fix_max_connections to resize alarm_queue (Bug #1435)

include/queues.h:
  resize_queue()
include/thr_alarm.h:
  resize_thr_alarm() to resize alarm_queue
mysys/queues.c:
  resize_queue()
mysys/thr_alarm.c:
  resize_thr_alarm() to resize alarm_queue

2 files changed, 27 insertions, 7 deletions

diff --git a/mysys/queues.c b/mysys/queues.c
index fe642131d74..ae69684f9e4 100644
--- a/mysys/queues.c
+++ b/mysys/queues.c
@@ -44,25 +44,35 @@ int init_queue(QUEUE *queue, uint max_elements, uint offset_to_key,
 }
 
 /*
-  Reinitialize queue for new usage;  Note that you can't currently resize
-  the number of elements!  If you need this, fix it :)
+  Reinitialize queue for new usage;
 */
 
-
 int reinit_queue(QUEUE *queue, uint max_elements, uint offset_to_key,
                pbool max_at_top, int (*compare) (void *, byte *, byte *),
                void *first_cmp_arg)
 {
   DBUG_ENTER("reinit_queue");
-  if (queue->max_elements < max_elements)
-    /* It's real easy to do realloc here, just don't want to bother */
-    DBUG_RETURN(my_errno=EE_OUTOFMEMORY);
-
   queue->elements=0;
   queue->compare=compare;
   queue->first_cmp_arg=first_cmp_arg;
   queue->offset_to_key=offset_to_key;
   queue->max_at_top= max_at_top ? (-1 ^ 1) : 0;
+  resize_queue(queue, max_elements);
+  DBUG_RETURN(0);
+}
+
+int resize_queue(QUEUE *queue, uint max_elements)
+{
+  byte **new_root;
+  DBUG_ENTER("resize_queue");
+  if (queue->max_elements == max_elements)
+    DBUG_RETURN(0);
+  if ((new_root= (byte **) my_realloc((void *)queue->root,
+          (max_elements+1)*sizeof(void*), MYF(MY_WME))) == 0)
+    DBUG_RETURN(1);
+  set_if_smaller(queue->elements, max_elements);
+  queue->max_elements=max_elements;
+  queue->root=new_root;
   DBUG_RETURN(0);
 }
 
diff --git a/mysys/thr_alarm.c b/mysys/thr_alarm.c
index 2289f8208bc..5d2ac8b0099 100644
--- a/mysys/thr_alarm.c
+++ b/mysys/thr_alarm.c
@@ -120,6 +120,16 @@ void init_thr_alarm(uint max_alarms)
   DBUG_VOID_RETURN;
 }
 
+void resize_thr_alarm(uint max_alarms)
+{
+  pthread_mutex_lock(&LOCK_alarm);
+  /* it's ok not to shrink the queue sometimes */
+  if (alarm_queue.elements < max_alarms)
+    resize_queue(&alarm_queue,max_alarms+1);
+  pthread_mutex_unlock(&LOCK_alarm);
+  return;
+}
+
 /*
   Request alarm after sec seconds.