#include "lzf.h" /* LZF compression library */
#include "pqsort.h" /* Partial qsort for SORT+LIMIT */
+/* #define REDIS_HELGRIND_FRIENDLY */
+#if defined(__GNUC__) && defined(REDIS_HELGRIND_FRIENDLY)
+#warning "Remember to undef REDIS_HELGRIND_FRIENDLY before to commit"
+#endif
+
/* Error codes */
#define REDIS_OK 0
#define REDIS_ERR -1
#define REDIS_VM_MAX_NEAR_PAGES 65536
#define REDIS_VM_MAX_RANDOM_JUMP 4096
#define REDIS_VM_MAX_THREADS 32
+#define REDIS_THREAD_STACK_SIZE (1024*1024*4)
+/* The following is the number of completed I/O jobs to process when the
+ * handelr is called. 1 is the minimum, and also the default, as it allows
+ * to block as little as possible other accessing clients. While Virtual
+ * Memory I/O operations are performed by threads, this operations must
+ * be processed by the main thread when completed to take effect. */
+#define REDIS_MAX_COMPLETED_JOBS_PROCESSED 1
/* Client flags */
#define REDIS_CLOSE 1 /* This client connection should be closed ASAP */
#define REDIS_MONITOR 8 /* This client is a slave monitor, see MONITOR */
#define REDIS_MULTI 16 /* This client is in a MULTI context */
#define REDIS_BLOCKED 32 /* The client is waiting in a blocking operation */
-#define REDIS_IO_WAIT 64 /* The client is waiting for Virutal Memory I/O */
+#define REDIS_IO_WAIT 64 /* The client is waiting for Virtual Memory I/O */
/* Slave replication state - slave side */
#define REDIS_REPL_NONE 0 /* No active replication */
#define APPENDFSYNC_EVERYSEC 2
/* We can print the stacktrace, so our assert is defined this way: */
-#define redisAssert(_e) ((_e)?(void)0 : (_redisAssert(#_e),exit(1)))
-static void _redisAssert(char *estr);
+#define redisAssert(_e) ((_e)?(void)0 : (_redisAssert(#_e,__FILE__,__LINE__),exit(1)))
+static void _redisAssert(char *estr, char *file, int line);
/*================================= Data types ============================== */
int sort_bypattern;
/* Virtual memory configuration */
int vm_enabled;
+ char *vm_swap_file;
off_t vm_page_size;
off_t vm_pages;
unsigned long long vm_max_memory;
unsigned char *vm_bitmap; /* Bitmap of free/used pages */
time_t unixtime; /* Unix time sampled every second. */
/* Virtual memory I/O threads stuff */
- pthread_t io_threads[REDIS_VM_MAX_THREADS];
/* An I/O thread process an element taken from the io_jobs queue and
- * put the result of the operation in the io_done list. */
- list *io_jobs; /* List of VM I/O jobs */
- list *io_done; /* List of VM processed jobs */
+ * put the result of the operation in the io_done list. While the
+ * job is being processed, it's put on io_processing queue. */
+ list *io_newjobs; /* List of VM I/O jobs yet to be processed */
+ list *io_processing; /* List of VM I/O jobs being processed */
+ list *io_processed; /* List of VM I/O jobs already processed */
list *io_clients; /* All the clients waiting for SWAP I/O operations */
- pthread_mutex_t io_mutex; /* lock to access io_jobs and io_done */
+ pthread_mutex_t io_mutex; /* lock to access io_jobs/io_done/io_thread_job */
+ pthread_mutex_t obj_freelist_mutex; /* safe redis objects creation/free */
+ pthread_mutex_t io_swapfile_mutex; /* So we can lseek + write */
+ pthread_attr_t io_threads_attr; /* attributes for threads creation */
int io_active_threads; /* Number of running I/O threads */
int vm_max_threads; /* Max number of I/O threads running at the same time */
+ /* Our main thread is blocked on the event loop, locking for sockets ready
+ * to be read or written, so when a threaded I/O operation is ready to be
+ * processed by the main thread, the I/O thread will use a unix pipe to
+ * awake the main thread. The followings are the two pipe FDs. */
+ int io_ready_pipe_read;
+ int io_ready_pipe_write;
/* Virtual memory stats */
unsigned long long vm_stats_used_pages;
unsigned long long vm_stats_swapped_objects;
unsigned long long vm_stats_swapouts;
unsigned long long vm_stats_swapins;
+ FILE *devnull;
};
typedef void redisCommandProc(redisClient *c);
static double R_Zero, R_PosInf, R_NegInf, R_Nan;
/* VM threaded I/O request message */
-#define REDIS_IOREQ_LOAD 0
-#define REDIS_IOREQ_SWAP 1
-typedef struct ioreq {
- int type; /* Request type, REDIS_IOREQ_* */
- int dbid; /* Redis database ID */
+#define REDIS_IOJOB_LOAD 0 /* Load from disk to memory */
+#define REDIS_IOJOB_PREPARE_SWAP 1 /* Compute needed pages */
+#define REDIS_IOJOB_DO_SWAP 2 /* Swap from memory to disk */
+typedef struct iojon {
+ int type; /* Request type, REDIS_IOJOB_* */
+ redisDb *db;/* Redis database */
robj *key; /* This I/O request is about swapping this key */
- robj *val; /* the value to swap for REDIS_IOREQ_SWAP, otherwise this
+ robj *val; /* the value to swap for REDIS_IOREQ_*_SWAP, otherwise this
* field is populated by the I/O thread for REDIS_IOREQ_LOAD. */
off_t page; /* Swap page where to read/write the object */
-} ioreq;
+ off_t pages; /* Swap pages needed to safe object. PREPARE_SWAP return val */
+ int canceled; /* True if this command was canceled by blocking side of VM */
+ pthread_t thread; /* ID of the thread processing this entry */
+} iojob;
/*================================ Prototypes =============================== */
static void vmMarkPagesFree(off_t page, off_t count);
static robj *vmLoadObject(robj *key);
static robj *vmPreviewObject(robj *key);
-static int vmSwapOneObject(void);
+static int vmSwapOneObjectBlocking(void);
+static int vmSwapOneObjectThreaded(void);
static int vmCanSwapOut(void);
-static void freeOneObjectFromFreelist(void);
+static int tryFreeOneObjectFromFreelist(void);
+static void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
+static void vmThreadedIOCompletedJob(aeEventLoop *el, int fd, void *privdata, int mask);
+static void vmCancelThreadedIOJob(robj *o);
+static void lockThreadedIO(void);
+static void unlockThreadedIO(void);
+static int vmSwapObjectThreaded(robj *key, robj *val, redisDb *db);
+static void freeIOJob(iojob *j);
+static void queueIOJob(iojob *j);
+static int vmWriteObjectOnSwap(robj *o, off_t page);
+static robj *vmReadObjectFromSwap(off_t page, int type);
+static void waitEmptyIOJobsQueue(void);
+static void vmReopenSwapFile(void);
static void authCommand(redisClient *c);
static void pingCommand(redisClient *c);
now = time(NULL);
strftime(buf,64,"%d %b %H:%M:%S",localtime(&now));
- fprintf(fp,"%s %c ",buf,c[level]);
+ fprintf(fp,"[%d] %s %c ",(int)getpid(),buf,c[level]);
vfprintf(fp, fmt, ap);
fprintf(fp,"\n");
fflush(fp);
return hash;
}
+/* Sets type and expires */
static dictType setDictType = {
dictEncObjHash, /* hash function */
NULL, /* key dup */
NULL /* val destructor */
};
+/* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
static dictType zsetDictType = {
dictEncObjHash, /* hash function */
NULL, /* key dup */
dictVanillaFree /* val destructor of malloc(sizeof(double)) */
};
+/* Db->dict */
static dictType hashDictType = {
dictObjHash, /* hash function */
NULL, /* key dup */
dictRedisObjectDestructor /* val destructor */
};
+/* Db->expires */
+static dictType keyptrDictType = {
+ dictObjHash, /* hash function */
+ NULL, /* key dup */
+ NULL, /* val dup */
+ dictObjKeyCompare, /* key compare */
+ dictRedisObjectDestructor, /* key destructor */
+ NULL /* val destructor */
+};
+
/* Keylist hash table type has unencoded redis objects as keys and
* lists as values. It's used for blocking operations (BLPOP) */
static dictType keylistDictType = {
redisClient *c;
listNode *ln;
time_t now = time(NULL);
+ listIter li;
- listRewind(server.clients);
- while ((ln = listYield(server.clients)) != NULL) {
+ listRewind(server.clients,&li);
+ while ((ln = listNext(&li)) != NULL) {
c = listNodeValue(ln);
if (server.maxidletime &&
!(c->flags & REDIS_SLAVE) && /* no timeout for slaves */
while (server.vm_enabled && zmalloc_used_memory() >
server.vm_max_memory)
{
- if (listLength(server.objfreelist)) {
- freeOneObjectFromFreelist();
- } else if (vmSwapOneObject() == REDIS_ERR) {
- if ((loops % 30) == 0 && zmalloc_used_memory() >
- (server.vm_max_memory+server.vm_max_memory/10)) {
- redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
- }
- break;
+ int retval;
+
+ if (tryFreeOneObjectFromFreelist() == REDIS_OK) continue;
+ retval = (server.vm_max_threads == 0) ?
