1 /* 2 * Copyright (c) 2001, 2010, 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 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_SATBQUEUE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_SATBQUEUE_HPP 27 28 #include "gc_implementation/g1/ptrQueue.hpp" 29 30 class ObjectClosure; 31 class JavaThread; 32 33 // A ptrQueue whose elements are "oops", pointers to object heads. 34 class ObjPtrQueue: public PtrQueue { 35 public: 36 ObjPtrQueue(PtrQueueSet* qset_, bool perm = false) : 37 // SATB queues are only active during marking cycles. We create 38 // them with their active field set to false. If a thread is 39 // created during a cycle and its SATB queue needs to be activated 40 // before the thread starts running, we'll need to set its active 41 // field to true. This is done in JavaThread::initialize_queues(). 42 PtrQueue(qset_, perm, false /* active */) { } 43 // Apply the closure to all elements, and reset the index to make the 44 // buffer empty. 45 void apply_closure(ObjectClosure* cl); 46 47 // Apply the closure to all elements of "buf", down to "index" (inclusive.) 48 static void apply_closure_to_buffer(ObjectClosure* cl, 49 void** buf, size_t index, size_t sz); 50 51 void verify_oops_in_buffer() NOT_DEBUG_RETURN; 52 }; 53 54 55 56 class SATBMarkQueueSet: public PtrQueueSet { 57 ObjectClosure* _closure; 58 ObjectClosure** _par_closures; // One per ParGCThread. 59 60 ObjPtrQueue _shared_satb_queue; 61 62 // Utility function to support sequential and parallel versions. If 63 // "par" is true, then "worker" is the par thread id; if "false", worker 64 // is ignored. 65 bool apply_closure_to_completed_buffer_work(bool par, int worker); 66 67 #ifdef ASSERT 68 void dump_active_values(JavaThread* first, bool expected_active); 69 #endif // ASSERT 70 71 public: 72 SATBMarkQueueSet(); 73 74 void initialize(Monitor* cbl_mon, Mutex* fl_lock, 75 int process_completed_threshold, 76 Mutex* lock); 77 78 static void handle_zero_index_for_thread(JavaThread* t); 79 80 // Apply "set_active(b)" to all Java threads' SATB queues. It should be 81 // called only with the world stopped. The method will assert that the 82 // SATB queues of all threads it visits, as well as the SATB queue 83 // set itself, has an active value same as expected_active. 84 void set_active_all_threads(bool b, bool expected_active); 85 86 // Register "blk" as "the closure" for all queues. Only one such closure 87 // is allowed. The "apply_closure_to_completed_buffer" method will apply 88 // this closure to a completed buffer, and "iterate_closure_all_threads" 89 // applies it to partially-filled buffers (the latter should only be done 90 // with the world stopped). 91 void set_closure(ObjectClosure* closure); 92 // Set the parallel closures: pointer is an array of pointers to 93 // closures, one for each parallel GC thread. 94 void set_par_closure(int i, ObjectClosure* closure); 95 96 // If there is a registered closure for buffers, apply it to all entries 97 // in all currently-active buffers. This should only be applied at a 98 // safepoint. (Currently must not be called in parallel; this should 99 // change in the future.) 100 void iterate_closure_all_threads(); 101 // Parallel version of the above. 102 void par_iterate_closure_all_threads(int worker); 103 104 // If there exists some completed buffer, pop it, then apply the 105 // registered closure to all its elements, and return true. If no 106 // completed buffers exist, return false. 107 bool apply_closure_to_completed_buffer() { 108 return apply_closure_to_completed_buffer_work(false, 0); 109 } 110 // Parallel version of the above. 111 bool par_apply_closure_to_completed_buffer(int worker) { 112 return apply_closure_to_completed_buffer_work(true, worker); 113 } 114 115 ObjPtrQueue* shared_satb_queue() { return &_shared_satb_queue; } 116 117 // If a marking is being abandoned, reset any unprocessed log buffers. 118 void abandon_partial_marking(); 119 120 }; 121 122 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_SATBQUEUE_HPP