Fixed that nested transactions now work by letting the outer most transaction...

Fixed that nested transactions now work by letting the outer most transaction have the responsibilty of starting and rolling back the transaction. If any of the inner transactions swallow the exception raised, though, the transaction will not be rolled back. So always let the transaction bubble up even when you've dealt with local issues. Closes #231 and #340.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@242 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Fixed that nested transactions now work by letting the outer most transaction have the responsibilty of starting and rolling back the transaction.
+  If any of the inner transactions swallow the exception raised, though, the transaction will not be rolled back. So always let the transaction
+  bubble up even when you've dealt with local issues. Closes #231 and #340.
+
 * Fixed validates_{confirmation,acceptance}_of to only happen when the virtual attributes are not nil #348 [dpiddy@gmail.com]
 
 * Added a require_association hook on const_missing that makes it possible to use any model class without requiring it first. This makes STI look like:

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -298,16 +298,16 @@ def reset_runtime # :nodoc:
       end
 
       # Wrap a block in a transaction.  Returns result of block.
-      def transaction
+      def transaction(start_db_transaction = true)
         begin
           if block_given?
-            begin_db_transaction
+            begin_db_transaction if start_db_transaction
             result = yield
-            commit_db_transaction
+            commit_db_transaction if start_db_transaction
             result
           end
         rescue Exception => database_transaction_rollback
-          rollback_db_transaction
+          rollback_db_transaction if start_db_transaction
           raise
         end
       end

activerecord/lib/active_record/transactions.rb

@@ -77,13 +77,17 @@ def self.append_features(base)
     # Tribute: Object-level transactions are implemented by Transaction::Simple by Austin Ziegler.
     module ClassMethods      
       def transaction(*objects, &block)
-        TRANSACTION_MUTEX.lock
+        TRANSACTION_MUTEX.synchronize do
+          Thread.current['open_transactions'] ||= 0
+          Thread.current['start_db_transaction'] = (Thread.current['open_transactions'] == 0)
+          Thread.current['open_transactions'] += 1
+        end
 
         begin
           objects.each { |o| o.extend(Transaction::Simple) }
           objects.each { |o| o.start_transaction }
 
-          result = connection.transaction(&block)
+          result = connection.transaction(Thread.current['start_db_transaction'], &block)
 
           objects.each { |o| o.commit_transaction }
           return result
@@ -91,7 +95,9 @@ def transaction(*objects, &block)
           objects.each { |o| o.abort_transaction }
           raise
         ensure
-          TRANSACTION_MUTEX.unlock
+          TRANSACTION_MUTEX.synchronize do
+            Thread.current['open_transactions'] -= 1
+          end
         end
       end
     end
@@ -101,19 +107,11 @@ def transaction(*objects, &block)
     end
 
     def destroy_with_transactions #:nodoc:
-      if TRANSACTION_MUTEX.locked?
-        destroy_without_transactions
-      else
-        transaction { destroy_without_transactions }
-      end
+      transaction { destroy_without_transactions }
     end
     
     def save_with_transactions(perform_validation = true) #:nodoc:
-      if TRANSACTION_MUTEX.locked?
-        save_without_transactions(perform_validation)
-      else
-        transaction { save_without_transactions(perform_validation) }
-      end
+      transaction { save_without_transactions(perform_validation) }
     end
   end
 end

activerecord/test/transactions_test.rb

@@ -84,7 +84,7 @@ def test_callback_rollback_in_save
     end
   end
 
-  def xtest_nested_explicit_transactions
+  def test_nested_explicit_transactions
     Topic.transaction do
       Topic.transaction do
         @first.approved  = 1