Fixed a race condition in VM happening when a key was deleted while there was a clien...

[redis.git] / src / db.c

diff --git a/src/db.c b/src/db.c
index d8a5d0b2d64f75e475df00dcfd4371e08dc7c7f7..ca520c8259d0b7758baf11fd0037345b653885af 100644 (file)
--- a/src/db.c
+++ b/src/db.c
@@ -123,6 +123,11 @@ robj *dbRandomKey(redisDb *db) {
 
 /* Delete a key, value, and associated expiration entry if any, from the DB */
 int dbDelete(redisDb *db, robj *key) {
+    /* If VM is enabled make sure to awake waiting clients for this key:
+     * deleting the key will kill the I/O thread bringing the key from swap
+     * to memory, so the client will never be notified and unblocked if we
+     * don't do it now. */
+    handleClientsBlockedOnSwappedKey(db,key);
     /* Deleting an entry from the expires dict will not free the sds of
      * the key, because it is shared with the main dictionary. */
     if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
@@ -221,19 +226,19 @@ void keysCommand(redisClient *c) {
     dictIterator *di;
     dictEntry *de;
     sds pattern = c->argv[1]->ptr;
-    int plen = sdslen(pattern);
+    int plen = sdslen(pattern), allkeys;
     unsigned long numkeys = 0;
     robj *lenobj = createObject(REDIS_STRING,NULL);
 
     di = dictGetIterator(c->db->dict);
     addReply(c,lenobj);
     decrRefCount(lenobj);
+    allkeys = (pattern[0] == '*' && pattern[1] == '\0');
     while((de = dictNext(di)) != NULL) {
         sds key = dictGetEntryKey(de);
         robj *keyobj;
 
-        if ((pattern[0] == '*' && pattern[1] == '\0') ||
-            stringmatchlen(pattern,plen,key,sdslen(key),0)) {
+        if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
             keyobj = createStringObject(key,sdslen(key));
             if (expireIfNeeded(c->db,keyobj) == 0) {
                 addReplyBulk(c,keyobj);
@@ -394,23 +399,16 @@ int removeExpire(redisDb *db, robj *key) {
     /* An expire may only be removed if there is a corresponding entry in the
      * main dict. Otherwise, the key will never be freed. */
     redisAssert(dictFind(db->dict,key->ptr) != NULL);
-    if (dictDelete(db->expires,key->ptr) == DICT_OK) {
-        return 1;
-    } else {
-        return 0;
-    }
+    return dictDelete(db->expires,key->ptr) == DICT_OK;
 }
 
-int setExpire(redisDb *db, robj *key, time_t when) {
+void setExpire(redisDb *db, robj *key, time_t when) {
     dictEntry *de;
 
     /* Reuse the sds from the main dict in the expire dict */
-    redisAssert((de = dictFind(db->dict,key->ptr)) != NULL);
-    if (dictAdd(db->expires,dictGetEntryKey(de),(void*)when) == DICT_ERR) {
-        return 0;
-    } else {
-        return 1;
-    }
+    de = dictFind(db->dict,key->ptr);
+    redisAssert(de != NULL);
+    dictReplace(db->expires,dictGetEntryKey(de),(void*)when);
 }
 
 /* Return the expire time of the specified key, or -1 if no expire
@@ -450,7 +448,8 @@ void propagateExpire(redisDb *db, robj *key) {
     if (listLength(server.slaves))
         replicationFeedSlaves(server.slaves,db->id,argv,2);
 
-    decrRefCount(key);
+    decrRefCount(argv[0]);
+    decrRefCount(argv[1]);
 }
 
 int expireIfNeeded(redisDb *db, robj *key) {
@@ -503,13 +502,10 @@ void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
         return;
     } else {
         time_t when = time(NULL)+seconds;
-        if (setExpire(c->db,key,when)) {
-            addReply(c,shared.cone);
-            touchWatchedKey(c->db,key);
-            server.dirty++;
-        } else {
-            addReply(c,shared.czero);
-        }
+        setExpire(c->db,key,when);
+        addReply(c,shared.cone);
+        touchWatchedKey(c->db,key);
+        server.dirty++;
         return;
     }
 }
@@ -523,13 +519,28 @@ void expireatCommand(redisClient *c) {
 }
 
 void ttlCommand(redisClient *c) {
-    time_t expire;
-    int ttl = -1;
+    time_t expire, ttl = -1;
 
     expire = getExpire(c->db,c->argv[1]);
     if (expire != -1) {
-        ttl = (int) (expire-time(NULL));
+        ttl = (expire-time(NULL));
         if (ttl < 0) ttl = -1;
     }
-    addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",ttl));
+    addReplyLongLong(c,(long long)ttl);
+}
+
+void persistCommand(redisClient *c) {
+    dictEntry *de;
+
+    de = dictFind(c->db->dict,c->argv[1]->ptr);
+    if (de == NULL) {
+        addReply(c,shared.czero);
+    } else {
+        if (removeExpire(c->db,c->argv[1])) {
+            addReply(c,shared.cone);
+            server.dirty++;
+        } else {
+            addReply(c,shared.czero);
+        }
+    }
 }