promotion_failure_occurred) {
    // If there was no promotion failure, the preserved mark stacks
    // should be empty.
    _preserved_marks_set->assert_empty();
  }
  return promotion_failure_occurred;
}

#if TASKQUEUE_STATS
void
PSPromotionManager::print_local_stats(outputStream* const out, uint i) const {
  #define FMT " " SIZE_FORMAT_W(10)
  out->print_cr("%3u" FMT FMT FMT FMT,
                i, _array_chunk_pushes, _array_chunk_steals,
                _arrays_chunked, _array_chunks_processed);
  #undef FMT
}

static const char* const pm_stats_hdr[] = {
  " ----partial array---- arrays array",
  "thr push steal chunked chunks",
  "--- ---------- ---------- ---------- ----------"
};

void PSPromotionManager::print_taskqueue_stats() {
  if (!log_is_enabled(Trace, gc, task, stats)) {
    return;
  }
  Log(gc, task, stats) log;
  ResourceMark rm;
  LogStream ls(log.trace());

  stack_array_depth()->print_taskqueue_stats(&ls, "Oop Queue");

  const uint hlines = sizeof(pm_stats_hdr) / sizeof(pm_stats_hdr[0]);
  for (uint i = 0; i < hlines; ++i) ls.print_cr("%s", pm_stats_hdr[i]);
  for (uint i = 0; i < ParallelGCThreads; ++i) {
    manager_array(i)->print_local_stats(&ls, i);
  }
}

void PSPromotionManager::reset_stats() {
  claimed_stack_depth()->stats.reset();
  _array_chunk_pushes = _array_chunk_steals = 0;
  _arrays_chunked = _array_chunks_processed = 0;
}
#endif // TASKQUEUE_STATS

PSPromotionManager::PSPromotionManager() {
  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  // We set the old lab's start array.
  _old_lab.set_start_array(old_gen()->start_array());

  uint queue_size;
  queue_size = claimed_stack_depth()->max_elems();

  if (ParallelGCThreads == 1) {
    _target_stack_size = 0;
  } else {
    // don't let the target stack size to be more than 1/4 of the entries
    _target_stack_size = (uint) MIN2((uint) GCDrainStackTargetSize,
                                     (uint) (queue_size / 4));
  }

  _array_chunk_size = ParGCArrayScanChunk;
  // let's choose 1.5x the chunk size
  _min_array_size_for_chunking = 3 * _array_chunk_size / 2;

  _preserved_marks = NULL;

  reset();
}

void PSPromotionManager::reset() {
  assert(stacks_empty(), "reset of non-empty stack");

  // We need to get an assert in here to make sure the labs are always flushed.

  // Do not prefill the LAB's, save heap wastage!
  HeapWord* lab_base = young_space()->top();
  _young_lab.initialize(MemRegion(lab_base, (size_t)0));
  _young_gen_is_full = false;

  lab_base = old_gen()->object_space()->top();
  _old_lab.initialize(MemRegion(lab_base, (size_t)0));
  _old_gen_is_full = false;

  _promotion_failed_info.reset();

  TASKQUEUE_STATS_ONLY(reset_stats());
}

void PSPromotionManager::register_preserved_marks(PreservedMarks* preserved_marks) {
  assert(_preserved_marks == NULL, "do not set it twice");
  _preserved_marks = preserved_marks;
}

void PSPromotionManager::restore_preserved_marks() {
  _preserved_marks_set->restore(&ParallelScavengeHeap::heap()->workers());
}

void PSPromotionManager::drain_stacks_depth(bool totally_drain) {
  totally_drain = totally_drain || (_target_stack_size == 0);

  PSScannerTasksQueue* const tq = claimed_stack_depth();
  do {
    ScannerTask task;

