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 void dictRedisObjectDestructor(void *privdata, void *val)
 256 {
 257     DICT_NOTUSED(privdata);
 258
 259     if (val == NULL) return; /* Values of swapped out keys as set to NULL */
 260     decrRefCount(val);
 261 }
 262
 263 void dictSdsDestructor(void *privdata, void *val)
 264 {
 265     DICT_NOTUSED(privdata);
 266
 267     sdsfree(val);
 268 }
 269
 270 int dictObjKeyCompare(void *privdata, const void *key1,
 271         const void *key2)
 272 {
 273     const robj *o1 = key1, *o2 = key2;
 274     return dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 275 }
 276
 277 unsigned int dictObjHash(const void *key) {
 278     const robj *o = key;
 279     return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 280 }
 281
 282 unsigned int dictSdsHash(const void *key) {
 283     return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
 284 }
 285
 286 int dictEncObjKeyCompare(void *privdata, const void *key1,
 287         const void *key2)
 288 {
 289     robj *o1 = (robj*) key1, *o2 = (robj*) key2;
 290     int cmp;
 291
 292     if (o1->encoding == REDIS_ENCODING_INT &&
 293         o2->encoding == REDIS_ENCODING_INT)
 294             return o1->ptr == o2->ptr;
 295
 296     o1 = getDecodedObject(o1);
 297     o2 = getDecodedObject(o2);
 298     cmp = dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 299     decrRefCount(o1);
 300     decrRefCount(o2);
 301     return cmp;
 302 }
 303
 304 unsigned int dictEncObjHash(const void *key) {
 305     robj *o = (robj*) key;
 306
 307     if (o->encoding == REDIS_ENCODING_RAW) {
 308         return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 309     } else {
 310         if (o->encoding == REDIS_ENCODING_INT) {
 311             char buf[32];
 312             int len;
 313
 314             len = ll2string(buf,32,(long)o->ptr);
 315             return dictGenHashFunction((unsigned char*)buf, len);
 316         } else {
 317             unsigned int hash;
 318
 319             o = getDecodedObject(o);
 320             hash = dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 321             decrRefCount(o);
 322             return hash;
 323         }
 324     }
 325 }
 326
 327 /* Sets type */
 328 dictType setDictType = {
 329     dictEncObjHash,            /* hash function */
 330     NULL,                      /* key dup */
 331     NULL,                      /* val dup */
 332     dictEncObjKeyCompare,      /* key compare */
 333     dictRedisObjectDestructor, /* key destructor */
 334     NULL                       /* val destructor */
 335 };
 336
 337 /* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
 338 dictType zsetDictType = {
 339     dictEncObjHash,            /* hash function */
 340     NULL,                      /* key dup */
 341     NULL,                      /* val dup */
 342     dictEncObjKeyCompare,      /* key compare */
 343     dictRedisObjectDestructor, /* key destructor */
 344     NULL                       /* val destructor */
 345 };
 346
 347 /* Db->dict, keys are sds strings, vals are Redis objects. */
 348 dictType dbDictType = {
 349     dictSdsHash,                /* hash function */
 350     NULL,                       /* key dup */
 351     NULL,                       /* val dup */
 352     dictSdsKeyCompare,          /* key compare */
 353     dictSdsDestructor,          /* key destructor */
 354     dictRedisObjectDestructor   /* val destructor */
 355 };
 356
 357 /* Db->expires */
 358 dictType keyptrDictType = {
 359     dictSdsHash,               /* hash function */
 360     NULL,                      /* key dup */
 361     NULL,                      /* val dup */
 362     dictSdsKeyCompare,         /* key compare */
 363     NULL,                      /* key destructor */
 364     NULL                       /* val destructor */
 365 };
 366
 367 /* Hash type hash table (note that small hashes are represented with zimpaps) */
 368 dictType hashDictType = {
 369     dictEncObjHash,             /* hash function */
 370     NULL,                       /* key dup */
 371     NULL,                       /* val dup */
 372     dictEncObjKeyCompare,       /* key compare */
 373     dictRedisObjectDestructor,  /* key destructor */
 374     dictRedisObjectDestructor   /* val destructor */
 375 };
 376
 377 /* Keylist hash table type has unencoded redis objects as keys and
 378  * lists as values. It's used for blocking operations (BLPOP) and to
 379  * map swapped keys to a list of clients waiting for this keys to be loaded. */
 380 dictType keylistDictType = {
 381     dictObjHash,                /* hash function */
 382     NULL,                       /* key dup */
 383     NULL,                       /* val dup */
 384     dictObjKeyCompare,          /* key compare */
 385     dictRedisObjectDestructor,  /* key destructor */
 386     dictListDestructor          /* val destructor */
 387 };
 388
 389 int htNeedsResize(dict *dict) {
 390     long long size, used;
 391
 392     size = dictSlots(dict);
 393     used = dictSize(dict);
 394     return (size && used && size > DICT_HT_INITIAL_SIZE &&
 395             (used*100/size < REDIS_HT_MINFILL));
 396 }
 397
 398 /* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
 399  * we resize the hash table to save memory */
 400 void tryResizeHashTables(void) {
 401     int j;
 402
 403     for (j = 0; j < server.dbnum; j++) {
 404         if (htNeedsResize(server.db[j].dict))
 405             dictResize(server.db[j].dict);
 406         if (htNeedsResize(server.db[j].expires))
 407             dictResize(server.db[j].expires);
 408     }
 409 }
 410
 411 /* Our hash table implementation performs rehashing incrementally while
 412  * we write/read from the hash table. Still if the server is idle, the hash
 413  * table will use two tables for a long time. So we try to use 1 millisecond
 414  * of CPU time at every serverCron() loop in order to rehash some key. */
 415 void incrementallyRehash(void) {
 416     int j;
 417
 418     for (j = 0; j < server.dbnum; j++) {
 419         if (dictIsRehashing(server.db[j].dict)) {
 420             dictRehashMilliseconds(server.db[j].dict,1);
 421             break; /* already used our millisecond for this loop... */
 422         }
 423     }
 424 }
 425
 426 /* This function is called once a background process of some kind terminates,
 427  * as we want to avoid resizing the hash tables when there is a child in order
 428  * to play well with copy-on-write (otherwise when a resize happens lots of
 429  * memory pages are copied). The goal of this function is to update the ability
 430  * for dict.c to resize the hash tables accordingly to the fact we have o not
 431  * running childs. */
 432 void updateDictResizePolicy(void) {
 433     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
 434         dictEnableResize();
 435     else
 436         dictDisableResize();
 437 }
 438
 439 /* ======================= Cron: called every 100 ms ======================== */
 440
 441 /* Try to expire a few timed out keys. The algorithm used is adaptive and
 442  * will use few CPU cycles if there are few expiring keys, otherwise
 443  * it will get more aggressive to avoid that too much memory is used by
 444  * keys that can be removed from the keyspace. */
 445 void activeExpireCycle(void) {
 446     int j;
 447
 448     for (j = 0; j < server.dbnum; j++) {
 449         int expired;
 450         redisDb *db = server.db+j;
 451
 452         /* Continue to expire if at the end of the cycle more than 25%
 453          * of the keys were expired. */
 454         do {
 455             long num = dictSize(db->expires);
 456             time_t now = time(NULL);
 457
 458             expired = 0;
 459             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
 460                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
 461             while (num--) {
 462                 dictEntry *de;
 463                 time_t t;
 464
 465                 if ((de = dictGetRandomKey(db->expires)) == NULL) break;
 466                 t = (time_t) dictGetEntryVal(de);
 467                 if (now > t) {
 468                     sds key = dictGetEntryKey(de);
 469                     robj *keyobj = createStringObject(key,sdslen(key));
 470
 471                     propagateExpire(db,keyobj);
 472                     dbDelete(db,keyobj);
 473                     decrRefCount(keyobj);
 474                     expired++;
 475                     server.stat_expiredkeys++;
 476                 }
 477             }
 478         } while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
 479     }
 480 }
 481
 482 void updateLRUClock(void) {
 483     server.lruclock = (time(NULL)/REDIS_LRU_CLOCK_RESOLUTION) &
 484                                                 REDIS_LRU_CLOCK_MAX;
 485 }
 486
 487 int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 488     int j, loops = server.cronloops++;
 489     REDIS_NOTUSED(eventLoop);
 490     REDIS_NOTUSED(id);
 491     REDIS_NOTUSED(clientData);
 492
 493     /* We take a cached value of the unix time in the global state because
 494      * with virtual memory and aging there is to store the current time
 495      * in objects at every object access, and accuracy is not needed.
