src/redis.c

   1 /*
   2  * Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  *   * Redistributions of source code must retain the above copyright notice,
   9  *     this list of conditions and the following disclaimer.
  10  *   * Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  *   * Neither the name of Redis nor the names of its contributors may be used
  14  *     to endorse or promote products derived from this software without
  15  *     specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  * POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "redis.h"
  31
  32 #ifdef HAVE_BACKTRACE
  33 #include <execinfo.h>
  34 #include <ucontext.h>
  35 #endif /* HAVE_BACKTRACE */
  36
  37 #include <time.h>
  38 #include <signal.h>
  39 #include <sys/wait.h>
  40 #include <errno.h>
  41 #include <assert.h>
  42 #include <ctype.h>
  43 #include <stdarg.h>
  44 #include <arpa/inet.h>
  45 #include <sys/stat.h>
  46 #include <fcntl.h>
  47 #include <sys/time.h>
  48 #include <sys/resource.h>
  49 #include <sys/uio.h>
  50 #include <limits.h>
  51 #include <float.h>
  52 #include <math.h>
  53 #include <pthread.h>
  54 #include <sys/resource.h>
  55
  56 /* Our shared "common" objects */
  57
  58 struct sharedObjectsStruct shared;
  59
  60 /* Global vars that are actally used as constants. The following double
  61  * values are used for double on-disk serialization, and are initialized
  62  * at runtime to avoid strange compiler optimizations. */
  63
  64 double R_Zero, R_PosInf, R_NegInf, R_Nan;
  65
  66 /*================================= Globals ================================= */
  67
  68 /* Global vars */
  69 struct redisServer server; /* server global state */
  70 struct redisCommand *commandTable;
  71 struct redisCommand readonlyCommandTable[] = {
  72     {"get",getCommand,2,0,NULL,1,1,1},
  73     {"set",setCommand,3,REDIS_CMD_DENYOOM,NULL,0,0,0},
  74     {"setnx",setnxCommand,3,REDIS_CMD_DENYOOM,NULL,0,0,0},
  75     {"setex",setexCommand,4,REDIS_CMD_DENYOOM,NULL,0,0,0},
  76     {"append",appendCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
  77     {"substr",substrCommand,4,0,NULL,1,1,1},
  78     {"strlen",strlenCommand,2,0,NULL,1,1,1},
  79     {"del",delCommand,-2,0,NULL,0,0,0},
  80     {"exists",existsCommand,2,0,NULL,1,1,1},
  81     {"incr",incrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
  82     {"decr",decrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
  83     {"mget",mgetCommand,-2,0,NULL,1,-1,1},
  84     {"rpush",rpushCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
  85     {"lpush",lpushCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
  86     {"rpushx",rpushxCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
  87     {"lpushx",lpushxCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
  88     {"linsert",linsertCommand,5,REDIS_CMD_DENYOOM,NULL,1,1,1},
  89     {"rpop",rpopCommand,2,0,NULL,1,1,1},
  90     {"lpop",lpopCommand,2,0,NULL,1,1,1},
  91     {"brpop",brpopCommand,-3,0,NULL,1,1,1},
  92     {"blpop",blpopCommand,-3,0,NULL,1,1,1},
  93     {"llen",llenCommand,2,0,NULL,1,1,1},
  94     {"lindex",lindexCommand,3,0,NULL,1,1,1},
  95     {"lset",lsetCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
  96     {"lrange",lrangeCommand,4,0,NULL,1,1,1},
  97     {"ltrim",ltrimCommand,4,0,NULL,1,1,1},
  98     {"lrem",lremCommand,4,0,NULL,1,1,1},
  99     {"rpoplpush",rpoplpushcommand,3,REDIS_CMD_DENYOOM,NULL,1,2,1},
 100     {"sadd",saddCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
 101     {"srem",sremCommand,3,0,NULL,1,1,1},
 102     {"smove",smoveCommand,4,0,NULL,1,2,1},
 103     {"sismember",sismemberCommand,3,0,NULL,1,1,1},
 104     {"scard",scardCommand,2,0,NULL,1,1,1},
 105     {"spop",spopCommand,2,0,NULL,1,1,1},
 106     {"srandmember",srandmemberCommand,2,0,NULL,1,1,1},
 107     {"sinter",sinterCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
 108     {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
 109     {"sunion",sunionCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
 110     {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
 111     {"sdiff",sdiffCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
 112     {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
 113     {"smembers",sinterCommand,2,0,NULL,1,1,1},
 114     {"zadd",zaddCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 115     {"zincrby",zincrbyCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 116     {"zrem",zremCommand,3,0,NULL,1,1,1},
 117     {"zremrangebyscore",zremrangebyscoreCommand,4,0,NULL,1,1,1},
 118     {"zremrangebyrank",zremrangebyrankCommand,4,0,NULL,1,1,1},
 119     {"zunionstore",zunionstoreCommand,-4,REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
 120     {"zinterstore",zinterstoreCommand,-4,REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
 121     {"zrange",zrangeCommand,-4,0,NULL,1,1,1},
 122     {"zrangebyscore",zrangebyscoreCommand,-4,0,NULL,1,1,1},
 123     {"zrevrangebyscore",zrevrangebyscoreCommand,-4,0,NULL,1,1,1},
 124     {"zcount",zcountCommand,4,0,NULL,1,1,1},
 125     {"zrevrange",zrevrangeCommand,-4,0,NULL,1,1,1},
 126     {"zcard",zcardCommand,2,0,NULL,1,1,1},
 127     {"zscore",zscoreCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
 128     {"zrank",zrankCommand,3,0,NULL,1,1,1},
 129     {"zrevrank",zrevrankCommand,3,0,NULL,1,1,1},
 130     {"hset",hsetCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 131     {"hsetnx",hsetnxCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 132     {"hget",hgetCommand,3,0,NULL,1,1,1},
 133     {"hmset",hmsetCommand,-4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 134     {"hmget",hmgetCommand,-3,0,NULL,1,1,1},
 135     {"hincrby",hincrbyCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
 136     {"hdel",hdelCommand,3,0,NULL,1,1,1},
 137     {"hlen",hlenCommand,2,0,NULL,1,1,1},
 138     {"hkeys",hkeysCommand,2,0,NULL,1,1,1},
 139     {"hvals",hvalsCommand,2,0,NULL,1,1,1},
 140     {"hgetall",hgetallCommand,2,0,NULL,1,1,1},
 141     {"hexists",hexistsCommand,3,0,NULL,1,1,1},
 142     {"incrby",incrbyCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
 143     {"decrby",decrbyCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
 144     {"getset",getsetCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
 145     {"mset",msetCommand,-3,REDIS_CMD_DENYOOM,NULL,1,-1,2},
 146     {"msetnx",msetnxCommand,-3,REDIS_CMD_DENYOOM,NULL,1,-1,2},
 147     {"randomkey",randomkeyCommand,1,0,NULL,0,0,0},
 148     {"select",selectCommand,2,0,NULL,0,0,0},
 149     {"move",moveCommand,3,0,NULL,1,1,1},
 150     {"rename",renameCommand,3,0,NULL,1,1,1},
 151     {"renamenx",renamenxCommand,3,0,NULL,1,1,1},
 152     {"expire",expireCommand,3,0,NULL,0,0,0},
 153     {"expireat",expireatCommand,3,0,NULL,0,0,0},
 154     {"keys",keysCommand,2,0,NULL,0,0,0},
 155     {"dbsize",dbsizeCommand,1,0,NULL,0,0,0},
 156     {"auth",authCommand,2,0,NULL,0,0,0},
 157     {"ping",pingCommand,1,0,NULL,0,0,0},
 158     {"echo",echoCommand,2,0,NULL,0,0,0},
 159     {"save",saveCommand,1,0,NULL,0,0,0},
 160     {"bgsave",bgsaveCommand,1,0,NULL,0,0,0},
 161     {"bgrewriteaof",bgrewriteaofCommand,1,0,NULL,0,0,0},
 162     {"shutdown",shutdownCommand,1,0,NULL,0,0,0},
 163     {"lastsave",lastsaveCommand,1,0,NULL,0,0,0},
 164     {"type",typeCommand,2,0,NULL,1,1,1},
 165     {"multi",multiCommand,1,0,NULL,0,0,0},
 166     {"exec",execCommand,1,REDIS_CMD_DENYOOM,execBlockClientOnSwappedKeys,0,0,0},
 167     {"discard",discardCommand,1,0,NULL,0,0,0},
 168     {"sync",syncCommand,1,0,NULL,0,0,0},
 169     {"flushdb",flushdbCommand,1,0,NULL,0,0,0},
 170     {"flushall",flushallCommand,1,0,NULL,0,0,0},
 171     {"sort",sortCommand,-2,REDIS_CMD_DENYOOM,NULL,1,1,1},
 172     {"info",infoCommand,1,0,NULL,0,0,0},
 173     {"monitor",monitorCommand,1,0,NULL,0,0,0},
 174     {"ttl",ttlCommand,2,0,NULL,1,1,1},
 175     {"persist",persistCommand,2,0,NULL,1,1,1},
 176     {"slaveof",slaveofCommand,3,0,NULL,0,0,0},
 177     {"debug",debugCommand,-2,0,NULL,0,0,0},
 178     {"config",configCommand,-2,0,NULL,0,0,0},
 179     {"subscribe",subscribeCommand,-2,0,NULL,0,0,0},
 180     {"unsubscribe",unsubscribeCommand,-1,0,NULL,0,0,0},
 181     {"psubscribe",psubscribeCommand,-2,0,NULL,0,0,0},