    // Drain overflow stack first, so other threads can steal from
    // claimed stack while we work.
    while (tq->pop_overflow(task)) {
      process_popped_location_depth(task);
    }

    if (totally_drain) {
      while (tq->pop_local(task)) {
        process_popped_location_depth(task);
      }
    } else {
      while (tq->size() > _target_stack_size && tq->pop_local(task)) {
        process_popped_location_depth(task);
      }
    }
  } while ((totally_drain && !tq->taskqueue_empty()) || !tq->overflow_empty());

  assert(!totally_drain || tq->taskqueue_empty(), "Sanity");
  assert(totally_drain || tq->size() <= _target_stack_size, "Sanity");
  assert(tq->overflow_empty(), "Sanity");
}

void PSPromotionManager::flush_labs() {
  assert(stacks_empty(), "Attempt to flush lab with live stack");

  // If either promotion lab fills up, we can flush the
  // lab but not refill it, so check first.
  assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity");
  if (!_young_lab.is_flushed())
    _young_lab.flush();

  assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity");
  if (!_old_lab.is_flushed())
    _old_lab.flush();

  // Let PSScavenge know if we overflowed
  if (_young_gen_is_full) {
    PSScavenge::set_survivor_overflow(true);
  }
}

template <class T> void PSPromotionManager::process_array_chunk_work(
                                                 oop obj,
                                                 int start, int end) {
  assert(start <= end, "invariant");
  T* const base      = (T*)objArrayOop(obj)->base();
  T* p               = base + start;
  T* const chunk_end = base + end;
  while (p < chunk_end) {
    if (PSScavenge::should_scavenge(p)) {
      claim_or_forward_depth(p);
    }
    ++p;
  }
}

void PSPromotionManager::process_array_chunk(PartialArrayScanTask task) {
  assert(PSChunkLargeArrays, "invariant");

  oop old = task.to_source_array();
  assert(old->is_objArray(), "invariant");
  assert(old->is_forwarded(), "invariant");

  TASKQUEUE_STATS_ONLY(++_array_chunks_processed);

  oop const obj = old->forwardee();

  int start;
  int const end = arrayOop(old)->length();
  if (end > (int) _min_array_size_for_chunking) {
    // we'll chunk more
    start = end - _array_chunk_size;
    assert(start > 0, "invariant");
    arrayOop(old)->set_length(start);
    push_depth(ScannerTask(PartialArrayScanTask(old)));
    TASKQUEUE_STATS_ONLY(++_array_chunk_pushes);
  } else {
    // this is the final chunk for this array
    start = 0;
    int const actual_length = arrayOop(obj)->length();
    arrayOop(old)->set_length(actual_length);
  }

  if (UseCompressedOops) {
    process_array_chunk_work<narrowOop>(obj, start, end);
  } else {
    process_array_chunk_work<oop>(obj, start, end);
  }
}

oop PSPromotionManager::oop_promotion_failed(oop obj, markWord obj_mark) {
  assert(_old_gen_is_full || PromotionFailureALot, "Sanity");

  // Attempt to CAS in the header.
  // This tests if the header is still the same as when
  // this started.  If it is the same (i.e., no forwarding
  // pointer has been installed), then this thread owns
  // it.
  if (obj->forward_to_atomic(obj, obj_mark) == NULL) {
    // We won any races, we "own" this object.
    assert(obj == obj->forwardee(), "Sanity");

    _promotion_failed_info.register_copy_failure(obj->size());

    ContinuationGCSupport::transform_stack_chunk(obj);

    push_contents(obj);

    // Save the markWord of promotion-failed objs in _preserved_marks for later
    // restoration. This way we don't have to walk the young-gen to locate
    // these promotion-failed objs.
    _preserved_marks->push_always(obj, obj_mark);
  }  else {
    // We lost, someone else "owns" this object
    guarantee(obj->is_forwarded(), "Object must be forwarded if the cas failed.");

    // No unallocation to worry about.
    obj = obj->forwardee();
  }

  return obj;
}

quality73%

¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.