zmalloc_enable_thread_safeness(); /* we need thread safe zmalloc() */
- redisLog(REDIS_NOTICE,"Initializing Disk Store at %s", server.ds_path);
+ redisLog(REDIS_NOTICE,"Opening Disk Store: %s", server.ds_path);
/* Open Disk Store */
if (dsOpen() != REDIS_OK) {
redisLog(REDIS_WARNING,"Fatal error opening disk store. Exiting.");
dbDelete(best_db,kobj);
decrRefCount(kobj);
}
+ return REDIS_OK;
}
/* Return true if it's safe to swap out objects in a given moment.
void freeIOJob(iojob *j) {
decrRefCount(j->key);
+ /* j->val can be NULL if the job is about deleting the key from disk. */
+ if (j->val) decrRefCount(j->val);
zfree(j);
}
/* 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,"COMPLETED Job type: %d, ID %p, key: %s", j->type, (void*)j->id, (unsigned char*)j->key->ptr);
+ redisLog(REDIS_DEBUG,"COMPLETED Job type %s, key: %s",
+ (j->type == REDIS_IOJOB_LOAD) ? "load" : "save",
+ (unsigned char*)j->key->ptr);
de = dictFind(j->db->dict,j->key->ptr);
redisAssert(de != NULL);
if (j->type == REDIS_IOJOB_LOAD) {
- redisDb *db;
- vmpointer *vp = dictGetEntryVal(de);
-
- /* Key loaded, bring it at home */
- vmMarkPagesFree(vp->page,vp->usedpages);
- redisLog(REDIS_DEBUG, "VM: object %s loaded from disk (threaded)",
- (unsigned char*) j->key->ptr);
- server.vm_stats_swapped_objects--;
- server.vm_stats_swapins++;
- dictGetEntryVal(de) = j->val;
- incrRefCount(j->val);
- db = j->db;
+ /* Create the key-value pair in the in-memory database */
+ dbAdd(j->db,j->key,j->val);
/* Handle clients waiting for this key to be loaded. */
- handleClientsBlockedOnSwappedKey(db,j->key);
+ handleClientsBlockedOnSwappedKey(j->db,j->key);
freeIOJob(j);
- zfree(vp);
- } else if (j->type == REDIS_IOJOB_DO_SWAP) {
- vmpointer *vp;
-
- /* Key swapped. We can finally free some memory. */
- if (j->val->storage != REDIS_VM_SWAPPING) {
- vmpointer *vp = (vmpointer*) j->id;
- printf("storage: %d\n",vp->storage);
- printf("key->name: %s\n",(char*)j->key->ptr);
- 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(j->val->storage == REDIS_VM_SWAPPING);
- vp = createVmPointer(j->val->type);
- vp->page = j->page;
- vp->usedpages = j->pages;
- dictGetEntryVal(de) = vp;
- /* Fix the storage otherwise decrRefCount will attempt to
- * remove the associated I/O job */
- j->val->storage = REDIS_VM_MEMORY;
- decrRefCount(j->val);
- redisLog(REDIS_DEBUG,
- "VM: object %s swapped out at %lld (%lld pages) (threaded)",
- (unsigned char*) j->key->ptr,
- (unsigned long long) j->page, (unsigned long long) j->pages);
- server.vm_stats_swapped_objects++;
- server.vm_stats_swapouts++;
+ } else if (j->type == REDIS_IOJOB_SAVE) {
+ redisAssert(j->val->storage == REDIS_DS_SAVING);
+ j->val->storage = REDIS_DS_MEMORY;
freeIOJob(j);
- /* Put a few more swap requests in queue if we are still
- * out of memory */
- if (trytoswap && 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) {
- trytoswap = 0;
- break;
- }
- }
- }
}
processed++;
if (processed == toprocess) return;
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 %ld got a new job (type %d): %p about key '%s'",
- (long) pthread_self(), j->type, (void*)j, (char*)j->key->ptr);
+ redisLog(REDIS_DEBUG,"Thread %ld: new job type %s: %p about key '%s'",
+ (long) pthread_self(),
+ (j->type == REDIS_IOJOB_LOAD) ? "load" : "save",
+ (void*)j, (char*)j->key->ptr);
/* Process the Job */
if (j->type == REDIS_IOJOB_LOAD) {
- vmpointer *vp = (vmpointer*)j->id;
- j->val = vmReadObjectFromSwap(j->page,vp->vtype);
- } else if (j->type == REDIS_IOJOB_PREPARE_SWAP) {
- j->pages = rdbSavedObjectPages(j->val);
- } else if (j->type == REDIS_IOJOB_DO_SWAP) {
- if (vmWriteObjectOnSwap(j->val,j->page) == REDIS_ERR)
- j->canceled = 1;
+ j->val = dsGet(j->db,j->key);
+ redisAssert(j->val != NULL);
+ } else if (j->type == REDIS_IOJOB_SAVE) {
+ redisAssert(j->val->storage == REDIS_DS_SAVING);
+ if (j->val)
+ dsSet(j->db,j->key,j->val);
+ else
+ dsDel(j->db,j->key);
}
/* Done: insert the job into the processed queue */
spawnIOThread();
}
-int vmSwapObjectThreaded(robj *key, robj *val, redisDb *db) {
+void dsCreateIOJob(int type, redisDb *db, robj *key, robj *val) {
iojob *j;
j = zmalloc(sizeof(*j));
- j->type = REDIS_IOJOB_PREPARE_SWAP;
+ j->type = type;
j->db = db;
j->key = key;
incrRefCount(key);
- j->id = j->val = val;
+ j->val = val;
incrRefCount(val);
- j->canceled = 0;
- j->thread = (pthread_t) -1;
- val->storage = REDIS_VM_SWAPPING;
