src/share/vm/memory/metachunk.hpp

Fri, 01 Feb 2013 23:48:08 +0100

author
ctornqvi
date
Fri, 01 Feb 2013 23:48:08 +0100
changeset 4512
4102b59539ce
parent 4382
e51c9860cf66
child 5007
c23dbf0e8ab7
permissions
-rw-r--r--

8005012: Add WB APIs to better support NMT testing
Summary: Add WB API functions to enable better NMT testing
Reviewed-by: dholmes, zgu

jmasa@4196 1 /*
jmasa@4196 2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
jmasa@4196 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jmasa@4196 4 *
jmasa@4196 5 * This code is free software; you can redistribute it and/or modify it
jmasa@4196 6 * under the terms of the GNU General Public License version 2 only, as
jmasa@4196 7 * published by the Free Software Foundation.
jmasa@4196 8 *
jmasa@4196 9 * This code is distributed in the hope that it will be useful, but WITHOUT
jmasa@4196 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jmasa@4196 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
jmasa@4196 12 * version 2 for more details (a copy is included in the LICENSE file that
jmasa@4196 13 * accompanied this code).
jmasa@4196 14 *
jmasa@4196 15 * You should have received a copy of the GNU General Public License version
jmasa@4196 16 * 2 along with this work; if not, write to the Free Software Foundation,
jmasa@4196 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jmasa@4196 18 *
jmasa@4196 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jmasa@4196 20 * or visit www.oracle.com if you need additional information or have any
jmasa@4196 21 * questions.
jmasa@4196 22 *
jmasa@4196 23 */
jmasa@4196 24 #ifndef SHARE_VM_MEMORY_METACHUNK_HPP
jmasa@4196 25 #define SHARE_VM_MEMORY_METACHUNK_HPP
jmasa@4196 26
jmasa@4196 27 // Metachunk - Quantum of allocation from a Virtualspace
jmasa@4196 28 // Metachunks are reused (when freed are put on a global freelist) and
jmasa@4196 29 // have no permanent association to a SpaceManager.
jmasa@4196 30
jmasa@4196 31 // +--------------+ <- end
jmasa@4196 32 // | | --+ ---+
jmasa@4196 33 // | | | free |
jmasa@4196 34 // | | | |
jmasa@4196 35 // | | | | capacity
jmasa@4196 36 // | | | |
jmasa@4196 37 // | | <- top --+ |
jmasa@4196 38 // | | ---+ |
jmasa@4196 39 // | | | used |
jmasa@4196 40 // | | | |
jmasa@4196 41 // | | | |
jmasa@4196 42 // +--------------+ <- bottom ---+ ---+
jmasa@4196 43
jmasa@4196 44 class Metachunk VALUE_OBJ_CLASS_SPEC {
jmasa@4196 45 // link to support lists of chunks
jmasa@4196 46 Metachunk* _next;
jmasa@4196 47 Metachunk* _prev;
jmasa@4196 48
jmasa@4196 49 MetaWord* _bottom;
jmasa@4196 50 MetaWord* _end;
jmasa@4196 51 MetaWord* _top;
jmasa@4196 52 size_t _word_size;
jmasa@4196 53 // Used in a guarantee() so included in the Product builds
jmasa@4196 54 // even through it is only for debugging.
jmasa@4196 55 bool _is_free;
jmasa@4196 56
jmasa@4196 57 // Metachunks are allocated out of a MetadataVirtualSpace and
jmasa@4196 58 // and use some of its space to describe itself (plus alignment
jmasa@4196 59 // considerations). Metadata is allocated in the rest of the chunk.
jmasa@4196 60 // This size is the overhead of maintaining the Metachunk within
jmasa@4196 61 // the space.
jmasa@4196 62 static size_t _overhead;
jmasa@4196 63
jmasa@4196 64 void set_bottom(MetaWord* v) { _bottom = v; }
jmasa@4196 65 void set_end(MetaWord* v) { _end = v; }
