Thu, 27 May 2010 19:08:38 -0700
6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair
coleenp@622 | 1 | /* |
trims@1907 | 2 | * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved. |
coleenp@622 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
coleenp@622 | 4 | * |
coleenp@622 | 5 | * This code is free software; you can redistribute it and/or modify it |
coleenp@622 | 6 | * under the terms of the GNU General Public License version 2 only, as |
coleenp@622 | 7 | * published by the Free Software Foundation. |
coleenp@622 | 8 | * |
coleenp@622 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
coleenp@622 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
coleenp@622 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
coleenp@622 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
coleenp@622 | 13 | * accompanied this code). |
coleenp@622 | 14 | * |
coleenp@622 | 15 | * You should have received a copy of the GNU General Public License version |
coleenp@622 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
coleenp@622 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
coleenp@622 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
coleenp@622 | 22 | * |
coleenp@622 | 23 | */ |
coleenp@622 | 24 | |
coleenp@622 | 25 | // |
coleenp@622 | 26 | // Free block maintenance for Concurrent Mark Sweep Generation |
coleenp@622 | 27 | // |
coleenp@622 | 28 | // The main data structure for free blocks are |
coleenp@622 | 29 | // . an indexed array of small free blocks, and |
coleenp@622 | 30 | // . a dictionary of large free blocks |
coleenp@622 | 31 | // |
coleenp@622 | 32 | |
coleenp@622 | 33 | // No virtuals in FreeChunk (don't want any vtables). |
coleenp@622 | 34 | |
coleenp@622 | 35 | // A FreeChunk is merely a chunk that can be in a doubly linked list |
coleenp@622 | 36 | // and has a size field. NOTE: FreeChunks are distinguished from allocated |
coleenp@622 | 37 | // objects in two ways (by the sweeper), depending on whether the VM is 32 or |
coleenp@622 | 38 | // 64 bits. |
coleenp@622 | 39 | // In 32 bits or 64 bits without CompressedOops, the second word (prev) has the |
coleenp@622 | 40 | // LSB set to indicate a free chunk; allocated objects' klass() pointers |
coleenp@622 | 41 | // don't have their LSB set. The corresponding bit in the CMSBitMap is |
coleenp@622 | 42 | // set when the chunk is allocated. There are also blocks that "look free" |
coleenp@622 | 43 | // but are not part of the free list and should not be coalesced into larger |
coleenp@622 | 44 | // free blocks. These free blocks have their two LSB's set. |
coleenp@622 | 45 | |
coleenp@622 | 46 | class FreeChunk VALUE_OBJ_CLASS_SPEC { |
coleenp@622 | 47 | friend class VMStructs; |
coleenp@622 | 48 | // For 64 bit compressed oops, the markOop encodes both the size and the |
coleenp@622 | 49 | // indication that this is a FreeChunk and not an object. |
coleenp@622 | 50 | volatile size_t _size; |
coleenp@622 | 51 | FreeChunk* _prev; |
coleenp@622 | 52 | FreeChunk* _next; |
coleenp@622 | 53 | |
coleenp@622 | 54 | markOop mark() const volatile { return (markOop)_size; } |
coleenp@622 | 55 | void set_mark(markOop m) { _size = (size_t)m; } |
coleenp@622 | 56 | |
coleenp@622 | 57 | public: |
coleenp@622 | 58 | NOT_PRODUCT(static const size_t header_size();) |
coleenp@622 | 59 | |
coleenp@622 | 60 | // Returns "true" if the address indicates that the block represents |
coleenp@622 | 61 | // a free chunk. |
coleenp@622 | 62 | static bool indicatesFreeChunk(const HeapWord* addr) { |
coleenp@622 | 63 | // Force volatile read from addr because value might change between |
coleenp@622 | 64 | // calls. We really want the read of _mark and _prev from this pointer |
coleenp@622 | 65 | // to be volatile but making the fields volatile causes all sorts of |
