overflow detection in INCR family functions

[redis.git] / src / object.c

diff --git a/src/object.c b/src/object.c
index bba448241b0000ef68f15288b233469e6ffe30f7..de62f504cc69ff9696dcf4b7b2b70a438d8a7a35 100644 (file)
--- a/src/object.c
+++ b/src/object.c
@@ -3,22 +3,12 @@
 #include <math.h>
 
 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));
-    }
+    robj *o = zmalloc(sizeof(*o));
     o->type = type;
     o->encoding = REDIS_ENCODING_RAW;
     o->ptr = ptr;
     o->refcount = 1;
+
     /* Set the LRU to the current lruclock (minutes resolution).
      * We do this regardless of the fact VM is active as LRU is also
      * used for the maxmemory directive when Redis is used as cache.
@@ -204,11 +194,7 @@ void decrRefCount(void *obj) {
         default: redisPanic("Unknown object type"); break;
         }
         o->ptr = NULL; /* defensive programming. We'll see NULL in traces. */
-        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);
+        zfree(o);
     }
 }
 
@@ -245,8 +231,12 @@ robj *tryObjectEncoding(robj *o) {
      * range and if this is the main thread, since when VM is enabled we
      * have the constraint that I/O thread should only handle non-shared
      * objects, in order to avoid race conditions (we don't have per-object
-     * locking). */
-    if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
+     * locking).
+     *
+     * Note that we also avoid using shared integers when maxmemory is used
+     * because very object needs to have a private LRU field for the LRU
+     * algorithm to work well. */
+    if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS &&
         pthread_equal(pthread_self(),server.mainthread)) {
         decrRefCount(o);
         incrRefCount(shared.integers[value]);