CHANGED DEFAULT: set ActiveRecord::Base.allow_concurrency to false. Most AR usage is in single-threaded applications.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3728 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* CHANGED DEFAULT: set ActiveRecord::Base.allow_concurrency to false.  Most AR usage is in single-threaded applications. [Jeremy Kemper]
+
 * Renamed the "oci" adapter to "oracle", but kept the old name as an alias #4017 [schoenm@earthlink.net]
 
 * Fixed that Base.save should always return false if the save didn't succeed, including if it has halted by before_save's #1861, #2477 [DHH]

activerecord/lib/active_record/base.rb

@@ -306,12 +306,12 @@ module ActiveRecord #:nodoc:
     # This is set to :local by default.
     cattr_accessor :default_timezone
     @@default_timezone = :local
-    
+
     # Determines whether or not to use a connection for each thread, or a single shared connection for all threads.
-    # Defaults to true; Railties' WEBrick server sets this to false.
+    # Defaults to false. Set to true if you're writing a threaded application.
     cattr_accessor :allow_concurrency
-    @@allow_concurrency = true
-    
+    @@allow_concurrency = false
+
     # Determines whether to speed up access by generating optimized reader
     # methods to avoid expensive calls to method_missing when accessing
     # attributes by name. You might want to set this to false in development