1 /* 2 * Copyright (c) 2001, 2007, 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 25 class ReferenceProcessor; 26 27 // G1MarkSweep takes care of global mark-compact garbage collection for a 28 // G1CollectedHeap using a four-phase pointer forwarding algorithm. All 29 // generations are assumed to support marking; those that can also support 30 // compaction. 31 // 32 // Class unloading will only occur when a full gc is invoked. 33 34 35 class G1MarkSweep : AllStatic { 36 friend class VM_G1MarkSweep; 37 friend class Scavenge; 38 39 public: 40 41 static void invoke_at_safepoint(ReferenceProcessor* rp, 42 bool clear_all_softrefs); 43 44 private: 45 46 // Mark live objects 47 static void mark_sweep_phase1(bool& marked_for_deopt, 48 bool clear_all_softrefs); 49 // Calculate new addresses 50 static void mark_sweep_phase2(); 51 // Update pointers 52 static void mark_sweep_phase3(); 53 // Move objects to new positions 54 static void mark_sweep_phase4(); 55 56 static void allocate_stacks(); 57 };