release/src/router/mysql/server-tools/instance-manager/instance.h

   1 #ifndef INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_H
   2 #define INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_H
   3 /* Copyright (c) 2004-2007 MySQL AB
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; version 2 of the License.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  17
  18 #include <my_global.h>
  19 #include <m_string.h>
  20
  21 #include "instance_options.h"
  22 #include "priv.h"
  23
  24 #if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
  25 #pragma interface
  26 #endif
  27
  28 class Instance_map;
  29 class Thread_registry;
  30
  31
  32 /**
  33   Instance_name -- the class represents instance name -- a string of length
  34   less than MAX_INSTANCE_NAME_SIZE.
  35
  36   Generally, this is just a string with self-memory-management and should be
  37   eliminated in the future.
  38 */
  39
  40 class Instance_name
  41 {
  42 public:
  43   Instance_name(const LEX_STRING *name);
  44
  45 public:
  46   inline const LEX_STRING *get_str() const
  47   {
  48     return &str;
  49   }
  50
  51   inline const char *get_c_str() const
  52   {
  53     return str.str;
  54   }
  55
  56   inline uint get_length() const
  57   {
  58     return str.length;
  59   }
  60
  61 private:
  62   LEX_STRING str;
  63   char str_buffer[MAX_INSTANCE_NAME_SIZE];
  64 };
  65
  66
  67 class Instance
  68 {
  69 public:
  70   /* States of an instance. */
  71   enum enum_instance_state
  72   {
  73     STOPPED,
  74     NOT_STARTED,
  75     STARTING,
  76     STARTED,
  77     JUST_CRASHED,
  78     CRASHED,
  79     CRASHED_AND_ABANDONED,
  80     STOPPING
  81   };
  82
  83 public:
  84   /**
  85     The constant defines name of the default mysqld-instance ("mysqld").
  86   */
  87   static const LEX_STRING DFLT_INSTANCE_NAME;
  88
  89 public:
  90   static bool is_name_valid(const LEX_STRING *name);
  91   static bool is_mysqld_compatible_name(const LEX_STRING *name);
  92
  93 public:
  94   Instance();
  95   ~Instance();
  96
  97   bool init(const LEX_STRING *name_arg);
  98   bool complete_initialization();
  99
 100 public:
 101   bool is_active();
 102
 103   bool is_mysqld_running();
 104
 105   bool start_mysqld();
 106   bool stop_mysqld();
 107   bool kill_mysqld(int signo);
 108
 109   void lock();
 110   void unlock();
 111
 112   const char *get_state_name();
 113
 114   void reset_stat();
 115
 116 public:
 117   /**
 118     The operation is intended to check if the instance is mysqld-compatible
 119     or not.
 120   */
 121   inline bool is_mysqld_compatible() const;
 122
 123   /**
 124     The operation is intended to check if the instance is configured properly
 125     or not. Misconfigured instances are not managed.
 126   */
 127   inline bool is_configured() const;
 128
 129   /**
 130     The operation returns TRUE if the instance is guarded and FALSE otherwise.
 131   */
 132   inline bool is_guarded() const;
 133
 134   /**
 135     The operation returns name of the instance.
 136   */
 137   inline const LEX_STRING *get_name() const;
 138
 139   /**
 140     The operation returns the current state of the instance.
 141
 142     NOTE: At the moment should be used only for guarded instances.
 143   */
 144   inline enum_instance_state get_state() const;
 145
 146   /**
 147     The operation changes the state of the instance.
 148
 149     NOTE: At the moment should be used only for guarded instances.
 150     TODO: Make private.
 151   */
 152   inline void set_state(enum_instance_state new_state);
 153
 154   /**
 155     The operation returns crashed flag.
 156   */
 157   inline bool is_crashed();
 158
 159 public:
 160   /**
 161     This attributes contains instance options.
 162
 163     TODO: Make private.
 164   */
 165   Instance_options options;
 166
 167 private:
 168   /**
 169     monitoring_thread_active is TRUE if there is a thread that monitors the
 170     corresponding mysqld-process.
 171   */
 172   bool monitoring_thread_active;
 173
 174   /**
 175     crashed is TRUE when corresponding mysqld-process has been died after
 176     start.
 177   */
 178   bool crashed;
 179
 180   /**
 181     configured is TRUE when the instance is configured and FALSE otherwise.
 182     Misconfigured instances are not managed.
 183   */
 184   bool configured;
 185
 186   /*
 187     mysqld_compatible specifies whether the instance is mysqld-compatible
 188     or not. Mysqld-compatible instances can contain only mysqld-specific
 189     options. At the moment an instance is mysqld-compatible if its name is
 190     "mysqld".
 191
 192     The idea is that [mysqld] section should contain only mysqld-specific
 193     options (no Instance Manager-specific options) to be readable by mysqld
 194     program.
 195   */
 196   bool mysqld_compatible;
 197
 198   /*
 199     Mutex protecting the instance.
 200   */
 201   pthread_mutex_t LOCK_instance;
 202
 203 private:
 204   /* Guarded-instance attributes. */
 205
 206   /* state of an instance (i.e. STARTED, CRASHED, etc.) */
 207   enum_instance_state state;
 208
 209 public:
 210   /* the amount of attemts to restart instance (cleaned up at success) */
 211   int restart_counter;
 212
 213   /* triggered at a crash */
 214   time_t crash_moment;
 215
 216   /* General time field. Used to provide timeouts (at shutdown and restart) */
 217   time_t last_checked;
 218
 219 private:
 220   static const char *get_instance_state_name(enum_instance_state state);
 221
 222 private:
 223   void remove_pid();
 224
 225   bool wait_for_stop();
 226
 227 private:
 228   friend class Instance_monitor;
 229 };
 230
 231
 232 inline bool Instance::is_mysqld_compatible() const
 233 {
 234   return mysqld_compatible;
 235 }
 236
 237
 238 inline bool Instance::is_configured() const
 239 {
 240   return configured;
 241 }
 242
 243
 244 inline bool Instance::is_guarded() const
 245 {
 246   return !options.nonguarded;
 247 }
 248
 249
 250 inline const LEX_STRING *Instance::get_name() const
 251 {
 252   return &options.instance_name;
 253 }
 254
 255
 256 inline Instance::enum_instance_state Instance::get_state() const
 257 {
 258   return state;
 259 }
 260
 261
 262 inline void Instance::set_state(enum_instance_state new_state)
 263 {
 264   state= new_state;
 265 }
 266
 267
 268 inline bool Instance::is_crashed()
 269 {
 270   return crashed;
 271 }
 272
 273 #endif /* INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_H */