+ vmSwapOneObjectBlocking() :
+ vmSwapOneObjectThreaded();
+ if (retval == REDIS_ERR && (loops % 30) == 0 &&
+ zmalloc_used_memory() >
+ (server.vm_max_memory+server.vm_max_memory/10))
+ {
+ redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
}
+ /* Note that when using threade I/O we free just one object,
+ * because anyway when the I/O thread in charge to swap this
+ * object out will finish, the handler of completed jobs
+ * will try to swap more objects if we are still out of memory. */
+ if (retval == REDIS_ERR || server.vm_max_threads > 0) break;
}
}
server.blockedclients = 0;
server.maxmemory = 0;
server.vm_enabled = 0;
+ server.vm_swap_file = zstrdup("/tmp/redis-%p.vm");
server.vm_page_size = 256; /* 256 bytes per page */
server.vm_pages = 1024*1024*100; /* 104 millions of pages */
server.vm_max_memory = 1024LL*1024*1024*1; /* 1 GB of RAM */
signal(SIGPIPE, SIG_IGN);
setupSigSegvAction();
+ server.devnull = fopen("/dev/null","w");
+ if (server.devnull == NULL) {
+ redisLog(REDIS_WARNING, "Can't open /dev/null: %s", server.neterr);
+ exit(1);
+ }
server.clients = listCreate();
server.slaves = listCreate();
server.monitors = listCreate();
}
for (j = 0; j < server.dbnum; j++) {
server.db[j].dict = dictCreate(&hashDictType,NULL);
- server.db[j].expires = dictCreate(&setDictType,NULL);
+ server.db[j].expires = dictCreate(&keyptrDictType,NULL);
server.db[j].blockingkeys = dictCreate(&keylistDictType,NULL);
server.db[j].id = j;
}
server.stat_starttime = time(NULL);
server.unixtime = time(NULL);
aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
+ if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
+ acceptHandler, NULL) == AE_ERR) oom("creating file event");
if (server.appendonly) {
server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
goto loaderr;
}
} else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
- server.requirepass = zstrdup(argv[1]);
+ server.requirepass = zstrdup(argv[1]);
} else if (!strcasecmp(argv[0],"pidfile") && argc == 2) {
- server.pidfile = zstrdup(argv[1]);
+ server.pidfile = zstrdup(argv[1]);
} else if (!strcasecmp(argv[0],"dbfilename") && argc == 2) {
- server.dbfilename = zstrdup(argv[1]);
+ server.dbfilename = zstrdup(argv[1]);
} else if (!strcasecmp(argv[0],"vm-enabled") && argc == 2) {
if ((server.vm_enabled = yesnotoi(argv[1])) == -1) {
err = "argument must be 'yes' or 'no'"; goto loaderr;
}
+ } else if (!strcasecmp(argv[0],"vm-swap-file") && argc == 2) {
+ zfree(server.vm_swap_file);
+ server.vm_swap_file = zstrdup(argv[1]);
} else if (!strcasecmp(argv[0],"vm-max-memory") && argc == 2) {
server.vm_max_memory = strtoll(argv[1], NULL, 10);
} else if (!strcasecmp(argv[0],"vm-page-size") && argc == 2) {
if (ln) listDelNode(server.io_clients,ln);
listRelease(c->io_keys);
}
+ listRelease(c->io_keys);
/* Other cleanup */
if (c->flags & REDIS_SLAVE) {
if (c->replstate == REDIS_REPL_SEND_BULK && c->repldbfd != -1)
int copylen = 0;
char buf[GLUEREPLY_UP_TO];
listNode *ln;
+ listIter li;
robj *o;
- listRewind(c->reply);
- while((ln = listYield(c->reply))) {
+ listRewind(c->reply,&li);
+ while((ln = listNext(&li))) {
int objlen;
o = ln->value;
static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc) {
listNode *ln;
+ listIter li;
int outc = 0, j;
robj **outv;
/* (args*2)+1 is enough room for args, spaces, newlines */
* be sure to free objects if there is no slave in a replication state
* able to be feed with commands */
for (j = 0; j < outc; j++) incrRefCount(outv[j]);
- listRewind(slaves);
- while((ln = listYield(slaves))) {
+ listRewind(slaves,&li);
+ while((ln = listNext(&li))) {
redisClient *slave = ln->value;
/* Don't feed slaves that are still waiting for BGSAVE to start */
static robj *createObject(int type, void *ptr) {
robj *o;
+ if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
if (listLength(server.objfreelist)) {
listNode *head = listFirst(server.objfreelist);
o = listNodeValue(head);
listDelNode(server.objfreelist,head);
+ if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
} else {
if (server.vm_enabled) {
+ pthread_mutex_unlock(&server.obj_freelist_mutex);
o = zmalloc(sizeof(*o));
} else {
o = zmalloc(sizeof(*o)-sizeof(struct redisObjectVM));
o->ptr = ptr;
o->refcount = 1;
if (server.vm_enabled) {
+ /* Note that this code may run in the context of an I/O thread
+ * and accessing to server.unixtime in theory is an error
+ * (no locks). But in practice this is safe, and even if we read
+ * garbage Redis will not fail, as it's just a statistical info */
o->vm.atime = server.unixtime;
o->storage = REDIS_VM_MEMORY;
}
}
static robj *dupStringObject(robj *o) {
+ assert(o->encoding == REDIS_ENCODING_RAW);
return createStringObject(o->ptr,sdslen(o->ptr));
}
static void decrRefCount(void *obj) {
robj *o = obj;
- /* REDIS_VM_SWAPPED */
- if (server.vm_enabled && o->storage == REDIS_VM_SWAPPED) {
- redisAssert(o->refcount == 1);
+ /* Object is swapped out, or in the process of being loaded. */
+ if (server.vm_enabled &&
+ (o->storage == REDIS_VM_SWAPPED || o->storage == REDIS_VM_LOADING))
+ {
+ if (o->storage == REDIS_VM_SWAPPED || o->storage == REDIS_VM_LOADING) {
+ redisAssert(o->refcount == 1);
+ }
+ if (o->storage == REDIS_VM_LOADING) vmCancelThreadedIOJob(obj);
redisAssert(o->type == REDIS_STRING);
freeStringObject(o);
vmMarkPagesFree(o->vm.page,o->vm.usedpages);
+ pthread_mutex_lock(&server.obj_freelist_mutex);
if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
!listAddNodeHead(server.objfreelist,o))
zfree(o);
+ pthread_mutex_unlock(&server.obj_freelist_mutex);
server.vm_stats_swapped_objects--;
return;
}
- /* REDIS_VM_MEMORY */
+ /* Object is in memory, or in the process of being swapped out. */
if (--(o->refcount) == 0) {
+ if (server.vm_enabled && o->storage == REDIS_VM_SWAPPING)
+ vmCancelThreadedIOJob(obj);
switch(o->type) {
case REDIS_STRING: freeStringObject(o); break;
case REDIS_LIST: freeListObject(o); break;
case REDIS_HASH: freeHashObject(o); break;
default: redisAssert(0 != 0); break;
}
+ if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
!listAddNodeHead(server.objfreelist,o))
zfree(o);
+ if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
}
}
robj *val = dictGetEntryVal(de);
if (server.vm_enabled) {
- if (key->storage == REDIS_VM_MEMORY) {
+ if (key->storage == REDIS_VM_MEMORY ||
+ key->storage == REDIS_VM_SWAPPING)
+ {
+ /* If we were swapping the object out, stop it, this key
+ * was requested. */
+ if (key->storage == REDIS_VM_SWAPPING)
+ vmCancelThreadedIOJob(key);
/* Update the access time of the key for the aging algorithm. */
key->vm.atime = server.unixtime;
} else {
static int rdbSaveStringObject(FILE *fp, robj *obj) {
int retval;
- obj = getDecodedObject(obj);
- retval = rdbSaveStringObjectRaw(fp,obj);
- decrRefCount(obj);
+ /* Avoid incr/decr ref count business when possible.
