In EventuallyPersistentStore, move stop task funcs to deinitialize() from dtor

In the class EventuallyPersistentStore, after an instance is created, some
operations are done to create tasks, etc in the func initialize(). However,
these are undone during dtor of the class. This is not always safe as
flagged by the thread sanitizer in
http://cv.jenkins.couchbase.com/job/ep-engine-threadsanitizer-master/1479/

This commit does the undoing of initialize() stuff in deinitialize() before
delete.

Change-Id: Ie090fd74b7bad77642666d85969c97ae5001a027
Reviewed-on: http://review.couchbase.org/68974
Tested-by: buildbot <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: manudhundi

src/ep.cc

@@ -560,11 +560,11 @@ bool EventuallyPersistentStore::initialize() {
     return true;
 }
 
-EventuallyPersistentStore::~EventuallyPersistentStore() {
+void EventuallyPersistentStore::deinitialize() {
     stopWarmup();
     stopBgFetcher();
-    ExecutorPool::get()->stopTaskGroup(engine.getTaskable().getGID(), NONIO_TASK_IDX,
-                                       stats.forceShutdown);
+    ExecutorPool::get()->stopTaskGroup(engine.getTaskable().getGID(),
+                                       NONIO_TASK_IDX, stats.forceShutdown);
 
     ExecutorPool::get()->cancel(statsSnapshotTaskId);
 
@@ -576,7 +576,9 @@ EventuallyPersistentStore::~EventuallyPersistentStore() {
 
     ExecutorPool::get()->unregisterTaskable(engine.getTaskable(),
                                             stats.forceShutdown);
+}
 
+EventuallyPersistentStore::~EventuallyPersistentStore() {
     delete [] vb_mutexes;
     delete [] schedule_vbstate_persist;
     delete [] stats.schedulingHisto;

src/ep.h

@@ -210,8 +210,18 @@ class EventuallyPersistentStore {
     EventuallyPersistentStore(EventuallyPersistentEngine &theEngine);
     ~EventuallyPersistentStore();
 
+    /**
+     * Start necessary tasks.
+     * Client calling initialize must also call deinitialize before deleting
+     * the EventuallyPersistentStore instance
+     */
     bool initialize();
 
+    /**
+     * Stop tasks started in initialize()
+     */
+    void deinitialize();
+
     /**
      * Set an item in the store.
      * @param item the item to set

src/ep_engine.cc

@@ -6401,6 +6401,7 @@ ENGINE_ERROR_CODE EventuallyPersistentEngine::sendNotMyVBucketResponse(
 }
 
 EventuallyPersistentEngine::~EventuallyPersistentEngine() {
+    epstore->deinitialize();
     delete epstore;
     delete workload;
     delete dcpConnMap_;