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 | 92 |
1 files changed, 60 insertions, 32 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 37a9d216df..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 @@ -185,8 +202,9 @@ module ActiveRecord 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. @@ -203,23 +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 @@ -233,7 +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 @@ -244,11 +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 @@ -261,10 +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 @@ -288,10 +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 |