1 /*
2  * Copyright (c) 2001, 2017, 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_DIRTYCARDQUEUE_HPP
26 #define SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP
27 
28 #include "gc/g1/ptrQueue.hpp"
29 #include "memory/allocation.hpp"
30 
31 class FreeIdSet;
32 class DirtyCardQueueSet;
33 
34 // A closure class for processing card table entries.  Note that we don't
35 // require these closure objects to be stack-allocated.
36 class CardTableEntryClosure: public CHeapObj<mtGC> {
37 public:
38   // Process the card whose card table entry is "card_ptr".  If returns
39   // "false", terminate the iteration early.
40   virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i) = 0;
41 };
42 
43 // A ptrQueue whose elements are "oops", pointers to object heads.
44 class DirtyCardQueue: public PtrQueue {
45 public:
46   DirtyCardQueue(DirtyCardQueueSet* qset, bool permanent = false);
47 
48   // Flush before destroying; queue may be used to capture pending work while
49   // doing something else, with auto-flush on completion.
50   ~DirtyCardQueue();
51 
52   // Process queue entries and release resources.
flush()53   void flush() { flush_impl(); }
54 
55   // Compiler support.
byte_offset_of_index()56   static ByteSize byte_offset_of_index() {
57     return PtrQueue::byte_offset_of_index<DirtyCardQueue>();
58   }
59   using PtrQueue::byte_width_of_index;
60 
byte_offset_of_buf()61   static ByteSize byte_offset_of_buf() {
62     return PtrQueue::byte_offset_of_buf<DirtyCardQueue>();
63   }
64   using PtrQueue::byte_width_of_buf;
65 
66 };
67 
68 
69 
70 class DirtyCardQueueSet: public PtrQueueSet {
71   DirtyCardQueue _shared_dirty_card_queue;
72 
73   // Apply the closure to the elements of "node" from it's index to
74   // buffer_size.  If all closure applications return true, then
75   // returns true.  Stops processing after the first closure
76   // application that returns false, and returns false from this
77   // function.  If "consume" is true, the node's index is updated to
78   // exclude the processed elements, e.g. up to the element for which
79   // the closure returned false.
80   bool apply_closure_to_buffer(CardTableEntryClosure* cl,
81                                BufferNode* node,
82                                bool consume,
83                                uint worker_i = 0);
84 
85   // If there are more than stop_at completed buffers, pop one, apply
86   // the specified closure to its active elements, and return true.
87   // Otherwise return false.
88   //
89   // A completely processed buffer is freed.  However, if a closure
90   // invocation returns false, processing is stopped and the partially
91   // processed buffer (with its index updated to exclude the processed
92   // elements, e.g. up to the element for which the closure returned
93   // false) is returned to the completed buffer set.
94   //
95   // If during_pause is true, stop_at must be zero, and the closure
96   // must never return false.
97   bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
98                                          uint worker_i,
99                                          size_t stop_at,
100                                          bool during_pause);
101 
102   bool mut_process_buffer(BufferNode* node);
103 
104   // Protected by the _cbl_mon.
105   FreeIdSet* _free_ids;
106 
107   // The number of completed buffers processed by mutator and rs thread,
108   // respectively.
109   jint _processed_buffers_mut;
110   jint _processed_buffers_rs_thread;
111 
112   // Current buffer node used for parallel iteration.
113   BufferNode* volatile _cur_par_buffer_node;
114 
115   void concatenate_log(DirtyCardQueue& dcq);
116 
117 public:
118   DirtyCardQueueSet(bool notify_when_complete = true);
119 
120   void initialize(Monitor* cbl_mon,
121                   Mutex* fl_lock,
122                   int process_completed_threshold,
123                   int max_completed_queue,
124                   Mutex* lock,
125                   DirtyCardQueueSet* fl_owner,
126                   bool init_free_ids = false);
127 
128   // The number of parallel ids that can be claimed to allow collector or
129   // mutator threads to do card-processing work.
130   static uint num_par_ids();
131 
132   static void handle_zero_index_for_thread(JavaThread* t);
133 
134   // Apply G1RefineCardConcurrentlyClosure to completed buffers until there are stop_at
135   // completed buffers remaining.
136   bool refine_completed_buffer_concurrently(uint worker_i, size_t stop_at);
137 
138   // Apply the given closure to all completed buffers. The given closure's do_card_ptr
139   // must never return false. Must only be called during GC.
140   bool apply_closure_during_gc(CardTableEntryClosure* cl, uint worker_i);
141 
142   BufferNode* get_completed_buffer(size_t stop_at);
143 
reset_for_par_iteration()144   void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
145   // Applies the current closure to all completed buffers, non-consumptively.
146   // Can be used in parallel, all callers using the iteration state initialized
147   // by reset_for_par_iteration.
148   void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
149 
shared_dirty_card_queue()150   DirtyCardQueue* shared_dirty_card_queue() {
151     return &_shared_dirty_card_queue;
152   }
153 
154   // Deallocate any completed log buffers
155   void clear();
156 
157   // If a full collection is happening, reset partial logs, and ignore
158   // completed ones: the full collection will make them all irrelevant.
159   void abandon_logs();
160 
161   // If any threads have partial logs, add them to the global list of logs.
162   void concatenate_logs();
clear_n_completed_buffers()163   void clear_n_completed_buffers() { _n_completed_buffers = 0;}
164 
processed_buffers_mut()165   jint processed_buffers_mut() {
166     return _processed_buffers_mut;
167   }
processed_buffers_rs_thread()168   jint processed_buffers_rs_thread() {
169     return _processed_buffers_rs_thread;
170   }
171 
172 };
173 
174 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP
175