1 /*

     2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 #include "precompiled.hpp"

    25 #include "gc/z/zHeap.inline.hpp"

    26 #include "gc/z/zUncommitter.hpp"

    27 #include "runtime/mutexLocker.hpp"

    28 #include "runtime/os.hpp"

    29 

    30 ZUncommitter::ZUncommitter() :

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

    32     _stop(false) {

    33   set_name("ZUncommitter");

    34   create_and_start();

    35 }

    36 

    37 bool ZUncommitter::idle(uint64_t timeout) {

    38   // Idle for at least one second

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

    40 

    41   for (;;) {

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

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

    44     const uint64_t now = os::elapsedTime();

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

    46 

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

    48     if (remaining > 0 && !_stop) {

    49       ml.wait(remaining * MILLIUNITS);

    50     } else {

    51       return !_stop;

    52     }

    53   }

    54 }

    55 

    56 void ZUncommitter::run_service() {

    57   for (;;) {

    58     // Try uncommit unused memory

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

    60 

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

    62 

    63     // Idle until next attempt

    64     if (!idle(timeout)) {

    65       return;

    66     }

    67   }

    68 }

    69 

    70 void ZUncommitter::stop_service() {

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

    72   _stop = true;

    73   ml.notify();

    74 }