 182     {"punsubscribe",punsubscribeCommand,-1,0,NULL,0,0,0},
 183     {"publish",publishCommand,3,REDIS_CMD_FORCE_REPLICATION,NULL,0,0,0},
 184     {"watch",watchCommand,-2,0,NULL,0,0,0},
 185     {"unwatch",unwatchCommand,1,0,NULL,0,0,0}
 186 };
 187
 188 /*============================ Utility functions ============================ */
 189
 190 void redisLog(int level, const char *fmt, ...) {
 191     va_list ap;
 192     FILE *fp;
 193     char *c = ".-*#";
 194     char buf[64];
 195     time_t now;
 196
 197     if (level < server.verbosity) return;
 198
 199     fp = (server.logfile == NULL) ? stdout : fopen(server.logfile,"a");
 200     if (!fp) return;
 201
 202     va_start(ap, fmt);
 203     now = time(NULL);
 204     strftime(buf,64,"%d %b %H:%M:%S",localtime(&now));
 205     fprintf(fp,"[%d] %s %c ",(int)getpid(),buf,c[level]);
 206     vfprintf(fp, fmt, ap);
 207     fprintf(fp,"\n");
 208     fflush(fp);
 209     va_end(ap);
 210
 211     if (server.logfile) fclose(fp);
 212 }
 213
 214 /* Redis generally does not try to recover from out of memory conditions
 215  * when allocating objects or strings, it is not clear if it will be possible
 216  * to report this condition to the client since the networking layer itself
 217  * is based on heap allocation for send buffers, so we simply abort.
 218  * At least the code will be simpler to read... */
 219 void oom(const char *msg) {
 220     redisLog(REDIS_WARNING, "%s: Out of memory\n",msg);
 221     sleep(1);
 222     abort();
 223 }
 224
 225 /*====================== Hash table type implementation  ==================== */
 226
 227 /* This is an hash table type that uses the SDS dynamic strings libary as
 228  * keys and radis objects as values (objects can hold SDS strings,
 229  * lists, sets). */
 230
 231 void dictVanillaFree(void *privdata, void *val)
 232 {
 233     DICT_NOTUSED(privdata);
 234     zfree(val);
 235 }
 236
 237 void dictListDestructor(void *privdata, void *val)
 238 {
 239     DICT_NOTUSED(privdata);
 240     listRelease((list*)val);
 241 }
 242
 243 int dictSdsKeyCompare(void *privdata, const void *key1,
 244         const void *key2)
 245 {
 246     int l1,l2;
 247     DICT_NOTUSED(privdata);
 248
 249     l1 = sdslen((sds)key1);
 250     l2 = sdslen((sds)key2);
 251     if (l1 != l2) return 0;
 252     return memcmp(key1, key2, l1) == 0;
 253 }
 254
 255 /* A case insensitive version used for the command lookup table. */
 256 int dictSdsKeyCaseCompare(void *privdata, const void *key1,
 257         const void *key2)
 258 {
 259     DICT_NOTUSED(privdata);
 260
 261     return strcasecmp(key1, key2) == 0;
 262 }
 263
 264 void dictRedisObjectDestructor(void *privdata, void *val)
 265 {
 266     DICT_NOTUSED(privdata);
 267
 268     if (val == NULL) return; /* Values of swapped out keys as set to NULL */
 269     decrRefCount(val);
 270 }
 271
 272 void dictSdsDestructor(void *privdata, void *val)
 273 {
 274     DICT_NOTUSED(privdata);
 275
 276     sdsfree(val);
 277 }
 278
 279 int dictObjKeyCompare(void *privdata, const void *key1,
 280         const void *key2)
 281 {
 282     const robj *o1 = key1, *o2 = key2;
 283     return dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 284 }
 285
 286 unsigned int dictObjHash(const void *key) {
 287     const robj *o = key;
 288     return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 289 }
 290
 291 unsigned int dictSdsHash(const void *key) {
 292     return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
 293 }
 294
 295 unsigned int dictSdsCaseHash(const void *key) {
 296     return dictGenCaseHashFunction((unsigned char*)key, sdslen((char*)key));
 297 }
 298
 299 int dictEncObjKeyCompare(void *privdata, const void *key1,
 300         const void *key2)
 301 {
 302     robj *o1 = (robj*) key1, *o2 = (robj*) key2;
 303     int cmp;
 304
 305     if (o1->encoding == REDIS_ENCODING_INT &&
 306         o2->encoding == REDIS_ENCODING_INT)
 307             return o1->ptr == o2->ptr;
 308
 309     o1 = getDecodedObject(o1);
 310     o2 = getDecodedObject(o2);
 311     cmp = dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 312     decrRefCount(o1);
 313     decrRefCount(o2);
 314     return cmp;
 315 }
 316
 317 unsigned int dictEncObjHash(const void *key) {
 318     robj *o = (robj*) key;
 319
 320     if (o->encoding == REDIS_ENCODING_RAW) {
 321         return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 322     } else {
 323         if (o->encoding == REDIS_ENCODING_INT) {
 324             char buf[32];
 325             int len;
 326
 327             len = ll2string(buf,32,(long)o->ptr);
 328             return dictGenHashFunction((unsigned char*)buf, len);
 329         } else {
 330             unsigned int hash;
 331
 332             o = getDecodedObject(o);
 333             hash = dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 334             decrRefCount(o);
 335             return hash;
 336         }
 337     }
 338 }
 339
 340 /* Sets type */
 341 dictType setDictType = {
 342     dictEncObjHash,            /* hash function */
 343     NULL,                      /* key dup */
 344     NULL,                      /* val dup */
 345     dictEncObjKeyCompare,      /* key compare */
 346     dictRedisObjectDestructor, /* key destructor */
 347     NULL                       /* val destructor */
 348 };
 349
 350 /* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
 351 dictType zsetDictType = {
 352     dictEncObjHash,            /* hash function */
 353     NULL,                      /* key dup */
 354     NULL,                      /* val dup */
 355     dictEncObjKeyCompare,      /* key compare */
 356     dictRedisObjectDestructor, /* key destructor */
 357     NULL                       /* val destructor */
 358 };
 359
 360 /* Db->dict, keys are sds strings, vals are Redis objects. */
 361 dictType dbDictType = {
 362     dictSdsHash,                /* hash function */
 363     NULL,                       /* key dup */
 364     NULL,                       /* val dup */
 365     dictSdsKeyCompare,          /* key compare */
 366     dictSdsDestructor,          /* key destructor */
 367     dictRedisObjectDestructor   /* val destructor */
 368 };
 369
 370 /* Db->expires */
 371 dictType keyptrDictType = {
 372     dictSdsHash,               /* hash function */
 373     NULL,                      /* key dup */
 374     NULL,                      /* val dup */
 375     dictSdsKeyCompare,         /* key compare */
 376     NULL,                      /* key destructor */
 377     NULL                       /* val destructor */
 378 };
 379
 380 /* Command table. sds string -> command struct pointer. */
 381 dictType commandTableDictType = {
 382     dictSdsCaseHash,           /* hash function */
 383     NULL,                      /* key dup */
 384     NULL,                      /* val dup */
 385     dictSdsKeyCaseCompare,     /* key compare */
 386     dictSdsDestructor,         /* key destructor */
 387     NULL                       /* val destructor */
 388 };
 389
 390 /* Hash type hash table (note that small hashes are represented with zimpaps) */
 391 dictType hashDictType = {
 392     dictEncObjHash,             /* hash function */
 393     NULL,                       /* key dup */
 394     NULL,                       /* val dup */
 395     dictEncObjKeyCompare,       /* key compare */
 396     dictRedisObjectDestructor,  /* key destructor */
 397     dictRedisObjectDestructor   /* val destructor */
 398 };
 399
 400 /* Keylist hash table type has unencoded redis objects as keys and
 401  * lists as values. It's used for blocking operations (BLPOP) and to
 402  * map swapped keys to a list of clients waiting for this keys to be loaded. */
 403 dictType keylistDictType = {
 404     dictObjHash,                /* hash function */
 405     NULL,                       /* key dup */
 406     NULL,                       /* val dup */
 407     dictObjKeyCompare,          /* key compare */
 408     dictRedisObjectDestructor,  /* key destructor */
 409     dictListDestructor          /* val destructor */
 410 };
 411
 412 int htNeedsResize(dict *dict) {
 413     long long size, used;
 414
 415     size = dictSlots(dict);
 416     used = dictSize(dict);
 417     return (size && used && size > DICT_HT_INITIAL_SIZE &&
