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
30ZUncommitter::ZUncommitter() :
31 _monitor(Monitor::leaf, "ZUncommitter", false, Monitor::_safepoint_check_never),
32 _stop(false) {
33 set_name("ZUncommitter");
34 create_and_start();
35}
36
37bool 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
56void 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
70void ZUncommitter::stop_service() {
71 MonitorLocker ml(&_monitor, Monitor::_no_safepoint_check_flag);
72 _stop = true;
73 ml.notify();
74}
75