/*

 * Copyright (c) 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 "gc/z/zHeap.inline.hpp"

#include "gc/z/zUncommitter.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/os.hpp"

ZUncommitter::ZUncommitter() :

    _monitor(Monitor::leaf, "ZUncommitter", false, Monitor::_safepoint_check_never),

    _stop(false) {

  set_name("ZUncommitter");

  create_and_start();

}

bool ZUncommitter::idle(uint64_t timeout) {

  // Idle for at least one second

  const uint64_t expires = os::elapsedTime() + MAX2(timeout, 1ul);

  for (;;) {

    // We might wake up spuriously from wait, so always recalculate

    // the timeout after a wakeup to see if we need to wait again.

    const uint64_t now = os::elapsedTime();

    const uint64_t remaining = expires - MIN2(expires, now);

    MonitorLocker ml(&_monitor, Monitor::_no_safepoint_check_flag);

    if (remaining > 0 && !_stop) {

      ml.wait(remaining * MILLIUNITS);

    } else {

      return !_stop;

    }

  }

}

void ZUncommitter::run_service() {

  for (;;) {

    // Try uncommit unused memory

    const uint64_t timeout = ZHeap::heap()->uncommit(ZUncommitDelay);

    log_trace(gc, heap)("Uncommit Timeout: " UINT64_FORMAT "s", timeout);

    // Idle until next attempt

    if (!idle(timeout)) {

      return;

    }

  }

}

void ZUncommitter::stop_service() {

  MonitorLocker ml(&_monitor, Monitor::_no_safepoint_check_flag);

  _stop = true;

  ml.notify();

}