+ * This plays well with copy-on-write given that we are probably
+ * in a child process (BGSAVE). Also this makes sure key objects
+ * of swapped objects are not incRefCount-ed (an assert does not allow
+ * this in order to avoid bugs) */
+ if (obj->encoding != REDIS_ENCODING_RAW) {
+ obj = getDecodedObject(obj);
+ retval = rdbSaveStringObjectRaw(fp,obj);
+ decrRefCount(obj);
+ } else {
+ retval = rdbSaveStringObjectRaw(fp,obj);
+ }
return retval;
}
} else if (o->type == REDIS_LIST) {
/* Save a list value */
list *list = o->ptr;
+ listIter li;
listNode *ln;
- listRewind(list);
if (rdbSaveLen(fp,listLength(list)) == -1) return -1;
- while((ln = listYield(list))) {
+ listRewind(list,&li);
+ while((ln = listNext(&li))) {
robj *eleobj = listNodeValue(ln);
if (rdbSaveStringObject(fp,eleobj) == -1) return -1;
* the rdbSaveObject() function. Currently we use a trick to get
* this length with very little changes to the code. In the future
* we could switch to a faster solution. */
-static off_t rdbSavedObjectLen(robj *o) {
- static FILE *fp = NULL;
-
- if (fp == NULL) fp = fopen("/dev/null","w");
- assert(fp != NULL);
-
+static off_t rdbSavedObjectLen(robj *o, FILE *fp) {
+ if (fp == NULL) fp = server.devnull;
rewind(fp);
assert(rdbSaveObject(fp,o) != 1);
return ftello(fp);
}
/* Return the number of pages required to save this object in the swap file */
-static off_t rdbSavedObjectPages(robj *o) {
- off_t bytes = rdbSavedObjectLen(o);
+static off_t rdbSavedObjectPages(robj *o, FILE *fp) {
+ off_t bytes = rdbSavedObjectLen(o,fp);
return (bytes+(server.vm_page_size-1))/server.vm_page_size;
}
int j;
time_t now = time(NULL);
+ /* Wait for I/O therads to terminate, just in case this is a
+ * foreground-saving, to avoid seeking the swap file descriptor at the
+ * same time. */
+ if (server.vm_enabled)
+ waitEmptyIOJobsQueue();
+
snprintf(tmpfile,256,"temp-%d.rdb", (int) getpid());
fp = fopen(tmpfile,"w");
if (!fp) {
}
/* Save the key and associated value. This requires special
* handling if the value is swapped out. */
- if (!server.vm_enabled || key->storage == REDIS_VM_MEMORY) {
+ if (!server.vm_enabled || key->storage == REDIS_VM_MEMORY ||
+ key->storage == REDIS_VM_SWAPPING) {
/* Save type, key, value */
if (rdbSaveType(fp,o->type) == -1) goto werr;
if (rdbSaveStringObject(fp,key) == -1) goto werr;
if (rdbSaveObject(fp,o) == -1) goto werr;
} else {
- robj *po, *newkey;
+ /* REDIS_VM_SWAPPED or REDIS_VM_LOADING */
+ robj *po;
/* Get a preview of the object in memory */
po = vmPreviewObject(key);
- /* Also duplicate the key object, to pass around a standard
- * string object. */
- newkey = dupStringObject(key);
/* Save type, key, value */
if (rdbSaveType(fp,key->vtype) == -1) goto werr;
- if (rdbSaveStringObject(fp,newkey) == -1) goto werr;
+ if (rdbSaveStringObject(fp,key) == -1) goto werr;
if (rdbSaveObject(fp,po) == -1) goto werr;
/* Remove the loaded object from memory */
decrRefCount(po);
- decrRefCount(newkey);
}
}
dictReleaseIterator(di);
pid_t childpid;
if (server.bgsavechildpid != -1) return REDIS_ERR;
+ if (server.vm_enabled) waitEmptyIOJobsQueue();
if ((childpid = fork()) == 0) {
/* Child */
+ if (server.vm_enabled) vmReopenSwapFile();
close(server.fd);
if (rdbSave(filename) == REDIS_OK) {
exit(0);
loadedkeys++;
if (server.vm_enabled && (loadedkeys % 5000) == 0) {
while (zmalloc_used_memory() > server.vm_max_memory) {
- if (vmSwapOneObject() == REDIS_ERR) break;
+ if (vmSwapOneObjectBlocking() == REDIS_ERR) break;
}
}
}
if (server.appendonly) {
/* Append only file: fsync() the AOF and exit */
fsync(server.appendfd);
+ if (server.vm_enabled) unlink(server.vm_swap_file);
exit(0);
} else {
/* Snapshotting. Perform a SYNC SAVE and exit */
unlink(server.pidfile);
redisLog(REDIS_WARNING,"%zu bytes used at exit",zmalloc_used_memory());
redisLog(REDIS_WARNING,"Server exit now, bye bye...");
+ if (server.vm_enabled) unlink(server.vm_swap_file);
exit(0);
} else {
/* Ooops.. error saving! The best we can do is to continue operating.
