1 /*
   2  * Copyright (c) 1997, 2014, 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   static const char* _runtime_version;
  79 
  80   // In this class, we promote the minor version of release to be the
  81   // major version for releases >= 5 in anticipation of the JDK doing the
  82   // same thing.  For example, we represent "1.5.0" as major version 5 (we
  83   // drop the leading 1 and use 5 as the 'major').
  84 
  85   uint8_t _major;
  86   uint8_t _minor;
  87   uint8_t _micro;
  88   uint8_t _update;
  89   uint8_t _special;
  90   uint8_t _build;
  91 
  92   // If partially initialized, the above fields are invalid and we know
  93   // that we're less than major version 6.
  94   bool _partially_initialized;
  95 
  96   bool _thread_park_blocker;
  97   bool _pending_list_uses_discovered_field;
  98   bool _post_vm_init_hook_enabled;
  99 
 100   bool is_valid() const {
 101     return (_major != 0 || _partially_initialized);
 102   }
 103 
 104   // initializes or partially initializes the _current static field
 105   static void initialize();
 106 
 107   // Completes initialization for a pre-JDK6 version.
 108   static void fully_initialize(uint8_t major, uint8_t minor = 0,
 109                                uint8_t micro = 0, uint8_t update = 0);
 110 
 111  public:
 112 
 113   // Returns true if the the current version has only been partially initialized
 114   static bool is_partially_initialized() {
 115     return _current._partially_initialized;
 116   }
 117 
 118   JDK_Version() : _major(0), _minor(0), _micro(0), _update(0),
 119                   _special(0), _build(0), _partially_initialized(false),
 120                   _thread_park_blocker(false), _post_vm_init_hook_enabled(false),
 121                   _pending_list_uses_discovered_field(false) {}
 122 
 123   JDK_Version(uint8_t major, uint8_t minor = 0, uint8_t micro = 0,
 124               uint8_t update = 0, uint8_t special = 0, uint8_t build = 0,
 125               bool thread_park_blocker = false, bool post_vm_init_hook_enabled = false,
 126               bool pending_list_uses_discovered_field = false) :
 127       _major(major), _minor(minor), _micro(micro), _update(update),
 128       _special(special), _build(build), _partially_initialized(false),
 129       _thread_park_blocker(thread_park_blocker),
 130       _post_vm_init_hook_enabled(post_vm_init_hook_enabled),
 131       _pending_list_uses_discovered_field(pending_list_uses_discovered_field) {}
 132 
 133   // Returns the current running JDK version
 134   static JDK_Version current() { return _current; }
 135 
 136   // Factory methods for convenience
 137   static JDK_Version jdk(uint8_t m) {
 138     return JDK_Version(m);
 139   }
 140 
 141   static JDK_Version jdk_update(uint8_t major, uint8_t update_number) {
 142     return JDK_Version(major, 0, 0, update_number);
 143   }
 144 
 145   uint8_t major_version() const          { return _major; }
 146   uint8_t minor_version() const          { return _minor; }
 147   uint8_t micro_version() const          { return _micro; }
 148   uint8_t update_version() const         { return _update; }
 149   uint8_t special_update_version() const { return _special; }
 150   uint8_t build_number() const           { return _build; }
 151 
 152   bool supports_thread_park_blocker() const {
 153     return _thread_park_blocker;
 154   }
 155   bool post_vm_init_hook_enabled() const {
 156     return _post_vm_init_hook_enabled;
 157   }
 158   // For compatibility wrt pre-4965777 JDK's
 159   bool pending_list_uses_discovered_field() const {
 160     return _pending_list_uses_discovered_field;
 161   }
 162 
 163   // Performs a full ordering comparison using all fields (update, build, etc.)
 164   int compare(const JDK_Version& other) const;
 165 
 166   /**
 167    * Performs comparison using only the major version, returning negative
 168    * if the major version of 'this' is less than the parameter, 0 if it is
 169    * equal, and a positive value if it is greater.
 170    */
 171   int compare_major(int version) const {
 172     if (_partially_initialized) {
 173       if (version >= 6) {
 174         return -1;
 175       } else {
 176         assert(false, "Can't make this comparison during init time");
 177         return -1; // conservative
 178       }
 179     } else {
 180       return major_version() - version;
 181     }
 182   }
 183 
 184   void to_string(char* buffer, size_t buflen) const;
 185 
 186   static const char* runtime_name() {
 187     return _runtime_name;
 188   }
 189   static void set_runtime_name(const char* name) {
 190     _runtime_name = name;
 191   }
 192 
 193   static const char* runtime_version() {
 194     return _runtime_version;
 195   }
 196   static void set_runtime_version(const char* version) {
 197     _runtime_version = version;
 198   }
 199 
 200 };
 201 
 202 #endif // SHARE_VM_RUNTIME_JAVA_HPP