From 50cd4bdc99ebaf3ac879e4e7fea43c5b55ca5f68 Mon Sep 17 00:00:00 2001
From: Nick <nick@nicksieger.com>
Date: Sat, 19 Apr 2008 12:42:43 -0500
Subject: Introduce synchronization around connection pool access
- use new active support Module#synchronize
- allow_concurrency now switches between a null monitor and a
regular monitor (defaulting to null monitor to avoid overhead)
---
.../abstract/connection_pool.rb | 15 ++++---
.../abstract/connection_specification.rb | 49 ++++++++++++++++------
.../test/cases/threaded_connections_test.rb | 4 ++
3 files changed, 47 insertions(+), 21 deletions(-)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 8685988e80..8f241a39ca 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -1,14 +1,12 @@
+require 'set'
+
module ActiveRecord
module ConnectionAdapters
class ConnectionPool
- # Check for activity after at least +verification_timeout+ seconds.
- # Defaults to 0 (always check.)
- attr_accessor :verification_timeout
+ delegate :verification_timeout, :to => "::ActiveRecord::Base"
attr_reader :active_connections, :spec
def initialize(spec)
- @verification_timeout = 0
-
# The thread id -> adapter cache.
@active_connections = {}
@@ -44,7 +42,7 @@ module ActiveRecord
end
end
- # Clears the cache which maps classes
+ # Clears the cache which maps classes
def clear_reloadable_connections!
@active_connections.each do |name, conn|
if conn.requires_reloading?
@@ -60,7 +58,7 @@ module ActiveRecord
conn.disconnect!
end
active_connections.each_value do |connection|
- connection.verify!(@verification_timeout)
+ connection.verify!(verification_timeout)
end
end
@@ -70,7 +68,7 @@ module ActiveRecord
name = active_connection_name
if conn = active_connections[name]
# Verify the connection.
- conn.verify!(@verification_timeout)
+ conn.verify!(verification_timeout)
else
self.connection = spec
conn = active_connections[name]
@@ -119,6 +117,7 @@ module ActiveRecord
def clear_entries!(cache, keys, &block)
keys.each do |key|
+ next unless cache.has_key?(key)
block.call(key, cache[key])
cache.delete(key)
end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
index b2771c60e7..e262b2bac5 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
@@ -1,4 +1,4 @@
-require 'set'
+require 'monitor'
module ActiveRecord
class Base
@@ -9,6 +9,15 @@ module ActiveRecord
end
end
+ class NullMonitor
+ def synchronize
+ yield
+ end
+ end
+
+ cattr_accessor :connection_pools_lock, :instance_writer => false
+ @@connection_pools_lock = NullMonitor.new
+
# Check for activity after at least +verification_timeout+ seconds.
# Defaults to 0 (always check.)
cattr_accessor :verification_timeout, :instance_writer => false
@@ -18,8 +27,18 @@ module ActiveRecord
@@connection_pools = {}
class << self
+ def allow_concurrency=(flag)
+ if @@allow_concurrency != flag
+ if flag
+ self.connection_pools_lock = Monitor.new
+ else
+ self.connection_pools_lock = NullMonitor.new
+ end
+ end
+ end
+
# for internal use only
- def active_connections
+ def active_connections #:nodoc:
@@connection_pools.inject({}) do |hash,kv|
hash[kv.first] = kv.last.active_connection
hash.delete(kv.first) unless hash[kv.first]
@@ -36,22 +55,16 @@ module ActiveRecord
# Clears the cache which maps classes to connections.
def clear_active_connections!
- clear_cache!(@@connection_pools) do |name, pool|
- pool.clear_active_connections!
- end
+ @@connection_pools.each_value {|pool| pool.clear_active_connections! }
end
- # Clears the cache which maps classes
+ # Clears the cache which maps classes
def clear_reloadable_connections!
- clear_cache!(@@connection_pools) do |name, pool|
- pool.clear_reloadable_connections!
- end
+ @@connection_pools.each_value {|pool| pool.clear_reloadable_connections! }
end
def clear_all_connections!
- clear_cache!(@@connection_pools) do |name, pool|
- pool.disconnect!
- end
+ clear_cache!(@@connection_pools) {|name, pool| pool.disconnect! }
end
# Verify active connections.
@@ -59,6 +72,9 @@ module ActiveRecord
@@connection_pools.each_value {|pool| pool.verify_active_connections!}
end
+ synchronize :active_connections, :clear_active_connections!, :clear_reloadable_connections!,
+ :clear_all_connections!, :verify_active_connections!, :with => :connection_pools_lock
+
private
def clear_cache!(cache, &block)
cache.each(&block) if block_given?
@@ -107,7 +123,9 @@ module ActiveRecord
raise AdapterNotSpecified unless defined? RAILS_ENV
establish_connection(RAILS_ENV)
when ConnectionSpecification
- @@connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)
+ connection_pools_lock.synchronize do
+ @@connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)
+ end
when Symbol, String
if configuration = configurations[spec.to_s]
establish_connection(configuration)
@@ -171,5 +189,10 @@ module ActiveRecord
pool.disconnect! if pool
pool.spec.config if pool
end
+
+ class << self
+ synchronize :retrieve_connection, :retrieve_connection_pool, :connected?,
+ :remove_connection, :with => :connection_pools_lock
+ end
end
end
diff --git a/activerecord/test/cases/threaded_connections_test.rb b/activerecord/test/cases/threaded_connections_test.rb
index 9bf7217958..3f88f79189 100644
--- a/activerecord/test/cases/threaded_connections_test.rb
+++ b/activerecord/test/cases/threaded_connections_test.rb
@@ -11,11 +11,15 @@ unless %w(FrontBase).include? ActiveRecord::Base.connection.adapter_name
def setup
@connection = ActiveRecord::Base.remove_connection
@connections = []
+ @allow_concurrency = ActiveRecord::Base.allow_concurrency
+ ActiveRecord::Base.allow_concurrency = true
end
def teardown
# clear the connection cache
ActiveRecord::Base.clear_active_connections!
+ # set allow_concurrency to saved value
+ ActiveRecord::Base.allow_concurrency = @allow_concurrency
# reestablish old connection
ActiveRecord::Base.establish_connection(@connection)
end
--
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