1/*
2 * Copyright (c) 2015, 2017, 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/zCPU.hpp"
26#include "logging/log.hpp"
27#include "memory/padded.inline.hpp"
28#include "runtime/os.hpp"
29#include "runtime/thread.inline.hpp"
30#include "utilities/debug.hpp"
31
32#define ZCPU_UNKNOWN_AFFINITY (Thread*)-1;
33#define ZCPU_UNKNOWN_SELF (Thread*)-2;
34
35PaddedEnd<ZCPU::ZCPUAffinity>* ZCPU::_affinity = NULL;
36__thread Thread* ZCPU::_self = ZCPU_UNKNOWN_SELF;
37__thread uint32_t ZCPU::_cpu = 0;
38
39void ZCPU::initialize() {
40 assert(_affinity == NULL, "Already initialized");
41 const uint32_t ncpus = count();
42
43 _affinity = PaddedArray<ZCPUAffinity, mtGC>::create_unfreeable(ncpus);
44
45 for (uint32_t i = 0; i < ncpus; i++) {
46 _affinity[i]._thread = ZCPU_UNKNOWN_AFFINITY;
47 }
48
49 log_info(gc, init)("CPUs: %u total, %u available",
50 os::processor_count(),
51 os::initial_active_processor_count());
52}
53
54uint32_t ZCPU::count() {
55 return os::processor_count();
56}
57
58uint32_t ZCPU::id() {
59 assert(_affinity != NULL, "Not initialized");
60
61 // Fast path
62 if (_affinity[_cpu]._thread == _self) {
63 return _cpu;
64 }
65
66 // Slow path
67 _self = Thread::current();
68 _cpu = os::processor_id();
69
70 // Update affinity table
71 _affinity[_cpu]._thread = _self;
72
73 return _cpu;
74}
75