vm_version.hpp revision 3718:b9a9ed0f8eeb 
1/*
2 * Copyright (c) 1997, 2012, 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
6 * under the terms of the GNU General Public License version 2 only, as
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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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25#ifndef SHARE_VM_RUNTIME_VM_VERSION_HPP
26#define SHARE_VM_RUNTIME_VM_VERSION_HPP
27
28#include "memory/allocation.hpp"
29#include "utilities/ostream.hpp"
30
31// VM_Version provides information about the VM.
32
33class Abstract_VM_Version: AllStatic {
34 protected:
35  friend class VMStructs;
36  static const char*  _s_vm_release;
37  static const char*  _s_internal_vm_info_string;
38  // These are set by machine-dependent initializations
39  static bool         _supports_cx8;
40  static bool         _supports_atomic_getset4;
41  static bool         _supports_atomic_getset8;
42  static bool         _supports_atomic_getadd4;
43  static bool         _supports_atomic_getadd8;
44  static unsigned int _logical_processors_per_package;
45  static int          _vm_major_version;
46  static int          _vm_minor_version;
47  static int          _vm_build_number;
48  static bool         _initialized;
49  static int          _parallel_worker_threads;
50  static bool         _parallel_worker_threads_initialized;
51  static int          _reserve_for_allocation_prefetch;
52
53  static unsigned int nof_parallel_worker_threads(unsigned int num,
54                                                  unsigned int dem,
55                                                  unsigned int switch_pt);
56 public:
57  static void initialize();
58
59  // Name
60  static const char* vm_name();
61  // Vendor
62  static const char* vm_vendor();
63  // VM version information string printed by launcher (java -version)
64  static const char* vm_info_string();
65  static const char* vm_release();
66  static const char* vm_platform_string();
67  static const char* vm_build_user();
68
69  static int vm_major_version()               { assert(_initialized, "not initialized"); return _vm_major_version; }
70  static int vm_minor_version()               { assert(_initialized, "not initialized"); return _vm_minor_version; }
71  static int vm_build_number()                { assert(_initialized, "not initialized"); return _vm_build_number; }
72
73  // Gets the jvm_version_info.jvm_version defined in jvm.h
74  static unsigned int jvm_version();
75
76  // Internal version providing additional build information
77  static const char* internal_vm_info_string();
78  static const char* jre_release_version();
79
80  // does HW support an 8-byte compare-exchange operation?
81  static bool supports_cx8()  {return _supports_cx8;}
82  // does HW support atomic get-and-set or atomic get-and-add?  Used
83  // to guide intrinsification decisions for Unsafe atomic ops
84  static bool supports_atomic_getset4()  {return _supports_atomic_getset4;}
85  static bool supports_atomic_getset8()  {return _supports_atomic_getset8;}
86  static bool supports_atomic_getadd4()  {return _supports_atomic_getadd4;}
87  static bool supports_atomic_getadd8()  {return _supports_atomic_getadd8;}
88
89  static unsigned int logical_processors_per_package() {
90    return _logical_processors_per_package;
91  }
92
93  // Need a space at the end of TLAB for prefetch instructions
94  // which may fault when accessing memory outside of heap.
95  static int reserve_for_allocation_prefetch() {
96    return _reserve_for_allocation_prefetch;
97  }
98
99  // ARCH specific policy for the BiasedLocking
100  static bool use_biased_locking()  { return true; }
101
102  // Number of page sizes efficiently supported by the hardware.  Most chips now
103  // support two sizes, thus this default implementation.  Processor-specific
104  // subclasses should define new versions to hide this one as needed.  Note
105  // that the O/S may support more sizes, but at most this many are used.
106  static uint page_size_count() { return 2; }
107
108  // Returns the number of parallel threads to be used for VM
109  // work.  If that number has not been calculated, do so and
110  // save it.  Returns ParallelGCThreads if it is set on the
111  // command line.
112  static unsigned int parallel_worker_threads();
113  // Calculates and returns the number of parallel threads.  May
114  // be VM version specific.
115  static unsigned int calc_parallel_worker_threads();
116};
117
118#endif // SHARE_VM_RUNTIME_VM_VERSION_HPP
119