 496      * To access a global var is faster than calling time(NULL) */
 497     server.unixtime = time(NULL);
 498     /* We have just 22 bits per object for LRU information.
 499      * So we use an (eventually wrapping) LRU clock with 10 seconds resolution.
 500      * 2^22 bits with 10 seconds resoluton is more or less 1.5 years.
 501      *
 502      * Note that even if this will wrap after 1.5 years it's not a problem,
 503      * everything will still work but just some object will appear younger
 504      * to Redis. But for this to happen a given object should never be touched
 505      * for 1.5 years.
 506      *
 507      * Note that you can change the resolution altering the
 508      * REDIS_LRU_CLOCK_RESOLUTION define.
 509      */
 510     updateLRUClock();
 511
 512     /* We received a SIGTERM, shutting down here in a safe way, as it is
 513      * not ok doing so inside the signal handler. */
 514     if (server.shutdown_asap) {
 515         if (prepareForShutdown() == REDIS_OK) exit(0);
 516         redisLog(REDIS_WARNING,"SIGTERM received but errors trying to shut down the server, check the logs for more information");
 517     }
 518
 519     /* Show some info about non-empty databases */
 520     for (j = 0; j < server.dbnum; j++) {
 521         long long size, used, vkeys;
 522
 523         size = dictSlots(server.db[j].dict);
 524         used = dictSize(server.db[j].dict);
 525         vkeys = dictSize(server.db[j].expires);
 526         if (!(loops % 50) && (used || vkeys)) {
 527             redisLog(REDIS_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
 528             /* dictPrintStats(server.dict); */
 529         }
 530     }
 531
 532     /* We don't want to resize the hash tables while a bacground saving
 533      * is in progress: the saving child is created using fork() that is
 534      * implemented with a copy-on-write semantic in most modern systems, so
 535      * if we resize the HT while there is the saving child at work actually
 536      * a lot of memory movements in the parent will cause a lot of pages
 537      * copied. */
 538     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) {
 539         if (!(loops % 10)) tryResizeHashTables();
 540         if (server.activerehashing) incrementallyRehash();
 541     }
 542
 543     /* Show information about connected clients */
 544     if (!(loops % 50)) {
 545         redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use",
 546             listLength(server.clients)-listLength(server.slaves),
 547             listLength(server.slaves),
 548             zmalloc_used_memory());
 549     }
 550
 551     /* Close connections of timedout clients */
 552     if ((server.maxidletime && !(loops % 100)) || server.blpop_blocked_clients)
 553         closeTimedoutClients();
 554
 555     /* Check if a background saving or AOF rewrite in progress terminated */
 556     if (server.bgsavechildpid != -1 || server.bgrewritechildpid != -1) {
 557         int statloc;
 558         pid_t pid;
 559
 560         if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
 561             if (pid == server.bgsavechildpid) {
 562                 backgroundSaveDoneHandler(statloc);
 563             } else {
 564                 backgroundRewriteDoneHandler(statloc);
 565             }
 566             updateDictResizePolicy();
 567         }
 568     } else {
 569         /* If there is not a background saving in progress check if
 570          * we have to save now */
 571          time_t now = time(NULL);
 572          for (j = 0; j < server.saveparamslen; j++) {
 573             struct saveparam *sp = server.saveparams+j;
 574
 575             if (server.dirty >= sp->changes &&
 576                 now-server.lastsave > sp->seconds) {
 577                 redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
 578                     sp->changes, sp->seconds);
 579                 rdbSaveBackground(server.dbfilename);
 580                 break;
 581             }
 582          }
 583     }
 584
 585     /* Expire a few keys per cycle, only if this is a master.
 586      * On slaves we wait for DEL operations synthesized by the master
 587      * in order to guarantee a strict consistency. */
 588     if (server.masterhost == NULL) activeExpireCycle();
 589
 590     /* Swap a few keys on disk if we are over the memory limit and VM
 591      * is enbled. Try to free objects from the free list first. */
 592     if (vmCanSwapOut()) {
 593         while (server.vm_enabled && zmalloc_used_memory() >
 594                 server.vm_max_memory)
 595         {
 596             int retval;
 597
 598             if (tryFreeOneObjectFromFreelist() == REDIS_OK) continue;
 599             retval = (server.vm_max_threads == 0) ?