 418             (used*100/size < REDIS_HT_MINFILL));
 419 }
 420
 421 /* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
 422  * we resize the hash table to save memory */
 423 void tryResizeHashTables(void) {
 424     int j;
 425
 426     for (j = 0; j < server.dbnum; j++) {
 427         if (htNeedsResize(server.db[j].dict))
 428             dictResize(server.db[j].dict);
 429         if (htNeedsResize(server.db[j].expires))
 430             dictResize(server.db[j].expires);
 431     }
 432 }
 433
 434 /* Our hash table implementation performs rehashing incrementally while
 435  * we write/read from the hash table. Still if the server is idle, the hash
 436  * table will use two tables for a long time. So we try to use 1 millisecond
 437  * of CPU time at every serverCron() loop in order to rehash some key. */
 438 void incrementallyRehash(void) {
 439     int j;
 440
 441     for (j = 0; j < server.dbnum; j++) {
 442         if (dictIsRehashing(server.db[j].dict)) {
 443             dictRehashMilliseconds(server.db[j].dict,1);
 444             break; /* already used our millisecond for this loop... */
 445         }
 446     }
 447 }
 448
 449 /* This function is called once a background process of some kind terminates,
 450  * as we want to avoid resizing the hash tables when there is a child in order
 451  * to play well with copy-on-write (otherwise when a resize happens lots of
 452  * memory pages are copied). The goal of this function is to update the ability
 453  * for dict.c to resize the hash tables accordingly to the fact we have o not
 454  * running childs. */
 455 void updateDictResizePolicy(void) {
 456     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
 457         dictEnableResize();
 458     else
 459         dictDisableResize();
 460 }
 461
 462 /* ======================= Cron: called every 100 ms ======================== */
 463
 464 /* Try to expire a few timed out keys. The algorithm used is adaptive and
 465  * will use few CPU cycles if there are few expiring keys, otherwise
 466  * it will get more aggressive to avoid that too much memory is used by
 467  * keys that can be removed from the keyspace. */
 468 void activeExpireCycle(void) {
 469     int j;
 470
 471     for (j = 0; j < server.dbnum; j++) {
 472         int expired;
 473         redisDb *db = server.db+j;
 474
 475         /* Continue to expire if at the end of the cycle more than 25%
 476          * of the keys were expired. */
 477         do {
 478             long num = dictSize(db->expires);
 479             time_t now = time(NULL);
 480
 481             expired = 0;
 482             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
 483                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
 484             while (num--) {
 485                 dictEntry *de;
 486                 time_t t;
 487
 488                 if ((de = dictGetRandomKey(db->expires)) == NULL) break;
 489                 t = (time_t) dictGetEntryVal(de);
 490                 if (now > t) {
 491                     sds key = dictGetEntryKey(de);
 492                     robj *keyobj = createStringObject(key,sdslen(key));
 493
 494                     propagateExpire(db,keyobj);
 495                     dbDelete(db,keyobj);
 496                     decrRefCount(keyobj);
 497                     expired++;
 498                     server.stat_expiredkeys++;
 499                 }
 500             }
 501         } while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
 502     }
 503 }
 504
 505 void updateLRUClock(void) {
 506     server.lruclock = (time(NULL)/REDIS_LRU_CLOCK_RESOLUTION) &
 507                                                 REDIS_LRU_CLOCK_MAX;
 508 }
 509
 510 int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 511     int j, loops = server.cronloops++;
 512     REDIS_NOTUSED(eventLoop);
 513     REDIS_NOTUSED(id);
 514     REDIS_NOTUSED(clientData);
 515
 516     /* We take a cached value of the unix time in the global state because
 517      * with virtual memory and aging there is to store the current time
 518      * in objects at every object access, and accuracy is not needed.
 519      * To access a global var is faster than calling time(NULL) */
 520     server.unixtime = time(NULL);
 521     /* We have just 22 bits per object for LRU information.
 522      * So we use an (eventually wrapping) LRU clock with 10 seconds resolution.
 523      * 2^22 bits with 10 seconds resoluton is more or less 1.5 years.
 524      *
 525      * Note that even if this will wrap after 1.5 years it's not a problem,
 526      * everything will still work but just some object will appear younger
 527      * to Redis. But for this to happen a given object should never be touched
 528      * for 1.5 years.
 529      *
 530      * Note that you can change the resolution altering the
 531      * REDIS_LRU_CLOCK_RESOLUTION define.
 532      */
 533     updateLRUClock();
 534
 535     /* We received a SIGTERM, shutting down here in a safe way, as it is
 536      * not ok doing so inside the signal handler. */
 537     if (server.shutdown_asap) {
 538         if (prepareForShutdown() == REDIS_OK) exit(0);
 539         redisLog(REDIS_WARNING,"SIGTERM received but errors trying to shut down the server, check the logs for more information");
 540     }
 541
 542     /* Show some info about non-empty databases */
 543     for (j = 0; j < server.dbnum; j++) {
 544         long long size, used, vkeys;
 545
 546         size = dictSlots(server.db[j].dict);
 547         used = dictSize(server.db[j].dict);
 548         vkeys = dictSize(server.db[j].expires);
 549         if (!(loops % 50) && (used || vkeys)) {
 550             redisLog(REDIS_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
 551             /* dictPrintStats(server.dict); */
 552         }
 553     }
 554
 555     /* We don't want to resize the hash tables while a bacground saving
 556      * is in progress: the saving child is created using fork() that is
 557      * implemented with a copy-on-write semantic in most modern systems, so
 558      * if we resize the HT while there is the saving child at work actually
 559      * a lot of memory movements in the parent will cause a lot of pages
 560      * copied. */
 561     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) {
 562         if (!(loops % 10)) tryResizeHashTables();
 563         if (server.activerehashing) incrementallyRehash();
 564     }
 565
 566     /* Show information about connected clients */
 567     if (!(loops % 50)) {
 568         redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use",
 569             listLength(server.clients)-listLength(server.slaves),
 570             listLength(server.slaves),
 571             zmalloc_used_memory());
 572     }
 573
 574     /* Close connections of timedout clients */
 575     if ((server.maxidletime && !(loops % 100)) || server.blpop_blocked_clients)
 576         closeTimedoutClients();
 577
 578     /* Check if a background saving or AOF rewrite in progress terminated */
 579     if (server.bgsavechildpid != -1 || server.bgrewritechildpid != -1) {
 580         int statloc;
 581         pid_t pid;
 582
 583         if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
 584             if (pid == server.bgsavechildpid) {
 585                 backgroundSaveDoneHandler(statloc);
 586             } else {
 587                 backgroundRewriteDoneHandler(statloc);
 588             }
 589             updateDictResizePolicy();
 590         }
 591     } else {
 592         /* If there is not a background saving in progress check if
 593          * we have to save now */
 594          time_t now = time(NULL);
 595          for (j = 0; j < server.saveparamslen; j++) {
 596             struct saveparam *sp = server.saveparams+j;
 597
 598             if (server.dirty >= sp->changes &&
 599                 now-server.lastsave > sp->seconds) {
 600                 redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
 601                     sp->changes, sp->seconds);
 602                 rdbSaveBackground(server.dbfilename);
 603                 break;
 604             }
 605          }
 606     }
 607
 608     /* Expire a few keys per cycle, only if this is a master.
