1 /*
2 * Copyright (c) 2001, 2014, 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
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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 class SATBMarkQueueSet;
33
34 // A ptrQueue whose elements are "oops", pointers to object heads.
35 class ObjPtrQueue: public PtrQueue {
36 friend class Threads;
37 friend class SATBMarkQueueSet;
38 friend class G1RemarkThreadsClosure;
39
40 private:
41 // Filter out unwanted entries from the buffer.
42 void filter();
43
44 // Apply the closure to all elements.
45 void apply_closure(ObjectClosure* cl);
46
47 // Apply the closure to all elements and empty the buffer;
48 void apply_closure_and_empty(ObjectClosure* cl);
49
50 // Apply the closure to all elements of "buf", down to "index" (inclusive.)
51 static void apply_closure_to_buffer(ObjectClosure* cl,
52 void** buf, size_t index, size_t sz);
53
54 public:
55 ObjPtrQueue(PtrQueueSet* qset, bool perm = false) :
56 // SATB queues are only active during marking cycles. We create
57 // them with their active field set to false. If a thread is
58 // created during a cycle and its SATB queue needs to be activated
59 // before the thread starts running, we'll need to set its active
60 // field to true. This is done in JavaThread::initialize_queues().
61 PtrQueue(qset, perm, false /* active */) { }
62
63 // Process queue entries and free resources.
64 void flush();
65
66 // Overrides PtrQueue::should_enqueue_buffer(). See the method's
67 // definition for more information.
68 virtual bool should_enqueue_buffer();
69
70 #ifndef PRODUCT
71 // Helpful for debugging
72 void print(const char* name);
73 static void print(const char* name, void** buf, size_t index, size_t sz);
74 #endif // PRODUCT
75
76 void verify_oops_in_buffer() NOT_DEBUG_RETURN;
77 };
78
79 class SATBMarkQueueSet: public PtrQueueSet {
80 ObjectClosure* _closure;
81 ObjectClosure** _par_closures; // One per ParGCThread.
82
83 ObjPtrQueue _shared_satb_queue;
84
85 // Utility function to support sequential and parallel versions. If
86 // "par" is true, then "worker" is the par thread id; if "false", worker
87 // is ignored.
88 bool apply_closure_to_completed_buffer_work(bool par, uint worker);
89
90 #ifdef ASSERT
91 void dump_active_states(bool expected_active);
92 void verify_active_states(bool expected_active);
93 #endif // ASSERT
94
95 public:
96 SATBMarkQueueSet();
97
98 void initialize(Monitor* cbl_mon, Mutex* fl_lock,
99 int process_completed_threshold,
100 Mutex* lock);
101
102 static void handle_zero_index_for_thread(JavaThread* t);
103
104 // Apply "set_active(active)" to all SATB queues in the set. It should be
105 // called only with the world stopped. The method will assert that the
106 // SATB queues of all threads it visits, as well as the SATB queue
107 // set itself, has an active value same as expected_active.
108 void set_active_all_threads(bool active, bool expected_active);
109
110 // Filter all the currently-active SATB buffers.
111 void filter_thread_buffers();
112
113 // Register "blk" as "the closure" for all queues. Only one such closure
114 // is allowed. The "apply_closure_to_completed_buffer" method will apply
115 // this closure to a completed buffer, and "iterate_closure_all_threads"
116 // applies it to partially-filled buffers (the latter should only be done
117 // with the world stopped).
118 void set_closure(ObjectClosure* closure);
119 // Set the parallel closures: pointer is an array of pointers to
120 // closures, one for each parallel GC thread.
121 void set_par_closure(int i, ObjectClosure* closure);
122
123 // If there exists some completed buffer, pop it, then apply the
124 // registered closure to all its elements, and return true. If no
125 // completed buffers exist, return false.
126 bool apply_closure_to_completed_buffer() {
127 return apply_closure_to_completed_buffer_work(false, 0);
128 }
129 // Parallel version of the above.
130 bool par_apply_closure_to_completed_buffer(uint worker) {
131 return apply_closure_to_completed_buffer_work(true, worker);
132 }
133
134 // Apply the given closure on enqueued and currently-active buffers
135 // respectively. Both methods are read-only, i.e., they do not
136 // modify any of the buffers.
137 void iterate_completed_buffers_read_only(ObjectClosure* cl);
138 void iterate_thread_buffers_read_only(ObjectClosure* cl);
139
140 #ifndef PRODUCT
141 // Helpful for debugging
142 void print_all(const char* msg);
143 #endif // PRODUCT
144
145 ObjPtrQueue* shared_satb_queue() { return &_shared_satb_queue; }
146
147 // If a marking is being abandoned, reset any unprocessed log buffers.
148 void abandon_partial_marking();
149 };
150
151 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_SATBQUEUE_HPP