jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp

Tue, 17 Oct 2017 12:58:25 +0800

author: aoqi
date: Tue, 17 Oct 2017 12:58:25 +0800
changeset 7994: 04ff2f6cd0eb
parent 7653: b6a1bf5222c5
parent 7535: 7ae4e26cb1e0
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 2013, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "gc_implementation/g1/dirtyCardQueue.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1HotCardCache.hpp"
 #include "gc_implementation/g1/g1RemSet.hpp"
 #include "runtime/atomic.hpp"
 G1HotCardCache::G1HotCardCache(G1CollectedHeap *g1h):
   _g1h(g1h), _hot_cache(NULL), _use_cache(false), _card_counts(g1h) {}
 void G1HotCardCache::initialize(G1RegionToSpaceMapper* card_counts_storage) {
   if (default_use_cache()) {
     _use_cache = true;
     _hot_cache_size = (size_t)1 << G1ConcRSLogCacheSize;
     _hot_cache = NEW_C_HEAP_ARRAY(jbyte*, _hot_cache_size, mtGC);
     reset_hot_cache_internal();
     // For refining the cards in the hot cache in parallel
     _hot_cache_par_chunk_size = (int)(ParallelGCThreads > 0 ? ClaimChunkSize : _hot_cache_size);
     _hot_cache_par_claimed_idx = 0;
     _card_counts.initialize(card_counts_storage);
   }
 }
 G1HotCardCache::~G1HotCardCache() {
   if (default_use_cache()) {
     assert(_hot_cache != NULL, "Logic");
     FREE_C_HEAP_ARRAY(jbyte*, _hot_cache, mtGC);
   }
 }
 jbyte* G1HotCardCache::insert(jbyte* card_ptr) {
   uint count = _card_counts.add_card_count(card_ptr);
   if (!_card_counts.is_hot(count)) {
     // The card is not hot so do not store it in the cache;
     // return it for immediate refining.
     return card_ptr;
   }
   // Otherwise, the card is hot.
   size_t index = Atomic::add_ptr((intptr_t)1, (volatile intptr_t*)&_hot_cache_idx) - 1;
   size_t masked_index = index & (_hot_cache_size - 1);
   jbyte* current_ptr = _hot_cache[masked_index];
   // Try to store the new card pointer into the cache. Compare-and-swap to guard
   // against the unlikely event of a race resulting in another card pointer to
   // have already been written to the cache. In this case we will return
   // card_ptr in favor of the other option, which would be starting over. This
   // should be OK since card_ptr will likely be the older card already when/if
   // this ever happens.
   jbyte* previous_ptr = (jbyte*)Atomic::cmpxchg_ptr(card_ptr,
                                                     &_hot_cache[masked_index],
                                                     current_ptr);
   return (previous_ptr == current_ptr) ? previous_ptr : card_ptr;
 }
 void G1HotCardCache::drain(uint worker_i,
                            G1RemSet* g1rs,
                            DirtyCardQueue* into_cset_dcq) {
   if (!default_use_cache()) {
     assert(_hot_cache == NULL, "Logic");
     return;
   }
   assert(_hot_cache != NULL, "Logic");
   assert(!use_cache(), "cache should be disabled");
   while (_hot_cache_par_claimed_idx < _hot_cache_size) {
     size_t end_idx = Atomic::add_ptr((intptr_t)_hot_cache_par_chunk_size,
                                      (volatile intptr_t*)&_hot_cache_par_claimed_idx);
     size_t start_idx = end_idx - _hot_cache_par_chunk_size;
     // The current worker has successfully claimed the chunk [start_idx..end_idx)
     end_idx = MIN2(end_idx, _hot_cache_size);
     for (size_t i = start_idx; i < end_idx; i++) {
       jbyte* card_ptr = _hot_cache[i];
       if (card_ptr != NULL) {
         if (g1rs->refine_card(card_ptr, worker_i, true)) {
           // The part of the heap spanned by the card contains references
           // that point into the current collection set.
           // We need to record the card pointer in the DirtyCardQueueSet
           // that we use for such cards.
           //
           // The only time we care about recording cards that contain
           // references that point into the collection set is during
           // RSet updating while within an evacuation pause.
           // In this case worker_i should be the id of a GC worker thread
           assert(SafepointSynchronize::is_at_safepoint(), "Should be at a safepoint");
           assert(worker_i < ParallelGCThreads,
                  err_msg("incorrect worker id: %u", worker_i));
           into_cset_dcq->enqueue(card_ptr);
         }
       } else {
         break;
       }
     }
   }
   // The existing entries in the hot card cache, which were just refined
   // above, are discarded prior to re-enabling the cache near the end of the GC.
 }
 void G1HotCardCache::reset_card_counts(HeapRegion* hr) {
   _card_counts.clear_region(hr);
 }
 void G1HotCardCache::reset_card_counts() {
   _card_counts.clear_all();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/g1HotCardCache.cpp