db2/db_int.h

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997, 1998
   5  *      Sleepycat Software.  All rights reserved.
   6  *
   7  *      @(#)db_int.h.src        10.62 (Sleepycat) 5/23/98
   8  */
   9
  10 #ifndef _DB_INTERNAL_H_
  11 #define _DB_INTERNAL_H_
  12
  13 #include <db.h>                         /* Standard DB include file. */
  14 #include "queue.h"
  15
  16 /*******************************************************
  17  * General purpose constants and macros.
  18  *******************************************************/
  19 #define UINT16_T_MAX        0xffff      /* Maximum 16 bit unsigned. */
  20 #define UINT32_T_MAX    0xffffffff      /* Maximum 32 bit unsigned. */
  21
  22 #define DB_MIN_PGSIZE   0x000200        /* Minimum page size. */
  23 #define DB_MAX_PGSIZE   0x010000        /* Maximum page size. */
  24
  25 #define DB_MINCACHE     10              /* Minimum cached pages */
  26
  27 #define MEGABYTE        1048576
  28
  29 /*
  30  * If we are unable to determine the underlying filesystem block size, use
  31  * 8K on the grounds that most OS's use less than 8K as their VM page size.
  32  */
  33 #define DB_DEF_IOSIZE   (8 * 1024)
  34
  35 /*
  36  * Aligning items to particular sizes or in pages or memory.  ALIGNP is a
  37  * separate macro, as we've had to cast the pointer to different integral
  38  * types on different architectures.
  39  *
  40  * We cast pointers into unsigned longs when manipulating them because C89
  41  * guarantees that u_long is the largest available integral type and further,
  42  * to never generate overflows.  However, neither C89 or C9X  requires that
  43  * any integer type be large enough to hold a pointer, although C9X created
  44  * the intptr_t type, which is guaranteed to hold a pointer but may or may
  45  * not exist.  At some point in the future, we should test for intptr_t and
  46  * use it where available.
  47  */
  48 #undef  ALIGNTYPE
  49 #define ALIGNTYPE               u_long
  50 #undef  ALIGNP
  51 #define ALIGNP(value, bound)    ALIGN((ALIGNTYPE)value, bound)
  52 #undef  ALIGN
  53 #define ALIGN(value, bound)     (((value) + (bound) - 1) & ~((bound) - 1))
  54
  55 /*
  56  * There are several on-page structures that are declared to have a number of
  57  * fields followed by a variable length array of items.  The structure size
  58  * without including the variable length array or the address of the first of
  59  * those elements can be found using SSZ.
  60  *
  61  * This macro can also be used to find the offset of a structure element in a
  62  * structure.  This is used in various places to copy structure elements from
  63  * unaligned memory references, e.g., pointers into a packed page.
  64  *
  65  * There are two versions because compilers object if you take the address of
  66  * an array.
  67  */
  68 #undef  SSZ
  69 #define SSZ(name, field)        ((int)&(((name *)0)->field))
  70
  71 #undef  SSZA
  72 #define SSZA(name, field)       ((int)&(((name *)0)->field[0]))
  73
  74 /* Macros to return per-process address, offsets based on shared regions. */
  75 #define R_ADDR(base, offset)    ((void *)((u_int8_t *)((base)->addr) + offset))
  76 #define R_OFFSET(base, p)       ((u_int8_t *)(p) - (u_int8_t *)(base)->addr)
  77
  78 /* Free and free-string macros that overwrite memory. */
  79 #ifdef DIAGNOSTIC
  80 #undef  FREE
  81 #define FREE(p, len) {                                                  \
  82         memset(p, 0xff, len);                                           \
  83         __db_free(p);                                                   \
  84 }
  85 #undef  FREES
  86 #define FREES(p) {                                                      \
  87         FREE(p, strlen(p));                                             \
  88 }
  89 #else
  90 #undef  FREE
  91 #define FREE(p, len) {                                                  \
  92         __db_free(p);                                                   \
  93 }
  94 #undef  FREES
  95 #define FREES(p) {                                                      \
  96         __db_free(p);                                                   \
  97 }
  98 #endif
  99
 100 /* Structure used to print flag values. */
 101 typedef struct __fn {
 102         u_int32_t mask;                 /* Flag value. */
 103         const char *name;               /* Flag name. */
 104 } FN;
 105
 106 /* Set, clear and test flags. */
 107 #define F_SET(p, f)     (p)->flags |= (f)
 108 #define F_CLR(p, f)     (p)->flags &= ~(f)
 109 #define F_ISSET(p, f)   ((p)->flags & (f))
 110 #define LF_SET(f)       (flags |= (f))
 111 #define LF_CLR(f)       (flags &= ~(f))
 112 #define LF_ISSET(f)     (flags & (f))
 113
 114 /* Display separator string. */
 115 #undef  DB_LINE
 116 #define DB_LINE "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
 117
 118 /* Global variables. */
 119 typedef struct __db_globals {
 120         int db_mutexlocks;              /* DB_MUTEXLOCKS */
 121         int db_region_anon;             /* DB_REGION_ANON, DB_REGION_NAME */
 122         int db_region_init;             /* DB_REGION_INIT */
 123         int db_tsl_spins;               /* DB_TSL_SPINS */
 124         int db_pageyield;               /* DB_PAGEYIELD */
 125 } DB_GLOBALS;
 126 extern  DB_GLOBALS      __db_global_values;
 127 #define DB_GLOBAL(v)    __db_global_values.v
 128
 129 /* Unused, or not-used-yet variable.  "Shut that bloody compiler up!" */
 130 #define COMPQUIET(n, v) (n) = (v)
 131
 132 /*
 133  * Win16 needs specific syntax on callback functions.  Nobody else cares.
