1 /* 2 * Copyright (c) 2017, 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/zNMethodTableEntry.hpp" 26 #include "gc/z/zNMethodTableIteration.hpp" 27 #include "memory/iterator.hpp" 28 #include "runtime/atomic.hpp" 29 #include "utilities/debug.hpp" 30 #include "utilities/globalDefinitions.hpp" 31 32 ZNMethodTableIteration::ZNMethodTableIteration() : 33 _table(NULL), 34 _size(0), 35 _claimed(0) {} 36 37 bool ZNMethodTableIteration::in_progress() const { 38 return _table != NULL; 39 } 40 41 void ZNMethodTableIteration::nmethods_do_begin(ZNMethodTableEntry* table, size_t size) { 42 assert(!in_progress(), "precondition"); 43 44 _table = table; 45 _size = size; 46 _claimed = 0; 47 } 48 49 void ZNMethodTableIteration::nmethods_do_end() { 50 assert(_claimed >= _size, "Failed to claim all table entries"); 51 52 // Finish iteration 53 _table = NULL; 54 } 55 56 void ZNMethodTableIteration::nmethods_do(NMethodClosure* cl) { 57 for (;;) { 58 // Claim table partition. Each partition is currently sized to span 59 // two cache lines. This number is just a guess, but seems to work well. 60 const size_t partition_size = (ZCacheLineSize * 2) / sizeof(ZNMethodTableEntry); 61 const size_t partition_start = MIN2(Atomic::add(partition_size, &_claimed) - partition_size, _size); 62 const size_t partition_end = MIN2(partition_start + partition_size, _size); 63 if (partition_start == partition_end) { 64 // End of table 65 break; 66 } 67 68 // Process table partition 69 for (size_t i = partition_start; i < partition_end; i++) { 70 const ZNMethodTableEntry entry = _table[i]; 71 if (entry.registered()) { 72 cl->do_nmethod(entry.method()); 73 } 74 } 75 } 76 }