ysr@777: /*
xdono@1014:  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
ysr@777:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777:  * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777:  * have any questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
ysr@777: // There are various techniques that require threads to be able to log
ysr@777: // addresses.  For example, a generational write barrier might log
ysr@777: // the addresses of modified old-generation objects.  This type supports
ysr@777: // this operation.
ysr@777: 
ysr@777: class PtrQueueSet;
ysr@777: 
apetrusenko@984: class PtrQueue VALUE_OBJ_CLASS_SPEC {
ysr@777: 
ysr@777: protected:
ysr@777:   // The ptr queue set to which this queue belongs.
ysr@777:   PtrQueueSet* _qset;
ysr@777: 
ysr@777:   // Whether updates should be logged.
ysr@777:   bool _active;
ysr@777: 
ysr@777:   // The buffer.
ysr@777:   void** _buf;
ysr@777:   // The index at which an object was last enqueued.  Starts at "_sz"
ysr@777:   // (indicating an empty buffer) and goes towards zero.
ysr@777:   size_t _index;
ysr@777: 
ysr@777:   // The size of the buffer.
ysr@777:   size_t _sz;
ysr@777: 
ysr@777:   // If true, the queue is permanent, and doesn't need to deallocate
ysr@777:   // its buffer in the destructor (since that obtains a lock which may not
ysr@777:   // be legally locked by then.
ysr@777:   bool _perm;
ysr@777: 
ysr@777:   // If there is a lock associated with this buffer, this is that lock.
ysr@777:   Mutex* _lock;
ysr@777: 
ysr@777:   PtrQueueSet* qset() { return _qset; }
ysr@777: 
ysr@777: public:
ysr@777:   // Initialize this queue to contain a null buffer, and be part of the
ysr@777:   // given PtrQueueSet.
ysr@777:   PtrQueue(PtrQueueSet*, bool perm = false);
ysr@777:   // Release any contained resources.
iveresov@876:   void flush();
iveresov@876:   // Calls flush() when destroyed.
iveresov@876:   ~PtrQueue() { flush(); }
ysr@777: 
ysr@777:   // Associate a lock with a ptr queue.
ysr@777:   void set_lock(Mutex* lock) { _lock = lock; }
ysr@777: 
ysr@777:   void reset() { if (_buf != NULL) _index = _sz; }
ysr@777: 
ysr@777:   // Enqueues the given "obj".
ysr@777:   void enqueue(void* ptr) {
ysr@777:     if (!_active) return;
ysr@777:     else enqueue_known_active(ptr);
ysr@777:   }
ysr@777: 
ysr@777:   inline void handle_zero_index();
ysr@777:   void locking_enqueue_completed_buffer(void** buf);
ysr@777: 
ysr@777:   void enqueue_known_active(void* ptr);
ysr@777: 
ysr@777:   size_t size() {
ysr@777:     assert(_sz >= _index, "Invariant.");
ysr@777:     return _buf == NULL ? 0 : _sz - _index;
ysr@777:   }
ysr@777: 
ysr@777:   // Set the "active" property of the queue to "b".  An enqueue to an
ysr@777:   // inactive thread is a no-op.  Setting a queue to inactive resets its
ysr@777:   // log to the empty state.
ysr@777:   void set_active(bool b) {
ysr@777:     _active = b;
ysr@777:     if (!b && _buf != NULL) {
ysr@777:       _index = _sz;
ysr@777:     } else if (b && _buf != NULL) {
ysr@777:       assert(_index == _sz, "invariant: queues are empty when activated.");
ysr@777:     }
ysr@777:   }
ysr@777: 
ysr@777:   static int byte_index_to_index(int ind) {
ysr@777:     assert((ind % oopSize) == 0, "Invariant.");
ysr@777:     return ind / oopSize;
ysr@777:   }
ysr@777: 
ysr@777:   static int index_to_byte_index(int byte_ind) {
ysr@777:     return byte_ind * oopSize;
ysr@777:   }
ysr@777: 
ysr@777:   // To support compiler.
ysr@777:   static ByteSize byte_offset_of_index() {
ysr@777:     return byte_offset_of(PtrQueue, _index);
ysr@777:   }
ysr@777:   static ByteSize byte_width_of_index() { return in_ByteSize(sizeof(size_t)); }
ysr@777: 
ysr@777:   static ByteSize byte_offset_of_buf() {
ysr@777:     return byte_offset_of(PtrQueue, _buf);
ysr@777:   }
ysr@777:   static ByteSize byte_width_of_buf() { return in_ByteSize(sizeof(void*)); }
ysr@777: 
ysr@777:   static ByteSize byte_offset_of_active() {
ysr@777:     return byte_offset_of(PtrQueue, _active);
ysr@777:   }
ysr@777:   static ByteSize byte_width_of_active() { return in_ByteSize(sizeof(bool)); }
ysr@777: 
ysr@777: };
ysr@777: 
ysr@777: // A PtrQueueSet represents resources common to a set of pointer queues.
ysr@777: // In particular, the individual queues allocate buffers from this shared
ysr@777: // set, and return completed buffers to the set.
ysr@777: // All these variables are are protected by the TLOQ_CBL_mon. XXX ???
