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
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  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_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) = 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.
  53   void flush() { flush_impl(); }
  54 
  55   // Apply the closure to all elements, and reset the index to make the
  56   // buffer empty.  If a closure application returns "false", return
  57   // "false" immediately, halting the iteration.  If "consume" is true,
  58   // deletes processed entries from logs.
  59   bool apply_closure(CardTableEntryClosure* cl,
  60                      bool consume = true,
  61                      uint worker_i = 0);
  62 
  63   // Apply the closure to all elements of "buf", down to "index"
  64   // (inclusive.)  If returns "false", then a closure application returned
  65   // "false", and we return immediately.  If "consume" is true, entries are
  66   // set to NULL as they are processed, so they will not be processed again
  67   // later.
  68   static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
  69                                       void** buf, size_t index, size_t sz,
  70                                       bool consume = true,
  71                                       uint worker_i = 0);
  72   void **get_buf() { return _buf;}
  73   size_t get_index() { return _index;}
  74   void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
  75 
  76   // Compiler support.
  77   static ByteSize byte_offset_of_index() {
  78     return PtrQueue::byte_offset_of_index<DirtyCardQueue>();
  79   }
  80   using PtrQueue::byte_width_of_index;
  81 
  82   static ByteSize byte_offset_of_buf() {
  83     return PtrQueue::byte_offset_of_buf<DirtyCardQueue>();
  84   }
  85   using PtrQueue::byte_width_of_buf;
  86 
  87 };
  88 
  89 
  90 
  91 class DirtyCardQueueSet: public PtrQueueSet {
  92   // The closure used in mut_process_buffer().
  93   CardTableEntryClosure* _mut_process_closure;
  94 
  95   DirtyCardQueue _shared_dirty_card_queue;
  96 
  97   // Override.
  98   bool mut_process_buffer(void** buf);
  99 
 100   // Protected by the _cbl_mon.
 101   FreeIdSet* _free_ids;
 102 
 103   // The number of completed buffers processed by mutator and rs thread,
 104   // respectively.
 105   jint _processed_buffers_mut;
 106   jint _processed_buffers_rs_thread;
 107 
 108   // Current buffer node used for parallel iteration.
 109   BufferNode* volatile _cur_par_buffer_node;
 110 public:
 111   DirtyCardQueueSet(bool notify_when_complete = true);
 112 
 113   void initialize(CardTableEntryClosure* cl,
 114                   Monitor* cbl_mon,
 115                   Mutex* fl_lock,
 116                   size_t process_completed_threshold,
 117                   size_t max_completed_queue,
 118                   Mutex* lock,
 119                   DirtyCardQueueSet* fl_owner,
 120                   bool init_free_ids = false);
 121 
 122   // The number of parallel ids that can be claimed to allow collector or
 123   // mutator threads to do card-processing work.
 124   static uint num_par_ids();
 125 
 126   static void handle_zero_index_for_thread(JavaThread* t);
 127 
 128   // If there exists some completed buffer, pop it, then apply the
 129   // specified closure to all its elements, nulling out those elements
 130   // processed.  If all elements are processed, returns "true".  If no
 131   // completed buffers exist, returns false.  If a completed buffer exists,
 132   // but is only partially completed before a "yield" happens, the
 133   // partially completed buffer (with its processed elements set to NULL)
 134   // is returned to the completed buffer set, and this call returns false.
 135   bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
 136                                          uint worker_i,
 137                                          size_t stop_at,
 138                                          bool during_pause);
 139 
 140   BufferNode* get_completed_buffer(size_t stop_at);
 141 
 142   // Applies the current closure to all completed buffers,
 143   // non-consumptively.
 144   void apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
 145 
 146   void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
 147   // Applies the current closure to all completed buffers, non-consumptively.
 148   // Parallel version.
 149   void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
 150 
 151   DirtyCardQueue* shared_dirty_card_queue() {
 152     return &_shared_dirty_card_queue;
 153   }
 154 
 155   // Deallocate any completed log buffers
 156   void clear();
 157 
 158   // If a full collection is happening, reset partial logs, and ignore
 159   // completed ones: the full collection will make them all irrelevant.
 160   void abandon_logs();
 161 
 162   // If any threads have partial logs, add them to the global list of logs.
 163   void concatenate_logs();
 164   void clear_n_completed_buffers() { _n_completed_buffers = 0;}
 165 
 166   jint processed_buffers_mut() {
 167     return _processed_buffers_mut;
 168   }
 169   jint processed_buffers_rs_thread() {
 170     return _processed_buffers_rs_thread;
 171   }
 172 
 173 };
 174 
 175 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP
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