1 /* 2 * Copyright (c) 2001, 2016, 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_G1_SATBMARKQUEUE_HPP 26 #define SHARE_VM_GC_G1_SATBMARKQUEUE_HPP 27 28 #include "gc/g1/ptrQueue.hpp" 29 #include "memory/allocation.hpp" 30 31 class JavaThread; 32 class SATBMarkQueueSet; 33 34 // Base class for processing the contents of a SATB buffer. 35 class SATBBufferClosure : public StackObj { 36 protected: 37 ~SATBBufferClosure() { } 38 39 public: 40 // Process the SATB entries in the designated buffer range. 41 virtual void do_buffer(void** buffer, size_t size) = 0; 42 }; 43 44 // A PtrQueue whose elements are (possibly stale) pointers to object heads. 45 class SATBMarkQueue: public PtrQueue { 46 friend class SATBMarkQueueSet; 47 48 private: 49 // Filter out unwanted entries from the buffer. 50 void filter(); 51 52 public: 53 SATBMarkQueue(SATBMarkQueueSet* qset, bool permanent = false); 54 55 // Process queue entries and free resources. 56 void flush(); 57 58 // Apply cl to the active part of the buffer. 59 // Prerequisite: Must be at a safepoint. 60 void apply_closure_and_empty(SATBBufferClosure* cl); 61 62 // Overrides PtrQueue::should_enqueue_buffer(). See the method's 63 // definition for more information. 64 virtual bool should_enqueue_buffer(); 65 66 #ifndef PRODUCT 67 // Helpful for debugging 68 void print(const char* name); 69 #endif // PRODUCT 70 71 // Compiler support. 72 static ByteSize byte_offset_of_index() { 73 return PtrQueue::byte_offset_of_index<SATBMarkQueue>(); 74 } 75 using PtrQueue::byte_width_of_index; 76 77 static ByteSize byte_offset_of_buf() { 78 return PtrQueue::byte_offset_of_buf<SATBMarkQueue>(); 79 } 80 using PtrQueue::byte_width_of_buf; 81 82 static ByteSize byte_offset_of_active() { 83 return PtrQueue::byte_offset_of_active<SATBMarkQueue>(); 84 } 85 using PtrQueue::byte_width_of_active; 86 87 }; 88 89 class SATBMarkQueueSet: public PtrQueueSet { 90 SATBMarkQueue _shared_satb_queue; 91 92 #ifdef ASSERT 93 void dump_active_states(bool expected_active); 94 void verify_active_states(bool expected_active); 95 #endif // ASSERT 96 97 public: 98 SATBMarkQueueSet(); 99 100 void initialize(Monitor* cbl_mon, Mutex* fl_lock, 101 int process_completed_threshold, 102 Mutex* lock); 103 104 static void handle_zero_index_for_thread(JavaThread* t); 105 106 // Apply "set_active(active)" to all SATB queues in the set. It should be 107 // called only with the world stopped. The method will assert that the 108 // SATB queues of all threads it visits, as well as the SATB queue 109 // set itself, has an active value same as expected_active. 110 void set_active_all_threads(bool active, bool expected_active); 111 112 // Filter all the currently-active SATB buffers. 113 void filter_thread_buffers(); 114 115 // If there exists some completed buffer, pop and process it, and 116 // return true. Otherwise return false. Processing a buffer 117 // consists of applying the closure to the active range of the 118 // buffer; the leading entries may be excluded due to filtering. 119 bool apply_closure_to_completed_buffer(SATBBufferClosure* cl); 120 121 #ifndef PRODUCT 122 // Helpful for debugging 123 void print_all(const char* msg); 124 #endif // PRODUCT 125 126 SATBMarkQueue* shared_satb_queue() { return &_shared_satb_queue; } 127 128 // If a marking is being abandoned, reset any unprocessed log buffers. 129 void abandon_partial_marking(); 130 }; 131 132 #endif // SHARE_VM_GC_G1_SATBMARKQUEUE_HPP