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 // SATB queues are only active during marking cycles. We create 33 // them with their active field set to false. If a thread is 34 // created during a cycle and its SATB queue needs to be activated 35 // before the thread starts running, we'll need to set its active 36 // field to true. This is done in JavaThread::initialize_queues(). 37 PtrQueue(qset_, perm, false /* active */) { } 38 // Apply the closure to all elements, and reset the index to make the 39 // buffer empty. 40 void apply_closure(ObjectClosure* cl); 41 42 // Apply the closure to all elements of "buf", down to "index" (inclusive.) 43 static void apply_closure_to_buffer(ObjectClosure* cl, 44 void** buf, size_t index, size_t sz); 45 46 void verify_oops_in_buffer() NOT_DEBUG_RETURN; 47 }; 48 49 50 51 class SATBMarkQueueSet: public PtrQueueSet { 52 ObjectClosure* _closure; 53 ObjectClosure** _par_closures; // One per ParGCThread. 54 55 ObjPtrQueue _shared_satb_queue; 56 57 // Utility function to support sequential and parallel versions. If 58 // "par" is true, then "worker" is the par thread id; if "false", worker 59 // is ignored. 60 bool apply_closure_to_completed_buffer_work(bool par, int worker); 61 62 #ifdef ASSERT 63 void dump_active_values(JavaThread* first, bool expected_active); 64 #endif // ASSERT 65 66 public: 67 SATBMarkQueueSet(); 68 69 void initialize(Monitor* cbl_mon, Mutex* fl_lock, 70 int process_completed_threshold, 71 Mutex* lock); 72 73 static void handle_zero_index_for_thread(JavaThread* t); 74 75 // Apply "set_active(b)" to all Java threads' SATB queues. It should be 76 // called only with the world stopped. The method will assert that the 77 // SATB queues of all threads it visits, as well as the SATB queue 78 // set itself, has an active value same as expected_active. 79 void set_active_all_threads(bool b, bool expected_active); 80 81 // Register "blk" as "the closure" for all queues. Only one such closure 82 // is allowed. The "apply_closure_to_completed_buffer" method will apply 83 // this closure to a completed buffer, and "iterate_closure_all_threads" 84 // applies it to partially-filled buffers (the latter should only be done 85 // with the world stopped). 86 void set_closure(ObjectClosure* closure); 87 // Set the parallel closures: pointer is an array of pointers to 88 // closures, one for each parallel GC thread. 89 void set_par_closure(int i, ObjectClosure* closure); 90 91 // If there is a registered closure for buffers, apply it to all entries 92 // in all currently-active buffers. This should only be applied at a 93 // safepoint. (Currently must not be called in parallel; this should 94 // change in the future.) 95 void iterate_closure_all_threads(); 96 // Parallel version of the above. 97 void par_iterate_closure_all_threads(int worker); 98 99 // If there exists some completed buffer, pop it, then apply the 100 // registered closure to all its elements, and return true. If no 101 // completed buffers exist, return false. 102 bool apply_closure_to_completed_buffer() { 103 return apply_closure_to_completed_buffer_work(false, 0); 104 } 105 // Parallel version of the above. 106 bool par_apply_closure_to_completed_buffer(int worker) { 107 return apply_closure_to_completed_buffer_work(true, worker); 108 } 109 110 ObjPtrQueue* shared_satb_queue() { return &_shared_satb_queue; } 111 112 // If a marking is being abandoned, reset any unprocessed log buffers. 113 void abandon_partial_marking(); 114 115 };