jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/ptrQueue.hpp@37f87013dfd8 (annotated)

src/share/vm/gc_implementation/g1/ptrQueue.hpp@37f87013dfd8 (annotated)

src/share/vm/gc_implementation/g1/ptrQueue.hpp

Thu, 05 Jun 2008 15:57:56 -0700

author: ysr
date: Thu, 05 Jun 2008 15:57:56 -0700
changeset 777: 37f87013dfd8
child 876: da9cb4e97a5f
permissions: -rw-r--r--

6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

 /*
  * 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.
  *
  */
 // There are various techniques that require threads to be able to log
 // addresses.  For example, a generational write barrier might log
 // the addresses of modified old-generation objects.  This type supports
 // this operation.
 class PtrQueueSet;
 class PtrQueue: public CHeapObj {
 protected:
   // The ptr queue set to which this queue belongs.
   PtrQueueSet* _qset;
   // Whether updates should be logged.
   bool _active;
   // The buffer.
   void** _buf;
   // The index at which an object was last enqueued.  Starts at "_sz"
   // (indicating an empty buffer) and goes towards zero.
   size_t _index;
   // The size of the buffer.
   size_t _sz;
   // If true, the queue is permanent, and doesn't need to deallocate
   // its buffer in the destructor (since that obtains a lock which may not
   // be legally locked by then.
   bool _perm;
   // If there is a lock associated with this buffer, this is that lock.
   Mutex* _lock;
   PtrQueueSet* qset() { return _qset; }
 public:
   // Initialize this queue to contain a null buffer, and be part of the
   // given PtrQueueSet.
   PtrQueue(PtrQueueSet*, bool perm = false);
   // Release any contained resources.
   ~PtrQueue();
   // Associate a lock with a ptr queue.
   void set_lock(Mutex* lock) { _lock = lock; }
   void reset() { if (_buf != NULL) _index = _sz; }
   // Enqueues the given "obj".
   void enqueue(void* ptr) {
     if (!_active) return;
     else enqueue_known_active(ptr);
   }
   inline void handle_zero_index();
   void locking_enqueue_completed_buffer(void** buf);
   void enqueue_known_active(void* ptr);
   size_t size() {
     assert(_sz >= _index, "Invariant.");
     return _buf == NULL ? 0 : _sz - _index;
   }
   // Set the "active" property of the queue to "b".  An enqueue to an
   // inactive thread is a no-op.  Setting a queue to inactive resets its
   // log to the empty state.
   void set_active(bool b) {
     _active = b;
     if (!b && _buf != NULL) {
       _index = _sz;
     } else if (b && _buf != NULL) {
       assert(_index == _sz, "invariant: queues are empty when activated.");
     }
   }
   static int byte_index_to_index(int ind) {
     assert((ind % oopSize) == 0, "Invariant.");
     return ind / oopSize;
   }
   static int index_to_byte_index(int byte_ind) {
     return byte_ind * oopSize;
   }
   // To support compiler.
   static ByteSize byte_offset_of_index() {
     return byte_offset_of(PtrQueue, _index);
   }
   static ByteSize byte_width_of_index() { return in_ByteSize(sizeof(size_t)); }
   static ByteSize byte_offset_of_buf() {
     return byte_offset_of(PtrQueue, _buf);
   }
   static ByteSize byte_width_of_buf() { return in_ByteSize(sizeof(void*)); }
   static ByteSize byte_offset_of_active() {
     return byte_offset_of(PtrQueue, _active);
   }
   static ByteSize byte_width_of_active() { return in_ByteSize(sizeof(bool)); }
 };
 // A PtrQueueSet represents resources common to a set of pointer queues.
 // In particular, the individual queues allocate buffers from this shared
 // set, and return completed buffers to the set.
 // All these variables are are protected by the TLOQ_CBL_mon. XXX ???
 class PtrQueueSet: public CHeapObj {
 protected:
   class CompletedBufferNode: public CHeapObj {
   public:
     void** buf;
     size_t index;
     CompletedBufferNode* next;
     CompletedBufferNode() : buf(NULL),
       index(0), next(NULL){ }
   };
   Monitor* _cbl_mon;  // Protects the fields below.
   CompletedBufferNode* _completed_buffers_head;
   CompletedBufferNode* _completed_buffers_tail;
   size_t _n_completed_buffers;
   size_t _process_completed_threshold;
   volatile bool _process_completed;
   // This (and the interpretation of the first element as a "next"
   // pointer) are protected by the TLOQ_FL_lock.
   Mutex* _fl_lock;
   void** _buf_free_list;
   size_t _buf_free_list_sz;
   // The size of all buffers in the set.
   size_t _sz;
   bool _all_active;
   // If true, notify_all on _cbl_mon when the threshold is reached.
   bool _notify_when_complete;
   // Maximum number of elements allowed on completed queue: after that,
   // enqueuer does the work itself.  Zero indicates no maximum.
   int _max_completed_queue;
   int completed_buffers_list_length();
   void assert_completed_buffer_list_len_correct_locked();
   void assert_completed_buffer_list_len_correct();
 protected:
   // A mutator thread does the the work of processing a buffer.
   // Returns "true" iff the work is complete (and the buffer may be
   // deallocated).
   virtual bool mut_process_buffer(void** buf) {
     ShouldNotReachHere();
     return false;
   }
 public:
   // Create an empty ptr queue set.
   PtrQueueSet(bool notify_when_complete = false);
   // Because of init-order concerns, we can't pass these as constructor
   // arguments.
   void initialize(Monitor* cbl_mon, Mutex* fl_lock,
                   int max_completed_queue = 0) {
     _max_completed_queue = max_completed_queue;
     assert(cbl_mon != NULL && fl_lock != NULL, "Init order issue?");
     _cbl_mon = cbl_mon; _fl_lock = fl_lock;
   }
   // Return an empty oop array of size _sz (required to be non-zero).
   void** allocate_buffer();
   // Return an empty buffer to the free list.  The "buf" argument is
   // required to be a pointer to the head of an array of length "_sz".
   void deallocate_buffer(void** buf);
   // Declares that "buf" is a complete buffer.
   void enqueue_complete_buffer(void** buf, size_t index = 0,
                                bool ignore_max_completed = false);
   bool completed_buffers_exist_dirty() {
     return _n_completed_buffers > 0;
   }
   bool process_completed_buffers() { return _process_completed; }
   bool active() { return _all_active; }
   // Set the buffer size.  Should be called before any "enqueue" operation
   // can be called.  And should only be called once.
   void set_buffer_size(size_t sz);
   // Get the buffer size.
   size_t buffer_size() { return _sz; }
   // Set the number of completed buffers that triggers log processing.
   void set_process_completed_threshold(size_t sz);
   // Must only be called at a safe point.  Indicates that the buffer free
   // list size may be reduced, if that is deemed desirable.
   void reduce_free_list();
   size_t completed_buffers_num() { return _n_completed_buffers; }
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/ptrQueue.hpp@37f87013dfd8 (annotated)

src/share/vm/gc_implementation/g1/ptrQueue.hpp