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

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

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

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.
  *
  */
 # include "incls/_precompiled.incl"
 # include "incls/_ptrQueue.cpp.incl"
 PtrQueue::PtrQueue(PtrQueueSet* qset_, bool perm) :
   _qset(qset_), _buf(NULL), _index(0), _active(false),
   _perm(perm), _lock(NULL)
 {}
 PtrQueue::~PtrQueue() {
   if (!_perm && _buf != NULL) {
     if (_index == _sz) {
       // No work to do.
       qset()->deallocate_buffer(_buf);
     } else {
       // We must NULL out the unused entries, then enqueue.
       for (size_t i = 0; i < _index; i += oopSize) {
         _buf[byte_index_to_index((int)i)] = NULL;
       }
       qset()->enqueue_complete_buffer(_buf);
       _buf = NULL;
     }
   }
 }
 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;
 }
 void PtrQueue::enqueue_known_active(void* ptr) {
   assert(0 <= _index && _index <= _sz, "Invariant.");
   assert(_index == 0 || _buf != NULL, "invariant");
   while (_index == 0) {
     handle_zero_index();
   }
   assert(_index > 0, "postcondition");
   _index -= oopSize;
   _buf[byte_index_to_index((int)_index)] = ptr;
   assert(0 <= _index && _index <= _sz, "Invariant.");
 }
 void PtrQueue::locking_enqueue_completed_buffer(void** buf) {
   assert(_lock->owned_by_self(), "Required.");
   _lock->unlock();
   qset()->enqueue_complete_buffer(buf);
   // We must relock only because the caller will unlock, for the normal
   // case.
   _lock->lock_without_safepoint_check();
 }
 PtrQueueSet::PtrQueueSet(bool notify_when_complete) :
   _max_completed_queue(0),
   _cbl_mon(NULL), _fl_lock(NULL),
   _notify_when_complete(notify_when_complete),
   _sz(0),
   _completed_buffers_head(NULL),
   _completed_buffers_tail(NULL),
   _n_completed_buffers(0),
   _process_completed_threshold(0), _process_completed(false),
   _buf_free_list(NULL), _buf_free_list_sz(0)
 {}
 void** PtrQueueSet::allocate_buffer() {
   assert(_sz > 0, "Didn't set a buffer size.");
   MutexLockerEx x(_fl_lock, Mutex::_no_safepoint_check_flag);
   if (_buf_free_list != NULL) {
     void** res = _buf_free_list;
     _buf_free_list = (void**)_buf_free_list[0];
     _buf_free_list_sz--;
     // Just override the next pointer with NULL, just in case we scan this part
     // of the buffer.
     res[0] = NULL;
     return res;
   } else {
     return NEW_C_HEAP_ARRAY(void*, _sz);
   }
 }
 void PtrQueueSet::deallocate_buffer(void** buf) {
   assert(_sz > 0, "Didn't set a buffer size.");
   MutexLockerEx x(_fl_lock, Mutex::_no_safepoint_check_flag);
   buf[0] = (void*)_buf_free_list;
   _buf_free_list = buf;
   _buf_free_list_sz++;
 }
 void PtrQueueSet::reduce_free_list() {
   // For now we'll adopt the strategy of deleting half.
   MutexLockerEx x(_fl_lock, Mutex::_no_safepoint_check_flag);
   size_t n = _buf_free_list_sz / 2;
   while (n > 0) {
     assert(_buf_free_list != NULL, "_buf_free_list_sz must be wrong.");
     void** head = _buf_free_list;
     _buf_free_list = (void**)_buf_free_list[0];
     FREE_C_HEAP_ARRAY(void*,head);
     n--;
   }
 }
 void PtrQueueSet::enqueue_complete_buffer(void** buf, size_t index, bool ignore_max_completed) {
   // I use explicit locking here because there's a bailout in the middle.
   _cbl_mon->lock_without_safepoint_check();
   Thread* thread = Thread::current();
   assert( ignore_max_completed ||
           thread->is_Java_thread() ||
           SafepointSynchronize::is_at_safepoint(),
           "invariant" );
   ignore_max_completed = ignore_max_completed || !thread->is_Java_thread();
   if (!ignore_max_completed && _max_completed_queue > 0 &&
       _n_completed_buffers >= (size_t) _max_completed_queue) {
     _cbl_mon->unlock();
     bool b = mut_process_buffer(buf);
     if (b) {
       deallocate_buffer(buf);
       return;
     }
     // Otherwise, go ahead and enqueue the buffer.  Must reaquire the lock.
     _cbl_mon->lock_without_safepoint_check();
   }
   // Here we still hold the _cbl_mon.
   CompletedBufferNode* cbn = new CompletedBufferNode;
   cbn->buf = buf;
   cbn->next = NULL;
   cbn->index = index;
   if (_completed_buffers_tail == NULL) {
     assert(_completed_buffers_head == NULL, "Well-formedness");
     _completed_buffers_head = cbn;
     _completed_buffers_tail = cbn;
   } else {
     _completed_buffers_tail->next = cbn;
     _completed_buffers_tail = cbn;
   }
   _n_completed_buffers++;
   if (!_process_completed &&
       _n_completed_buffers == _process_completed_threshold) {
     _process_completed = true;
     if (_notify_when_complete)
       _cbl_mon->notify_all();
   }
   debug_only(assert_completed_buffer_list_len_correct_locked());
   _cbl_mon->unlock();
 }
 int PtrQueueSet::completed_buffers_list_length() {
   int n = 0;
   CompletedBufferNode* cbn = _completed_buffers_head;
   while (cbn != NULL) {
     n++;
     cbn = cbn->next;
   }
   return n;
 }
 void PtrQueueSet::assert_completed_buffer_list_len_correct() {
   MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   assert_completed_buffer_list_len_correct_locked();
 }
 void PtrQueueSet::assert_completed_buffer_list_len_correct_locked() {
   guarantee((size_t)completed_buffers_list_length() ==  _n_completed_buffers,
             "Completed buffer length is wrong.");
 }
 void PtrQueueSet::set_buffer_size(size_t sz) {
   assert(_sz == 0 && sz > 0, "Should be called only once.");
   _sz = sz * oopSize;
 }
 void PtrQueueSet::set_process_completed_threshold(size_t sz) {
   _process_completed_threshold = sz;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

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

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