diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb | 191 |
1 files changed, 106 insertions, 85 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 b8f99adc22..46c7fc71ac 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb @@ -2,6 +2,7 @@ require 'thread' require 'monitor' require 'set' require 'active_support/core_ext/module/deprecation' +require 'timeout' module ActiveRecord # Raised when a connection could not be obtained within the connection @@ -11,9 +12,6 @@ module ActiveRecord # Raised when a connection pool is full and another connection is requested class PoolFullError < ConnectionNotEstablished - def initialize size, timeout - super("Connection pool of size #{size} and timeout #{timeout}s is full") - end end module ConnectionAdapters @@ -94,6 +92,21 @@ module ActiveRecord attr_accessor :automatic_reconnect, :timeout attr_reader :spec, :connections, :size, :reaper + class Latch # :nodoc: + def initialize + @mutex = Mutex.new + @cond = ConditionVariable.new + end + + def release + @mutex.synchronize { @cond.broadcast } + end + + def await + @mutex.synchronize { @cond.wait @mutex } + end + end + # Creates a new ConnectionPool object. +spec+ is a ConnectionSpecification # object which describes database connection information (e.g. adapter, # host name, username, password, etc), as well as the maximum size for @@ -115,6 +128,7 @@ module ActiveRecord # default max pool size to 5 @size = (spec.config[:pool] && spec.config[:pool].to_i) || 5 + @latch = Latch.new @connections = [] @automatic_reconnect = true end @@ -128,18 +142,21 @@ module ActiveRecord @reserved_connections[current_connection_id] ||= checkout end - # Check to see if there is an active connection in this connection - # pool. + # Is there an open connection that is being used for the current thread? def active_connection? - active_connections.any? + @reserved_connections.fetch(current_connection_id) { + return false + }.in_use? end # Signal that the thread is finished with the current connection. # #release_connection releases the connection-thread association # and returns the connection to the pool. def release_connection(with_id = current_connection_id) - conn = @reserved_connections.delete(with_id) - checkin conn if conn + synchronize do + conn = @reserved_connections.delete(with_id) + checkin conn if conn + end end # If a connection already exists yield it to the block. If no connection @@ -184,19 +201,10 @@ module ActiveRecord end end - # Verify active connections and remove and disconnect connections - # associated with stale threads. - def verify_active_connections! #:nodoc: - synchronize do - @connections.each do |connection| - connection.verify! - end - end - end - def clear_stale_cached_connections! # :nodoc: + reap end - deprecate :clear_stale_cached_connections! + deprecate :clear_stale_cached_connections! => "Please use #reap instead" # Check-out a database connection from the pool, indicating that you want # to use it. You should call #checkin when you no longer need this. @@ -213,23 +221,23 @@ module ActiveRecord # Raises: # - PoolFullError: no connection can be obtained from the pool. def checkout - # Checkout an available connection - synchronize do - # Try to find a connection that hasn't been leased, and lease it - conn = connections.find { |c| c.lease } - - # If all connections were leased, and we have room to expand, - # create a new connection and lease it. - if !conn && connections.size < size - conn = checkout_new_connection - conn.lease - end + loop do + # Checkout an available connection + synchronize do + # Try to find a connection that hasn't been leased, and lease it + conn = connections.find { |c| c.lease } + + # If all connections were leased, and we have room to expand, + # create a new connection and lease it. + if !conn && connections.size < size + conn = checkout_new_connection + conn.lease + end - if conn - checkout_and_verify conn - else - raise PoolFullError.new(size, timeout) + return checkout_and_verify(conn) if conn end + + Timeout.timeout(@timeout, PoolFullError) { @latch.await } end end @@ -243,7 +251,10 @@ module ActiveRecord conn.run_callbacks :checkin do conn.expire end + + release conn end + @latch.release end # Remove a connection from the connection pool. The connection will @@ -254,11 +265,9 @@ module ActiveRecord # FIXME: we might want to store the key on the connection so that removing # from the reserved hash will be a little easier. - thread_id = @reserved_connections.keys.find { |k| - @reserved_connections[k] == conn - } - @reserved_connections.delete thread_id if thread_id + release conn end + @latch.release end # Removes dead connections from the pool. A dead connection can occur @@ -271,10 +280,23 @@ module ActiveRecord remove conn if