if (sortval->type == REDIS_LIST) {
list *list = sortval->ptr;
listNode *ln;
+ listIter li;
- listRewind(list);
- while((ln = listYield(list))) {
+ listRewind(list,&li);
+ while((ln = listNext(&li))) {
robj *ele = ln->value;
vector[j].obj = ele;
vector[j].u.score = 0;
addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",outputlen));
for (j = start; j <= end; j++) {
listNode *ln;
+ listIter li;
+
if (!getop) {
addReplyBulkLen(c,vector[j].obj);
addReply(c,vector[j].obj);
addReply(c,shared.crlf);
}
- listRewind(operations);
- while((ln = listYield(operations))) {
+ listRewind(operations,&li);
+ while((ln = listNext(&li))) {
redisSortOperation *sop = ln->value;
robj *val = lookupKeyByPattern(c->db,sop->pattern,
vector[j].obj);
/* STORE option specified, set the sorting result as a List object */
for (j = start; j <= end; j++) {
listNode *ln;
+ listIter li;
+
if (!getop) {
listAddNodeTail(listPtr,vector[j].obj);
incrRefCount(vector[j].obj);
}
- listRewind(operations);
- while((ln = listYield(operations))) {
+ listRewind(operations,&li);
+ while((ln = listNext(&li))) {
redisSortOperation *sop = ln->value;
robj *val = lookupKeyByPattern(c->db,sop->pattern,
vector[j].obj);
);
}
if (server.vm_enabled) {
+ lockThreadedIO();
info = sdscatprintf(info,
"vm_conf_max_memory:%llu\r\n"
"vm_conf_page_size:%llu\r\n"
"vm_stats_swapped_objects:%llu\r\n"
"vm_stats_swappin_count:%llu\r\n"
"vm_stats_swappout_count:%llu\r\n"
+ "vm_stats_io_newjobs_len:%lu\r\n"
+ "vm_stats_io_processing_len:%lu\r\n"
+ "vm_stats_io_processed_len:%lu\r\n"
+ "vm_stats_io_waiting_clients:%lu\r\n"
+ "vm_stats_io_active_threads:%lu\r\n"
,(unsigned long long) server.vm_max_memory,
(unsigned long long) server.vm_page_size,
(unsigned long long) server.vm_pages,
(unsigned long long) server.vm_stats_used_pages,
(unsigned long long) server.vm_stats_swapped_objects,
(unsigned long long) server.vm_stats_swapins,
- (unsigned long long) server.vm_stats_swapouts
+ (unsigned long long) server.vm_stats_swapouts,
+ (unsigned long) listLength(server.io_newjobs),
+ (unsigned long) listLength(server.io_processing),
+ (unsigned long) listLength(server.io_processed),
+ (unsigned long) listLength(server.io_clients),
+ (unsigned long) server.io_active_threads
);
+ unlockThreadedIO();
}
for (j = 0; j < server.dbnum; j++) {
long long keys, vkeys;
* registering differences since the server forked to save */
redisClient *slave;
listNode *ln;
+ listIter li;
- listRewind(server.slaves);
- while((ln = listYield(server.slaves))) {
+ listRewind(server.slaves,&li);
+ while((ln = listNext(&li))) {
slave = ln->value;
if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) break;
}
static void updateSlavesWaitingBgsave(int bgsaveerr) {
listNode *ln;
int startbgsave = 0;
+ listIter li;
- listRewind(server.slaves);
- while((ln = listYield(server.slaves))) {
+ listRewind(server.slaves,&li);
+ while((ln = listNext(&li))) {
redisClient *slave = ln->value;
if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) {
}
if (startbgsave) {
if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
- listRewind(server.slaves);
+ listIter li;
+
+ listRewind(server.slaves,&li);
redisLog(REDIS_WARNING,"SYNC failed. BGSAVE failed");
- while((ln = listYield(server.slaves))) {
+ while((ln = listNext(&li))) {
redisClient *slave = ln->value;
if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START)
/* ============================ Maxmemory directive ======================== */
-/* Free one object form the pre-allocated objects free list. This is useful
- * under low mem conditions as by default we take 1 million free objects
- * allocated. */
-static void freeOneObjectFromFreelist(void) {
+/* Try to free one object form the pre-allocated objects free list.
+ * This is useful under low mem conditions as by default we take 1 million
+ * free objects allocated. On success REDIS_OK is returned, otherwise
+ * REDIS_ERR. */
+static int tryFreeOneObjectFromFreelist(void) {
robj *o;
- listNode *head = listFirst(server.objfreelist);
- o = listNodeValue(head);
- listDelNode(server.objfreelist,head);
- zfree(o);
+ if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
+ if (listLength(server.objfreelist)) {
+ listNode *head = listFirst(server.objfreelist);
+ o = listNodeValue(head);
+ listDelNode(server.objfreelist,head);
+ if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
+ zfree(o);
+ return REDIS_OK;
+ } else {
+ if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
+ return REDIS_ERR;
+ }
}
/* This function gets called when 'maxmemory' is set on the config file to limit
*/
static void freeMemoryIfNeeded(void) {
while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) {
- if (listLength(server.objfreelist)) {
- freeOneObjectFromFreelist();
- } else {
- int j, k, freed = 0;
-
- for (j = 0; j < server.dbnum; j++) {
- int minttl = -1;
- robj *minkey = NULL;
- struct dictEntry *de;
-
- if (dictSize(server.db[j].expires)) {
- freed = 1;
- /* From a sample of three keys drop the one nearest to
- * the natural expire */
- for (k = 0; k < 3; k++) {
- time_t t;
-
- de = dictGetRandomKey(server.db[j].expires);
- t = (time_t) dictGetEntryVal(de);
- if (minttl == -1 || t < minttl) {
- minkey = dictGetEntryKey(de);
- minttl = t;
- }
+ int j, k, freed = 0;
+
+ if (tryFreeOneObjectFromFreelist() == REDIS_OK) continue;
+ for (j = 0; j < server.dbnum; j++) {
+ int minttl = -1;
+ robj *minkey = NULL;
+ struct dictEntry *de;
+
+ if (dictSize(server.db[j].expires)) {
+ freed = 1;
+ /* From a sample of three keys drop the one nearest to
+ * the natural expire */
+ for (k = 0; k < 3; k++) {
+ time_t t;
+
+ de = dictGetRandomKey(server.db[j].expires);
+ t = (time_t) dictGetEntryVal(de);
+ if (minttl == -1 || t < minttl) {
+ minkey = dictGetEntryKey(de);
+ minttl = t;
}
- deleteKey(server.db+j,minkey);
}
+ deleteKey(server.db+j,minkey);
}
- if (!freed) return; /* nothing to free... */
}
+ if (!freed) return; /* nothing to free... */
}
}
loadedkeys++;
if (server.vm_enabled && (loadedkeys % 5000) == 0) {
while (zmalloc_used_memory() > server.vm_max_memory) {
- if (vmSwapOneObject() == REDIS_ERR) break;
+ if (vmSwapOneObjectBlocking() == REDIS_ERR) break;
}
}
}
/* Write an object into a file in the bulk format $<count>\r\n<payload>\r\n */
static int fwriteBulk(FILE *fp, robj *obj) {
char buf[128];
- obj = getDecodedObject(obj);
+ int decrrc = 0;
+
+ /* Avoid the incr/decr ref count business if possible to help
+ * copy-on-write (we are often in a child process when this function
+ * is called).
