Merge pull request redis#4028 from zintrepid/prevent_expirations_while_paused

Prevent expirations and evictions while paused

Author: antirez

src/evict.c

@@ -380,6 +380,12 @@ int freeMemoryIfNeeded(void) {
     long long delta;
     int slaves = listLength(server.slaves);
 
+    /* We cannot free memory while clients are paused as this will require
+     * evictions which modify the dataset and will break the guarantee that
+     * data will be static while clients are paused. */
+    if (clientsArePaused())
+        goto cant_free;
+
     /* Check if we are over the memory usage limit. If we are not, no need
      * to subtract the slaves output buffers. We can just return ASAP. */
     mem_reported = zmalloc_used_memory();

src/expire.c

@@ -105,6 +105,10 @@ void activeExpireCycle(int type) {
     int dbs_per_call = CRON_DBS_PER_CALL;
     long long start = ustime(), timelimit;
 
+    /* We cannot expire keys while clients are paused as the dataset is
+     * supposed to be static. */
+    if (clientsArePaused()) return;
+
     if (type == ACTIVE_EXPIRE_CYCLE_FAST) {
         /* Don't start a fast cycle if the previous cycle did not exited
          * for time limt. Also don't repeat a fast cycle for the same period