src/hotspot/share/oops/instanceRefKlass.inline.hpp

/*
 * Copyright (c) 2015, 2024, 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.
 *
 */

#ifndef SHARE_OOPS_INSTANCEREFKLASS_INLINE_HPP
#define SHARE_OOPS_INSTANCEREFKLASS_INLINE_HPP

#include "oops/instanceRefKlass.hpp"

#include "classfile/javaClasses.inline.hpp"
#include "gc/shared/referenceProcessor.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "oops/access.inline.hpp"
#include "oops/instanceKlass.inline.hpp"
#include "oops/oop.inline.hpp"
#include "utilities/debug.hpp"
#include "utilities/devirtualizer.inline.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/macros.hpp"

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::do_referent(oop obj, OopClosureType* closure, Contains& contains) {
  T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj);
  if (contains(referent_addr)) {
    Devirtualizer::do_oop(closure, referent_addr);
  }
}

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::do_discovered(oop obj, OopClosureType* closure, Contains& contains) {
  T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj);
  if (contains(discovered_addr)) {
    Devirtualizer::do_oop(closure, discovered_addr);
  }
}

static inline oop load_referent(oop obj, ReferenceType type) {
  if (type == REF_PHANTOM) {
    return HeapAccess<ON_PHANTOM_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  } else {
    return HeapAccess<ON_WEAK_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  }
}

template <typename T, class OopClosureType>
bool InstanceRefKlass::try_discover(oop obj, ReferenceType type, OopClosureType* closure) {
  ReferenceDiscoverer* rd = closure->ref_discoverer();
  if (rd != nullptr) {
    oop referent = load_referent(obj, type);
    if (referent != nullptr) {
      if (!referent->is_gc_marked()) {
        // Only try to discover if not yet marked.
        return rd->discover_reference(obj, type);
      }
    }
  }
  return false;
}

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::oop_oop_iterate_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  // Try to discover reference and return if it succeeds.
  if (try_discover<T>(obj, type, closure)) {
    return;
  }

  // Treat referent and discovered as normal oops.
  do_referent<T>(obj, closure, contains);
  do_discovered<T>(obj, closure, contains);
}

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains) {
  assert(closure->ref_discoverer() == nullptr, "ReferenceDiscoverer should not be set");
  do_referent<T>(obj, closure, contains);
  do_discovered<T>(obj, closure, contains);
}

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::oop_oop_iterate_fields_except_referent(oop obj, OopClosureType* closure, Contains& contains) {
  assert(closure->ref_discoverer() == nullptr, "ReferenceDiscoverer should not be set");
  do_discovered<T>(obj, closure, contains);
}

template <typename T, class OopClosureType, class Contains>
void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure, Contains& contains) {
  switch (closure->reference_iteration_mode()) {
    case OopIterateClosure::DO_DISCOVERY:
      trace_reference_gc<T>("do_discovery", obj);
      oop_oop_iterate_discovery<T>(obj, reference_type(), closure, contains);
      break;
    case OopIterateClosure::DO_FIELDS:
      trace_reference_gc<T>("do_fields", obj);
      oop_oop_iterate_fields<T>(obj, closure, contains);
      break;
    case OopIterateClosure::DO_FIELDS_EXCEPT_REFERENT:
      trace_reference_gc<T>("do_fields_except_referent", obj);
      oop_oop_iterate_fields_except_referent<T>(obj, closure, contains);
      break;
    default:
      ShouldNotReachHere();
  }
}

class AlwaysContains {
 public:
  template <typename T> bool operator()(T* p) const { return true; }
};

template <typename T, class OopClosureType>
void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure) {
  AlwaysContains always_contains;
  oop_oop_iterate_ref_processing<T>(obj, closure, always_contains);
}

class MrContains {
  const MemRegion _mr;
 public:
  MrContains(MemRegion mr) : _mr(mr) {}
  template <typename T> bool operator()(T* p) const { return _mr.contains(p); }
};

template <typename T, class OopClosureType>
void InstanceRefKlass::oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
  const MrContains contains(mr);
  oop_oop_iterate_ref_processing<T>(obj, closure, contains);
}

template <typename T, class OopClosureType>
void InstanceRefKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
  InstanceKlass::oop_oop_iterate<T>(obj, closure);

  oop_oop_iterate_ref_processing<T>(obj, closure);
}

template <typename T, class OopClosureType>
void InstanceRefKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
  InstanceKlass::oop_oop_iterate_reverse<T>(obj, closure);

  oop_oop_iterate_ref_processing<T>(obj, closure);
}

template <typename T, class OopClosureType>
void InstanceRefKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
  InstanceKlass::oop_oop_iterate_bounded<T>(obj, closure, mr);

  oop_oop_iterate_ref_processing_bounded<T>(obj, closure, mr);
}

#ifdef ASSERT
template <typename T>
void InstanceRefKlass::trace_reference_gc(const char *s, oop obj) {
  struct Stream : public LogStream {
    Stream() : LogStream(LogTarget(Trace, gc, ref)()) {}
    void print_contents_cr(oop* addr)       { print_cr(PTR_FORMAT,   *(uintptr_t*)addr); }
    void print_contents_cr(narrowOop* addr) { print_cr(UINT32_FORMAT_X_0, *(uint32_t*)addr); }
  } stream;

  if (stream.is_enabled()) {
    T* referent_addr   = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
    T* discovered_addr = (T*) java_lang_ref_Reference::discovered_addr_raw(obj);

    stream.print_cr("InstanceRefKlass %s for obj " PTR_FORMAT, s, p2i(obj));
    stream.print("     referent_addr/* " PTR_FORMAT " / ", p2i(referent_addr));
    stream.print_contents_cr(referent_addr);
    stream.print("     discovered_addr/* " PTR_FORMAT " / ", p2i(discovered_addr));
    stream.print_contents_cr(discovered_addr);
  }
}
#endif

#endif // SHARE_OOPS_INSTANCEREFKLASS_INLINE_HPP