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/shared/ (Sun/Oracle ^©) Datei vom 13.11.2022 mit Größe 6 kB

Quelle scavengableNMethods.cpp Sprache: C

/*
* Copyright (c) 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/

#include "precompiled.hpp"
#include "code/codeCache.hpp"
#include "code/nmethod.hpp"
#include "gc/shared/scavengableNMethods.hpp"
#include "gc/shared/scavengableNMethodsData.hpp"
#include "runtime/mutexLocker.hpp"
#include "utilities/debug.hpp"

static ScavengableNMethodsData gc_data(nmethod* nm) {
  return ScavengableNMethodsData(nm);
}

nmethod* ScavengableNMethods::_head = NULL;
BoolObjectClosure* ScavengableNMethods::_is_scavengable = NULL;

void ScavengableNMethods::initialize(BoolObjectClosure* is_scavengable) {
  _is_scavengable = is_scavengable;
}

// Conditionally adds the nmethod to the list if it is
// not already on the list and has a scavengeable root.
void ScavengableNMethods::register_nmethod(nmethod* nm) {
  assert_locked_or_safepoint(CodeCache_lock);

  ScavengableNMethodsData data = gc_data(nm);

  if (data.on_list() || !has_scavengable_oops(nm)) {
    return;
  }

  data.set_on_list();
  data.set_next(_head);

  _head = nm;
}

void ScavengableNMethods::unregister_nmethod(nmethod* nm) {
  assert_locked_or_safepoint(CodeCache_lock);

  if (gc_data(nm).on_list()) {
    nmethod* prev = NULL;
    for (nmethod* cur = _head; cur != NULL; cur = gc_data(cur).next()) {
      if (cur == nm) {
        unlist_nmethod(cur, prev);
        return;
      }
      prev = cur;
    }
  }
}

#ifndef PRODUCT

class DebugScavengableOops: public OopClosure {
  BoolObjectClosure* _is_scavengable;
  nmethod*           _nm;
  bool               _ok;
public:
  DebugScavengableOops(BoolObjectClosure* is_scavengable, nmethod* nm) :
      _is_scavengable(is_scavengable),
      _nm(nm),
      _ok(true) { }

  bool ok() { return _ok; }
  virtual void do_oop(oop* p) {
    if (*p == NULL || !_is_scavengable->do_object_b(*p)) {
      return;
    }

    if (_ok) {
      _nm->print_nmethod(true);
      _ok = false;
    }
    tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
                  p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
    (*p)->print();
  }
  virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};

#endif // PRODUCT

void ScavengableNMethods::verify_nmethod(nmethod* nm) {
#ifndef PRODUCT
  if (!gc_data(nm).on_list()) {
    // Actually look inside, to verify the claim that it's clean.
    DebugScavengableOops cl(_is_scavengable, nm);
    nm->oops_do(&cl);
    if (!cl.ok())
      fatal("found an unadvertised bad scavengable oop in the code cache");
  }
  assert(gc_data(nm).not_marked(), "");
#endif // PRODUCT
}

class HasScavengableOops: public OopClosure {
  BoolObjectClosure* _is_scavengable;
  bool               _found;
public:
  HasScavengableOops(BoolObjectClosure* is_scavengable, nmethod* nm) :
      _is_scavengable(is_scavengable),
      _found(false) {}

  bool found() { return _found; }
  virtual void do_oop(oop* p) {
    if (!_found && *p != NULL && _is_scavengable->do_object_b(*p)) {
      _found = true;
    }
  }
  virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};

bool ScavengableNMethods::has_scavengable_oops(nmethod* nm) {
  HasScavengableOops cl(_is_scavengable, nm);
  nm->oops_do(&cl);
  return cl.found();
}

// Walk the list of methods which might contain oops to the java heap.
void ScavengableNMethods::nmethods_do_and_prune(CodeBlobToOopClosure* cl) {
  assert_locked_or_safepoint(CodeCache_lock);

  debug_only(mark_on_list_nmethods());

  nmethod* prev = NULL;
  nmethod* cur = _head;
  while (cur != NULL) {
    ScavengableNMethodsData data = gc_data(cur);
    debug_only(data.clear_marked());
    assert(data.on_list(), "else shouldn't be on this list");

    if (cl != NULL) {
      cl->do_code_blob(cur);
    }

    nmethod* const next = data.next();

    if (!has_scavengable_oops(cur)) {
      unlist_nmethod(cur, prev);
    } else {
      prev = cur;
    }

    cur = next;
  }

  // Check for stray marks.
  debug_only(verify_unlisted_nmethods(NULL));
}

void ScavengableNMethods::prune_nmethods() {
  nmethods_do_and_prune(NULL /* No closure */);
}

// Walk the list of methods which might contain oops to the java heap.
void ScavengableNMethods::nmethods_do(CodeBlobToOopClosure* cl) {
  nmethods_do_and_prune(cl);
}

#ifndef PRODUCT
void ScavengableNMethods::asserted_non_scavengable_nmethods_do(CodeBlobClosure* cl) {
  // While we are here, verify the integrity of the list.
  mark_on_list_nmethods();
  for (nmethod* cur = _head; cur != NULL; cur = gc_data(cur).next()) {
    assert(gc_data(cur).on_list(), "else shouldn't be on this list");
    gc_data(cur).clear_marked();
  }
  verify_unlisted_nmethods(cl);
}
#endif // PRODUCT

void ScavengableNMethods::unlist_nmethod(nmethod* nm, nmethod* prev) {
  assert_locked_or_safepoint(CodeCache_lock);

  assert((prev == NULL && _head == nm) ||
         (prev != NULL && gc_data(prev).next() == nm), "precondition");

  ScavengableNMethodsData data = gc_data(nm);

  if (prev == NULL) {
    _head = data.next();
  } else {
    gc_data(prev).set_next(data.next());
  }
  data.set_next(NULL);
  data.clear_on_list();
}

#ifndef PRODUCT
// Temporarily mark nmethods that are claimed to be on the scavenge list.
void ScavengableNMethods::mark_on_list_nmethods() {
  NMethodIterator iter(NMethodIterator::all_blobs);
  while(iter.next()) {
    nmethod* nm = iter.method();
    ScavengableNMethodsData data = gc_data(nm);
    assert(data.not_marked(), "clean state");
    if (data.on_list())
      data.set_marked();
  }
}

// If the closure is given, run it on the unlisted nmethods.
// Also make sure that the effects of mark_on_list_nmethods is gone.
void ScavengableNMethods::verify_unlisted_nmethods(CodeBlobClosure* cl) {
  NMethodIterator iter(NMethodIterator::all_blobs);
  while(iter.next()) {
    nmethod* nm = iter.method();

    verify_nmethod(nm);

    if (cl != NULL && !gc_data(nm).on_list()) {
      cl->do_code_blob(nm);
    }
  }
}

#endif //PRODUCT

quality90%

¤ Dauer der Verarbeitung: 0.4 Sekunden ¤

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.