/*
 * Copyright (c) 2012, 2016, 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
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 */


#include "precompiled.hpp"

#include "memory/metaspace/constants.hpp"
#include "memory/metaspace/commitMask.hpp"
#include "memory/metaspace/metaspaceCommon.hpp"
#include "runtime/stubRoutines.hpp"

#include "utilities/align.hpp"
#include "utilities/debug.hpp"

namespace metaspace {

#ifdef ASSERT

volatile u1 x;

void CommitMask::verify(bool slow) const {

  // Walk the whole commit mask.
  // For each 1 bit, check if the associated granule is accessible.
  // For each 0 bit, check if the associated granule is not accessible. Slow mode only.

  assert_is_aligned(_base, constants::commit_granule_bytes);
  assert_is_aligned(_word_size, constants::commit_granule_words);

  if (slow) {
    assert(CanUseSafeFetch32, "We need SafeFetch for this test.");
  }

  for (idx_t i = 0; i < size(); i ++) {
    const MetaWord* const p = _base + (i * constants::commit_granule_words);
    if (at(i)) {
      // Should be accessible. Just touch it.
      x ^= *(u1*)p;
    } else {
      // Should not be accessible.
      if (slow) {
        // Note: results may differ between platforms. On Linux, this should be true since
        // we uncommit memory by setting protection to PROT_NONE. We may have to look if
        // this works as expected on other platforms.
        assert(os::is_readable_pointer(p) == false, "Should not be accessible.");
      }
    }
  }

}

#endif // ASSERT

} // namespace metaspace