coleenp@622 | 66 | // compilation errors. |
coleenp@622 | 67 | return ((volatile FreeChunk*)addr)->isFree(); |
coleenp@622 | 68 | } |
coleenp@622 | 69 | |
coleenp@622 | 70 | bool isFree() const volatile { |
coleenp@622 | 71 | LP64_ONLY(if (UseCompressedOops) return mark()->is_cms_free_chunk(); else) |
coleenp@622 | 72 | return (((intptr_t)_prev) & 0x1) == 0x1; |
coleenp@622 | 73 | } |
coleenp@622 | 74 | bool cantCoalesce() const { |
coleenp@622 | 75 | assert(isFree(), "can't get coalesce bit on not free"); |
coleenp@622 | 76 | return (((intptr_t)_prev) & 0x2) == 0x2; |
coleenp@622 | 77 | } |
coleenp@622 | 78 | void dontCoalesce() { |
coleenp@622 | 79 | // the block should be free |
coleenp@622 | 80 | assert(isFree(), "Should look like a free block"); |
coleenp@622 | 81 | _prev = (FreeChunk*)(((intptr_t)_prev) | 0x2); |
coleenp@622 | 82 | } |
coleenp@622 | 83 | FreeChunk* prev() const { |
coleenp@622 | 84 | return (FreeChunk*)(((intptr_t)_prev) & ~(0x3)); |
coleenp@622 | 85 | } |
coleenp@622 | 86 | |
coleenp@622 | 87 | debug_only(void* prev_addr() const { return (void*)&_prev; }) |
jmasa@698 | 88 | debug_only(void* next_addr() const { return (void*)&_next; }) |
jmasa@698 | 89 | debug_only(void* size_addr() const { return (void*)&_size; }) |
coleenp@622 | 90 | |
coleenp@622 | 91 | size_t size() const volatile { |
coleenp@622 | 92 | LP64_ONLY(if (UseCompressedOops) return mark()->get_size(); else ) |
coleenp@622 | 93 | return _size; |
coleenp@622 | 94 | } |
coleenp@622 | 95 | void setSize(size_t sz) { |
coleenp@622 | 96 | LP64_ONLY(if (UseCompressedOops) set_mark(markOopDesc::set_size_and_free(sz)); else ) |
coleenp@622 | 97 | _size = sz; |
coleenp@622 | 98 | } |
coleenp@622 | 99 | |
coleenp@622 | 100 | FreeChunk* next() const { return _next; } |
coleenp@622 | 101 | |
coleenp@622 | 102 | void linkAfter(FreeChunk* ptr) { |
coleenp@622 | 103 | linkNext(ptr); |
coleenp@622 | 104 | if (ptr != NULL) ptr->linkPrev(this); |
coleenp@622 | 105 | } |
coleenp@622 | 106 | void linkAfterNonNull(FreeChunk* ptr) { |
coleenp@622 | 107 | assert(ptr != NULL, "precondition violation"); |
coleenp@622 | 108 | linkNext(ptr); |
coleenp@622 | 109 | ptr->linkPrev(this); |
coleenp@622 | 110 | } |
coleenp@622 | 111 | void linkNext(FreeChunk* ptr) { _next = ptr; } |
coleenp@622 | 112 | void linkPrev(FreeChunk* ptr) { |
coleenp@622 | 113 | LP64_ONLY(if (UseCompressedOops) _prev = ptr; else) |
coleenp@622 | 114 | _prev = (FreeChunk*)((intptr_t)ptr | 0x1); |
coleenp@622 | 115 | } |
coleenp@622 | 116 | void clearPrev() { _prev = NULL; } |
coleenp@622 | 117 | void clearNext() { _next = NULL; } |
coleenp@622 | 118 | void markNotFree() { |
coleenp@622 | 119 | LP64_ONLY(if (UseCompressedOops) set_mark(markOopDesc::prototype());) |
coleenp@622 | 120 | // Also set _prev to null |
coleenp@622 | 121 | _prev = NULL; |
coleenp@622 | 122 | } |
coleenp@622 | 123 | |
coleenp@622 | 124 | // Return the address past the end of this chunk |
coleenp@622 | 125 | HeapWord* end() const { return ((HeapWord*) this) + size(); } |
coleenp@622 | 126 | |
coleenp@622 | 127 | // debugging |
coleenp@622 | 128 | void verify() const PRODUCT_RETURN; |
coleenp@622 | 129 | void verifyList() const PRODUCT_RETURN; |
coleenp@622 | 130 | void mangleAllocated(size_t size) PRODUCT_RETURN; |
coleenp@622 | 131 | void mangleFreed(size_t size) PRODUCT_RETURN; |
ysr@1580 | 132 | |
ysr@1580 | 133 | void print_on(outputStream* st); |
coleenp@622 | 134 | }; |
coleenp@622 | 135 | |
coleenp@622 | 136 | // Alignment helpers etc. |
coleenp@622 | 137 | #define numQuanta(x,y) ((x+y-1)/y) |
coleenp@622 | 138 | enum AlignmentConstants { |
coleenp@622 | 139 | MinChunkSize = numQuanta(sizeof(FreeChunk), MinObjAlignmentInBytes) * MinObjAlignment |
coleenp@622 | 140 | }; |
coleenp@622 | 141 |