 609      * On slaves we wait for DEL operations synthesized by the master
 610      * in order to guarantee a strict consistency. */
 611     if (server.masterhost == NULL) activeExpireCycle();
 612
 613     /* Swap a few keys on disk if we are over the memory limit and VM
 614      * is enbled. Try to free objects from the free list first. */
 615     if (vmCanSwapOut()) {
 616         while (server.vm_enabled && zmalloc_used_memory() >
 617                 server.vm_max_memory)
 618         {
 619             int retval = (server.vm_max_threads == 0) ?
 620                         vmSwapOneObjectBlocking() :
 621                         vmSwapOneObjectThreaded();
 622             if (retval == REDIS_ERR && !(loops % 300) &&
 623                 zmalloc_used_memory() >
 624                 (server.vm_max_memory+server.vm_max_memory/10))
 625             {
 626                 redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
 627             }
 628             /* Note that when using threade I/O we free just one object,
 629              * because anyway when the I/O thread in charge to swap this
 630              * object out will finish, the handler of completed jobs
 631              * will try to swap more objects if we are still out of memory. */
 632             if (retval == REDIS_ERR || server.vm_max_threads > 0) break;
 633         }
 634     }
 635
 636     /* Replication cron function -- used to reconnect to master and
 637      * to detect transfer failures. */
 638     if (!(loops % 10)) replicationCron();
 639
 640     return 100;
 641 }
 642
 643 /* This function gets called every time Redis is entering the
 644  * main loop of the event driven library, that is, before to sleep
 645  * for ready file descriptors. */
 646 void beforeSleep(struct aeEventLoop *eventLoop) {
 647     REDIS_NOTUSED(eventLoop);
 648
 649     /* Awake clients that got all the swapped keys they requested */
 650     if (server.vm_enabled && listLength(server.io_ready_clients)) {
 651         listIter li;
 652         listNode *ln;
 653
 654         listRewind(server.io_ready_clients,&li);
 655         while((ln = listNext(&li))) {
 656             redisClient *c = ln->value;
 657             struct redisCommand *cmd;
 658
 659             /* Resume the client. */
 660             listDelNode(server.io_ready_clients,ln);
 661             c->flags &= (~REDIS_IO_WAIT);
 662             server.vm_blocked_clients--;
 663             aeCreateFileEvent(server.el, c->fd, AE_READABLE,
 664                 readQueryFromClient, c);
 665             cmd = lookupCommand(c->argv[0]->ptr);
 666             redisAssert(cmd != NULL);
 667             call(c,cmd);
 668             resetClient(c);
 669             /* There may be more data to process in the input buffer. */
 670             if (c->querybuf && sdslen(c->querybuf) > 0)
 671                 processInputBuffer(c);
 672         }
 673     }
 674     /* Write the AOF buffer on disk */
 675     flushAppendOnlyFile();
 676 }
 677
 678 /* =========================== Server initialization ======================== */
 679
 680 void createSharedObjects(void) {
 681     int j;
 682
 683     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
 684     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
 685     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
 686     shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
 687     shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
 688     shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
 689     shared.cnegone = createObject(REDIS_STRING,sdsnew(":-1\r\n"));
 690     shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
 691     shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
 692     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
 693     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
 694     shared.queued = createObject(REDIS_STRING,sdsnew("+QUEUED\r\n"));
 695     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
 696         "-ERR Operation against a key holding the wrong kind of value\r\n"));
 697     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
 698         "-ERR no such key\r\n"));
 699     shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
 700         "-ERR syntax error\r\n"));
 701     shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
 702         "-ERR source and destination objects are the same\r\n"));
 703     shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
 704         "-ERR index out of range\r\n"));
 705     shared.space = createObject(REDIS_STRING,sdsnew(" "));
 706     shared.colon = createObject(REDIS_STRING,sdsnew(":"));
 707     shared.plus = createObject(REDIS_STRING,sdsnew("+"));
 708     shared.select0 = createStringObject("select 0\r\n",10);
 709     shared.select1 = createStringObject("select 1\r\n",10);
 710     shared.select2 = createStringObject("select 2\r\n",10);
 711     shared.select3 = createStringObject("select 3\r\n",10);
 712     shared.select4 = createStringObject("select 4\r\n",10);
 713     shared.select5 = createStringObject("select 5\r\n",10);
 714     shared.select6 = createStringObject("select 6\r\n",10);
 715     shared.select7 = createStringObject("select 7\r\n",10);
 716     shared.select8 = createStringObject("select 8\r\n",10);
 717     shared.select9 = createStringObject("select 9\r\n",10);
 718     shared.messagebulk = createStringObject("$7\r\nmessage\r\n",13);
 719     shared.pmessagebulk = createStringObject("$8\r\npmessage\r\n",14);
 720     shared.subscribebulk = createStringObject("$9\r\nsubscribe\r\n",15);
 721     shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18);
 722     shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
 723     shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
 724     shared.mbulk3 = createStringObject("*3\r\n",4);
 725     shared.mbulk4 = createStringObject("*4\r\n",4);
 726     for (j = 0; j < REDIS_SHARED_INTEGERS; j++) {
 727         shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j);
 728         shared.integers[j]->encoding = REDIS_ENCODING_INT;
 729     }
 730 }
 731
 732 void initServerConfig() {
 733     server.port = REDIS_SERVERPORT;
 734     server.bindaddr = NULL;
 735     server.unixsocket = NULL;
 736     server.ipfd = -1;
 737     server.sofd = -1;
 738     server.dbnum = REDIS_DEFAULT_DBNUM;
 739     server.verbosity = REDIS_VERBOSE;
 740     server.maxidletime = REDIS_MAXIDLETIME;
 741     server.saveparams = NULL;
 742     server.logfile = NULL; /* NULL = log on standard output */
 743     server.glueoutputbuf = 1;
 744     server.daemonize = 0;
 745     server.appendonly = 0;
 746     server.appendfsync = APPENDFSYNC_EVERYSEC;
 747     server.no_appendfsync_on_rewrite = 0;
 748     server.lastfsync = time(NULL);
 749     server.appendfd = -1;
 750     server.appendseldb = -1; /* Make sure the first time will not match */
 751     server.pidfile = zstrdup("/var/run/redis.pid");
 752     server.dbfilename = zstrdup("dump.rdb");
 753     server.appendfilename = zstrdup("appendonly.aof");
 754     server.requirepass = NULL;
 755     server.rdbcompression = 1;
 756     server.activerehashing = 1;
 757     server.maxclients = 0;
 758     server.blpop_blocked_clients = 0;
 759     server.maxmemory = 0;
 760     server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;
 761     server.maxmemory_samples = 3;
 762     server.vm_enabled = 0;
 763     server.vm_swap_file = zstrdup("/tmp/redis-%p.vm");
 764     server.vm_page_size = 256;          /* 256 bytes per page */
 765     server.vm_pages = 1024*1024*100;    /* 104 millions of pages */
 766     server.vm_max_memory = 1024LL*1024*1024*1; /* 1 GB of RAM */
 767     server.vm_max_threads = 4;
 768     server.vm_blocked_clients = 0;
 769     server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
 770     server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
 771     server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
 772     server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE;
 773     server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES;
 774     server.shutdown_asap = 0;