lockThreadedIO();
queueIOJob(j);
unlockThreadedIO();
- return REDIS_OK;
+}
+
+void cacheScheduleForFlush(redisDb *db, robj *key) {
+ dirtykey *dk;
+ dictEntry *de;
+
+ de = dictFind(db->dict,key->ptr);
+ if (de) {
+ robj *val = dictGetEntryVal(de);
+ if (val->storage == REDIS_DS_DIRTY)
+ return;
+ else
+ val->storage = REDIS_DS_DIRTY;
+ }
+
+ redisLog(REDIS_DEBUG,"Scheduling key %s for saving",key->ptr);
+ dk = zmalloc(sizeof(*dk));
+ dk->db = db;
+ dk->key = key;
+ incrRefCount(key);
+ dk->ctime = time(NULL);
+ listAddNodeTail(server.cache_flush_queue, key);
+}
+
+void cacheCron(void) {
+ time_t now = time(NULL);
+ listNode *ln;
+
+ /* Sync stuff on disk */
+ while((ln = listFirst(server.cache_flush_queue)) != NULL) {
+ dirtykey *dk = ln->value;
+
+ if ((now - dk->ctime) >= server.cache_flush_delay) {
+ struct dictEntry *de;
+ robj *val;
+
+ redisLog(REDIS_DEBUG,"Creating IO Job to save key %s",dk->key->ptr);
+
+ /* Lookup the key. We need to check if it's still here and
+ * possibly access to the value. */
+ de = dictFind(dk->db->dict,dk->key->ptr);
+ if (de) {
+ val = dictGetEntryVal(de);
+ redisAssert(val->storage == REDIS_DS_DIRTY);
+ val->storage = REDIS_DS_SAVING;
+ } else {
+ /* Setting the value to NULL tells the IO thread to delete
+ * the key on disk. */
+ val = NULL;
+ }
+ dsCreateIOJob(REDIS_IOJOB_SAVE,dk->db,dk->key,val);
+ listDelNode(server.cache_flush_queue,ln);
+ } else {
+ break; /* too early */
+ }
+ }
+
+ /* Reclaim memory from the object cache */
+ while (server.ds_enabled && zmalloc_used_memory() >
+ server.cache_max_memory)
+ {
+ if (cacheFreeOneEntry() == REDIS_ERR) break;
+ }
}
/* ============ Virtual Memory - Blocking clients on missing keys =========== */
/* This function makes the clinet 'c' waiting for the key 'key' to be loaded.
- * If there is not already a job loading the key, it is craeted.
- * The key is added to the io_keys list in the client structure, and also
+ * If the key is already in memory we don't need to block, regardless
+ * of the storage of the value object for this key:
+ *
+ * - If it's REDIS_DS_MEMORY we have the key in memory.
+ * - If it's REDIS_DS_DIRTY they key was modified, but still in memory.
+ * - if it's REDIS_DS_SAVING the key is being saved by an IO Job. When
+ * the client will lookup the key it will block if the key is still
+ * in this stage but it's more or less the best we can do.
+ *
+ * FIXME: we should try if it's actually better to suspend the client
+ * accessing an object that is being saved, and awake it only when
+ * the saving was completed.
+ *
+ * Otherwise if the key is not in memory, we block the client and start
+ * an IO Job to load it:
+ *
+ * the key is added to the io_keys list in the client structure, and also
* in the hash table mapping swapped keys to waiting clients, that is,
* server.io_waited_keys. */
int waitForSwappedKey(redisClient *c, robj *key) {
struct dictEntry *de;
- robj *o;
list *l;
- /* If the key does not exist or is already in RAM we don't need to
- * block the client at all. */
+ /* Return ASAP if the key is in memory */
de = dictFind(c->db->dict,key->ptr);
- if (de == NULL) return 0;
- o = dictGetEntryVal(de);
- if (o->storage == REDIS_VM_MEMORY) {
- return 0;
- } else if (o->storage == REDIS_VM_SWAPPING) {
- /* We were swapping the key, undo it! */
- vmCancelThreadedIOJob(o);
- return 0;
- }
-
- /* OK: the key is either swapped, or being loaded just now. */
+ if (de != NULL) return 0;
/* Add the key to the list of keys this client is waiting for.
* This maps clients to keys they are waiting for. */
listAddNodeTail(l,c);
/* Are we already loading the key from disk? If not create a job */
- if (o->storage == REDIS_VM_SWAPPED) {
- iojob *j;
- vmpointer *vp = (vmpointer*)o;
-
- o->storage = REDIS_VM_LOADING;
- j = zmalloc(sizeof(*j));
- j->type = REDIS_IOJOB_LOAD;
- j->db = c->db;
- j->id = (robj*)vp;
- j->key = key;
- incrRefCount(key);
- j->page = vp->page;
- j->val = NULL;
- j->canceled = 0;
- j->thread = (pthread_t) -1;
- lockThreadedIO();
- queueIOJob(j);
- unlockThreadedIO();
- }
+ if (de == NULL)
+ dsCreateIOJob(REDIS_IOJOB_LOAD,c->db,key,NULL);
return 1;
}
if (listLength(c->io_keys)) {
c->flags |= REDIS_IO_WAIT;
aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
- server.vm_blocked_clients++;
+ server.cache_blocked_clients++;
return 1;
} else {
return 0;
projects / redis.git / blobdiff