apetrusenko@984: class PtrQueueSet VALUE_OBJ_CLASS_SPEC {
ysr@777: 
ysr@777: protected:
ysr@777: 
ysr@777:   class CompletedBufferNode: public CHeapObj {
ysr@777:   public:
ysr@777:     void** buf;
ysr@777:     size_t index;
ysr@777:     CompletedBufferNode* next;
ysr@777:     CompletedBufferNode() : buf(NULL),
ysr@777:       index(0), next(NULL){ }
ysr@777:   };
ysr@777: 
ysr@777:   Monitor* _cbl_mon;  // Protects the fields below.
ysr@777:   CompletedBufferNode* _completed_buffers_head;
ysr@777:   CompletedBufferNode* _completed_buffers_tail;
ysr@777:   size_t _n_completed_buffers;
ysr@777:   size_t _process_completed_threshold;
ysr@777:   volatile bool _process_completed;
ysr@777: 
ysr@777:   // This (and the interpretation of the first element as a "next"
ysr@777:   // pointer) are protected by the TLOQ_FL_lock.
ysr@777:   Mutex* _fl_lock;
ysr@777:   void** _buf_free_list;
ysr@777:   size_t _buf_free_list_sz;
iveresov@1051:   // Queue set can share a freelist. The _fl_owner variable
iveresov@1051:   // specifies the owner. It is set to "this" by default.
iveresov@1051:   PtrQueueSet* _fl_owner;
ysr@777: 
ysr@777:   // The size of all buffers in the set.
ysr@777:   size_t _sz;
ysr@777: 
ysr@777:   bool _all_active;
ysr@777: 
ysr@777:   // If true, notify_all on _cbl_mon when the threshold is reached.
ysr@777:   bool _notify_when_complete;
ysr@777: 
ysr@777:   // Maximum number of elements allowed on completed queue: after that,
ysr@777:   // enqueuer does the work itself.  Zero indicates no maximum.
ysr@777:   int _max_completed_queue;
ysr@777: 
ysr@777:   int completed_buffers_list_length();
ysr@777:   void assert_completed_buffer_list_len_correct_locked();
ysr@777:   void assert_completed_buffer_list_len_correct();
ysr@777: 
ysr@777: protected:
ysr@777:   // A mutator thread does the the work of processing a buffer.
ysr@777:   // Returns "true" iff the work is complete (and the buffer may be
ysr@777:   // deallocated).
ysr@777:   virtual bool mut_process_buffer(void** buf) {
ysr@777:     ShouldNotReachHere();
ysr@777:     return false;
ysr@777:   }
ysr@777: 
ysr@777: public:
ysr@777:   // Create an empty ptr queue set.
ysr@777:   PtrQueueSet(bool notify_when_complete = false);
ysr@777: 
ysr@777:   // Because of init-order concerns, we can't pass these as constructor
ysr@777:   // arguments.
ysr@777:   void initialize(Monitor* cbl_mon, Mutex* fl_lock,
iveresov@1051:                   int max_completed_queue = 0,
iveresov@1051:                   PtrQueueSet *fl_owner = NULL) {
ysr@777:     _max_completed_queue = max_completed_queue;
ysr@777:     assert(cbl_mon != NULL && fl_lock != NULL, "Init order issue?");
iveresov@1051:     _cbl_mon = cbl_mon;
iveresov@1051:     _fl_lock = fl_lock;
iveresov@1051:     _fl_owner = (fl_owner != NULL) ? fl_owner : this;
ysr@777:   }
ysr@777: 
ysr@777:   // Return an empty oop array of size _sz (required to be non-zero).
ysr@777:   void** allocate_buffer();
ysr@777: 
ysr@777:   // Return an empty buffer to the free list.  The "buf" argument is
ysr@777:   // required to be a pointer to the head of an array of length "_sz".
ysr@777:   void deallocate_buffer(void** buf);
ysr@777: 
ysr@777:   // Declares that "buf" is a complete buffer.
ysr@777:   void enqueue_complete_buffer(void** buf, size_t index = 0,
ysr@777:                                bool ignore_max_completed = false);
ysr@777: 
ysr@777:   bool completed_buffers_exist_dirty() {
ysr@777:     return _n_completed_buffers > 0;
ysr@777:   }
ysr@777: 
ysr@777:   bool process_completed_buffers() { return _process_completed; }
ysr@777: 
ysr@777:   bool active() { return _all_active; }
ysr@777: 
ysr@777:   // Set the buffer size.  Should be called before any "enqueue" operation
ysr@777:   // can be called.  And should only be called once.
ysr@777:   void set_buffer_size(size_t sz);
ysr@777: 
ysr@777:   // Get the buffer size.
ysr@777:   size_t buffer_size() { return _sz; }
ysr@777: 
ysr@777:   // Set the number of completed buffers that triggers log processing.
ysr@777:   void set_process_completed_threshold(size_t sz);
ysr@777: 
ysr@777:   // Must only be called at a safe point.  Indicates that the buffer free
ysr@777:   // list size may be reduced, if that is deemed desirable.
ysr@777:   void reduce_free_list();
ysr@777: 
ysr@777:   size_t completed_buffers_num() { return _n_completed_buffers; }
iveresov@1051: 
iveresov@1051:   void merge_bufferlists(PtrQueueSet* src);
iveresov@1051:   void merge_freelists(PtrQueueSet* src);
ysr@777: };