 775
 776     updateLRUClock();
 777     resetServerSaveParams();
 778
 779     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
 780     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
 781     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
 782     /* Replication related */
 783     server.isslave = 0;
 784     server.masterauth = NULL;
 785     server.masterhost = NULL;
 786     server.masterport = 6379;
 787     server.master = NULL;
 788     server.replstate = REDIS_REPL_NONE;
 789     server.repl_serve_stale_data = 1;
 790
 791     /* Double constants initialization */
 792     R_Zero = 0.0;
 793     R_PosInf = 1.0/R_Zero;
 794     R_NegInf = -1.0/R_Zero;
 795     R_Nan = R_Zero/R_Zero;
 796
 797     /* Command table -- we intiialize it here as it is part of the
 798      * initial configuration, since command names may be changed via
 799      * redis.conf using the rename-command directive. */
 800     server.commands = dictCreate(&commandTableDictType,NULL);
 801     populateCommandTable();
 802     server.delCommand = lookupCommandByCString("del");
 803     server.multiCommand = lookupCommandByCString("multi");
 804 }
 805
 806 void initServer() {
 807     int j;
 808
 809     signal(SIGHUP, SIG_IGN);
 810     signal(SIGPIPE, SIG_IGN);
 811     setupSigSegvAction();
 812
 813     server.mainthread = pthread_self();
 814     server.devnull = fopen("/dev/null","w");
 815     if (server.devnull == NULL) {
 816         redisLog(REDIS_WARNING, "Can't open /dev/null: %s", server.neterr);
 817         exit(1);
 818     }
 819     server.clients = listCreate();
 820     server.slaves = listCreate();
 821     server.monitors = listCreate();
 822     createSharedObjects();
 823     server.el = aeCreateEventLoop();
 824     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
 825     server.ipfd = anetTcpServer(server.neterr,server.port,server.bindaddr);
 826     if (server.ipfd == ANET_ERR) {
 827         redisLog(REDIS_WARNING, "Opening port: %s", server.neterr);
 828         exit(1);
 829     }
 830     if (server.unixsocket != NULL) {
 831         unlink(server.unixsocket); /* don't care if this fails */
 832         server.sofd = anetUnixServer(server.neterr,server.unixsocket);
 833         if (server.sofd == ANET_ERR) {
 834             redisLog(REDIS_WARNING, "Opening socket: %s", server.neterr);
 835             exit(1);
 836         }
 837     }
 838     if (server.ipfd < 0 && server.sofd < 0) {
 839         redisLog(REDIS_WARNING, "Configured to not listen anywhere, exiting.");
 840         exit(1);
 841     }
 842     for (j = 0; j < server.dbnum; j++) {
 843         server.db[j].dict = dictCreate(&dbDictType,NULL);
 844         server.db[j].expires = dictCreate(&keyptrDictType,NULL);
 845         server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
 846         server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
 847         if (server.vm_enabled)
 848             server.db[j].io_keys = dictCreate(&keylistDictType,NULL);
 849         server.db[j].id = j;
 850     }
 851     server.pubsub_channels = dictCreate(&keylistDictType,NULL);
 852     server.pubsub_patterns = listCreate();
 853     listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
 854     listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
 855     server.cronloops = 0;
 856     server.bgsavechildpid = -1;
 857     server.bgrewritechildpid = -1;
 858     server.bgrewritebuf = sdsempty();
 859     server.aofbuf = sdsempty();
 860     server.lastsave = time(NULL);
 861     server.dirty = 0;
 862     server.stat_numcommands = 0;
 863     server.stat_numconnections = 0;
 864     server.stat_expiredkeys = 0;
 865     server.stat_starttime = time(NULL);
 866     server.stat_keyspace_misses = 0;
 867     server.stat_keyspace_hits = 0;
 868     server.unixtime = time(NULL);
 869     aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
 870     if (server.ipfd > 0 && aeCreateFileEvent(server.el,server.ipfd,AE_READABLE,
 871         acceptTcpHandler,NULL) == AE_ERR) oom("creating file event");
 872     if (server.sofd > 0 && aeCreateFileEvent(server.el,server.sofd,AE_READABLE,
 873         acceptUnixHandler,NULL) == AE_ERR) oom("creating file event");
 874
 875     if (server.appendonly) {
 876         server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
 877         if (server.appendfd == -1) {
 878             redisLog(REDIS_WARNING, "Can't open the append-only file: %s",
 879                 strerror(errno));
 880             exit(1);
 881         }
 882     }
 883
 884     if (server.vm_enabled) vmInit();
 885 }
 886
 887 /* Populates the Redis Command Table starting from the hard coded list
 888  * we have on top of redis.c file. */
 889 void populateCommandTable(void) {
 890     int j;
 891     int numcommands = sizeof(readonlyCommandTable)/sizeof(struct redisCommand);
 892
 893     for (j = 0; j < numcommands; j++) {
 894         struct redisCommand *c = readonlyCommandTable+j;
 895         int retval;
 896
 897         retval = dictAdd(server.commands, sdsnew(c->name), c);
 898         assert(retval == DICT_OK);
 899     }
 900 }
 901
 902 /* ====================== Commands lookup and execution ===================== */
 903
 904 struct redisCommand *lookupCommand(sds name) {
 905     return dictFetchValue(server.commands, name);
 906 }
 907
 908 struct redisCommand *lookupCommandByCString(char *s) {
 909     struct redisCommand *cmd;
 910     sds name = sdsnew(s);
 911
 912     cmd = dictFetchValue(server.commands, name);
 913     sdsfree(name);
 914     return cmd;
 915 }
 916
 917 /* Call() is the core of Redis execution of a command */
 918 void call(redisClient *c, struct redisCommand *cmd) {
 919     long long dirty;
 920
 921     dirty = server.dirty;
 922     cmd->proc(c);
 923     dirty = server.dirty-dirty;
 924
 925     if (server.appendonly && dirty)
 926         feedAppendOnlyFile(cmd,c->db->id,c->argv,c->argc);
 927     if ((dirty || cmd->flags & REDIS_CMD_FORCE_REPLICATION) &&
 928         listLength(server.slaves))
 929         replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
 930     if (listLength(server.monitors))
 931         replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc);
 932     server.stat_numcommands++;
 933 }
 934
 935 /* If this function gets called we already read a whole
 936  * command, argments are in the client argv/argc fields.
 937  * processCommand() execute the command or prepare the
 938  * server for a bulk read from the client.
 939  *
 940  * If 1 is returned the client is still alive and valid and
 941  * and other operations can be performed by the caller. Otherwise
 942  * if 0 is returned the client was destroied (i.e. after QUIT). */
 943 int processCommand(redisClient *c) {
 944     struct redisCommand *cmd;
 945
 946     /* The QUIT command is handled separately. Normal command procs will
 947      * go through checking for replication and QUIT will cause trouble
 948      * when FORCE_REPLICATION is enabled and would be implemented in
 949      * a regular command proc. */
 950     if (!strcasecmp(c->argv[0]->ptr,"quit")) {
 951         addReply(c,shared.ok);
 952         c->flags |= REDIS_CLOSE_AFTER_REPLY;
 953         return REDIS_ERR;
 954     }
 955
 956     /* Now lookup the command and check ASAP about trivial error conditions
 957      * such wrong arity, bad command name and so forth. */
 958     cmd = lookupCommand(c->argv[0]->ptr);
 959     if (!cmd) {
 960         addReplyErrorFormat(c,"unknown command '%s'",
 961             (char*)c->argv[0]->ptr);
 962         return REDIS_OK;
 963     } else if ((cmd->arity > 0 && cmd->arity != c->argc) ||
 964                (c->argc < -cmd->arity)) {
 965         addReplyErrorFormat(c,"wrong number of arguments for '%s' command",
 966             cmd->name);
 967         return REDIS_OK;
 968     }
 969
 970     /* Check if the user is authenticated */
 971     if (server.requirepass && !c->authenticated && cmd->proc != authCommand) {
 972         addReplyError(c,"operation not permitted");
 973         return REDIS_OK;
 974     }
 975
 976     /* Handle the maxmemory directive.
