/*

 * Copyright (c) 2018, 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/nmethod.hpp"

#include "gc/z/zBarrierSetNMethod.hpp"

#include "gc/z/zGlobals.hpp"

#include "gc/z/zLock.inline.hpp"

#include "gc/z/zOopClosures.hpp"

#include "gc/z/zNMethod.hpp"

#include "gc/z/zThreadLocalData.hpp"

#include "logging/log.hpp"

bool ZBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {

  ZLocker<ZReentrantLock> locker(ZNMethod::lock_for_nmethod(nm));

  log_trace(nmethod, barrier)("Entered critical zone for %p", nm);

  if (!is_armed(nm)) {

    // Some other thread got here first and healed the oops

    // and disarmed the nmethod.

    return true;

  }

  if (nm->is_unloading()) {

    // We don't need to take the lock when unlinking nmethods from

    // the Method, because it is only concurrently unlinked by

    // the entry barrier, which acquires the per nmethod lock.

    nm->unlink_from_method();

    // We can end up calling nmethods that are unloading

    // since we clear compiled ICs lazily. Returning false

    // will re-resovle the call and update the compiled IC.

    return false;

  }

  // Heal oops and disarm

  ZNMethodOopClosure cl;

  ZNMethod::nmethod_oops_do(nm, &cl);

  disarm(nm);

  return true;

}

int ZBarrierSetNMethod::disarmed_value() const {

  // We override the default BarrierSetNMethod::disarmed_value() since

  // this can be called by GC threads, which doesn't keep an up to date

  // address_bad_mask.

  const uintptr_t disarmed_addr = ((uintptr_t)&ZAddressBadMask) + ZNMethodDisarmedOffset;

  return *((int*)disarmed_addr);

}

ByteSize ZBarrierSetNMethod::thread_disarmed_offset() const {

  return ZThreadLocalData::nmethod_disarmed_offset();

}