jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp@c96030fff130

6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

     1 /*

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     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

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     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

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    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

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    25 # include "incls/_precompiled.incl"

    26 # include "incls/_freeChunk.cpp.incl"

    28 #ifndef PRODUCT

    30 #define baadbabeHeapWord badHeapWordVal

    31 #define deadbeefHeapWord 0xdeadbeef

    33 size_t const FreeChunk::header_size() {

    34   return sizeof(FreeChunk)/HeapWordSize;

    35 }

    37 void FreeChunk::mangleAllocated(size_t size) {

    38   // mangle all but the header of a just-allocated block

    39   // of storage

    40   assert(size >= MinChunkSize, "smallest size of object");

    41   // we can't assert that _size == size because this may be an

    42   // allocation out of a linear allocation block

    43   assert(sizeof(FreeChunk) % HeapWordSize == 0,

    44          "shouldn't write beyond chunk");

    45   HeapWord* addr = (HeapWord*)this;

    46   size_t hdr = header_size();

    47   Copy::fill_to_words(addr + hdr, size - hdr, baadbabeHeapWord);

    48 }

    50 void FreeChunk::mangleFreed(size_t sz) {

    51   assert(baadbabeHeapWord != deadbeefHeapWord, "Need distinct patterns");

    52   // mangle all but the header of a just-freed block of storage

    53   // just prior to passing it to the storage dictionary

    54   assert(sz >= MinChunkSize, "smallest size of object");

    55   assert(sz == size(), "just checking");

    56   HeapWord* addr = (HeapWord*)this;

    57   size_t hdr = header_size();

    58   Copy::fill_to_words(addr + hdr, sz - hdr, deadbeefHeapWord);

    59 }

    61 void FreeChunk::verifyList() const {

    62   FreeChunk* nextFC = next();

    63   if (nextFC != NULL) {

    64     assert(this == nextFC->prev(), "broken chain");

    65     assert(size() == nextFC->size(), "wrong size");

    66     nextFC->verifyList();

    67   }

    68 }

    69 #endif

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp@c96030fff130

src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp