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

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
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#ifndef SHARE_OOPS_OOPHANDLE_INLINE_HPP
#define SHARE_OOPS_OOPHANDLE_INLINE_HPP

#include "oops/oopHandle.hpp"

#include "oops/access.inline.hpp"
#include "gc/shared/oopStorage.inline.hpp"

inline oop OopHandle::resolve() const {
  if (_obj == nullptr) {
    return (oop) nullptr;
  } else {
    oop oop = NativeAccess<>::oop_load(_obj);
    assert(oopDesc::is_oop_or_null(oop), "Should be oop: " PTR_FORMAT, p2i(oop));
    return oop;
  }
}

inline oop OopHandle::peek() const {
  if (_obj == nullptr) {
    return (oop) nullptr;
  } else {
    oop obj = NativeAccess<AS_NO_KEEPALIVE>::oop_load(_obj);
    assert(oopDesc::is_oop_or_null(obj), "Should be oop: " PTR_FORMAT, p2i(obj));
    return obj;
  }
}

inline OopHandle::OopHandle(OopStorage* storage, oop obj) :
    _obj(storage->allocate()) {
  if (_obj == nullptr) {
    vm_exit_out_of_memory(sizeof(oop), OOM_MALLOC_ERROR,
                          "Cannot create oop handle");
  }
  assert(oopDesc::is_oop_or_null(obj), "Should be oop: " PTR_FORMAT, p2i(obj));
  NativeAccess<>::oop_store(_obj, obj);
}

inline void OopHandle::release(OopStorage* storage) {
  if (_obj != nullptr) {
    // Clear the OopHandle first
    NativeAccess<>::oop_store(_obj, nullptr);
    storage->release(_obj);
    _obj = nullptr;
  }
}

inline void OopHandle::replace(oop obj) {
  assert(!is_empty(), "Must not use replace on empty handle");
  assert(oopDesc::is_oop_or_null(obj), "Should be oop: " PTR_FORMAT, p2i(obj));
  NativeAccess<>::oop_store(_obj, obj);
}

inline oop OopHandle::xchg(oop new_value) {
  assert(!is_empty(), "Must not use xchg on empty handle");
  assert(oopDesc::is_oop_or_null(new_value), "Should be oop: " PTR_FORMAT, p2i(new_value));
  oop obj = NativeAccess<MO_SEQ_CST>::oop_atomic_xchg(_obj, new_value);
  assert(oopDesc::is_oop_or_null(obj), "Should be oop: " PTR_FORMAT, p2i(obj));
  return obj;
}

inline oop OopHandle::cmpxchg(oop old_value, oop new_value) {
  assert(!is_empty(), "Must not use cmpxchg on empty handle");
  assert(oopDesc::is_oop_or_null(new_value), "Should be oop: " PTR_FORMAT, p2i(new_value));
  oop obj = NativeAccess<MO_SEQ_CST>::oop_atomic_cmpxchg(_obj, old_value, new_value);
  assert(oopDesc::is_oop_or_null(obj), "Should be oop: " PTR_FORMAT, p2i(obj));
  return obj;
}

#endif // SHARE_OOPS_OOPHANDLE_INLINE_HPP