/*

 * Copyright (c) 2018, 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_RUNTIME_JNIHANDLES_INLINE_HPP

#define SHARE_RUNTIME_JNIHANDLES_INLINE_HPP

#include "oops/oop.hpp"

#include "runtime/jniHandles.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

inline bool JNIHandles::is_jweak(jobject handle) {

  STATIC_ASSERT(weak_tag_size == 1);

  STATIC_ASSERT(weak_tag_value == 1);

  return (reinterpret_cast<uintptr_t>(handle) & weak_tag_mask) != 0;

}

inline oop& JNIHandles::jobject_ref(jobject handle) {

  assert(!is_jweak(handle), "precondition");

  return *reinterpret_cast<oop*>(handle);

}

inline oop& JNIHandles::jweak_ref(jobject handle) {

  assert(is_jweak(handle), "precondition");

  char* ptr = reinterpret_cast<char*>(handle) - weak_tag_value;

  return *reinterpret_cast<oop*>(ptr);

}

// external_guard is true if called from resolve_external_guard.

template<bool external_guard>

inline oop JNIHandles::resolve_impl(jobject handle) {

  assert(handle != NULL, "precondition");

  assert(!current_thread_in_native(), "must not be in native");

  oop result;

  if (is_jweak(handle)) {       // Unlikely

    result = resolve_jweak(handle);

  } else {

    result = jobject_ref(handle);

    // Construction of jobjects canonicalize a null value into a null

    // jobject, so for non-jweak the pointee should never be null.

    assert(external_guard || result != NULL, "Invalid JNI handle");

  }

  return result;

}

inline oop JNIHandles::resolve(jobject handle) {

  oop result = NULL;

  if (handle != NULL) {

    result = resolve_impl<false /* external_guard */ >(handle);

  }

  return result;

}

inline oop JNIHandles::resolve_non_null(jobject handle) {

  assert(handle != NULL, "JNI handle should not be null");

  oop result = resolve_impl<false /* external_guard */ >(handle);

  assert(result != NULL, "NULL read from jni handle");

  return result;

}

inline void JNIHandles::destroy_local(jobject handle) {

  if (handle != NULL) {

    assert(!is_jweak(handle), "Invalid JNI local handle");

    jobject_ref(handle) = NULL;

  }

}

#endif // SHARE_RUNTIME_JNIHANDLES_INLINE_HPP