 134  */
 135 #ifndef DB_CALLBACK
 136 #define DB_CALLBACK     /* Nothing. */
 137 #endif
 138
 139 /*******************************************************
 140  * Files.
 141  *******************************************************/
 142  /*
 143   * We use 1024 as the maximum path length.  It's too hard to figure out what
 144   * the real path length is, as it was traditionally stored in <sys/param.h>,
 145   * and that file isn't always available.
 146   */
 147 #undef  MAXPATHLEN
 148 #define MAXPATHLEN      1024
 149
 150 #define PATH_DOT        "."     /* Current working directory. */
 151 #define PATH_SEPARATOR  "/"     /* Path separator character. */
 152
 153 /*******************************************************
 154  * Mutex support.
 155  *******************************************************/
 156 typedef unsigned char tsl_t;
 157
 158
 159
 160 /*
 161  * !!!
 162  * Various systems require different alignments for mutexes (the worst we've
 163  * seen so far is 16-bytes on some HP architectures).  The mutex (tsl_t) must
 164  * be first in the db_mutex_t structure, which must itself be first in the
 165  * region.  This ensures the alignment is as returned by mmap(2), which should
 166  * be sufficient.  All other mutex users must ensure proper alignment locally.
 167  */
 168 #define MUTEX_ALIGNMENT 1
 169
 170 /*
 171  * The offset of a mutex in memory.
 172  *
 173  * !!!
 174  * Not an off_t, so backing file offsets MUST be less than 4Gb.  See the
 175  * off field of the db_mutex_t as well.
 176  */
 177 #define MUTEX_LOCK_OFFSET(a, b) ((u_int32_t)((u_int8_t *)b - (u_int8_t *)a))
 178
 179 typedef struct _db_mutex_t {
 180 #ifdef HAVE_SPINLOCKS
 181         tsl_t     tsl_resource;         /* Resource test and set. */
 182 #ifdef DIAGNOSTIC
 183         u_int32_t pid;                  /* Lock holder: 0 or process pid. */
 184 #endif
 185 #else
 186         u_int32_t off;                  /* Backing file offset. */
 187         u_int32_t pid;                  /* Lock holder: 0 or process pid. */
 188 #endif
 189         u_int32_t spins;                /* Spins before block. */
 190         u_int32_t mutex_set_wait;       /* Granted after wait. */
 191         u_int32_t mutex_set_nowait;     /* Granted without waiting. */
 192 } db_mutex_t;
 193
 194 #include "mutex_ext.h"
 195
 196 /*******************************************************
 197  * Access methods.
