Another amendment to multithreading protection.

Converted to use of NSLock for avoiding competition on instances of GoogleReader and RefreshManager.
Expand the protected range of code.

GoogleReader.m

@@ -242,7 +242,7 @@ - (void)feedRequestDone:(ASIHTTPRequest *)request
 
 		Database *db = [Database sharedDatabase];
 		NSInteger newArticlesFromFeed = 0;
-		@synchronized(db){
+		[[RefreshManager articlesUpdateSemaphore] lock];
 			[db setFolderLastUpdateString:[refreshedFolder itemId] lastUpdateString:[NSString stringWithFormat:@"%@",[dict objectForKey:@"updated"]]];
 
 			// Here's where we add the articles to the database
@@ -268,7 +268,7 @@ - (void)feedRequestDone:(ASIHTTPRequest *)request
 
 			// Set the last update date for this folder.
 			[db setFolderLastUpdate:[refreshedFolder itemId] lastUpdate:[NSDate date]];
-		} //@synchronized
+		[[RefreshManager articlesUpdateSemaphore] unlock];
 
 		// Add to count of new articles so far
 		countOfNewArticles += newArticlesFromFeed;

RefreshManager.h

@@ -38,6 +38,7 @@
 }
 
 +(RefreshManager *)sharedManager;
++ (NSLock *)articlesUpdateSemaphore;
 -(void)refreshFolderIconCacheForSubscriptions:(NSArray *)foldersArray;
 //-(void)refreshSubscriptions:(NSArray *)foldersArray ignoringSubscriptionStatus:(BOOL)ignoreSubStatus;
 -(void)refreshSubscriptionsAfterRefresh:(NSArray *)foldersArray ignoringSubscriptionStatus:(BOOL)ignoreSubStatus;

RefreshManager.m

@@ -36,6 +36,7 @@
 
 // Singleton
 static RefreshManager * _refreshManager = nil;
+static NSLock * articlesUpdate_lock;
 
 // Private functions
 @interface RefreshManager (Private)
@@ -58,6 +59,17 @@ - (void)syncFinishedForFolder:(Folder *)folder;
 
 @implementation RefreshManager
 
++ (void)initialize
+{
+    // Initializes our multi-thread lock
+    articlesUpdate_lock = [[NSLock alloc] init];
+}
+
++ (NSLock *)articlesUpdateSemaphore
+{
+    return articlesUpdate_lock;
+}
+
 /* init
  * Initialise the class.
  */
@@ -784,7 +796,7 @@ -(void)finalizeFolderRefresh:(NSDictionary*)parameters;
 				[article release];
 			}
 
-			@synchronized(db){
+			[articlesUpdate_lock lock];
 				// Remember the last modified date
 				if (lastModifiedString != nil)
 					[db setFolderLastUpdateString:folderId lastUpdateString:lastModifiedString];
@@ -798,15 +810,13 @@ -(void)finalizeFolderRefresh:(NSDictionary*)parameters;
 
 				[folder clearCache];
                 // Should we wrap the entire loop or just individual article updates?
-                @synchronized(db) {
-					[db beginTransaction];
-					for (Article * article in articleArray)
-					{
-						if ([db createArticle:folderId article:article guidHistory:guidHistory] && ([article status] == MA_MsgStatus_New))
-							++newArticlesFromFeed;
-					}
-					[db commitTransaction];
+				[db beginTransaction];
+				for (Article * article in articleArray)
+				{
+					if ([db createArticle:folderId article:article guidHistory:guidHistory] && ([article status] == MA_MsgStatus_New))
+						++newArticlesFromFeed;
 				}
+				[db commitTransaction];
 			}
 
 			[db beginTransaction];
@@ -832,8 +842,6 @@ -(void)finalizeFolderRefresh:(NSDictionary*)parameters;
 				[db setFolderHomePage:folderId newHomePage:feedLink];
 
 			[db commitTransaction];
-
-			};
 
 			// Mark the feed as succeeded
 			[self setFolderErrorFlag:folder flag:NO];
@@ -843,6 +851,8 @@ -(void)finalizeFolderRefresh:(NSDictionary*)parameters;
 
 			// Set the last update date for this folder.
 			[db setFolderLastUpdate:folderId lastUpdate:[NSDate date]];
+
+			[articlesUpdate_lock unlock];
 		};
 
 		// Send status to the activity log