 600                         vmSwapOneObjectBlocking() :
 601                         vmSwapOneObjectThreaded();
 602             if (retval == REDIS_ERR && !(loops % 300) &&
 603                 zmalloc_used_memory() >
 604                 (server.vm_max_memory+server.vm_max_memory/10))
 605             {
 606                 redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
 607             }
 608             /* Note that when using threade I/O we free just one object,
 609              * because anyway when the I/O thread in charge to swap this
 610              * object out will finish, the handler of completed jobs
 611              * will try to swap more objects if we are still out of memory. */
 612             if (retval == REDIS_ERR || server.vm_max_threads > 0) break;
 613         }
 614     }
 615
 616     /* Check if we should connect to a MASTER */
 617     if (server.replstate == REDIS_REPL_CONNECT && !(loops % 10)) {
 618         redisLog(REDIS_NOTICE,"Connecting to MASTER...");
 619         if (syncWithMaster() == REDIS_OK) {
 620             redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync succeeded");
 621             if (server.appendonly) rewriteAppendOnlyFileBackground();
 622         }
 623     }
 624
 625     /* Update fragmentation info, used for fast RSS estimation */
 626     if (!(loops % 10)) server.fragmentation = zmalloc_get_fragmentation_ratio();
 627     return 100;
 628 }
 629
 630 /* This function gets called every time Redis is entering the
 631  * main loop of the event driven library, that is, before to sleep
 632  * for ready file descriptors. */
 633 void beforeSleep(struct aeEventLoop *eventLoop) {
 634     REDIS_NOTUSED(eventLoop);
 635
 636     /* Awake clients that got all the swapped keys they requested */
 637     if (server.vm_enabled && listLength(server.io_ready_clients)) {
 638         listIter li;
 639         listNode *ln;
 640
 641         listRewind(server.io_ready_clients,&li);
 642         while((ln = listNext(&li))) {
 643             redisClient *c = ln->value;
 644             struct redisCommand *cmd;
 645
 646             /* Resume the client. */
 647             listDelNode(server.io_ready_clients,ln);
 648             c->flags &= (~REDIS_IO_WAIT);
 649             server.vm_blocked_clients--;
 650             aeCreateFileEvent(server.el, c->fd, AE_READABLE,
 651                 readQueryFromClient, c);
 652             cmd = lookupCommand(c->argv[0]->ptr);
 653             redisAssert(cmd != NULL);
 654             call(c,cmd);
 655             resetClient(c);
 656             /* There may be more data to process in the input buffer. */
 657             if (c->querybuf && sdslen(c->querybuf) > 0)
 658                 processInputBuffer(c);
 659         }
 660     }
 661     /* Write the AOF buffer on disk */
 662     flushAppendOnlyFile();
 663 }
 664
 665 /* =========================== Server initialization ======================== */
 666
 667 void createSharedObjects(void) {
 668     int j;
 669
 670     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
 671     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
 672     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
 673     shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
 674     shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
 675     shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
 676     shared.cnegone = createObject(REDIS_STRING,sdsnew(":-1\r\n"));
 677     shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
 678     shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
 679     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
 680     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
 681     shared.queued = createObject(REDIS_STRING,sdsnew("+QUEUED\r\n"));
 682     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
 683         "-ERR Operation against a key holding the wrong kind of value\r\n"));
 684     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
 685         "-ERR no such key\r\n"));
 686     shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
 687         "-ERR syntax error\r\n"));
 688     shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
 689         "-ERR source and destination objects are the same\r\n"));
 690     shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
 691         "-ERR index out of range\r\n"));
 692     shared.space = createObject(REDIS_STRING,sdsnew(" "));
 693     shared.colon = createObject(REDIS_STRING,sdsnew(":"));
 694     shared.plus = createObject(REDIS_STRING,sdsnew("+"));
 695     shared.select0 = createStringObject("select 0\r\n",10);
 696     shared.select1 = createStringObject("select 1\r\n",10);
 697     shared.select2 = createStringObject("select 2\r\n",10);
 698     shared.select3 = createStringObject("select 3\r\n",10);
 699     shared.select4 = createStringObject("select 4\r\n",10);
 700     shared.select5 = createStringObject("select 5\r\n",10);
 701     shared.select6 = createStringObject("select 6\r\n",10);
 702     shared.select7 = createStringObject("select 7\r\n",10);
 703     shared.select8 = createStringObject("select 8\r\n",10);
 704     shared.select9 = createStringObject("select 9\r\n",10);
 705     shared.messagebulk = createStringObject("$7\r\nmessage\r\n",13);
 706     shared.pmessagebulk = createStringObject("$8\r\npmessage\r\n",14);
 707     shared.subscribebulk = createStringObject("$9\r\nsubscribe\r\n",15);
 708     shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18);
 709     shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
 710     shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
 711     shared.mbulk3 = createStringObject("*3\r\n",4);
 712     shared.mbulk4 = createStringObject("*4\r\n",4);
 713     for (j = 0; j < REDIS_SHARED_INTEGERS; j++) {
 714         shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j);
 715         shared.integers[j]->encoding = REDIS_ENCODING_INT;
 716     }
 717 }
 718
 719 void initServerConfig() {
 720     server.dbnum = REDIS_DEFAULT_DBNUM;
 721     server.port = REDIS_SERVERPORT;
 722     server.verbosity = REDIS_VERBOSE;
 723     server.maxidletime = REDIS_MAXIDLETIME;
 724     server.saveparams = NULL;
 725     server.logfile = NULL; /* NULL = log on standard output */
 726     server.bindaddr = NULL;
 727     server.glueoutputbuf = 1;
 728     server.daemonize = 0;
 729     server.appendonly = 0;
 730     server.appendfsync = APPENDFSYNC_EVERYSEC;
 731     server.no_appendfsync_on_rewrite = 0;
 732     server.lastfsync = time(NULL);
 733     server.appendfd = -1;
 734     server.appendseldb = -1; /* Make sure the first time will not match */
 735     server.pidfile = zstrdup("/var/run/redis.pid");
 736     server.dbfilename = zstrdup("dump.rdb");
 737     server.appendfilename = zstrdup("appendonly.aof");
 738     server.requirepass = NULL;
 739     server.rdbcompression = 1;
 740     server.activerehashing = 1;
 741     server.fragmentation = 1;
 742     server.maxclients = 0;
 743     server.blpop_blocked_clients = 0;
 744     server.maxmemory = 0;
 745     server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;
 746     server.maxmemory_samples = 3;
 747     server.vm_enabled = 0;
 748     server.vm_swap_file = zstrdup("/tmp/redis-%p.vm");
 749     server.vm_page_size = 256;          /* 256 bytes per page */
 750     server.vm_pages = 1024*1024*100;    /* 104 millions of pages */
 751     server.vm_max_memory = 1024LL*1024*1024*1; /* 1 GB of RAM */
