6711316: Open source the Garbage-First garbage collector

First mercurial integration of the code for the Garbage-First garbage collector.

Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

hotspot/src/share/vm/gc_implementation/g1/dirtyCardQueue.hpp

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+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+class FreeIdSet;
+
+// A closure class for processing card table entries.  Note that we don't
+// require these closure objects to be stack-allocated.
+class CardTableEntryClosure: public CHeapObj {
+public:
+  // Process the card whose card table entry is "card_ptr".  If returns
+  // "false", terminate the iteration early.
+  virtual bool do_card_ptr(jbyte* card_ptr, int worker_i = 0) = 0;
+};
+
+// A ptrQueue whose elements are "oops", pointers to object heads.
+class DirtyCardQueue: public PtrQueue {
+public:
+  DirtyCardQueue(PtrQueueSet* qset_, bool perm = false) :
+    PtrQueue(qset_, perm)
+  {
+    // Dirty card queues are always active.
+    _active = true;
+  }
+  // Apply the closure to all elements, and reset the index to make the
+  // buffer empty.  If a closure application returns "false", return
+  // "false" immediately, halting the iteration.  If "consume" is true,
+  // deletes processed entries from logs.
+  bool apply_closure(CardTableEntryClosure* cl,
+                     bool consume = true,
+                     size_t worker_i = 0);
+
+  // Apply the closure to all elements of "buf", down to "index"
+  // (inclusive.)  If returns "false", then a closure application returned
+  // "false", and we return immediately.  If "consume" is true, entries are
+  // set to NULL as they are processed, so they will not be processed again
+  // later.
+  static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
+                                      void** buf, size_t index, size_t sz,
+                                      bool consume = true,
+                                      int worker_i = 0);
+  void **get_buf() { return _buf;}
+  void set_buf(void **buf) {_buf = buf;}
+  size_t get_index() { return _index;}
+  void reinitialize() { _buf = 0; _sz = 0; _index = 0;}
+};
+
+
+
+class DirtyCardQueueSet: public PtrQueueSet {
+  CardTableEntryClosure* _closure;
+
+  DirtyCardQueue _shared_dirty_card_queue;
+
+  // Override.
+  bool mut_process_buffer(void** buf);
+
+  // Protected by the _cbl_mon.
+  FreeIdSet* _free_ids;
+
+  // The number of completed buffers processed by mutator and rs thread,
+  // respectively.
+  jint _processed_buffers_mut;
+  jint _processed_buffers_rs_thread;
+
+public:
+  DirtyCardQueueSet();
+
+  void initialize(Monitor* cbl_mon, Mutex* fl_lock,
+                  int max_completed_queue = 0,
+                  Mutex* lock = NULL);
+
+  // The number of parallel ids that can be claimed to allow collector or
+  // mutator threads to do card-processing work.
+  static size_t num_par_ids();
+
+  static void handle_zero_index_for_thread(JavaThread* t);
+
+  // Register "blk" as "the closure" for all queues.  Only one such closure
+  // is allowed.  The "apply_closure_to_completed_buffer" method will apply
+  // this closure to a completed buffer, and "iterate_closure_all_threads"
+  // applies it to partially-filled buffers (the latter should only be done
+  // with the world stopped).
+  void set_closure(CardTableEntryClosure* closure);
+
+  // If there is a registered closure for buffers, apply it to all entries
+  // in all currently-active buffers.  This should only be applied at a
+  // safepoint.  (Currently must not be called in parallel; this should
+  // change in the future.)  If "consume" is true, processed entries are
+  // discarded.
+  void iterate_closure_all_threads(bool consume = true,
+                                   size_t worker_i = 0);
+
+  // If there exists some completed buffer, pop it, then apply the
+  // registered closure to all its elements, nulling out those elements
+  // processed.  If all elements are processed, returns "true".  If no
+  // completed buffers exist, returns false.  If a completed buffer exists,
+  // but is only partially completed before a "yield" happens, the
+  // partially completed buffer (with its processed elements set to NULL)
+  // is returned to the completed buffer set, and this call returns false.
+  bool apply_closure_to_completed_buffer(int worker_i = 0,
+                                         int stop_at = 0,
+                                         bool with_CAS = false);
+  bool apply_closure_to_completed_buffer_helper(int worker_i,
+                                                CompletedBufferNode* nd);
+
+  CompletedBufferNode* get_completed_buffer_CAS();
+  CompletedBufferNode* get_completed_buffer_lock(int stop_at);
+  // Applies the current closure to all completed buffers,
+  // non-consumptively.
+  void apply_closure_to_all_completed_buffers();
+
+  DirtyCardQueue* shared_dirty_card_queue() {
+    return &_shared_dirty_card_queue;
+  }
+
+  // If a full collection is happening, reset partial logs, and ignore
+  // completed ones: the full collection will make them all irrelevant.
+  void abandon_logs();
+
+  // If any threads have partial logs, add them to the global list of logs.
+  void concatenate_logs();
+  void clear_n_completed_buffers() { _n_completed_buffers = 0;}
+
+  jint processed_buffers_mut() {
+    return _processed_buffers_mut;
+  }
+  jint processed_buffers_rs_thread() {
+    return _processed_buffers_rs_thread;
+  }
+
+};