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

Tue, 10 Jan 2012 18:58:13 -0500

author
tonyp
date
Tue, 10 Jan 2012 18:58:13 -0500
changeset 3416
2ace1c4ee8da
parent 3156
f08d439fab8c
child 4299
f34d701e952e
permissions
-rw-r--r--

6888336: G1: avoid explicitly marking and pushing objects in survivor spaces
Summary: This change simplifies the interaction between GC and concurrent marking. By disabling survivor spaces during the initial-mark pause we don't need to propagate marks of objects we copy during each GC (since we never need to copy an explicitly marked object).
Reviewed-by: johnc, brutisso

     1 /*
     2  * Copyright (c) 2001, 2010, 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
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    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
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "gc_implementation/g1/dirtyCardQueue.hpp"
    27 #include "gc_implementation/g1/heapRegionRemSet.hpp"
    28 #include "runtime/atomic.hpp"
    29 #include "runtime/mutexLocker.hpp"
    30 #include "runtime/safepoint.hpp"
    31 #include "runtime/thread.hpp"
    32 #include "utilities/workgroup.hpp"
    33 #ifdef TARGET_OS_FAMILY_linux
    34 # include "thread_linux.inline.hpp"
    35 #endif
    36 #ifdef TARGET_OS_FAMILY_solaris
    37 # include "thread_solaris.inline.hpp"
    38 #endif
    39 #ifdef TARGET_OS_FAMILY_windows
    40 # include "thread_windows.inline.hpp"
    41 #endif
    42 #ifdef TARGET_OS_FAMILY_bsd
    43 # include "thread_bsd.inline.hpp"
    44 #endif
    46 bool DirtyCardQueue::apply_closure(CardTableEntryClosure* cl,
    47                                    bool consume,
    48                                    size_t worker_i) {
    49   bool res = true;
    50   if (_buf != NULL) {
    51     res = apply_closure_to_buffer(cl, _buf, _index, _sz,
    52                                   consume,
    53                                   (int) worker_i);
    54     if (res && consume) _index = _sz;
    55   }
    56   return res;
    57 }
    59 bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
    60                                              void** buf,
    61                                              size_t index, size_t sz,
    62                                              bool consume,
    63                                              int worker_i) {
    64   if (cl == NULL) return true;
    65   for (size_t i = index; i < sz; i += oopSize) {
    66     int ind = byte_index_to_index((int)i);
    67     jbyte* card_ptr = (jbyte*)buf[ind];
    68     if (card_ptr != NULL) {
    69       // Set the entry to null, so we don't do it again (via the test
    70       // above) if we reconsider this buffer.
    71       if (consume) buf[ind] = NULL;
    72       if (!cl->do_card_ptr(card_ptr, worker_i)) return false;
    73     }
    74   }
    75   return true;
    76 }
    78 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
    79 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
    80 #endif // _MSC_VER
    82 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
    83   PtrQueueSet(notify_when_complete),
    84   _closure(NULL),
    85   _shared_dirty_card_queue(this, true /*perm*/),
    86   _free_ids(NULL),
    87   _processed_buffers_mut(0), _processed_buffers_rs_thread(0)
    88 {
    89   _all_active = true;
    90 }
    92 // Determines how many mutator threads can process the buffers in parallel.
    93 size_t DirtyCardQueueSet::num_par_ids() {
    94   return os::processor_count();
    95 }
    97 void DirtyCardQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
    98                                    int process_completed_threshold,
    99                                    int max_completed_queue,
   100                                    Mutex* lock, PtrQueueSet* fl_owner) {
   101   PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold,
   102                           max_completed_queue, fl_owner);
   103   set_buffer_size(G1UpdateBufferSize);
   104   _shared_dirty_card_queue.set_lock(lock);
   105   _free_ids = new FreeIdSet((int) num_par_ids(), _cbl_mon);
   106 }
   108 void DirtyCardQueueSet::handle_zero_index_for_thread(JavaThread* t) {
   109   t->dirty_card_queue().handle_zero_index();
   110 }
   112 void DirtyCardQueueSet::set_closure(CardTableEntryClosure* closure) {
   113   _closure = closure;
   114 }
   116 void DirtyCardQueueSet::iterate_closure_all_threads(bool consume,
   117                                                     size_t worker_i) {
   118   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   119   for(JavaThread* t = Threads::first(); t; t = t->next()) {
   120     bool b = t->dirty_card_queue().apply_closure(_closure, consume);
   121     guarantee(b, "Should not be interrupted.");
   122   }
   123   bool b = shared_dirty_card_queue()->apply_closure(_closure,
   124                                                     consume,
   125                                                     worker_i);
   126   guarantee(b, "Should not be interrupted.");
   127 }
   129 bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
   131   // Used to determine if we had already claimed a par_id
   132   // before entering this method.
   133   bool already_claimed = false;
   135   // We grab the current JavaThread.
   136   JavaThread* thread = JavaThread::current();
   138   // We get the the number of any par_id that this thread
   139   // might have already claimed.
   140   int worker_i = thread->get_claimed_par_id();
   142   // If worker_i is not -1 then the thread has already claimed
   143   // a par_id. We make note of it using the already_claimed value
   144   if (worker_i != -1) {
   145     already_claimed = true;
   146   } else {
   148     // Otherwise we need to claim a par id
   149     worker_i = _free_ids->claim_par_id();
   151     // And store the par_id value in the thread
   152     thread->set_claimed_par_id(worker_i);
   153   }
   155   bool b = false;
   156   if (worker_i != -1) {
   157     b = DirtyCardQueue::apply_closure_to_buffer(_closure, buf, 0,
   158                                                 _sz, true, worker_i);
