1/*
2 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. 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
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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.
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23 */
24
25#ifndef SHARE_JFR_RECORDER_STORAGE_JFRVIRTUALMEMORY_HPP
26#define SHARE_JFR_RECORDER_STORAGE_JFRVIRTUALMEMORY_HPP
27
28#include "jfr/utilities/jfrAllocation.hpp"
29
30class JfrVirtualMemoryManager;
31
32class JfrVirtualMemory : public JfrCHeapObj {
33 private:
34 JfrVirtualMemoryManager* _vmm;
35 const u1* _reserved_low; // lowest address of reservation
36 const u1* _reserved_high; // highest address of reservation
37 u1* _top; // current allocation address
38 const u1* _commit_point; // synch points for committing new memory
39 size_t _physical_commit_size_request_words; // aligned to os::vm_allocation_granularity()
40 size_t _aligned_datum_size_bytes; // datum alignment
41
42 bool commit_memory_block();
43 void* commit(size_t block_size_request_words);
44 void* index_ptr(size_t index); // index to address map
45
46 public:
47 JfrVirtualMemory();
48 ~JfrVirtualMemory();
49
50 // initialization will do the reservation and return it
51 void* initialize(size_t reservation_size_request_bytes, size_t block_size_request_bytes, size_t datum_size_bytes = 1);
52
53 void* new_datum(); // datum oriented allocation
54 void* get(size_t index); // direct access retrieval
55 size_t aligned_datum_size_bytes() const;
56
57 bool is_full() const; // limit of reservation committed and in use
58 bool is_empty() const;
59
60 size_t count() const; // how many
61 size_t live_set() const; // how much resident memory (actually in use)
62 size_t reserved_size() const; // size of reservation
63 bool compact(size_t index);
64};
65
66#endif // SHARE_JFR_RECORDER_STORAGE_JFRVIRTUALMEMORY_HPP
67