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 35 PaddedEnd<ZCPU::ZCPUAffinity>* ZCPU::_affinity = NULL; 36 __thread Thread* ZCPU::_self = ZCPU_UNKNOWN_SELF; 37 __thread uint32_t ZCPU::_cpu = 0; 38 39 void 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 54 uint32_t ZCPU::count() { 55 return os::processor_count(); 56 } 57 58 uint32_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 }