 752     server.vm_max_threads = 4;
 753     server.vm_blocked_clients = 0;
 754     server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
 755     server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
 756     server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
 757     server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE;
 758     server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES;
 759     server.shutdown_asap = 0;
 760
 761     updateLRUClock();
 762     resetServerSaveParams();
 763
 764     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
 765     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
 766     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
 767     /* Replication related */
 768     server.isslave = 0;
 769     server.masterauth = NULL;
 770     server.masterhost = NULL;
 771     server.masterport = 6379;
 772     server.master = NULL;
 773     server.replstate = REDIS_REPL_NONE;
 774
 775     /* Double constants initialization */
 776     R_Zero = 0.0;
 777     R_PosInf = 1.0/R_Zero;
 778     R_NegInf = -1.0/R_Zero;
 779     R_Nan = R_Zero/R_Zero;
 780 }
 781
 782 void initServer() {
 783     int j;
 784
 785     signal(SIGHUP, SIG_IGN);
 786     signal(SIGPIPE, SIG_IGN);
 787     setupSigSegvAction();
 788
 789     server.mainthread = pthread_self();
 790     server.devnull = fopen("/dev/null","w");
 791     if (server.devnull == NULL) {
 792         redisLog(REDIS_WARNING, "Can't open /dev/null: %s", server.neterr);
 793         exit(1);
 794     }
 795     server.clients = listCreate();
 796     server.slaves = listCreate();
 797     server.monitors = listCreate();
 798     server.objfreelist = listCreate();
 799     createSharedObjects();
 800     server.el = aeCreateEventLoop();
 801     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
 802     server.fd = anetTcpServer(server.neterr, server.port, server.bindaddr);
 803     if (server.fd == -1) {
 804         redisLog(REDIS_WARNING, "Opening TCP port: %s", server.neterr);
 805         exit(1);
 806     }
 807     for (j = 0; j < server.dbnum; j++) {
 808         server.db[j].dict = dictCreate(&dbDictType,NULL);
 809         server.db[j].expires = dictCreate(&keyptrDictType,NULL);
 810         server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
 811         server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
 812         if (server.vm_enabled)
 813             server.db[j].io_keys = dictCreate(&keylistDictType,NULL);
 814         server.db[j].id = j;
 815     }
 816     server.pubsub_channels = dictCreate(&keylistDictType,NULL);
 817     server.pubsub_patterns = listCreate();
 818     listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
 819     listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
 820     server.cronloops = 0;
 821     server.bgsavechildpid = -1;
 822     server.bgrewritechildpid = -1;
 823     server.bgrewritebuf = sdsempty();
 824     server.aofbuf = sdsempty();
 825     server.lastsave = time(NULL);
 826     server.dirty = 0;
 827     server.stat_numcommands = 0;
 828     server.stat_numconnections = 0;
 829     server.stat_expiredkeys = 0;
 830     server.stat_starttime = time(NULL);
 831     server.stat_keyspace_misses = 0;
 832     server.stat_keyspace_hits = 0;
 833     server.unixtime = time(NULL);
 834     aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
 835     if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
 836         acceptHandler, NULL) == AE_ERR) oom("creating file event");
 837
 838     if (server.appendonly) {
 839         server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
 840         if (server.appendfd == -1) {
 841             redisLog(REDIS_WARNING, "Can't open the append-only file: %s",
 842                 strerror(errno));
 843             exit(1);
 844         }
 845     }
 846
 847     if (server.vm_enabled) vmInit();
 848 }
 849
 850 int qsortRedisCommands(const void *r1, const void *r2) {
 851     return strcasecmp(
 852         ((struct redisCommand*)r1)->name,
 853         ((struct redisCommand*)r2)->name);
 854 }
 855
 856 void sortCommandTable() {
 857     /* Copy and sort the read-only version of the command table */
 858     commandTable = (struct redisCommand*)zmalloc(sizeof(readonlyCommandTable));
 859     memcpy(commandTable,readonlyCommandTable,sizeof(readonlyCommandTable));
 860     qsort(commandTable,
 861         sizeof(readonlyCommandTable)/sizeof(struct redisCommand),
 862         sizeof(struct redisCommand),qsortRedisCommands);
 863 }
 864
 865 /* ====================== Commands lookup and execution ===================== */
 866
 867 struct redisCommand *lookupCommand(char *name) {
 868     struct redisCommand tmp = {name,NULL,0,0,NULL,0,0,0};
 869     return bsearch(
 870         &tmp,
 871         commandTable,
 872         sizeof(readonlyCommandTable)/sizeof(struct redisCommand),
 873         sizeof(struct redisCommand),
 874         qsortRedisCommands);
 875 }
 876
 877 /* Call() is the core of Redis execution of a command */
 878 void call(redisClient *c, struct redisCommand *cmd) {
 879     long long dirty;
 880
 881     dirty = server.dirty;
 882     cmd->proc(c);
 883     dirty = server.dirty-dirty;
 884
 885     if (server.appendonly && dirty)
 886         feedAppendOnlyFile(cmd,c->db->id,c->argv,c->argc);
 887     if ((dirty || cmd->flags & REDIS_CMD_FORCE_REPLICATION) &&
 888         listLength(server.slaves))
 889         replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
 890     if (listLength(server.monitors))
 891         replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc);
 892     server.stat_numcommands++;
 893 }
 894
 895 /* If this function gets called we already read a whole
 896  * command, argments are in the client argv/argc fields.
 897  * processCommand() execute the command or prepare the
 898  * server for a bulk read from the client.
 899  *
 900  * If 1 is returned the client is still alive and valid and
 901  * and other operations can be performed by the caller. Otherwise
 902  * if 0 is returned the client was destroied (i.e. after QUIT). */
 903 int processCommand(redisClient *c) {
 904     struct redisCommand *cmd;
 905
 906     /* The QUIT command is handled separately. Normal command procs will
 907      * go through checking for replication and QUIT will cause trouble
 908      * when FORCE_REPLICATION is enabled and would be implemented in
 909      * a regular command proc. */
 910     if (!strcasecmp(c->argv[0]->ptr,"quit")) {
 911         addReply(c,shared.ok);
 912         c->flags |= REDIS_CLOSE_AFTER_REPLY;
 913         return REDIS_ERR;
 914     }
 915
 916     /* Now lookup the command and check ASAP about trivial error conditions
 917      * such wrong arity, bad command name and so forth. */
 918     cmd = lookupCommand(c->argv[0]->ptr);
 919     if (!cmd) {
 920         addReplyErrorFormat(c,"unknown command '%s'",
 921             (char*)c->argv[0]->ptr);
 922         return REDIS_OK;
 923     } else if ((cmd->arity > 0 && cmd->arity != c->argc) ||
 924                (c->argc < -cmd->arity)) {
 925         addReplyErrorFormat(c,"wrong number of arguments for '%s' command",
 926             cmd->name);
 927         return REDIS_OK;
 928     }
 929
 930     /* Check if the user is authenticated */
 931     if (server.requirepass && !c->authenticated && cmd->proc != authCommand) {
 932         addReplyError(c,"operation not permitted");
 933         return REDIS_OK;
 934     }
 935
 936     /* Handle the maxmemory directive.