+ * Also makes sure that key objects don't get incrRefCount-ed when VM
+ * is enabled */
+ if (obj->encoding != REDIS_ENCODING_RAW) {
+ obj = getDecodedObject(obj);
+ decrrc = 1;
+ }
snprintf(buf,sizeof(buf),"$%ld\r\n",(long)sdslen(obj->ptr));
if (fwrite(buf,strlen(buf),1,fp) == 0) goto err;
if (sdslen(obj->ptr) && fwrite(obj->ptr,sdslen(obj->ptr),1,fp) == 0)
goto err;
if (fwrite("\r\n",2,1,fp) == 0) goto err;
- decrRefCount(obj);
+ if (decrrc) decrRefCount(obj);
return 1;
err:
- decrRefCount(obj);
+ if (decrrc) decrRefCount(obj);
return 0;
}
int swapped;
key = dictGetEntryKey(de);
- if (!server.vm_enabled || key->storage == REDIS_VM_MEMORY) {
+ /* If the value for this key is swapped, load a preview in memory.
+ * We use a "swapped" flag to remember if we need to free the
+ * value object instead to just increment the ref count anyway
+ * in order to avoid copy-on-write of pages if we are forked() */
+ if (!server.vm_enabled || key->storage == REDIS_VM_MEMORY ||
+ key->storage == REDIS_VM_SWAPPING) {
o = dictGetEntryVal(de);
swapped = 0;
} else {
o = vmPreviewObject(key);
- key = dupStringObject(key);
swapped = 1;
}
expiretime = getExpire(db,key);
/* Emit the RPUSHes needed to rebuild the list */
list *list = o->ptr;
listNode *ln;
+ listIter li;
- listRewind(list);
- while((ln = listYield(list))) {
+ listRewind(list,&li);
+ while((ln = listNext(&li))) {
char cmd[]="*3\r\n$5\r\nRPUSH\r\n";
robj *eleobj = listNodeValue(ln);
if (fwriteBulk(fp,key) == 0) goto werr;
if (fwriteBulkLong(fp,expiretime) == 0) goto werr;
}
- /* We created a few temp objects if the key->value pair
- * was about a swapped out object. Free both. */
- if (swapped) {
- decrRefCount(key);
- decrRefCount(o);
- }
+ if (swapped) decrRefCount(o);
}
dictReleaseIterator(di);
}
pid_t childpid;
if (server.bgrewritechildpid != -1) return REDIS_ERR;
+ if (server.vm_enabled) waitEmptyIOJobsQueue();
if ((childpid = fork()) == 0) {
/* Child */
char tmpfile[256];
- close(server.fd);
+ if (server.vm_enabled) vmReopenSwapFile();
+ close(server.fd);
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
if (rewriteAppendOnlyFile(tmpfile) == REDIS_OK) {
exit(0);
unlink(tmpfile);
}
-/* =============================== Virtual Memory =========================== */
+/* Virtual Memory is composed mainly of two subsystems:
+ * - Blocking Virutal Memory
+ * - Threaded Virtual Memory I/O
+ * The two parts are not fully decoupled, but functions are split among two
+ * different sections of the source code (delimited by comments) in order to
+ * make more clear what functionality is about the blocking VM and what about
+ * the threaded (not blocking) VM.
+ *
+ * Redis VM design:
+ *
+ * Redis VM is a blocking VM (one that blocks reading swapped values from
+ * disk into memory when a value swapped out is needed in memory) that is made
+ * unblocking by trying to examine the command argument vector in order to
+ * load in background values that will likely be needed in order to exec
+ * the command. The command is executed only once all the relevant keys
+ * are loaded into memory.
+ *
+ * This basically is almost as simple of a blocking VM, but almost as parallel
+ * as a fully non-blocking VM.
+ */
+
+/* =================== Virtual Memory - Blocking Side ====================== */
+
+/* substitute the first occurrence of '%p' with the process pid in the
+ * swap file name. */
+static void expandVmSwapFilename(void) {
+ char *p = strstr(server.vm_swap_file,"%p");
+ sds new;
+
+ if (!p) return;
+ new = sdsempty();
+ *p = '\0';
+ new = sdscat(new,server.vm_swap_file);
+ new = sdscatprintf(new,"%ld",(long) getpid());
+ new = sdscat(new,p+2);
+ zfree(server.vm_swap_file);
+ server.vm_swap_file = new;
+}
+
static void vmInit(void) {
off_t totsize;
+ int pipefds[2];
+ size_t stacksize;
- server.vm_fp = fopen("/tmp/redisvm","w+b");
+ if (server.vm_max_threads != 0)
+ zmalloc_enable_thread_safeness(); /* we need thread safe zmalloc() */
+
+ expandVmSwapFilename();
+ redisLog(REDIS_NOTICE,"Using '%s' as swap file",server.vm_swap_file);
+ if ((server.vm_fp = fopen(server.vm_swap_file,"r+b")) == NULL) {
+ server.vm_fp = fopen(server.vm_swap_file,"w+b");
+ }
if (server.vm_fp == NULL) {
- redisLog(REDIS_WARNING,"Impossible to open the swap file. Exiting.");
+ redisLog(REDIS_WARNING,
+ "Impossible to open the swap file: %s. Exiting.",
+ strerror(errno));
exit(1);
}
server.vm_fd = fileno(server.vm_fp);
redisLog(REDIS_VERBOSE,"Allocated %lld bytes page table for %lld pages",
(long long) (server.vm_pages+7)/8, server.vm_pages);
memset(server.vm_bitmap,0,(server.vm_pages+7)/8);
- /* Try to remove the swap file, so the OS will really delete it from the
- * file system when Redis exists. */
- unlink("/tmp/redisvm");
- /* Initialize threaded I/O */
- server.io_jobs = listCreate();
- server.io_done = listCreate();
+ /* Initialize threaded I/O (used by Virtual Memory) */
+ server.io_newjobs = listCreate();
+ server.io_processing = listCreate();
+ server.io_processed = listCreate();
server.io_clients = listCreate();
pthread_mutex_init(&server.io_mutex,NULL);
+ pthread_mutex_init(&server.obj_freelist_mutex,NULL);
+ pthread_mutex_init(&server.io_swapfile_mutex,NULL);
server.io_active_threads = 0;
+ if (pipe(pipefds) == -1) {
+ redisLog(REDIS_WARNING,"Unable to intialized VM: pipe(2): %s. Exiting."
+ ,strerror(errno));
+ exit(1);
+ }
+ server.io_ready_pipe_read = pipefds[0];
+ server.io_ready_pipe_write = pipefds[1];
+ redisAssert(anetNonBlock(NULL,server.io_ready_pipe_read) != ANET_ERR);
+ /* LZF requires a lot of stack */
+ pthread_attr_init(&server.io_threads_attr);
+ pthread_attr_getstacksize(&server.io_threads_attr, &stacksize);
+ while (stacksize < REDIS_THREAD_STACK_SIZE) stacksize *= 2;
+ pthread_attr_setstacksize(&server.io_threads_attr, stacksize);
+ /* Listen for events in the threaded I/O pipe */
+ if (aeCreateFileEvent(server.el, server.io_ready_pipe_read, AE_READABLE,
+ vmThreadedIOCompletedJob, NULL) == AE_ERR)
+ oom("creating file event");
}
/* Mark the page as used */
* note: I implemented this function just after watching an episode of
* Battlestar Galactica, where the hybrid was continuing to say "JUMP!"