   159     if (b) Atomic::inc(&_processed_buffers_mut);
   161     // If we had not claimed an id before entering the method
   162     // then we must release the id.
   163     if (!already_claimed) {
   165       // we release the id
   166       _free_ids->release_par_id(worker_i);
   168       // and set the claimed_id in the thread to -1
   169       thread->set_claimed_par_id(-1);
   170     }
   171   }
   172   return b;
   173 }
   176 BufferNode*
   177 DirtyCardQueueSet::get_completed_buffer(int stop_at) {
   178   BufferNode* nd = NULL;
   179   MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   181   if ((int)_n_completed_buffers <= stop_at) {
   182     _process_completed = false;
   183     return NULL;
   184   }
   186   if (_completed_buffers_head != NULL) {
   187     nd = _completed_buffers_head;
   188     _completed_buffers_head = nd->next();
   189     if (_completed_buffers_head == NULL)
   190       _completed_buffers_tail = NULL;
   191     _n_completed_buffers--;
   192     assert(_n_completed_buffers >= 0, "Invariant");
   193   }
   194   debug_only(assert_completed_buffer_list_len_correct_locked());
   195   return nd;
   196 }
   198 bool DirtyCardQueueSet::
   199 apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
   200                                          int worker_i,
   201                                          BufferNode* nd) {
   202   if (nd != NULL) {
   203     void **buf = BufferNode::make_buffer_from_node(nd);
   204     size_t index = nd->index();
   205     bool b =
   206       DirtyCardQueue::apply_closure_to_buffer(cl, buf,
   207                                               index, _sz,
   208                                               true, worker_i);
   209     if (b) {
   210       deallocate_buffer(buf);
   211       return true;  // In normal case, go on to next buffer.
   212     } else {
   213       enqueue_complete_buffer(buf, index);
   214       return false;
   215     }
   216   } else {
   217     return false;
   218   }
   219 }
   221 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
   222                                                           int worker_i,
   223                                                           int stop_at,
   224                                                           bool during_pause) {
   225   assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause");
   226   BufferNode* nd = get_completed_buffer(stop_at);
   227   bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd);
   228   if (res) Atomic::inc(&_processed_buffers_rs_thread);
   229   return res;
   230 }
   232 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(int worker_i,
   233                                                           int stop_at,
   234                                                           bool during_pause) {
   235   return apply_closure_to_completed_buffer(_closure, worker_i,
   236                                            stop_at, during_pause);
   237 }
   239 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers() {
   240   BufferNode* nd = _completed_buffers_head;
   241   while (nd != NULL) {
   242     bool b =
   243       DirtyCardQueue::apply_closure_to_buffer(_closure,
   244                                               BufferNode::make_buffer_from_node(nd),
   245                                               0, _sz, false);
   246     guarantee(b, "Should not stop early.");
   247     nd = nd->next();
   248   }
   249 }
   251 // Deallocates any completed log buffers
   252 void DirtyCardQueueSet::clear() {
   253   BufferNode* buffers_to_delete = NULL;
   254   {
   255     MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   256     while (_completed_buffers_head != NULL) {
   257       BufferNode* nd = _completed_buffers_head;
   258       _completed_buffers_head = nd->next();
   259       nd->set_next(buffers_to_delete);
   260       buffers_to_delete = nd;
   261     }
   262     _n_completed_buffers = 0;
   263     _completed_buffers_tail = NULL;
   264     debug_only(assert_completed_buffer_list_len_correct_locked());
   265   }
   266   while (buffers_to_delete != NULL) {
   267     BufferNode* nd = buffers_to_delete;
   268     buffers_to_delete = nd->next();
   269     deallocate_buffer(BufferNode::make_buffer_from_node(nd));
   270   }
   272 }
   274 void DirtyCardQueueSet::abandon_logs() {
   275   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   276   clear();
   277   // Since abandon is done only at safepoints, we can safely manipulate
   278   // these queues.
   279   for (JavaThread* t = Threads::first(); t; t = t->next()) {
   280     t->dirty_card_queue().reset();
   281   }
   282   shared_dirty_card_queue()->reset();
   283 }
   286 void DirtyCardQueueSet::concatenate_logs() {
   287   // Iterate over all the threads, if we find a partial log add it to
   288   // the global list of logs.  Temporarily turn off the limit on the number
   289   // of outstanding buffers.
   290   int save_max_completed_queue = _max_completed_queue;
   291   _max_completed_queue = max_jint;
   292   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   293   for (JavaThread* t = Threads::first(); t; t = t->next()) {
   294     DirtyCardQueue& dcq = t->dirty_card_queue();
   295     if (dcq.size() != 0) {
   296       void **buf = t->dirty_card_queue().get_buf();
   297       // We must NULL out the unused entries, then enqueue.
   298       for (size_t i = 0; i < t->dirty_card_queue().get_index(); i += oopSize) {
   299         buf[PtrQueue::byte_index_to_index((int)i)] = NULL;
   300       }
   301       enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
   302       dcq.reinitialize();
   303     }
   304   }
   305   if (_shared_dirty_card_queue.size() != 0) {
   306     enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
   307                             _shared_dirty_card_queue.get_index());
   308     _shared_dirty_card_queue.reinitialize();
   309   }
   310   // Restore the completed buffer queue limit.
   311   _max_completed_queue = save_max_completed_queue;
   312 }

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