1 /*
   2  * Copyright (c) 1997, 2011, 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.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_JAVA_HPP
  26 #define SHARE_VM_RUNTIME_JAVA_HPP
  27 
  28 #include "runtime/os.hpp"
  29 
  30 // Register function to be called by before_exit
  31 extern "C" { void register_on_exit_function(void (*func)(void)) ;}
  32 
  33 // Execute code before all handles are released and thread is killed; prologue to vm_exit
  34 extern void before_exit(JavaThread * thread);
  35 
  36 // Forced VM exit (i.e, internal error or JVM_Exit)
  37 extern void vm_exit(int code);
  38 
  39 // Wrapper for ::exit()
  40 extern void vm_direct_exit(int code);
  41 
  42 // Shutdown the VM but do not exit the process
  43 extern void vm_shutdown();
  44 // Shutdown the VM and abort the process
  45 extern void vm_abort(bool dump_core=true);
  46 
  47 // Trigger any necessary notification of the VM being shutdown
  48 extern void notify_vm_shutdown();
  49 
  50 // VM exit if error occurs during initialization of VM
  51 extern void vm_exit_during_initialization(Handle exception);
  52 extern void vm_exit_during_initialization(Symbol* exception_name, const char* message);
  53 extern void vm_exit_during_initialization(const char* error, const char* message = NULL);
  54 extern void vm_shutdown_during_initialization(const char* error, const char* message = NULL);
  55 
  56 /**
  57  * Discovering the JDK_Version during initialization is tricky when the
  58  * running JDK is less than JDK6.  For JDK6 and greater, a "GetVersion"
  59  * function exists in libjava.so and we simply call it during the
  60  * 'initialize()' call to find the version.  For JDKs with version < 6, no
  61  * such call exists and we have to probe the JDK in order to determine
  62  * the exact version.  This probing cannot happen during late in
  63  * the VM initialization process so there's a period of time during
  64  * initialization when we don't know anything about the JDK version other than
  65  * that it less than version 6.  This is the "partially initialized" time,
  66  * when we can answer only certain version queries (such as, is the JDK
  67  * version greater than 5?  Answer: no).  Once the JDK probing occurs, we
  68  * know the version and are considered fully initialized.
  69  */
  70 class JDK_Version VALUE_OBJ_CLASS_SPEC {
  71   friend class VMStructs;
  72   friend class Universe;
  73   friend void JDK_Version_init();
  74  private:
  75 
  76   static JDK_Version _current;
  77   static const char* _runtime_name;
  78 
  79   // In this class, we promote the minor version of release to be the
  80   // major version for releases >= 5 in anticipation of the JDK doing the
  81   // same thing.  For example, we represent "1.5.0" as major version 5 (we
  82   // drop the leading 1 and use 5 as the 'major').
  83 
  84   uint8_t _major;
  85   uint8_t _minor;
  86   uint8_t _micro;
  87   uint8_t _update;
  88   uint8_t _special;
  89   uint8_t _build;
  90 
  91   // If partially initialized, the above fields are invalid and we know
  92   // that we're less than major version 6.
  93   bool _partially_initialized;
  94 
  95   bool _thread_park_blocker;
  96   bool _pending_list_uses_discovered_field;
  97   bool _post_vm_init_hook_enabled;
  98 
  99   bool is_valid() const {
 100     return (_major != 0 || _partially_initialized);
 101   }
 102 
 103   // initializes or partially initializes the _current static field
 104   static void initialize();
 105 
 106   // Completes initialization for a pre-JDK6 version.