 977      *
 978      * First we try to free some memory if possible (if there are volatile
 979      * keys in the dataset). If there are not the only thing we can do
 980      * is returning an error. */
 981     if (server.maxmemory) freeMemoryIfNeeded();
 982     if (server.maxmemory && (cmd->flags & REDIS_CMD_DENYOOM) &&
 983         zmalloc_used_memory() > server.maxmemory)
 984     {
 985         addReplyError(c,"command not allowed when used memory > 'maxmemory'");
 986         return REDIS_OK;
 987     }
 988
 989     /* Only allow SUBSCRIBE and UNSUBSCRIBE in the context of Pub/Sub */
 990     if ((dictSize(c->pubsub_channels) > 0 || listLength(c->pubsub_patterns) > 0)
 991         &&
 992         cmd->proc != subscribeCommand && cmd->proc != unsubscribeCommand &&
 993         cmd->proc != psubscribeCommand && cmd->proc != punsubscribeCommand) {
 994         addReplyError(c,"only (P)SUBSCRIBE / (P)UNSUBSCRIBE / QUIT allowed in this context");
 995         return REDIS_OK;
 996     }
 997
 998     /* Only allow INFO and SLAVEOF when slave-serve-stale-data is no and
 999      * we are a slave with a broken link with master. */
1000     if (server.masterhost && server.replstate != REDIS_REPL_CONNECTED &&
1001         server.repl_serve_stale_data == 0 &&
1002         cmd->proc != infoCommand && cmd->proc != slaveofCommand)
1003     {
1004         addReplyError(c,
1005             "link with MASTER is down and slave-serve-stale-data is set to no");
1006         return REDIS_OK;
1007     }
1008
1009     /* Exec the command */
1010     if (c->flags & REDIS_MULTI &&
1011         cmd->proc != execCommand && cmd->proc != discardCommand &&
1012         cmd->proc != multiCommand && cmd->proc != watchCommand)
1013     {
1014         queueMultiCommand(c,cmd);
1015         addReply(c,shared.queued);
1016     } else {
1017         if (server.vm_enabled && server.vm_max_threads > 0 &&
1018             blockClientOnSwappedKeys(c,cmd)) return REDIS_ERR;
1019         call(c,cmd);
1020     }
1021     return REDIS_OK;
1022 }
1023
1024 /*================================== Shutdown =============================== */
1025
1026 int prepareForShutdown() {
1027     redisLog(REDIS_WARNING,"User requested shutdown, saving DB...");
1028     /* Kill the saving child if there is a background saving in progress.
1029        We want to avoid race conditions, for instance our saving child may
1030        overwrite the synchronous saving did by SHUTDOWN. */
1031     if (server.bgsavechildpid != -1) {
1032         redisLog(REDIS_WARNING,"There is a live saving child. Killing it!");
1033         kill(server.bgsavechildpid,SIGKILL);
1034         rdbRemoveTempFile(server.bgsavechildpid);
1035     }
1036     if (server.appendonly) {
1037         /* Append only file: fsync() the AOF and exit */
1038         aof_fsync(server.appendfd);
1039         if (server.vm_enabled) unlink(server.vm_swap_file);
1040     } else if (server.saveparamslen > 0) {
1041         /* Snapshotting. Perform a SYNC SAVE and exit */
1042         if (rdbSave(server.dbfilename) != REDIS_OK) {
1043             /* Ooops.. error saving! The best we can do is to continue
1044              * operating. Note that if there was a background saving process,
1045              * in the next cron() Redis will be notified that the background
1046              * saving aborted, handling special stuff like slaves pending for
1047              * synchronization... */
1048             redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit");
1049             return REDIS_ERR;
1050         }
1051     } else {
1052         redisLog(REDIS_WARNING,"Not saving DB.");
1053     }
1054     if (server.daemonize) unlink(server.pidfile);
1055     redisLog(REDIS_WARNING,"Server exit now, bye bye...");
1056     return REDIS_OK;
1057 }
1058
1059 /*================================== Commands =============================== */
1060
1061 void authCommand(redisClient *c) {
1062     if (!server.requirepass || !strcmp(c->argv[1]->ptr, server.requirepass)) {
1063       c->authenticated = 1;
1064       addReply(c,shared.ok);
1065     } else {
1066       c->authenticated = 0;
1067       addReplyError(c,"invalid password");
1068     }
1069 }
1070
1071 void pingCommand(redisClient *c) {
1072     addReply(c,shared.pong);
1073 }
1074
1075 void echoCommand(redisClient *c) {
1076     addReplyBulk(c,c->argv[1]);
1077 }
1078
1079 /* Convert an amount of bytes into a human readable string in the form
1080  * of 100B, 2G, 100M, 4K, and so forth. */
1081 void bytesToHuman(char *s, unsigned long long n) {
1082     double d;
1083
1084     if (n < 1024) {
1085         /* Bytes */
1086         sprintf(s,"%lluB",n);
1087         return;
1088     } else if (n < (1024*1024)) {
1089         d = (double)n/(1024);
1090         sprintf(s,"%.2fK",d);
1091     } else if (n < (1024LL*1024*1024)) {
1092         d = (double)n/(1024*1024);
1093         sprintf(s,"%.2fM",d);
1094     } else if (n < (1024LL*1024*1024*1024)) {
1095         d = (double)n/(1024LL*1024*1024);
1096         sprintf(s,"%.2fG",d);
1097     }
1098 }
1099
1100 /* Create the string returned by the INFO command. This is decoupled
1101  * by the INFO command itself as we need to report the same information
1102  * on memory corruption problems. */
1103 sds genRedisInfoString(void) {
1104     sds info;
1105     time_t uptime = time(NULL)-server.stat_starttime;
1106     int j;
1107     char hmem[64];
1108     struct rusage self_ru, c_ru;
1109
1110     getrusage(RUSAGE_SELF, &self_ru);
1111     getrusage(RUSAGE_CHILDREN, &c_ru);
1112
1113     bytesToHuman(hmem,zmalloc_used_memory());
1114     info = sdscatprintf(sdsempty(),
1115         "redis_version:%s\r\n"
1116         "redis_git_sha1:%s\r\n"
1117         "redis_git_dirty:%d\r\n"
1118         "arch_bits:%s\r\n"
1119         "multiplexing_api:%s\r\n"
1120         "process_id:%ld\r\n"
1121         "uptime_in_seconds:%ld\r\n"
1122         "uptime_in_days:%ld\r\n"
1123         "lru_clock:%ld\r\n"
1124         "used_cpu_sys:%.2f\r\n"
1125         "used_cpu_user:%.2f\r\n"
1126         "used_cpu_sys_childrens:%.2f\r\n"
1127         "used_cpu_user_childrens:%.2f\r\n"
1128         "connected_clients:%d\r\n"
1129         "connected_slaves:%d\r\n"
1130         "blocked_clients:%d\r\n"
1131         "used_memory:%zu\r\n"
1132         "used_memory_human:%s\r\n"
1133         "used_memory_rss:%zu\r\n"
1134         "mem_fragmentation_ratio:%.2f\r\n"
1135         "use_tcmalloc:%d\r\n"
1136         "changes_since_last_save:%lld\r\n"
1137         "bgsave_in_progress:%d\r\n"
1138         "last_save_time:%ld\r\n"
1139         "bgrewriteaof_in_progress:%d\r\n"
1140         "total_connections_received:%lld\r\n"
1141         "total_commands_processed:%lld\r\n"
1142         "expired_keys:%lld\r\n"
1143         "keyspace_hits:%lld\r\n"
1144         "keyspace_misses:%lld\r\n"
1145         "hash_max_zipmap_entries:%zu\r\n"
1146         "hash_max_zipmap_value:%zu\r\n"
1147         "pubsub_channels:%ld\r\n"
1148         "pubsub_patterns:%u\r\n"
1149         "vm_enabled:%d\r\n"
1150         "role:%s\r\n"
1151         ,REDIS_VERSION,
1152         redisGitSHA1(),
1153         strtol(redisGitDirty(),NULL,10) > 0,
1154         (sizeof(long) == 8) ? "64" : "32",
1155         aeGetApiName(),
1156         (long) getpid(),
1157         uptime,
1158         uptime/(3600*24),
1159         (unsigned long) server.lruclock,
1160         (float)self_ru.ru_utime.tv_sec+(float)self_ru.ru_utime.tv_usec/1000000,
1161         (float)self_ru.ru_stime.tv_sec+(float)self_ru.ru_stime.tv_usec/1000000,
1162         (float)c_ru.ru_utime.tv_sec+(float)c_ru.ru_utime.tv_usec/1000000,
1163         (float)c_ru.ru_stime.tv_sec+(float)c_ru.ru_stime.tv_usec/1000000,
1164         listLength(server.clients)-listLength(server.slaves),
1165         listLength(server.slaves),
1166         server.blpop_blocked_clients,
1167         zmalloc_used_memory(),
1168         hmem,
1169         zmalloc_get_rss(),
1170         zmalloc_get_fragmentation_ratio(),
1171 #ifdef USE_TCMALLOC
1172         1,
1173 #else
1174         0,
1175 #endif
1176         server.dirty,
1177         server.bgsavechildpid != -1,
1178         server.lastsave,
1179         server.bgrewritechildpid != -1,
1180         server.stat_numconnections,
1181         server.stat_numcommands,
1182         server.stat_expiredkeys,
1183         server.stat_keyspace_hits,
1184         server.stat_keyspace_misses,
1185         server.hash_max_zipmap_entries,
1186         server.hash_max_zipmap_value,
1187         dictSize(server.pubsub_channels),
1188         listLength(server.pubsub_patterns),
1189         server.vm_enabled != 0,
1190         server.masterhost == NULL ? "master" : "slave"
1191     );
1192     if (server.masterhost) {
1193         info = sdscatprintf(info,
1194             "master_host:%s\r\n"
1195             "master_port:%d\r\n"
1196             "master_link_status:%s\r\n"
1197             "master_last_io_seconds_ago:%d\r\n"
1198             "master_sync_in_progress:%d\r\n"
1199             ,server.masterhost,
1200             server.masterport,
1201             (server.replstate == REDIS_REPL_CONNECTED) ?