 937      *
 938      * First we try to free some memory if possible (if there are volatile
 939      * keys in the dataset). If there are not the only thing we can do
 940      * is returning an error. */
 941     if (server.maxmemory) freeMemoryIfNeeded();
 942     if (server.maxmemory && (cmd->flags & REDIS_CMD_DENYOOM) &&
 943         zmalloc_used_memory() > server.maxmemory)
 944     {
 945         addReplyError(c,"command not allowed when used memory > 'maxmemory'");
 946         return REDIS_OK;
 947     }
 948
 949     /* Only allow SUBSCRIBE and UNSUBSCRIBE in the context of Pub/Sub */
 950     if ((dictSize(c->pubsub_channels) > 0 || listLength(c->pubsub_patterns) > 0)
 951         &&
 952         cmd->proc != subscribeCommand && cmd->proc != unsubscribeCommand &&
 953         cmd->proc != psubscribeCommand && cmd->proc != punsubscribeCommand) {
 954         addReplyError(c,"only (P)SUBSCRIBE / (P)UNSUBSCRIBE / QUIT allowed in this context");
 955         return REDIS_OK;
 956     }
 957
 958     /* Exec the command */
 959     if (c->flags & REDIS_MULTI &&
 960         cmd->proc != execCommand && cmd->proc != discardCommand &&
 961         cmd->proc != multiCommand && cmd->proc != watchCommand)
 962     {
 963         queueMultiCommand(c,cmd);
 964         addReply(c,shared.queued);
 965     } else {
 966         if (server.vm_enabled && server.vm_max_threads > 0 &&
 967             blockClientOnSwappedKeys(c,cmd)) return REDIS_ERR;
 968         call(c,cmd);
 969     }
 970     return REDIS_OK;
 971 }
 972
 973 /*================================== Shutdown =============================== */
 974
 975 int prepareForShutdown() {
 976     redisLog(REDIS_WARNING,"User requested shutdown, saving DB...");
 977     /* Kill the saving child if there is a background saving in progress.
 978        We want to avoid race conditions, for instance our saving child may
 979        overwrite the synchronous saving did by SHUTDOWN. */
 980     if (server.bgsavechildpid != -1) {
 981         redisLog(REDIS_WARNING,"There is a live saving child. Killing it!");
 982         kill(server.bgsavechildpid,SIGKILL);
 983         rdbRemoveTempFile(server.bgsavechildpid);
 984     }
 985     if (server.appendonly) {
 986         /* Append only file: fsync() the AOF and exit */
 987         aof_fsync(server.appendfd);
 988         if (server.vm_enabled) unlink(server.vm_swap_file);
 989     } else if (server.saveparamslen > 0) {
 990         /* Snapshotting. Perform a SYNC SAVE and exit */
 991         if (rdbSave(server.dbfilename) != REDIS_OK) {
 992             /* Ooops.. error saving! The best we can do is to continue
 993              * operating. Note that if there was a background saving process,
 994              * in the next cron() Redis will be notified that the background
 995              * saving aborted, handling special stuff like slaves pending for
 996              * synchronization... */
 997             redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit");
 998             return REDIS_ERR;
 999         }
1000     } else {
1001         redisLog(REDIS_WARNING,"Not saving DB.");
1002     }
1003     if (server.daemonize) unlink(server.pidfile);
1004     redisLog(REDIS_WARNING,"Server exit now, bye bye...");
1005     return REDIS_OK;
1006 }
1007
1008 /*================================== Commands =============================== */
1009
1010 void authCommand(redisClient *c) {
1011     if (!server.requirepass || !strcmp(c->argv[1]->ptr, server.requirepass)) {
1012       c->authenticated = 1;
1013       addReply(c,shared.ok);
1014     } else {
1015       c->authenticated = 0;
1016       addReplyError(c,"invalid password");
1017     }
1018 }
1019
1020 void pingCommand(redisClient *c) {
1021     addReply(c,shared.pong);
1022 }
1023
1024 void echoCommand(redisClient *c) {
1025     addReplyBulk(c,c->argv[1]);
1026 }
1027
1028 /* Convert an amount of bytes into a human readable string in the form
1029  * of 100B, 2G, 100M, 4K, and so forth. */
1030 void bytesToHuman(char *s, unsigned long long n) {
1031     double d;
1032
1033     if (n < 1024) {
1034         /* Bytes */
1035         sprintf(s,"%lluB",n);
1036         return;
1037     } else if (n < (1024*1024)) {
1038         d = (double)n/(1024);
1039         sprintf(s,"%.2fK",d);
1040     } else if (n < (1024LL*1024*1024)) {
1041         d = (double)n/(1024*1024);
1042         sprintf(s,"%.2fM",d);
1043     } else if (n < (1024LL*1024*1024*1024)) {
1044         d = (double)n/(1024LL*1024*1024);
1045         sprintf(s,"%.2fG",d);
1046     }
1047 }
1048
1049 /* Create the string returned by the INFO command. This is decoupled
1050  * by the INFO command itself as we need to report the same information
1051  * on memory corruption problems. */
1052 sds genRedisInfoString(void) {
1053     sds info;
1054     time_t uptime = time(NULL)-server.stat_starttime;
1055     int j;
1056     char hmem[64];
1057     struct rusage self_ru, c_ru;
1058
1059     getrusage(RUSAGE_SELF, &self_ru);
1060     getrusage(RUSAGE_CHILDREN, &c_ru);
1061
1062     bytesToHuman(hmem,zmalloc_used_memory());
1063     info = sdscatprintf(sdsempty(),
1064         "redis_version:%s\r\n"
1065         "redis_git_sha1:%s\r\n"
1066         "redis_git_dirty:%d\r\n"
1067         "arch_bits:%s\r\n"
1068         "multiplexing_api:%s\r\n"
1069         "process_id:%ld\r\n"
1070         "uptime_in_seconds:%ld\r\n"
1071         "uptime_in_days:%ld\r\n"
1072         "lru_clock:%ld\r\n"
1073         "used_cpu_sys:%.2f\r\n"
1074         "used_cpu_user:%.2f\r\n"
1075         "used_cpu_sys_childrens:%.2f\r\n"
1076         "used_cpu_user_childrens:%.2f\r\n"
1077         "connected_clients:%d\r\n"
1078         "connected_slaves:%d\r\n"
1079         "blocked_clients:%d\r\n"
1080         "used_memory:%zu\r\n"
1081         "used_memory_human:%s\r\n"
1082         "used_memory_rss:%zu\r\n"
1083         "used_memory_estimated_rss:%zu\r\n"
1084         "mem_fragmentation_ratio:%.2f\r\n"
1085         "use_tcmalloc:%d\r\n"
1086         "changes_since_last_save:%lld\r\n"
1087         "bgsave_in_progress:%d\r\n"
1088         "last_save_time:%ld\r\n"
1089         "bgrewriteaof_in_progress:%d\r\n"
