Makes sure we stop the dispatch_source to prevent cycle/leak

Author: flovilmart

Parse/Internal/PFEventuallyQueue.h

@@ -67,7 +67,7 @@ extern NSTimeInterval const PFEventuallyQueueDefaultTimeoutRetryInterval;
 - (void)start NS_REQUIRES_SUPER;
 - (void)resume NS_REQUIRES_SUPER;
 - (void)pause NS_REQUIRES_SUPER;
-
+- (void)stop NS_REQUIRES_SUPER;
 - (void)removeAllCommands NS_REQUIRES_SUPER;
 
 @end

Parse/Internal/PFEventuallyQueue.m

@@ -197,6 +197,10 @@ - (void)pause {
     dispatch_suspend(_processingQueueSource);
 }
 
+- (void)stop {
+    dispatch_source_cancel(_processingQueueSource);
+}
+
 - (void)removeAllCommands {
     dispatch_sync(_synchronizationQueue, ^{
         [_taskCompletionSources removeAllObjects];

Parse/Internal/ParseManager.m

@@ -174,12 +174,15 @@ - (PFEventuallyQueue *)eventuallyQueue {
                                 [PFPinningEventuallyQueue newDefaultPinningEventuallyQueueWithDataSource:self]
                                 :
                                 commandCache);
-
             // We still need to clear out the old command cache even if we're using Pinning in case
             // anything is left over when the user upgraded. Checking number of pending and then
             // clearing should be enough.
-            if (self.offlineStoreLoaded && commandCache.commandCount > 0) {
-                [commandCache removeAllCommands];
+            if (self.offlineStoreLoaded) {
+                if (commandCache.commandCount > 0) {
+                    [commandCache removeAllCommands];
+                }
+                // we won't need it after stop everything...
+                [commandCache stop];
             }
         }
 #endif
@@ -442,7 +445,6 @@ - (BFTask *)preloadDiskObjectsToMemoryAsync {
 #endif
                            ];
         [[BFTask taskForCompletionOfAllTasks:tasks] waitUntilFinished]; // Wait synchronously to make sure we are blocking preload queue.
-        [self eventuallyQueue];
 
         return nil;
     }];