 198  *******************************************************/
 199 /* Lock/unlock a DB thread. */
 200 #define DB_THREAD_LOCK(dbp)                                             \
 201         if (F_ISSET(dbp, DB_AM_THREAD))                                 \
 202             (void)__db_mutex_lock((db_mutex_t *)(dbp)->mutexp, -1);
 203 #define DB_THREAD_UNLOCK(dbp)                                           \
 204         if (F_ISSET(dbp, DB_AM_THREAD))                                 \
 205             (void)__db_mutex_unlock((db_mutex_t *)(dbp)->mutexp, -1);
 206
 207 /* Btree/recno local statistics structure. */
 208 struct __db_bt_lstat;   typedef struct __db_bt_lstat DB_BTREE_LSTAT;
 209 struct __db_bt_lstat {
 210         u_int32_t bt_freed;             /* Pages freed for reuse. */
 211         u_int32_t bt_pfxsaved;          /* Bytes saved by prefix compression. */
 212         u_int32_t bt_split;             /* Total number of splits. */
 213         u_int32_t bt_rootsplit;         /* Root page splits. */
 214         u_int32_t bt_fastsplit;         /* Fast splits. */
 215         u_int32_t bt_added;             /* Items added. */
 216         u_int32_t bt_deleted;           /* Items deleted. */
 217         u_int32_t bt_get;               /* Items retrieved. */
 218         u_int32_t bt_cache_hit;         /* Hits in fast-insert code. */
 219         u_int32_t bt_cache_miss;        /* Misses in fast-insert code. */
 220 };
 221
 222 /*******************************************************
 223  * Environment.
 224  *******************************************************/
 225 /* Type passed to __db_appname(). */
 226 typedef enum {
 227         DB_APP_NONE=0,                  /* No type (region). */
 228         DB_APP_DATA,                    /* Data file. */
 229         DB_APP_LOG,                     /* Log file. */
 230         DB_APP_TMP                      /* Temporary file. */
 231 } APPNAME;
 232
 233 /*******************************************************
 234  * Shared memory regions.
 235  *******************************************************/
 236 /*
 237  * The shared memory regions share an initial structure so that the general
 238  * region code can handle races between the region being deleted and other
 239  * processes waiting on the region mutex.
 240  *
 241  * !!!
 242  * Note, the mutex must be the first entry in the region; see comment above.
 243  */
 244 typedef struct _rlayout {
 245         db_mutex_t lock;                /* Region mutex. */
 246 #define DB_REGIONMAGIC  0x120897
 247         u_int32_t  valid;               /* Valid magic number. */
 248         u_int32_t  refcnt;              /* Region reference count. */
 249         size_t     size;                /* Region length. */
 250         int        majver;              /* Major version number. */
 251         int        minver;              /* Minor version number. */
 252         int        patch;               /* Patch version number. */
 253 #define INVALID_SEGID   -1
 254         int        segid;               /* shmget(2) ID, or Win16 segment ID. */
 255
 256 #define REGION_ANONYMOUS        0x01    /* Region is/should be in anon mem. */
 257         u_int32_t  flags;
 258 } RLAYOUT;
 259
 260 /*
 261  * DB creates all regions on 4K boundaries out of sheer paranoia, so that
 262  * we don't make the underlying VM unhappy.
 263  */
 264 #define DB_VMPAGESIZE   (4 * 1024)
 265 #define DB_ROUNDOFF(i) {                                                \
 266         (i) += DB_VMPAGESIZE - 1;                                       \
 267         (i) -= (i) % DB_VMPAGESIZE;                                     \
 268 }
 269
 270 /*
 271  * The interface to region attach is nasty, there is a lot of complex stuff
 272  * going on, which has to be retained between create/attach and detach.  The
 273  * REGINFO structure keeps track of it.
 274  */
 275 struct __db_reginfo;    typedef struct __db_reginfo REGINFO;
 276 struct __db_reginfo {
 277                                         /* Arguments. */
 278         DB_ENV     *dbenv;              /* Region naming info. */
 279         APPNAME     appname;            /* Region naming info. */
 280         char       *path;               /* Region naming info. */
 281         const char *file;               /* Region naming info. */
 282         int         mode;               /* Region mode, if a file. */
 283         size_t      size;               /* Region size. */
 284         u_int32_t   dbflags;            /* Region file open flags, if a file. */
 285
 286                                         /* Results. */
 287         char       *name;               /* Region name. */
 288         void       *addr;               /* Region address. */
 289         int         fd;                 /* Fcntl(2) locking file descriptor.
 290                                            NB: this is only valid if a regular
 291                                            file is backing the shared region,
 292                                            and mmap(2) is being used to map it
 293                                            into our address space. */
 294         int         segid;              /* shmget(2) ID, or Win16 segment ID. */
 295
 296                                         /* Shared flags. */
 297 /*                              0x0001  COMMON MASK with RLAYOUT structure. */
 298 #define REGION_CANGROW          0x0002  /* Can grow. */
 299 #define REGION_CREATED          0x0004  /* Created. */
 300 #define REGION_HOLDINGSYS       0x0008  /* Holding system resources. */
 301 #define REGION_LASTDETACH       0x0010  /* Delete on last detach. */
 302 #define REGION_MALLOC           0x0020  /* Created in malloc'd memory. */
 303 #define REGION_PRIVATE          0x0040  /* Private to thread/process. */
 304 #define REGION_REMOVED          0x0080  /* Already deleted. */
 305 #define REGION_SIZEDEF          0x0100  /* Use default region size if exists. */
 306         u_int32_t   flags;
 307 };
 308
 309 /*******************************************************
 310  * Mpool.