1090         "total_connections_received:%lld\r\n"
1091         "total_commands_processed:%lld\r\n"
1092         "expired_keys:%lld\r\n"
1093         "keyspace_hits:%lld\r\n"
1094         "keyspace_misses:%lld\r\n"
1095         "hash_max_zipmap_entries:%zu\r\n"
1096         "hash_max_zipmap_value:%zu\r\n"
1097         "pubsub_channels:%ld\r\n"
1098         "pubsub_patterns:%u\r\n"
1099         "vm_enabled:%d\r\n"
1100         "role:%s\r\n"
1101         ,REDIS_VERSION,
1102         redisGitSHA1(),
1103         strtol(redisGitDirty(),NULL,10) > 0,
1104         (sizeof(long) == 8) ? "64" : "32",
1105         aeGetApiName(),
1106         (long) getpid(),
1107         uptime,
1108         uptime/(3600*24),
1109         (unsigned long) server.lruclock,
1110         (float)self_ru.ru_utime.tv_sec+(float)self_ru.ru_utime.tv_usec/1000000,
1111         (float)self_ru.ru_stime.tv_sec+(float)self_ru.ru_stime.tv_usec/1000000,
1112         (float)c_ru.ru_utime.tv_sec+(float)c_ru.ru_utime.tv_usec/1000000,
1113         (float)c_ru.ru_stime.tv_sec+(float)c_ru.ru_stime.tv_usec/1000000,
1114         listLength(server.clients)-listLength(server.slaves),
1115         listLength(server.slaves),
1116         server.blpop_blocked_clients,
1117         zmalloc_used_memory(),
1118         hmem,
1119         zmalloc_get_rss(),
1120         redisEstimateRSS(),
1121         zmalloc_get_fragmentation_ratio(),
1122 #ifdef USE_TCMALLOC
1123         1,
1124 #else
1125         0,
1126 #endif
1127         server.dirty,
1128         server.bgsavechildpid != -1,
1129         server.lastsave,
1130         server.bgrewritechildpid != -1,
1131         server.stat_numconnections,
1132         server.stat_numcommands,
1133         server.stat_expiredkeys,
1134         server.stat_keyspace_hits,
1135         server.stat_keyspace_misses,
1136         server.hash_max_zipmap_entries,
1137         server.hash_max_zipmap_value,
1138         dictSize(server.pubsub_channels),
1139         listLength(server.pubsub_patterns),
1140         server.vm_enabled != 0,
1141         server.masterhost == NULL ? "master" : "slave"
1142     );
1143     if (server.masterhost) {
1144         info = sdscatprintf(info,
1145             "master_host:%s\r\n"
1146             "master_port:%d\r\n"
1147             "master_link_status:%s\r\n"
1148             "master_last_io_seconds_ago:%d\r\n"
1149             ,server.masterhost,
1150             server.masterport,
1151             (server.replstate == REDIS_REPL_CONNECTED) ?
1152                 "up" : "down",
1153             server.master ? ((int)(time(NULL)-server.master->lastinteraction)) : -1
1154         );
1155     }
1156     if (server.vm_enabled) {
1157         lockThreadedIO();
1158         info = sdscatprintf(info,
1159             "vm_conf_max_memory:%llu\r\n"
1160             "vm_conf_page_size:%llu\r\n"
1161             "vm_conf_pages:%llu\r\n"
1162             "vm_stats_used_pages:%llu\r\n"
1163             "vm_stats_swapped_objects:%llu\r\n"
1164             "vm_stats_swappin_count:%llu\r\n"
1165             "vm_stats_swappout_count:%llu\r\n"
1166             "vm_stats_io_newjobs_len:%lu\r\n"
1167             "vm_stats_io_processing_len:%lu\r\n"
1168             "vm_stats_io_processed_len:%lu\r\n"
1169             "vm_stats_io_active_threads:%lu\r\n"
1170             "vm_stats_blocked_clients:%lu\r\n"
1171             ,(unsigned long long) server.vm_max_memory,
1172             (unsigned long long) server.vm_page_size,
1173             (unsigned long long) server.vm_pages,
1174             (unsigned long long) server.vm_stats_used_pages,
1175             (unsigned long long) server.vm_stats_swapped_objects,
1176             (unsigned long long) server.vm_stats_swapins,
1177             (unsigned long long) server.vm_stats_swapouts,
1178             (unsigned long) listLength(server.io_newjobs),
1179             (unsigned long) listLength(server.io_processing),
1180             (unsigned long) listLength(server.io_processed),
1181             (unsigned long) server.io_active_threads,
1182             (unsigned long) server.vm_blocked_clients
1183         );
1184         unlockThreadedIO();
1185     }
1186     for (j = 0; j < server.dbnum; j++) {
1187         long long keys, vkeys;
1188
1189         keys = dictSize(server.db[j].dict);
1190         vkeys = dictSize(server.db[j].expires);
1191         if (keys || vkeys) {
1192             info = sdscatprintf(info, "db%d:keys=%lld,expires=%lld\r\n",
1193                 j, keys, vkeys);
1194         }
1195     }
1196     return info;
1197 }
1198
1199 void infoCommand(redisClient *c) {
1200     sds info = genRedisInfoString();
1201     addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
1202         (unsigned long)sdslen(info)));
1203     addReplySds(c,info);
1204     addReply(c,shared.crlf);
1205 }
1206
1207 void monitorCommand(redisClient *c) {
1208     /* ignore MONITOR if aleady slave or in monitor mode */
1209     if (c->flags & REDIS_SLAVE) return;
1210
1211     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
1212     c->slaveseldb = 0;
1213     listAddNodeTail(server.monitors,c);
1214     addReply(c,shared.ok);
1215 }
1216
1217 /* ============================ Maxmemory directive  ======================== */
1218
1219 /* Try to free one object form the pre-allocated objects free list.
1220  * This is useful under low mem conditions as by default we take 1 million
1221  * free objects allocated. On success REDIS_OK is returned, otherwise
1222  * REDIS_ERR. */
1223 int tryFreeOneObjectFromFreelist(void) {
1224     robj *o;
1225
1226     if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
1227     if (listLength(server.objfreelist)) {
1228         listNode *head = listFirst(server.objfreelist);
1229         o = listNodeValue(head);
1230         listDelNode(server.objfreelist,head);
1231         if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
1232         zfree(o);
1233         return REDIS_OK;
1234     } else {
1235         if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
1236         return REDIS_ERR;
1237     }
1238 }
1239
1240 /* A fast RSS sampling function.