*/
-static int vmFindContiguousPages(off_t *first, int n) {
+static int vmFindContiguousPages(off_t *first, off_t n) {
off_t base, offset = 0, since_jump = 0, numfree = 0;
if (server.vm_near_pages == REDIS_VM_MAX_NEAR_PAGES) {
return REDIS_ERR;
}
+/* Write the specified object at the specified page of the swap file */
+static int vmWriteObjectOnSwap(robj *o, off_t page) {
+ if (server.vm_enabled) pthread_mutex_lock(&server.io_swapfile_mutex);
+ if (fseeko(server.vm_fp,page*server.vm_page_size,SEEK_SET) == -1) {
+ if (server.vm_enabled) pthread_mutex_unlock(&server.io_swapfile_mutex);
+ redisLog(REDIS_WARNING,
+ "Critical VM problem in vmSwapObjectBlocking(): can't seek: %s",
+ strerror(errno));
+ return REDIS_ERR;
+ }
+ rdbSaveObject(server.vm_fp,o);
+ if (server.vm_enabled) pthread_mutex_unlock(&server.io_swapfile_mutex);
+ return REDIS_OK;
+}
+
/* Swap the 'val' object relative to 'key' into disk. Store all the information
* needed to later retrieve the object into the key object.
* If we can't find enough contiguous empty pages to swap the object on disk
* REDIS_ERR is returned. */
-static int vmSwapObject(robj *key, robj *val) {
- off_t pages = rdbSavedObjectPages(val);
+static int vmSwapObjectBlocking(robj *key, robj *val) {
+ off_t pages = rdbSavedObjectPages(val,NULL);
off_t page;
assert(key->storage == REDIS_VM_MEMORY);
assert(key->refcount == 1);
if (vmFindContiguousPages(&page,pages) == REDIS_ERR) return REDIS_ERR;
- if (fseeko(server.vm_fp,page*server.vm_page_size,SEEK_SET) == -1) {
- redisLog(REDIS_WARNING,
- "Critical VM problem in vmSwapObject(): can't seek: %s",
- strerror(errno));
- return REDIS_ERR;
- }
- rdbSaveObject(server.vm_fp,val);
+ if (vmWriteObjectOnSwap(val,page) == REDIS_ERR) return REDIS_ERR;
key->vm.page = page;
key->vm.usedpages = pages;
key->storage = REDIS_VM_SWAPPED;
return REDIS_OK;
}
-/* Load the value object relative to the 'key' object from swap to memory.
- * The newly allocated object is returned.
- *
- * If preview is true the unserialized object is returned to the caller but
- * no changes are made to the key object, nor the pages are marked as freed */
-static robj *vmGenericLoadObject(robj *key, int preview) {
- robj *val;
+static robj *vmReadObjectFromSwap(off_t page, int type) {
+ robj *o;
- redisAssert(key->storage == REDIS_VM_SWAPPED);
- if (fseeko(server.vm_fp,key->vm.page*server.vm_page_size,SEEK_SET) == -1) {
+ if (server.vm_enabled) pthread_mutex_lock(&server.io_swapfile_mutex);
+ if (fseeko(server.vm_fp,page*server.vm_page_size,SEEK_SET) == -1) {
redisLog(REDIS_WARNING,
"Unrecoverable VM problem in vmLoadObject(): can't seek: %s",
strerror(errno));
exit(1);
}
- val = rdbLoadObject(key->vtype,server.vm_fp);
- if (val == NULL) {
+ o = rdbLoadObject(type,server.vm_fp);
+ if (o == NULL) {
redisLog(REDIS_WARNING, "Unrecoverable VM problem in vmLoadObject(): can't load object from swap file: %s", strerror(errno));
exit(1);
}
+ if (server.vm_enabled) pthread_mutex_unlock(&server.io_swapfile_mutex);
+ return o;
+}
+
+/* Load the value object relative to the 'key' object from swap to memory.
+ * The newly allocated object is returned.
+ *
+ * If preview is true the unserialized object is returned to the caller but
+ * no changes are made to the key object, nor the pages are marked as freed */
+static robj *vmGenericLoadObject(robj *key, int preview) {
+ robj *val;
+
+ redisAssert(key->storage == REDIS_VM_SWAPPED);
+ val = vmReadObjectFromSwap(key->vm.page,key->vtype);
if (!preview) {
key->storage = REDIS_VM_MEMORY;
key->vm.atime = server.unixtime;
/* Plain object loading, from swap to memory */
static robj *vmLoadObject(robj *key) {
+ /* If we are loading the object in background, stop it, we
+ * need to load this object synchronously ASAP. */
+ if (key->storage == REDIS_VM_LOADING)
+ vmCancelThreadedIOJob(key);
return vmGenericLoadObject(key,0);
}
/* Try to swap an object that's a good candidate for swapping.
* Returns REDIS_OK if the object was swapped, REDIS_ERR if it's not possible
- * to swap any object at all. */
-static int vmSwapOneObject(void) {
+ * to swap any object at all.
+ *
+ * If 'usethreaded' is true, Redis will try to swap the object in background
+ * using I/O threads. */
+static int vmSwapOneObject(int usethreads) {
int j, i;
struct dictEntry *best = NULL;
double best_swappability = 0;
+ redisDb *best_db = NULL;
robj *key, *val;
for (j = 0; j < server.dbnum; j++) {
de = dictGetRandomKey(db->dict);
key = dictGetEntryKey(de);
val = dictGetEntryVal(de);
- if (key->storage != REDIS_VM_MEMORY) {
+ /* Only swap objects that are currently in memory.
+ *
+ * Also don't swap shared objects if threaded VM is on, as we
+ * try to ensure that the main thread does not touch the
+ * object while the I/O thread is using it, but we can't
+ * control other keys without adding additional mutex. */
+ if (key->storage != REDIS_VM_MEMORY ||
+ (server.vm_max_threads != 0 && val->refcount != 1)) {
if (maxtries) i--; /* don't count this try */
continue;
}
if (!best || swappability > best_swappability) {
best = de;
best_swappability = swappability;
+ best_db = db;
}
}
}
key = dictGetEntryKey(best) = newkey;
}
/* Swap it */
- if (vmSwapObject(key,val) == REDIS_OK) {
- dictGetEntryVal(best) = NULL;
+ if (usethreads) {
+ vmSwapObjectThreaded(key,val,best_db);
return REDIS_OK;
} else {
- return REDIS_ERR;
+ if (vmSwapObjectBlocking(key,val) == REDIS_OK) {
+ dictGetEntryVal(best) = NULL;
+ return REDIS_OK;
+ } else {
+ return REDIS_ERR;
+ }
}
}
+static int vmSwapOneObjectBlocking() {
+ return vmSwapOneObject(0);
+}
+
+static int vmSwapOneObjectThreaded() {
+ return vmSwapOneObject(1);
+}
+
/* Return true if it's safe to swap out objects in a given moment.
