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

Mon, 03 Aug 2009 12:59:30 -0700

author
johnc
date
Mon, 03 Aug 2009 12:59:30 -0700
changeset 1324
15c5903cf9e1
parent 1280
df6caf649ff7
child 1546
44f61c24ddab
permissions
-rw-r--r--

6865703: G1: Parallelize hot card cache cleanup
Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads.
Reviewed-by: jmasa, tonyp

     1 /*
     2  * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_satbQueue.cpp.incl"
    28 void ObjPtrQueue::apply_closure(ObjectClosure* cl) {
    29   if (_buf != NULL) {
    30     apply_closure_to_buffer(cl, _buf, _index, _sz);
    31     _index = _sz;
    32   }
    33 }
    35 void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl,
    36                                           void** buf, size_t index, size_t sz) {
    37   if (cl == NULL) return;
    38   for (size_t i = index; i < sz; i += oopSize) {
    39     oop obj = (oop)buf[byte_index_to_index((int)i)];
    40     // There can be NULL entries because of destructors.
    41     if (obj != NULL) {
    42       cl->do_object(obj);
    43     }
    44   }
    45 }
    47 #ifdef ASSERT
    48 void ObjPtrQueue::verify_oops_in_buffer() {
    49   if (_buf == NULL) return;
    50   for (size_t i = _index; i < _sz; i += oopSize) {
    51     oop obj = (oop)_buf[byte_index_to_index((int)i)];
    52     assert(obj != NULL && obj->is_oop(true /* ignore mark word */),
    53            "Not an oop");
    54   }
    55 }
    56 #endif
    58 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
    59 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
    60 #endif // _MSC_VER
    63 SATBMarkQueueSet::SATBMarkQueueSet() :
    64   PtrQueueSet(),
    65   _closure(NULL), _par_closures(NULL),
    66   _shared_satb_queue(this, true /*perm*/)
    67 {}
    69 void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
    70                                   int max_completed_queue,
    71                                   Mutex* lock) {
    72   PtrQueueSet::initialize(cbl_mon, fl_lock, max_completed_queue);
    73   _shared_satb_queue.set_lock(lock);
    74   if (ParallelGCThreads > 0) {
    75     _par_closures = NEW_C_HEAP_ARRAY(ObjectClosure*, ParallelGCThreads);
    76   }
    77 }
    80 void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) {
    81   DEBUG_ONLY(t->satb_mark_queue().verify_oops_in_buffer();)
    82   t->satb_mark_queue().handle_zero_index();
    83 }
    85 void SATBMarkQueueSet::set_active_all_threads(bool b) {
    86   _all_active = b;
    87   for(JavaThread* t = Threads::first(); t; t = t->next()) {
    88     t->satb_mark_queue().set_active(b);
    89   }
    90 }
    92 void SATBMarkQueueSet::set_closure(ObjectClosure* closure) {
    93   _closure = closure;
    94 }
    96 void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) {
    97   assert(ParallelGCThreads > 0 && _par_closures != NULL, "Precondition");
    98   _par_closures[i] = par_closure;
    99 }
   101 void SATBMarkQueueSet::iterate_closure_all_threads() {
   102   for(JavaThread* t = Threads::first(); t; t = t->next()) {
   103     t->satb_mark_queue().apply_closure(_closure);
   104   }
   105   shared_satb_queue()->apply_closure(_closure);
   106 }
   108 void SATBMarkQueueSet::par_iterate_closure_all_threads(int worker) {
   109   SharedHeap* sh = SharedHeap::heap();
   110   int parity = sh->strong_roots_parity();
   112   for(JavaThread* t = Threads::first(); t; t = t->next()) {
   113     if (t->claim_oops_do(true, parity)) {
   114       t->satb_mark_queue().apply_closure(_par_closures[worker]);
   115     }
   116   }
   117   // We'll have worker 0 do this one.
   118   if (worker == 0) {
   119     shared_satb_queue()->apply_closure(_par_closures[0]);
   120   }
   121 }
   123 bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par,
   124                                                               int worker) {
   125   CompletedBufferNode* nd = NULL;
   126   {
   127     MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   128     if (_completed_buffers_head != NULL) {
   129       nd = _completed_buffers_head;
   130       _completed_buffers_head = nd->next;
   131       if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
   132       _n_completed_buffers--;
   133       if (_n_completed_buffers == 0) _process_completed = false;
   134     }
   135   }
   136   ObjectClosure* cl = (par ? _par_closures[worker] : _closure);
   137   if (nd != NULL) {
   138     ObjPtrQueue::apply_closure_to_buffer(cl, nd->buf, 0, _sz);
   139     deallocate_buffer(nd->buf);
   140     delete nd;
   141     return true;
   142   } else {
   143     return false;
   144   }
   145 }
   147 void SATBMarkQueueSet::abandon_partial_marking() {
   148   CompletedBufferNode* buffers_to_delete = NULL;
   149   {
   150     MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
   151     while (_completed_buffers_head != NULL) {
   152       CompletedBufferNode* nd = _completed_buffers_head;
   153       _completed_buffers_head = nd->next;
   154       nd->next = buffers_to_delete;
   155       buffers_to_delete = nd;
   156     }
   157     _completed_buffers_tail = NULL;
   158     _n_completed_buffers = 0;
   159     DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
   160   }
   161   while (buffers_to_delete != NULL) {
   162     CompletedBufferNode* nd = buffers_to_delete;
   163     buffers_to_delete = nd->next;
   164     deallocate_buffer(nd->buf);
   165     delete nd;
   166   }
   167   assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
   168   // So we can safely manipulate these queues.
   169   for (JavaThread* t = Threads::first(); t; t = t->next()) {
   170     t->satb_mark_queue().reset();
   171   }
   172   shared_satb_queue()->reset();
   173 }

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