 311  *******************************************************/
 312 /*
 313  * File types for DB access methods.  Negative numbers are reserved to DB.
 314  */
 315 #define DB_FTYPE_BTREE          -1      /* Btree. */
 316 #define DB_FTYPE_HASH           -2      /* Hash. */
 317
 318 /* Structure used as the DB pgin/pgout pgcookie. */
 319 typedef struct __dbpginfo {
 320         size_t  db_pagesize;            /* Underlying page size. */
 321         int     needswap;               /* If swapping required. */
 322 } DB_PGINFO;
 323
 324 /*******************************************************
 325  * Log.
 326  *******************************************************/
 327 /* Initialize an LSN to 'zero'. */
 328 #define ZERO_LSN(LSN) {                                                 \
 329         (LSN).file = 0;                                                 \
 330         (LSN).offset = 0;                                               \
 331 }
 332
 333 /* Return 1 if LSN is a 'zero' lsn, otherwise return 0. */
 334 #define IS_ZERO_LSN(LSN)        ((LSN).file == 0)
 335
 336 /* Test if we need to log a change. */
 337 #define DB_LOGGING(dbp)                                                 \
 338         (F_ISSET(dbp, DB_AM_LOGGING) && !F_ISSET(dbp, DB_AM_RECOVER))
 339
 340 #ifdef DIAGNOSTIC
 341 /*
 342  * Debugging macro to log operations.
 343  *      If DEBUG_WOP is defined, log operations that modify the database.
 344  *      If DEBUG_ROP is defined, log operations that read the database.
 345  *
 346  * D dbp
 347  * T txn
 348  * O operation (string)
 349  * K key
 350  * A data
 351  * F flags
 352  */
 353 #define LOG_OP(D, T, O, K, A, F) {                                      \
 354         DB_LSN _lsn;                                                    \
 355         DBT _op;                                                        \
 356         if (DB_LOGGING((D))) {                                          \
 357                 memset(&_op, 0, sizeof(_op));                           \
 358                 _op.data = O;                                           \
 359                 _op.size = strlen(O) + 1;                               \
 360                 (void)__db_debug_log((D)->dbenv->lg_info,               \
 361                     T, &_lsn, 0, &_op, (D)->log_fileid, K, A, F);       \
 362         }                                                               \
 363 }
 364 #ifdef DEBUG_ROP
 365 #define DEBUG_LREAD(D, T, O, K, A, F)   LOG_OP(D, T, O, K, A, F)
 366 #else
 367 #define DEBUG_LREAD(D, T, O, K, A, F)
 368 #endif
 369 #ifdef DEBUG_WOP
 370 #define DEBUG_LWRITE(D, T, O, K, A, F)  LOG_OP(D, T, O, K, A, F)
 371 #else
 372 #define DEBUG_LWRITE(D, T, O, K, A, F)
 373 #endif
 374 #else
 375 #define DEBUG_LREAD(D, T, O, K, A, F)
 376 #define DEBUG_LWRITE(D, T, O, K, A, F)
 377 #endif /* DIAGNOSTIC */
 378
 379 /*******************************************************
 380  * Transactions and recovery.
 381  *******************************************************/
 382 /*
 383  * Out of band value for a lock.  The locks are returned to callers as offsets
 384  * into the lock regions.  Since the RLAYOUT structure begins all regions, an
 385  * offset of 0 is guaranteed not to be a valid lock.
 386  */
 387 #define LOCK_INVALID    0
 388
 389 /* The structure allocated for every transaction. */
 390 struct __db_txn {
 391         DB_TXNMGR       *mgrp;          /* Pointer to transaction manager. */
 392         DB_TXN          *parent;        /* Pointer to transaction's parent. */
 393         DB_LSN          last_lsn;       /* Lsn of last log write. */
 394         u_int32_t       txnid;          /* Unique transaction id. */
 395         size_t          off;            /* Detail structure within region. */
 396         TAILQ_ENTRY(__db_txn) links;
 397 };
 398
 399 #include "os_func.h"
 400 #include "os_ext.h"
 401
 402 #endif /* !_DB_INTERNAL_H_ */