conn.in_use? && stale > conn.last_use && !conn.active? end end + @latch.release end private + def release(conn) + thread_id = if @reserved_connections[current_connection_id] == conn + current_connection_id + else + @reserved_connections.keys.find { |k| + @reserved_connections[k] == conn + } + end + + @reserved_connections.delete thread_id if thread_id + end + def new_connection ActiveRecord::Base.send(spec.adapter_method, spec.config) end @@ -298,10 +320,6 @@ module ActiveRecord end c end - - def active_connections - @connections.find_all { |c| c.in_use? } - end end # ConnectionHandler is a collection of ConnectionPool objects. It is used @@ -328,16 +346,18 @@ module ActiveRecord # ActiveRecord::Base.connection_handler. Active Record models use this to # determine that connection pool that they should use. class ConnectionHandler - attr_reader :connection_pools - - def initialize(pools = {}) + def initialize(pools = Hash.new { |h,k| h[k] = {} }) @connection_pools = pools - @class_to_pool = {} + @class_to_pool = Hash.new { |h,k| h[k] = {} } + end + + def connection_pools + @connection_pools[Process.pid] end def establish_connection(name, spec) - @connection_pools[spec] ||= ConnectionAdapters::ConnectionPool.new(spec) - @class_to_pool[name] = @connection_pools[spec] + set_pool_for_spec spec, ConnectionAdapters::ConnectionPool.new(spec) + set_class_to_pool name, connection_pools[spec] end # Returns true if there are any active connections among the connection @@ -350,21 +370,16 @@ module ActiveRecord # and also returns connections to the pool cached by threads that are no # longer alive. def clear_active_connections! - @connection_pools.each_value {|pool| pool.release_connection } + connection_pools.each_value {|pool| pool.release_connection } end # Clears the cache which maps classes. def clear_reloadable_connections! - @connection_pools.each_value {|pool| pool.clear_reloadable_connections! } + connection_pools.each_value {|pool| pool.clear_reloadable_connections! } end def clear_all_connections! - @connection_pools.each_value {|pool| pool.disconnect! } - end - - # Verify active connections. - def verify_active_connections! #:nodoc: - @connection_pools.each_value {|pool| pool.verify_active_connections! } + connection_pools.each_value {|pool| pool.disconnect! } end # Locate the connection of the nearest super class. This can be an @@ -388,53 +403,56 @@ module ActiveRecord # can be used as an argument for establish_connection, for easily # re-establishing the connection. def remove_connection(klass) - pool = @class_to_pool.delete(klass.name) + pool = class_to_pool.delete(klass.name) return nil unless pool - @connection_pools.delete pool.spec + connection_pools.delete pool.spec pool.automatic_reconnect = false pool.disconnect! pool.spec.config end def retrieve_connection_pool(klass) - pool = @class_to_pool[klass.name] + pool = get_pool_for_class klass.name return pool if pool return nil if ActiveRecord::Model == klass retrieve_connection_pool klass.active_record_super end - end - - class ConnectionManagement - class Proxy # :nodoc: - attr_reader :body, :testing - def initialize(body, testing = false) - @body = body - @testing = testing - end + private - def method_missing(method_sym, *arguments, &block) - @body.send(method_sym, *arguments, &block) - end + def class_to_pool + @class_to_pool[Process.pid] + end - def respond_to?(method_sym, include_private = false) - super || @body.respond_to?(method_sym) - end + def set_pool_for_spec(spec, pool) + @connection_pools[Process.pid][spec] = pool + end - def each(&block) - body.each(&block) - end + def set_class_to_pool(name, pool) + @class_to_pool[Process.pid][name] = pool + pool + end - def close - body.close if body.respond_to?(:close) + def get_pool_for_class(klass) + @class_to_pool[Process.pid].fetch(klass) { + c_to_p = @class_to_pool.values.find { |class_to_pool| + class_to_pool[klass] + } - # Don't return connection (and perform implicit rollback) if - # this request is a part of integration test - ActiveRecord::Base.clear_active_connections! unless testing - end + if c_to_p + pool = c_to_p[klass] + pool = ConnectionAdapters::ConnectionPool.new pool.spec + set_pool_for_spec pool.spec, pool + set_class_to_pool klass, pool + else + set_class_to_pool klass, nil + end + } end + end + class ConnectionManagement def initialize(app) @app = app end @@ -442,9 +460,12 @@ module ActiveRecord def call(env) testing = env.key?('rack.test') - status, headers, body = @app.call(env) + response = @app.call(env) + response[2] = ::Rack::BodyProxy.new(response[2]) do + ActiveRecord::Base.clear_active_connections! unless testing + end - [status, headers, Proxy.new(body, testing)] + response rescue ActiveRecord::Base.clear_active_connections! unless testing raise |