1241  *
1242  * The function is reasonably accurate while fast, since it uses the trick of
1243  * using the server.fragmentation ratio that is computed every second and
1244  * is the ratio between the RSS and our zmalloc() count of allocated bytes.
1245  *
1246  * So in order to compute the current RSS used we just need to multiply
1247  * the zmalloc() memory reporting, that is as fast as reading a counter,
1248  * for the latest estimation of fragmentation.
1249  *
1250  * The behavior of this function is also very desirable because it is
1251  * very responsive to memory changes: while the real RSS is actually measured
1252  * in pages, the RSS estimation will actually change even if just a few bytes
1253  * are freed, and this is a good property when the function is used in order
1254  * to evict keys for Virtual Memory of for 'maxmemory' directive.
1255  *
1256  * Note that when the memory reported by zmalloc is smaller than the RSS
1257  * (that is, fragmentation < 1) this means that something is odd (many pages
1258  * swapped since the Redis instance is idle) and we consider the fragmentation
1259  * ratio 1. */
1260 size_t redisEstimateRSS(void) {
1261     size_t used = zmalloc_used_memory();
1262     float maxfrag;
1263
1264     if (server.fragmentation < 1) return used;
1265     maxfrag = (float)SIZE_MAX / used;
1266
1267     /* If multiplying memory usage reported by zmalloc per fragmentation
1268      * ratio will lead to an overflow we just return SIZE_MAX. */
1269     if (maxfrag < server.fragmentation) return SIZE_MAX;
1270
1271     return (size_t)((used * server.fragmentation));
1272 }
1273
1274 /* This function gets called when 'maxmemory' is set on the config file to limit
1275  * the max memory used by the server, and we are out of memory.
1276  * This function will try to, in order:
1277  *
1278  * - Free objects from the free list
1279  * - Try to remove keys with an EXPIRE set
1280  *
1281  * It is not possible to free enough memory to reach used-memory < maxmemory
1282  * the server will start refusing commands that will enlarge even more the
1283  * memory usage.
1284  */
1285 void freeMemoryIfNeeded(void) {
1286     /* Remove keys accordingly to the active policy as long as we are
1287      * over the memory limit. */
1288     while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) {
1289         int j, k, freed = 0;
1290
1291         /* Basic strategy -- remove objects from the free list. */
1292         if (tryFreeOneObjectFromFreelist() == REDIS_OK) continue;
1293
1294         for (j = 0; j < server.dbnum; j++) {
1295             long bestval = 0; /* just to prevent warning */
1296             sds bestkey = NULL;
1297             struct dictEntry *de;
1298             redisDb *db = server.db+j;
1299             dict *dict;
1300
1301             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1302                 server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM)
1303             {
1304                 dict = server.db[j].dict;
1305             } else {
1306                 dict = server.db[j].expires;
1307             }
1308             if (dictSize(dict) == 0) continue;
1309
1310             /* volatile-random and allkeys-random policy */
1311             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM ||
1312                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_RANDOM)
1313             {
1314                 de = dictGetRandomKey(dict);
1315                 bestkey = dictGetEntryKey(de);
1316             }
1317
1318             /* volatile-lru and allkeys-lru policy */
1319             else if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1320                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_LRU)
1321             {
1322                 for (k = 0; k < server.maxmemory_samples; k++) {
1323                     sds thiskey;
1324                     long thisval;
1325                     robj *o;
1326
1327                     de = dictGetRandomKey(dict);
1328                     thiskey = dictGetEntryKey(de);
1329                     o = dictGetEntryVal(de);
1330                     thisval = estimateObjectIdleTime(o);
1331
1332                     /* Higher idle time is better candidate for deletion */
1333                     if (bestkey == NULL || thisval > bestval) {
1334                         bestkey = thiskey;
1335                         bestval = thisval;
1336                     }
1337                 }
1338             }
1339
1340             /* volatile-ttl */
1341             else if (server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_TTL) {
1342                 for (k = 0; k < server.maxmemory_samples; k++) {
1343                     sds thiskey;
1344                     long thisval;
1345
1346                     de = dictGetRandomKey(dict);
1347                     thiskey = dictGetEntryKey(de);
1348                     thisval = (long) dictGetEntryVal(de);
1349
1350                     /* Expire sooner (minor expire unix timestamp) is better
1351                      * candidate for deletion */
1352                     if (bestkey == NULL || thisval < bestval) {
1353                         bestkey = thiskey;
1354                         bestval = thisval;
1355                     }
1356                 }
1357             }
1358
1359             /* Finally remove the selected key. */
1360             if (bestkey) {
1361                 robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
1362                 dbDelete(db,keyobj);
1363                 server.stat_expiredkeys++;
1364                 decrRefCount(keyobj);
1365                 freed++;
1366             }
1367         }
1368         if (!freed) return; /* nothing to free... */
1369     }
1370
1371     while(0) {
1372         int j, k, freed = 0;
1373         for (j = 0; j < server.dbnum; j++) {
1374             int minttl = -1;
1375             sds minkey = NULL;
1376             robj *keyobj = NULL;
1377             struct dictEntry *de;
1378
1379             if (dictSize(server.db[j].expires)) {
1380                 freed = 1;
1381                 /* From a sample of three keys drop the one nearest to
1382                  * the natural expire */
1383                 for (k = 0; k < 3; k++) {
1384                     time_t t;
1385
1386                     de = dictGetRandomKey(server.db[j].expires);
1387                     t = (time_t) dictGetEntryVal(de);
1388                     if (minttl == -1 || t < minttl) {
1389                         minkey = dictGetEntryKey(de);
1390                         minttl = t;
1391                     }
1392                 }
1393                 keyobj = createStringObject(minkey,sdslen(minkey));
1394                 dbDelete(server.db+j,keyobj);
1395                 server.stat_expiredkeys++;
1396                 decrRefCount(keyobj);
1397             }
1398         }
1399         if (!freed) return; /* nothing to free... */
1400     }
1401 }
1402
1403 /* =================================== Main! ================================ */