1202                 "up" : "down",
1203             server.master ? ((int)(time(NULL)-server.master->lastinteraction)) : -1,
1204             server.replstate == REDIS_REPL_TRANSFER
1205         );
1206
1207         if (server.replstate == REDIS_REPL_TRANSFER) {
1208             info = sdscatprintf(info,
1209                 "master_sync_left_bytes:%ld\r\n"
1210                 "master_sync_last_io_seconds_ago:%d\r\n"
1211                 ,(long)server.repl_transfer_left,
1212                 (int)(time(NULL)-server.repl_transfer_lastio)
1213             );
1214         }
1215     }
1216     if (server.vm_enabled) {
1217         lockThreadedIO();
1218         info = sdscatprintf(info,
1219             "vm_conf_max_memory:%llu\r\n"
1220             "vm_conf_page_size:%llu\r\n"
1221             "vm_conf_pages:%llu\r\n"
1222             "vm_stats_used_pages:%llu\r\n"
1223             "vm_stats_swapped_objects:%llu\r\n"
1224             "vm_stats_swappin_count:%llu\r\n"
1225             "vm_stats_swappout_count:%llu\r\n"
1226             "vm_stats_io_newjobs_len:%lu\r\n"
1227             "vm_stats_io_processing_len:%lu\r\n"
1228             "vm_stats_io_processed_len:%lu\r\n"
1229             "vm_stats_io_active_threads:%lu\r\n"
1230             "vm_stats_blocked_clients:%lu\r\n"
1231             ,(unsigned long long) server.vm_max_memory,
1232             (unsigned long long) server.vm_page_size,
1233             (unsigned long long) server.vm_pages,
1234             (unsigned long long) server.vm_stats_used_pages,
1235             (unsigned long long) server.vm_stats_swapped_objects,
1236             (unsigned long long) server.vm_stats_swapins,
1237             (unsigned long long) server.vm_stats_swapouts,
1238             (unsigned long) listLength(server.io_newjobs),
1239             (unsigned long) listLength(server.io_processing),
1240             (unsigned long) listLength(server.io_processed),
1241             (unsigned long) server.io_active_threads,
1242             (unsigned long) server.vm_blocked_clients
1243         );
1244         unlockThreadedIO();
1245     }
1246     for (j = 0; j < server.dbnum; j++) {
1247         long long keys, vkeys;
1248
1249         keys = dictSize(server.db[j].dict);
1250         vkeys = dictSize(server.db[j].expires);
1251         if (keys || vkeys) {
1252             info = sdscatprintf(info, "db%d:keys=%lld,expires=%lld\r\n",
1253                 j, keys, vkeys);
1254         }
1255     }
1256     return info;
1257 }
1258
1259 void infoCommand(redisClient *c) {
1260     sds info = genRedisInfoString();
1261     addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
1262         (unsigned long)sdslen(info)));
1263     addReplySds(c,info);
1264     addReply(c,shared.crlf);
1265 }
1266
1267 void monitorCommand(redisClient *c) {
1268     /* ignore MONITOR if aleady slave or in monitor mode */
1269     if (c->flags & REDIS_SLAVE) return;
1270
1271     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
1272     c->slaveseldb = 0;
1273     listAddNodeTail(server.monitors,c);
1274     addReply(c,shared.ok);
1275 }
1276
1277 /* ============================ Maxmemory directive  ======================== */
1278
1279 /* This function gets called when 'maxmemory' is set on the config file to limit
1280  * the max memory used by the server, and we are out of memory.
1281  * This function will try to, in order:
1282  *
1283  * - Free objects from the free list
1284  * - Try to remove keys with an EXPIRE set
1285  *
1286  * It is not possible to free enough memory to reach used-memory < maxmemory
1287  * the server will start refusing commands that will enlarge even more the
1288  * memory usage.
1289  */
1290 void freeMemoryIfNeeded(void) {
1291     /* Remove keys accordingly to the active policy as long as we are
1292      * over the memory limit. */
1293     while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) {
1294         int j, k, freed = 0;
1295
1296         for (j = 0; j < server.dbnum; j++) {
1297             long bestval = 0; /* just to prevent warning */
1298             sds bestkey = NULL;
1299             struct dictEntry *de;
1300             redisDb *db = server.db+j;
1301             dict *dict;
1302
1303             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1304                 server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM)
1305             {
1306                 dict = server.db[j].dict;
1307             } else {
1308                 dict = server.db[j].expires;
1309             }
1310             if (dictSize(dict) == 0) continue;
1311
1312             /* volatile-random and allkeys-random policy */
1313             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM ||
1314                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_RANDOM)
1315             {
1316                 de = dictGetRandomKey(dict);
1317                 bestkey = dictGetEntryKey(de);
1318             }
1319
1320             /* volatile-lru and allkeys-lru policy */
1321             else if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1322                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_LRU)
1323             {
1324                 for (k = 0; k < server.maxmemory_samples; k++) {
1325                     sds thiskey;
1326                     long thisval;
1327                     robj *o;
1328
1329                     de = dictGetRandomKey(dict);
1330                     thiskey = dictGetEntryKey(de);
1331                     o = dictGetEntryVal(de);
1332                     thisval = estimateObjectIdleTime(o);
1333
1334                     /* Higher idle time is better candidate for deletion */
1335                     if (bestkey == NULL || thisval > bestval) {
1336                         bestkey = thiskey;
1337                         bestval = thisval;
1338                     }
1339                 }
1340             }
1341
1342             /* volatile-ttl */
1343             else if (server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_TTL) {
1344                 for (k = 0; k < server.maxmemory_samples; k++) {
1345                     sds thiskey;
1346                     long thisval;
1347
1348                     de = dictGetRandomKey(dict);
1349                     thiskey = dictGetEntryKey(de);
1350                     thisval = (long) dictGetEntryVal(de);
1351
1352                     /* Expire sooner (minor expire unix timestamp) is better
1353                      * candidate for deletion */
1354                     if (bestkey == NULL || thisval < bestval) {
1355                         bestkey = thiskey;
1356                         bestval = thisval;
1357                     }
1358                 }
1359             }
1360
1361             /* Finally remove the selected key. */
1362             if (bestkey) {
1363                 robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
1364                 dbDelete(db,keyobj);
1365                 server.stat_expiredkeys++;
1366                 decrRefCount(keyobj);
1367                 freed++;
1368             }
1369         }
1370         if (!freed) return; /* nothing to free... */
1371     }
1372
1373     while(0) {
1374         int j, k, freed = 0;
1375         for (j = 0; j < server.dbnum; j++) {
1376             int minttl = -1;
1377             sds minkey = NULL;
1378             robj *keyobj = NULL;
1379             struct dictEntry *de;
1380
1381             if (dictSize(server.db[j].expires)) {
1382                 freed = 1;
1383                 /* From a sample of three keys drop the one nearest to
1384                  * the natural expire */
1385                 for (k = 0; k < 3; k++) {
1386                     time_t t;
1387
1388                     de = dictGetRandomKey(server.db[j].expires);
1389                     t = (time_t) dictGetEntryVal(de);
1390                     if (minttl == -1 || t < minttl) {