* Basically we don't want to swap objects out while there is a BGSAVE
* or a BGAEOREWRITE running in backgroud. */
return 1;
}
+/* =================== Virtual Memory - Threaded I/O ======================= */
+
+static void freeIOJob(iojob *j) {
+ if (j->type == REDIS_IOJOB_PREPARE_SWAP ||
+ j->type == REDIS_IOJOB_DO_SWAP)
+ decrRefCount(j->val);
+ decrRefCount(j->key);
+ zfree(j);
+}
+
+/* Every time a thread finished a Job, it writes a byte into the write side
+ * of an unix pipe in order to "awake" the main thread, and this function
+ * is called. */
+static void vmThreadedIOCompletedJob(aeEventLoop *el, int fd, void *privdata,
+ int mask)
+{
+ char buf[1];
+ int retval;
+ int processed = 0;
+ REDIS_NOTUSED(el);
+ REDIS_NOTUSED(mask);
+ REDIS_NOTUSED(privdata);
+
+ /* For every byte we read in the read side of the pipe, there is one
+ * I/O job completed to process. */
+ while((retval = read(fd,buf,1)) == 1) {
+ iojob *j;
+ listNode *ln;
+ robj *key;
+ struct dictEntry *de;
+
+ redisLog(REDIS_DEBUG,"Processing I/O completed job");
+
+ /* Get the processed element (the oldest one) */
+ lockThreadedIO();
+ assert(listLength(server.io_processed) != 0);
+ ln = listFirst(server.io_processed);
+ j = ln->value;
+ listDelNode(server.io_processed,ln);
+ unlockThreadedIO();
+ /* If this job is marked as canceled, just ignore it */
+ if (j->canceled) {
+ freeIOJob(j);
+ continue;
+ }
+ /* Post process it in the main thread, as there are things we
+ * can do just here to avoid race conditions and/or invasive locks */
+ redisLog(REDIS_DEBUG,"Job %p type: %d, key at %p (%s) refcount: %d\n", (void*) j, j->type, (void*)j->key, (char*)j->key->ptr, j->key->refcount);
+ de = dictFind(j->db->dict,j->key);
+ assert(de != NULL);
+ key = dictGetEntryKey(de);
+ if (j->type == REDIS_IOJOB_LOAD) {
+ /* Key loaded, bring it at home */
+ key->storage = REDIS_VM_MEMORY;
+ key->vm.atime = server.unixtime;
+ vmMarkPagesFree(key->vm.page,key->vm.usedpages);
+ redisLog(REDIS_DEBUG, "VM: object %s loaded from disk (threaded)",
+ (unsigned char*) key->ptr);
+ server.vm_stats_swapped_objects--;
+ server.vm_stats_swapins++;
+ freeIOJob(j);
+ } else if (j->type == REDIS_IOJOB_PREPARE_SWAP) {
+ /* Now we know the amount of pages required to swap this object.
+ * Let's find some space for it, and queue this task again
+ * rebranded as REDIS_IOJOB_DO_SWAP. */
+ if (!vmCanSwapOut() ||
+ vmFindContiguousPages(&j->page,j->pages) == REDIS_ERR)
+ {
+ /* Ooops... no space or we can't swap as there is
+ * a fork()ed Redis trying to save stuff on disk. */
+ freeIOJob(j);
+ key->storage = REDIS_VM_MEMORY; /* undo operation */
+ } else {
+ /* Note that we need to mark this pages as used now,
+ * if the job will be canceled, we'll mark them as freed
+ * again. */
+ vmMarkPagesUsed(j->page,j->pages);
+ j->type = REDIS_IOJOB_DO_SWAP;
+ lockThreadedIO();
+ queueIOJob(j);
+ unlockThreadedIO();
+ }
+ } else if (j->type == REDIS_IOJOB_DO_SWAP) {
+ robj *val;
+
+ /* Key swapped. We can finally free some memory. */
+ if (key->storage != REDIS_VM_SWAPPING) {
+ printf("key->storage: %d\n",key->storage);
+ printf("key->name: %s\n",(char*)key->ptr);
+ printf("key->refcount: %d\n",key->refcount);
+ printf("val: %p\n",(void*)j->val);
+ printf("val->type: %d\n",j->val->type);
+ printf("val->ptr: %s\n",(char*)j->val->ptr);
+ }
+ redisAssert(key->storage == REDIS_VM_SWAPPING);
+ val = dictGetEntryVal(de);
+ key->vm.page = j->page;
+ key->vm.usedpages = j->pages;
+ key->storage = REDIS_VM_SWAPPED;
+ key->vtype = j->val->type;
+ decrRefCount(val); /* Deallocate the object from memory. */
+ dictGetEntryVal(de) = NULL;
+ redisLog(REDIS_DEBUG,
+ "VM: object %s swapped out at %lld (%lld pages) (threaded)",
+ (unsigned char*) key->ptr,
+ (unsigned long long) j->page, (unsigned long long) j->pages);
+ server.vm_stats_swapped_objects++;
+ server.vm_stats_swapouts++;
+ freeIOJob(j);
+ /* Put a few more swap requests in queue if we are still
+ * out of memory */
+ if (vmCanSwapOut() && zmalloc_used_memory() > server.vm_max_memory){
+ int more = 1;
+ while(more) {
+ lockThreadedIO();
+ more = listLength(server.io_newjobs) <
+ (unsigned) server.vm_max_threads;
+ unlockThreadedIO();
+ /* Don't waste CPU time if swappable objects are rare. */
+ if (vmSwapOneObjectThreaded() == REDIS_ERR) break;
+ }
+ }
+ }
+ processed++;
+ if (processed == REDIS_MAX_COMPLETED_JOBS_PROCESSED) return;
+ }
+ if (retval < 0 && errno != EAGAIN) {
+ redisLog(REDIS_WARNING,
+ "WARNING: read(2) error in vmThreadedIOCompletedJob() %s",
+ strerror(errno));
+ }
+}
+
+static void lockThreadedIO(void) {
+ pthread_mutex_lock(&server.io_mutex);
+}
+
+static void unlockThreadedIO(void) {
+ pthread_mutex_unlock(&server.io_mutex);
+}
+
+/* Remove the specified object from the threaded I/O queue if still not
+ * processed, otherwise make sure to flag it as canceled. */
+static void vmCancelThreadedIOJob(robj *o) {
+ list *lists[3] = {
+ server.io_newjobs, /* 0 */
+ server.io_processing, /* 1 */
+ server.io_processed /* 2 */
+ };
+ int i;
+
+ assert(o->storage == REDIS_VM_LOADING || o->storage == REDIS_VM_SWAPPING);
+again:
+ lockThreadedIO();
+ /* Search for a matching key in one of the queues */
+ for (i = 0; i < 3; i++) {
+ listNode *ln;
+ listIter li;
+
+ listRewind(lists[i],&li);
+ while ((ln = listNext(&li)) != NULL) {
+ iojob *job = ln->value;
+
+ if (job->canceled) continue; /* Skip this, already canceled. */
+ if (compareStringObjects(job->key,o) == 0) {
+ redisLog(REDIS_DEBUG,"*** CANCELED %p (%s) (LIST ID %d)\n",
+ (void*)job, (char*)o->ptr, i);
+ /* Mark the pages as free since the swap didn't happened
+ * or happened but is now discarded. */
+ if (job->type == REDIS_IOJOB_DO_SWAP)
+ vmMarkPagesFree(job->page,job->pages);
+ /* Cancel the job. It depends on the list the job is
+ * living in. */
+ switch(i) {
+ case 0: /* io_newjobs */
+ /* If the job was yet not processed the best thing to do
+ * is to remove it from the queue at all */
+ freeIOJob(job);
+ listDelNode(lists[i],ln);
+ break;
+ case 1: /* io_processing */
+ /* Oh Shi- the thread is messing with the Job, and
+ * probably with the object if this is a
+ * PREPARE_SWAP or DO_SWAP job. Better to wait for the
+ * job to move into the next queue... */
+ if (job->type != REDIS_IOJOB_LOAD) {
+ /* Yes, we try again and again until the job
+ * is completed. */
+ unlockThreadedIO();
+ /* But let's wait some time for the I/O thread
+ * to finish with this job. After all this condition
+ * should be very rare. */
+ usleep(1);
+ goto again;
+ } else {
+ job->canceled = 1;
+ break;
+ }
+ case 2: /* io_processed */
+ /* The job was already processed, that's easy...