1404
1405 #ifdef __linux__
1406 int linuxOvercommitMemoryValue(void) {
1407     FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
1408     char buf[64];
1409
1410     if (!fp) return -1;
1411     if (fgets(buf,64,fp) == NULL) {
1412         fclose(fp);
1413         return -1;
1414     }
1415     fclose(fp);
1416
1417     return atoi(buf);
1418 }
1419
1420 void linuxOvercommitMemoryWarning(void) {
1421     if (linuxOvercommitMemoryValue() == 0) {
1422         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.");
1423     }
1424 }
1425 #endif /* __linux__ */
1426
1427 void createPidFile(void) {
1428     /* Try to write the pid file in a best-effort way. */
1429     FILE *fp = fopen(server.pidfile,"w");
1430     if (fp) {
1431         fprintf(fp,"%d\n",getpid());
1432         fclose(fp);
1433     }
1434 }
1435
1436 void daemonize(void) {
1437     int fd;
1438
1439     if (fork() != 0) exit(0); /* parent exits */
1440     setsid(); /* create a new session */
1441
1442     /* Every output goes to /dev/null. If Redis is daemonized but
1443      * the 'logfile' is set to 'stdout' in the configuration file
1444      * it will not log at all. */
1445     if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
1446         dup2(fd, STDIN_FILENO);
1447         dup2(fd, STDOUT_FILENO);
1448         dup2(fd, STDERR_FILENO);
1449         if (fd > STDERR_FILENO) close(fd);
1450     }
1451 }
1452
1453 void version() {
1454     printf("Redis server version %s (%s:%d)\n", REDIS_VERSION,
1455         redisGitSHA1(), atoi(redisGitDirty()) > 0);
1456     exit(0);
1457 }
1458
1459 void usage() {
1460     fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
1461     fprintf(stderr,"       ./redis-server - (read config from stdin)\n");
1462     exit(1);
1463 }
1464
1465 int main(int argc, char **argv) {
1466     time_t start;
1467
1468     initServerConfig();
1469     sortCommandTable();
1470     if (argc == 2) {
1471         if (strcmp(argv[1], "-v") == 0 ||
1472             strcmp(argv[1], "--version") == 0) version();
1473         if (strcmp(argv[1], "--help") == 0) usage();
1474         resetServerSaveParams();
1475         loadServerConfig(argv[1]);
1476     } else if ((argc > 2)) {
1477         usage();
1478     } else {
1479         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'");
1480     }
1481     if (server.daemonize) daemonize();
1482     initServer();
1483     if (server.daemonize) createPidFile();
1484     redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
1485 #ifdef __linux__
1486     linuxOvercommitMemoryWarning();
1487 #endif
1488     start = time(NULL);
1489     if (server.appendonly) {
1490         if (loadAppendOnlyFile(server.appendfilename) == REDIS_OK)
1491             redisLog(REDIS_NOTICE,"DB loaded from append only file: %ld seconds",time(NULL)-start);
1492     } else {
1493         if (rdbLoad(server.dbfilename) == REDIS_OK)
1494             redisLog(REDIS_NOTICE,"DB loaded from disk: %ld seconds",time(NULL)-start);
1495     }
1496     redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
1497     aeSetBeforeSleepProc(server.el,beforeSleep);
1498     aeMain(server.el);
1499     aeDeleteEventLoop(server.el);
1500     return 0;
1501 }
1502
1503 /* ============================= Backtrace support ========================= */
1504
1505 #ifdef HAVE_BACKTRACE
1506 void *getMcontextEip(ucontext_t *uc) {
1507 #if defined(__FreeBSD__)
1508     return (void*) uc->uc_mcontext.mc_eip;
1509 #elif defined(__dietlibc__)
1510     return (void*) uc->uc_mcontext.eip;
1511 #elif defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
1512   #if __x86_64__
1513     return (void*) uc->uc_mcontext->__ss.__rip;
1514   #else
1515     return (void*) uc->uc_mcontext->__ss.__eip;
1516   #endif
1517 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
1518   #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
1519     return (void*) uc->uc_mcontext->__ss.__rip;
1520   #else
1521     return (void*) uc->uc_mcontext->__ss.__eip;
1522   #endif
1523 #elif defined(__i386__)
1524     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
1525 #elif defined(__X86_64__) || defined(__x86_64__)
1526     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
1527 #elif defined(__ia64__) /* Linux IA64 */
1528     return (void*) uc->uc_mcontext.sc_ip;
1529 #else
1530     return NULL;
1531 #endif
1532 }
1533
1534 void segvHandler(int sig, siginfo_t *info, void *secret) {
1535     void *trace[100];
1536     char **messages = NULL;
1537     int i, trace_size = 0;
1538     ucontext_t *uc = (ucontext_t*) secret;
1539     sds infostring;
1540     struct sigaction act;
1541     REDIS_NOTUSED(info);
1542
1543     redisLog(REDIS_WARNING,
1544         "======= Ooops! Redis %s got signal: -%d- =======", REDIS_VERSION, sig);
1545     infostring = genRedisInfoString();
1546     redisLog(REDIS_WARNING, "%s",infostring);
1547     /* It's not safe to sdsfree() the returned string under memory
1548      * corruption conditions. Let it leak as we are going to abort */
1549
1550     trace_size = backtrace(trace, 100);
1551     /* overwrite sigaction with caller's address */
1552     if (getMcontextEip(uc) != NULL) {
1553         trace[1] = getMcontextEip(uc);
1554     }
1555     messages = backtrace_symbols(trace, trace_size);
1556
1557     for (i=1; i<trace_size; ++i)
1558         redisLog(REDIS_WARNING,"%s", messages[i]);
1559
1560     /* free(messages); Don't call free() with possibly corrupted memory. */
1561     if (server.daemonize) unlink(server.pidfile);
1562
1563     /* Make sure we exit with the right signal at the end. So for instance
1564      * the core will be dumped if enabled. */
1565     sigemptyset (&act.sa_mask);
1566     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction
1567      * is used. Otherwise, sa_handler is used */
1568     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1569     act.sa_handler = SIG_DFL;
1570     sigaction (sig, &act, NULL);
1571     kill(getpid(),sig);
1572 }
1573
1574 void sigtermHandler(int sig) {
1575     REDIS_NOTUSED(sig);
1576
1577     redisLog(REDIS_WARNING,"SIGTERM received, scheduling shutting down...");
1578     server.shutdown_asap = 1;
1579 }
1580
1581 void setupSigSegvAction(void) {
1582     struct sigaction act;
1583
1584     sigemptyset (&act.sa_mask);
1585     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction
1586      * is used. Otherwise, sa_handler is used */
1587     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
1588     act.sa_sigaction = segvHandler;
1589     sigaction (SIGSEGV, &act, NULL);
1590     sigaction (SIGBUS, &act, NULL);
1591     sigaction (SIGFPE, &act, NULL);
1592     sigaction (SIGILL, &act, NULL);
1593     sigaction (SIGBUS, &act, NULL);
1594
1595     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1596     act.sa_handler = sigtermHandler;
1597     sigaction (SIGTERM, &act, NULL);
1598     return;
1599 }
1600
1601 #else /* HAVE_BACKTRACE */
1602 void setupSigSegvAction(void) {
1603 }
1604 #endif /* HAVE_BACKTRACE */
1605
1606 /* The End */