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 ObjectClosure; 26 class JavaThread; 27 28 // A ptrQueue whose elements are "oops", pointers to object heads. 29 class ObjPtrQueue: public PtrQueue { 30 public: 31 ObjPtrQueue(PtrQueueSet* qset_, bool perm = false) : 32 PtrQueue(qset_, perm, qset_->is_active()) { } 33 // Apply the closure to all elements, and reset the index to make the 34 // buffer empty. 35 void apply_closure(ObjectClosure* cl); 36 37 // Apply the closure to all elements of "buf", down to "index" (inclusive.) 38 static void apply_closure_to_buffer(ObjectClosure* cl, 39 void** buf, size_t index, size_t sz); 40 41 void verify_oops_in_buffer() NOT_DEBUG_RETURN; 42 }; 43 44 45 46 class SATBMarkQueueSet: public PtrQueueSet { 47 ObjectClosure* _closure; 48 ObjectClosure** _par_closures; // One per ParGCThread. 49 50 ObjPtrQueue _shared_satb_queue; 51 52 // Utility function to support sequential and parallel versions. If 53 // "par" is true, then "worker" is the par thread id; if "false", worker 54 // is ignored. 55 bool apply_closure_to_completed_buffer_work(bool par, int worker); 56 57 #ifdef ASSERT 58 void dump_active_values(JavaThread* first, bool expected_active); 59 #endif // ASSERT 60 61 public: 62 SATBMarkQueueSet(); 63 64 void initialize(Monitor* cbl_mon, Mutex* fl_lock, 65 int process_completed_threshold, 66 Mutex* lock); 67 68 static void handle_zero_index_for_thread(JavaThread* t); 69 70 // Apply "set_active(b)" to all Java threads' SATB queues. It should be 71 // called only with the world stopped. The method will assert that the 72 // SATB queues of all threads it visits, as well as the SATB queue 73 // set itself, has an active value same as expected_active. 74 void set_active_all_threads(bool b, bool expected_active); 75 76 // Register "blk" as "the closure" for all queues. Only one such closure 77 // is allowed. The "apply_closure_to_completed_buffer" method will apply 78 // this closure to a completed buffer, and "iterate_closure_all_threads" 79 // applies it to partially-filled buffers (the latter should only be done 80 // with the world stopped). 81 void set_closure(ObjectClosure* closure); 82 // Set the parallel closures: pointer is an array of pointers to 83 // closures, one for each parallel GC thread. 84 void set_par_closure(int i, ObjectClosure* closure); 85 86 // If there is a registered closure for buffers, apply it to all entries 87 // in all currently-active buffers. This should only be applied at a 88 // safepoint. (Currently must not be called in parallel; this should 89 // change in the future.) 90 void iterate_closure_all_threads(); 91 // Parallel version of the above. 92 void par_iterate_closure_all_threads(int worker); 93 94 // If there exists some completed buffer, pop it, then apply the 95 // registered closure to all its elements, and return true. If no 96 // completed buffers exist, return false. 97 bool apply_closure_to_completed_buffer() { 98 return apply_closure_to_completed_buffer_work(false, 0); 99 } 100 // Parallel version of the above. 101 bool par_apply_closure_to_completed_buffer(int worker) { 102 return apply_closure_to_completed_buffer_work(true, worker); 103 } 104 105 ObjPtrQueue* shared_satb_queue() { return &_shared_satb_queue; } 106 107 // If a marking is being abandoned, reset any unprocessed log buffers. 108 void abandon_partial_marking(); 109 110 };