+ * just mark it as canceled so that we'll ignore it
+ * when processing completed jobs. */
+ job->canceled = 1;
+ break;
+ }
+ /* Finally we have to adjust the storage type of the object
+ * in order to "UNDO" the operaiton. */
+ if (o->storage == REDIS_VM_LOADING)
+ o->storage = REDIS_VM_SWAPPED;
+ else if (o->storage == REDIS_VM_SWAPPING)
+ o->storage = REDIS_VM_MEMORY;
+ unlockThreadedIO();
+ return;
+ }
+ }
+ }
+ unlockThreadedIO();
+ assert(1 != 1); /* We should never reach this */
+}
+
+static void *IOThreadEntryPoint(void *arg) {
+ iojob *j;
+ listNode *ln;
+ REDIS_NOTUSED(arg);
+
+ pthread_detach(pthread_self());
+ while(1) {
+ /* Get a new job to process */
+ lockThreadedIO();
+ if (listLength(server.io_newjobs) == 0) {
+#ifdef REDIS_HELGRIND_FRIENDLY
+ /* No new jobs? Wait and retry, because to be Helgrind
+ * (valgrind --tool=helgrind) what's needed is to take
+ * the same threads running instead to create/destroy threads
+ * as needed (otherwise valgrind will fail) */
+ unlockThreadedIO();
+ usleep(1); /* Give some time for the I/O thread to work. */
+ continue;
+#endif
+ /* No new jobs in queue, exit. */
+ redisLog(REDIS_DEBUG,"Thread %lld exiting, nothing to do",
+ (long long) pthread_self());
+ server.io_active_threads--;
+ unlockThreadedIO();
+ return NULL;
+ }
+ ln = listFirst(server.io_newjobs);
+ j = ln->value;
+ listDelNode(server.io_newjobs,ln);
+ /* Add the job in the processing queue */
+ j->thread = pthread_self();
+ listAddNodeTail(server.io_processing,j);
+ ln = listLast(server.io_processing); /* We use ln later to remove it */
+ unlockThreadedIO();
+ redisLog(REDIS_DEBUG,"Thread %lld got a new job (type %d): %p about key '%s'",
+ (long long) pthread_self(), j->type, (void*)j, (char*)j->key->ptr);
+
+ /* Process the Job */
+ if (j->type == REDIS_IOJOB_LOAD) {
+ } else if (j->type == REDIS_IOJOB_PREPARE_SWAP) {
+ FILE *fp = fopen("/dev/null","w+");
+ j->pages = rdbSavedObjectPages(j->val,fp);
+ fclose(fp);
+ } else if (j->type == REDIS_IOJOB_DO_SWAP) {
+ if (vmWriteObjectOnSwap(j->val,j->page) == REDIS_ERR)
+ j->canceled = 1;
+ }
+
+ /* Done: insert the job into the processed queue */
+ redisLog(REDIS_DEBUG,"Thread %lld completed the job: %p (key %s)",
+ (long long) pthread_self(), (void*)j, (char*)j->key->ptr);
+ lockThreadedIO();
+ listDelNode(server.io_processing,ln);
+ listAddNodeTail(server.io_processed,j);
+ unlockThreadedIO();
+
+ /* Signal the main thread there is new stuff to process */
+ assert(write(server.io_ready_pipe_write,"x",1) == 1);
+ }
+ return NULL; /* never reached */
+}
+
+static void spawnIOThread(void) {
+ pthread_t thread;
+
+ pthread_create(&thread,&server.io_threads_attr,IOThreadEntryPoint,NULL);
+ server.io_active_threads++;
+}
+
+/* We need to wait for the last thread to exit before we are able to
+ * fork() in order to BGSAVE or BGREWRITEAOF. */
+static void waitEmptyIOJobsQueue(void) {
+ while(1) {
+ lockThreadedIO();
+ if (listLength(server.io_newjobs) == 0 &&
+ listLength(server.io_processing) == 0 &&
+ server.io_active_threads == 0)
+ {
+ unlockThreadedIO();
+ return;
+ }
+ unlockThreadedIO();
+ usleep(10000); /* 10 milliseconds */
+ }
+}
+
+static void vmReopenSwapFile(void) {
+ fclose(server.vm_fp);
+ server.vm_fp = fopen(server.vm_swap_file,"r+b");
+ if (server.vm_fp == NULL) {
+ redisLog(REDIS_WARNING,"Can't re-open the VM swap file: %s. Exiting.",
+ server.vm_swap_file);
+ exit(1);
+ }
+ server.vm_fd = fileno(server.vm_fp);
+}
+
+/* This function must be called while with threaded IO locked */
+static void queueIOJob(iojob *j) {
+ redisLog(REDIS_DEBUG,"Queued IO Job %p type %d about key '%s'\n",
+ (void*)j, j->type, (char*)j->key->ptr);
+ listAddNodeTail(server.io_newjobs,j);
+ if (server.io_active_threads < server.vm_max_threads)
+ spawnIOThread();
+}
+
+static int vmSwapObjectThreaded(robj *key, robj *val, redisDb *db) {
+ iojob *j;
+
+ assert(key->storage == REDIS_VM_MEMORY);
+ assert(key->refcount == 1);
+
+ j = zmalloc(sizeof(*j));
+ j->type = REDIS_IOJOB_PREPARE_SWAP;
+ j->db = db;
+ j->key = dupStringObject(key);
+ j->val = val;
+ incrRefCount(val);
+ j->canceled = 0;
+ j->thread = (pthread_t) -1;
+ key->storage = REDIS_VM_SWAPPING;
+
+ lockThreadedIO();
+ queueIOJob(j);
+ unlockThreadedIO();
+ return REDIS_OK;
+}
+
/* ================================= Debugging ============================== */
static void debugCommand(redisClient *c) {
}
key = dictGetEntryKey(de);
val = dictGetEntryVal(de);
- if (server.vm_enabled && key->storage == REDIS_VM_MEMORY) {
+ if (server.vm_enabled && (key->storage == REDIS_VM_MEMORY ||
+ key->storage == REDIS_VM_SWAPPING)) {
addReplySds(c,sdscatprintf(sdsempty(),
"+Key at:%p refcount:%d, value at:%p refcount:%d "
"encoding:%d serializedlength:%lld\r\n",
(void*)key, key->refcount, (void*)val, val->refcount,
- val->encoding, rdbSavedObjectLen(val)));
+ val->encoding, (long long) rdbSavedObjectLen(val,NULL)));
} else {
addReplySds(c,sdscatprintf(sdsempty(),
"+Key at:%p refcount:%d, value swapped at: page %llu "
/* Swap it */
if (key->storage != REDIS_VM_MEMORY) {
addReplySds(c,sdsnew("-ERR This key is not in memory\r\n"));
- } else if (vmSwapObject(key,val) == REDIS_OK) {
+ } else if (vmSwapObjectBlocking(key,val) == REDIS_OK) {
dictGetEntryVal(de) = NULL;
addReply(c,shared.ok);
} else {
}
}
-static void _redisAssert(char *estr) {
+static void _redisAssert(char *estr, char *file, int line) {
redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
- redisLog(REDIS_WARNING,"==> %s\n",estr);
+ redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true\n",file,line,estr);
#ifdef HAVE_BACKTRACE
redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
*((char*)-1) = 'x';
FILE *fp;
if (fork() != 0) exit(0); /* parent exits */
- printf("New pid: %d\n", getpid());
setsid(); /* create a new session */
/* Every output goes to /dev/null. If Redis is daemonized but
if (rdbLoad(server.dbfilename) == REDIS_OK)
redisLog(REDIS_NOTICE,"DB loaded from disk");
}
- if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
- acceptHandler, NULL) == AE_ERR) oom("creating file event");
redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
aeMain(server.el);
aeDeleteEventLoop(server.el);
projects / redis.git / blobdiff