 107   static void fully_initialize(uint8_t major, uint8_t minor = 0,
 108                                uint8_t micro = 0, uint8_t update = 0);
 109 
 110  public:
 111 
 112   // Returns true if the the current version has only been partially initialized
 113   static bool is_partially_initialized() {
 114     return _current._partially_initialized;
 115   }
 116 
 117   JDK_Version() : _major(0), _minor(0), _micro(0), _update(0),
 118                   _special(0), _build(0), _partially_initialized(false),
 119                   _thread_park_blocker(false), _post_vm_init_hook_enabled(false),
 120                   _pending_list_uses_discovered_field(false) {}
 121 
 122   JDK_Version(uint8_t major, uint8_t minor = 0, uint8_t micro = 0,
 123               uint8_t update = 0, uint8_t special = 0, uint8_t build = 0,
 124               bool thread_park_blocker = false, bool post_vm_init_hook_enabled = false,
 125               bool pending_list_uses_discovered_field = false) :
 126       _major(major), _minor(minor), _micro(micro), _update(update),
 127       _special(special), _build(build), _partially_initialized(false),
 128       _thread_park_blocker(thread_park_blocker),
 129       _post_vm_init_hook_enabled(post_vm_init_hook_enabled),
 130       _pending_list_uses_discovered_field(pending_list_uses_discovered_field) {}
 131 
 132   // Returns the current running JDK version
 133   static JDK_Version current() { return _current; }
 134 
 135   // Factory methods for convenience
 136   static JDK_Version jdk(uint8_t m) {
 137     return JDK_Version(m);
 138   }
 139 
 140   static JDK_Version jdk_update(uint8_t major, uint8_t update_number) {
 141     return JDK_Version(major, 0, 0, update_number);
 142   }
 143 
 144   uint8_t major_version() const          { return _major; }
 145   uint8_t minor_version() const          { return _minor; }
 146   uint8_t micro_version() const          { return _micro; }
 147   uint8_t update_version() const         { return _update; }
 148   uint8_t special_update_version() const { return _special; }
 149   uint8_t build_number() const           { return _build; }
 150 
 151   bool supports_thread_park_blocker() const {
 152     return _thread_park_blocker;
 153   }
 154   bool post_vm_init_hook_enabled() const {
 155     return _post_vm_init_hook_enabled;
 156   }
 157   // For compatibility wrt pre-4965777 JDK's
 158   bool pending_list_uses_discovered_field() const {
 159     return _pending_list_uses_discovered_field;
 160   }
 161 
 162   // Performs a full ordering comparison using all fields (update, build, etc.)
 163   int compare(const JDK_Version& other) const;
 164 
 165   /**
 166    * Performs comparison using only the major version, returning negative
 167    * if the major version of 'this' is less than the parameter, 0 if it is
 168    * equal, and a positive value if it is greater.
 169    */
 170   int compare_major(int version) const {
 171     if (_partially_initialized) {
 172       if (version >= 6) {
 173         return -1;
 174       } else {
 175         assert(false, "Can't make this comparison during init time");
 176         return -1; // conservative
 177       }
 178     } else {
 179       return major_version() - version;
 180     }
 181   }
 182 
 183   void to_string(char* buffer, size_t buflen) const;
 184 
 185   static const char* runtime_name() {
 186     return _runtime_name;
 187   }
 188   static void set_runtime_name(const char* name) {
 189     _runtime_name = name;
 190   }
 191 
 192   // Convenience methods for queries on the current major/minor version
 193   static bool is_jdk12x_version() {
 194     return current().compare_major(2) == 0;
 195   }
 196 
 197   static bool is_jdk13x_version() {
 198     return current().compare_major(3) == 0;
 199   }
 200 
 201   static bool is_jdk14x_version() {
 202     return current().compare_major(4) == 0;
 203   }
 204 
 205   static bool is_jdk15x_version() {
 206     return current().compare_major(5) == 0;
 207   }
 208 
 209   static bool is_jdk16x_version() {
 210     return current().compare_major(6) == 0;
 211   }
 212 
 213   static bool is_jdk17x_version() {
 214     return current().compare_major(7) == 0;
 215   }
 216 
 217   static bool is_jdk18x_version() {
 218     return current().compare_major(8) == 0;
 219   }
 220 
 221   static bool is_gte_jdk13x_version() {
 222     return current().compare_major(3) >= 0;
 223   }
 224 
 225   static bool is_gte_jdk14x_version() {
 226     return current().compare_major(4) >= 0;
 227   }
 228 
 229   static bool is_gte_jdk15x_version() {
 230     return current().compare_major(5) >= 0;
 231   }
 232 
 233   static bool is_gte_jdk16x_version() {
 234     return current().compare_major(6) >= 0;
 235   }
 236 
 237   static bool is_gte_jdk17x_version() {
 238     return current().compare_major(7) >= 0;
 239   }
 240 
 241   static bool is_gte_jdk18x_version() {
 242     return current().compare_major(8) >= 0;
 243   }
 244 };
 245 
 246 #endif // SHARE_VM_RUNTIME_JAVA_HPP