Fix race condition: instance map wasn't locked for the

duration of the whole 'flush instances'. As a consequence,
it was possible to query instance map, while it is in the
inconsistent state. The patch was reworked after review.


server-tools/instance-manager/guardian.cc:
  do not lock instance map in Guardian_thread::init()
server-tools/instance-manager/instance_map.cc:
  Eliminate race condition: lock instance map and guardian
  for the duration of the whole "FLUSH INSTANCES" execution.
server-tools/instance-manager/instance_map.h:
  add new method. cleanup interface. add comments.
server-tools/instance-manager/manager.cc:
  use instance_map.flush_instances instead of instance_map.load() and guardian_thread.init()

1 files changed, 0 insertions, 2 deletions

diff --git a/server-tools/instance-manager/guardian.cc b/server-tools/instance-manager/guardian.cc
index 291b685ef1b..7a532263846 100644
--- a/server-tools/instance-manager/guardian.cc
+++ b/server-tools/instance-manager/guardian.cc
@@ -256,7 +256,6 @@ int Guardian_thread::init()
   Instance *instance;
   Instance_map::Iterator iterator(instance_map);
 
-  instance_map->lock();
   /* clear the list of guarded instances */
   free_root(&alloc, MYF(0));
   init_alloc_root(&alloc, MEM_ROOT_BLOCK_SIZE, 0);
@@ -272,7 +271,6 @@ int Guardian_thread::init()
       }
   }
 
-  instance_map->unlock();
   return 0;
 }