jmasa@4196 66 void set_top(MetaWord* v) { _top = v; }
jmasa@4196 67 void set_word_size(size_t v) { _word_size = v; }
jmasa@4196 68 public:
jmasa@4196 69 #ifdef ASSERT
jmasa@4382 70 Metachunk() : _bottom(NULL), _end(NULL), _top(NULL), _is_free(false),
jmasa@4382 71 _next(NULL), _prev(NULL) {}
jmasa@4196 72 #else
jmasa@4382 73 Metachunk() : _bottom(NULL), _end(NULL), _top(NULL),
jmasa@4382 74 _next(NULL), _prev(NULL) {}
jmasa@4196 75 #endif
jmasa@4196 76
jmasa@4196 77 // Used to add a Metachunk to a list of Metachunks
jmasa@4196 78 void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");}
jmasa@4196 79 void set_prev(Metachunk* v) { _prev = v; assert(v != this, "Boom");}
jmasa@4196 80
jmasa@4196 81 MetaWord* allocate(size_t word_size);
jmasa@4196 82 static Metachunk* initialize(MetaWord* ptr, size_t word_size);
jmasa@4196 83
jmasa@4196 84 // Accessors
jmasa@4196 85 Metachunk* next() const { return _next; }
jmasa@4196 86 Metachunk* prev() const { return _prev; }
jmasa@4196 87 MetaWord* bottom() const { return _bottom; }
jmasa@4196 88 MetaWord* end() const { return _end; }
jmasa@4196 89 MetaWord* top() const { return _top; }
jmasa@4196 90 size_t word_size() const { return _word_size; }
jmasa@4196 91 size_t size() const volatile { return _word_size; }
jmasa@4196 92 void set_size(size_t v) { _word_size = v; }
jmasa@4196 93 bool is_free() { return _is_free; }
jmasa@4196 94 void set_is_free(bool v) { _is_free = v; }
jmasa@4196 95 static size_t overhead() { return _overhead; }
jmasa@4196 96 void clear_next() { set_next(NULL); }
jmasa@4196 97 void link_prev(Metachunk* ptr) { set_prev(ptr); }
jmasa@4196 98 uintptr_t* end() { return ((uintptr_t*) this) + size(); }
jmasa@4196 99 bool cantCoalesce() const { return false; }
jmasa@4196 100 void link_next(Metachunk* ptr) { set_next(ptr); }
jmasa@4196 101 void link_after(Metachunk* ptr){
jmasa@4196 102 link_next(ptr);
jmasa@4196 103 if (ptr != NULL) ptr->link_prev(this);
jmasa@4196 104 }
jmasa@4196 105
jmasa@4196 106 // Reset top to bottom so chunk can be reused.
jmasa@4382 107 void reset_empty() { _top = (_bottom + _overhead); _next = NULL; _prev = NULL; }
jmasa@4196 108 bool is_empty() { return _top == (_bottom + _overhead); }
jmasa@4196 109
jmasa@4196 110 // used (has been allocated)
jmasa@4196 111 // free (available for future allocations)
jmasa@4196 112 // capacity (total size of chunk)
jmasa@4382 113 size_t used_word_size() const;
jmasa@4382 114 size_t free_word_size() const;
jmasa@4382 115 size_t capacity_word_size()const;
jmasa@4196 116
jmasa@4196 117 // Debug support
jmasa@4196 118 #ifdef ASSERT
jmasa@4196 119 void* prev_addr() const { return (void*)&_prev; }
jmasa@4196 120 void* next_addr() const { return (void*)&_next; }
jmasa@4196 121 void* size_addr() const { return (void*)&_word_size; }
jmasa@4196 122 #endif
jmasa@4196 123 bool verify_chunk_in_free_list(Metachunk* tc) const { return true; }
jmasa@4196 124 bool verify_par_locked() { return true; }
jmasa@4196 125
jmasa@4196 126 void assert_is_mangled() const {/* Don't check "\*/}
jmasa@4196 127
coleenp@4304 128 NOT_PRODUCT(void mangle();)
jmasa@4196 129
jmasa@4196 130 void print_on(outputStream* st) const;
jmasa@4196 131 void verify();
jmasa@4196 132 };
jmasa@4196 133 #endif // SHARE_VM_MEMORY_METACHUNK_HPP

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