1391                         minkey = dictGetEntryKey(de);
1392                         minttl = t;
1393                     }
1394                 }
1395                 keyobj = createStringObject(minkey,sdslen(minkey));
1396                 dbDelete(server.db+j,keyobj);
1397                 server.stat_expiredkeys++;
1398                 decrRefCount(keyobj);
1399             }
1400         }
1401         if (!freed) return; /* nothing to free... */
1402     }
1403 }
1404
1405 /* =================================== Main! ================================ */
1406
1407 #ifdef __linux__
1408 int linuxOvercommitMemoryValue(void) {
1409     FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
1410     char buf[64];
1411
1412     if (!fp) return -1;
1413     if (fgets(buf,64,fp) == NULL) {
1414         fclose(fp);
1415         return -1;
1416     }
1417     fclose(fp);
1418
1419     return atoi(buf);
1420 }
1421
1422 void linuxOvercommitMemoryWarning(void) {
1423     if (linuxOvercommitMemoryValue() == 0) {
1424         redisLog(REDIS_WARNING,"WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.");
1425     }
1426 }
1427 #endif /* __linux__ */
1428
1429 void createPidFile(void) {
1430     /* Try to write the pid file in a best-effort way. */
1431     FILE *fp = fopen(server.pidfile,"w");
1432     if (fp) {
1433         fprintf(fp,"%d\n",getpid());
1434         fclose(fp);
1435     }
1436 }
1437
1438 void daemonize(void) {
1439     int fd;
1440
1441     if (fork() != 0) exit(0); /* parent exits */
1442     setsid(); /* create a new session */
1443
1444     /* Every output goes to /dev/null. If Redis is daemonized but
1445      * the 'logfile' is set to 'stdout' in the configuration file
1446      * it will not log at all. */
1447     if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
1448         dup2(fd, STDIN_FILENO);
1449         dup2(fd, STDOUT_FILENO);
1450         dup2(fd, STDERR_FILENO);
1451         if (fd > STDERR_FILENO) close(fd);
1452     }
1453 }
1454
1455 void version() {
1456     printf("Redis server version %s (%s:%d)\n", REDIS_VERSION,
1457         redisGitSHA1(), atoi(redisGitDirty()) > 0);
1458     exit(0);
1459 }
1460
1461 void usage() {
1462     fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
1463     fprintf(stderr,"       ./redis-server - (read config from stdin)\n");
1464     exit(1);
1465 }
1466
1467 int main(int argc, char **argv) {
1468     time_t start;
1469
1470     initServerConfig();
1471     if (argc == 2) {
1472         if (strcmp(argv[1], "-v") == 0 ||
1473             strcmp(argv[1], "--version") == 0) version();
1474         if (strcmp(argv[1], "--help") == 0) usage();
1475         resetServerSaveParams();
1476         loadServerConfig(argv[1]);
1477     } else if ((argc > 2)) {
1478         usage();
1479     } else {
1480         redisLog(REDIS_WARNING,"Warning: no config file specified, using the default config. In order to specify a config file use 'redis-server /path/to/redis.conf'");
1481     }
1482     if (server.daemonize) daemonize();
1483     initServer();
1484     if (server.daemonize) createPidFile();
1485     redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
1486 #ifdef __linux__
1487     linuxOvercommitMemoryWarning();
1488 #endif
1489     start = time(NULL);
1490     if (server.appendonly) {
1491         if (loadAppendOnlyFile(server.appendfilename) == REDIS_OK)
1492             redisLog(REDIS_NOTICE,"DB loaded from append only file: %ld seconds",time(NULL)-start);
1493     } else {
1494         if (rdbLoad(server.dbfilename) == REDIS_OK)
1495             redisLog(REDIS_NOTICE,"DB loaded from disk: %ld seconds",time(NULL)-start);
1496     }
1497     if (server.ipfd > 0)
1498         redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
1499     if (server.sofd > 0)
1500         redisLog(REDIS_NOTICE,"The server is now ready to accept connections at %s", server.unixsocket);
1501     aeSetBeforeSleepProc(server.el,beforeSleep);
1502     aeMain(server.el);
1503     aeDeleteEventLoop(server.el);
1504     return 0;
1505 }
1506
1507 /* ============================= Backtrace support ========================= */
1508
1509 #ifdef HAVE_BACKTRACE
1510 void *getMcontextEip(ucontext_t *uc) {
1511 #if defined(__FreeBSD__)
1512     return (void*) uc->uc_mcontext.mc_eip;
1513 #elif defined(__dietlibc__)
1514     return (void*) uc->uc_mcontext.eip;
1515 #elif defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
1516   #if __x86_64__
1517     return (void*) uc->uc_mcontext->__ss.__rip;
1518   #else
1519     return (void*) uc->uc_mcontext->__ss.__eip;
1520   #endif
1521 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
1522   #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
1523     return (void*) uc->uc_mcontext->__ss.__rip;
1524   #else
1525     return (void*) uc->uc_mcontext->__ss.__eip;
1526   #endif
1527 #elif defined(__i386__)
1528     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
1529 #elif defined(__X86_64__) || defined(__x86_64__)
1530     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
1531 #elif defined(__ia64__) /* Linux IA64 */
1532     return (void*) uc->uc_mcontext.sc_ip;
1533 #else
1534     return NULL;
1535 #endif
1536 }
1537
1538 void segvHandler(int sig, siginfo_t *info, void *secret) {
1539     void *trace[100];
1540     char **messages = NULL;
1541     int i, trace_size = 0;
1542     ucontext_t *uc = (ucontext_t*) secret;
1543     sds infostring;
1544     struct sigaction act;
1545     REDIS_NOTUSED(info);
1546
1547     redisLog(REDIS_WARNING,
1548         "======= Ooops! Redis %s got signal: -%d- =======", REDIS_VERSION, sig);
1549     infostring = genRedisInfoString();
1550     redisLog(REDIS_WARNING, "%s",infostring);
1551     /* It's not safe to sdsfree() the returned string under memory
1552      * corruption conditions. Let it leak as we are going to abort */
1553
1554     trace_size = backtrace(trace, 100);
1555     /* overwrite sigaction with caller's address */
1556     if (getMcontextEip(uc) != NULL) {
1557         trace[1] = getMcontextEip(uc);
1558     }
1559     messages = backtrace_symbols(trace, trace_size);
1560
1561     for (i=1; i<trace_size; ++i)
1562         redisLog(REDIS_WARNING,"%s", messages[i]);
1563
1564     /* free(messages); Don't call free() with possibly corrupted memory. */
1565     if (server.daemonize) unlink(server.pidfile);
1566
1567     /* Make sure we exit with the right signal at the end. So for instance
1568      * the core will be dumped if enabled. */
1569     sigemptyset (&act.sa_mask);
1570     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction
1571      * is used. Otherwise, sa_handler is used */
1572     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1573     act.sa_handler = SIG_DFL;
1574     sigaction (sig, &act, NULL);
1575     kill(getpid(),sig);
1576 }
1577
1578 void sigtermHandler(int sig) {
1579     REDIS_NOTUSED(sig);
1580
1581     redisLog(REDIS_WARNING,"SIGTERM received, scheduling shutting down...");
1582     server.shutdown_asap = 1;
1583 }
1584
1585 void setupSigSegvAction(void) {
1586     struct sigaction act;
1587
1588     sigemptyset (&act.sa_mask);
1589     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction
1590      * is used. Otherwise, sa_handler is used */
1591     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
1592     act.sa_sigaction = segvHandler;
1593     sigaction (SIGSEGV, &act, NULL);
1594     sigaction (SIGBUS, &act, NULL);
1595     sigaction (SIGFPE, &act, NULL);
1596     sigaction (SIGILL, &act, NULL);
1597     sigaction (SIGBUS, &act, NULL);
1598
1599     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1600     act.sa_handler = sigtermHandler;
1601     sigaction (SIGTERM, &act, NULL);
1602     return;
1603 }
1604
1605 #else /* HAVE_BACKTRACE */
1606 void setupSigSegvAction(void) {
1607 }
1608 #endif /* HAVE_BACKTRACE */
1609
1610 /* The End */