1 /* 2 * Copyright 1997-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 // An NmethodSweeper is an incremental cleaner for: 26 // - cleanup inline caches 27 // - reclamation of unreferences zombie nmethods 28 // 29 30 class NMethodSweeper : public AllStatic { 31 static long _traversals; // Stack traversal count 32 static CodeBlob* _current; // Current nmethod 33 static int _seen; // Nof. nmethod we have currently processed in current pass of CodeCache 34 static int _invocations; // No. of invocations left until we are completed with this pass 35 36 static bool _rescan; // Indicates that we should do a full rescan of the 37 // of the code cache looking for work to do. 38 static int _locked_seen; // Number of locked nmethods encountered during the scan 39 static int _not_entrant_seen_on_stack; // Number of not entrant nmethod were are still on stack 40 41 42 static void process_nmethod(nmethod *nm); 43 public: 44 static long traversal_count() { return _traversals; } 45 46 static void sweep(); // Invoked at the end of each safepoint 47 48 static void notify(nmethod* nm) { 49 // Perform a full scan of the code cache from the beginning. No 50 // need to synchronize the setting of this flag since it only 51 // changes to false at safepoint so we can never overwrite it with false. 52 _rescan = true; 53 } 54 };