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 | 93 |
1 files changed, 48 insertions, 45 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 6535121075..ccd2899489 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb @@ -1,5 +1,5 @@ require 'thread' -require 'thread_safe' +require 'concurrent/map' require 'monitor' module ActiveRecord @@ -10,8 +10,9 @@ module ActiveRecord end # Raised when a pool was unable to get ahold of all its connections - # to perform a "group" action such as +ConnectionPool#disconnect!+ - # or +ConnectionPool#clear_reloadable_connections!+. + # to perform a "group" action such as + # {ActiveRecord::Base.connection_pool.disconnect!}[rdoc-ref:ConnectionAdapters::ConnectionPool#disconnect!] + # or {ActiveRecord::Base.clear_reloadable_connections!}[rdoc-ref:ConnectionAdapters::ConnectionHandler#clear_reloadable_connections!]. class ExclusiveConnectionTimeoutError < ConnectionTimeoutError end @@ -37,17 +38,18 @@ module ActiveRecord # Connections can be obtained and used from a connection pool in several # ways: # - # 1. Simply use ActiveRecord::Base.connection as with Active Record 2.1 and + # 1. Simply use {ActiveRecord::Base.connection}[rdoc-ref:ConnectionHandling.connection] + # as with Active Record 2.1 and # earlier (pre-connection-pooling). Eventually, when you're done with # the connection(s) and wish it to be returned to the pool, you call - # ActiveRecord::Base.clear_active_connections!. This will be the - # default behavior for Active Record when used in conjunction with + # {ActiveRecord::Base.clear_active_connections!}[rdoc-ref:ConnectionAdapters::ConnectionHandler#clear_active_connections!]. + # This will be the default behavior for Active Record when used in conjunction with # Action Pack's request handling cycle. # 2. Manually check out a connection from the pool with - # ActiveRecord::Base.connection_pool.checkout. You are responsible for + # {ActiveRecord::Base.connection_pool.checkout}[rdoc-ref:#checkout]. You are responsible for # returning this connection to the pool when finished by calling - # ActiveRecord::Base.connection_pool.checkin(connection). - # 3. Use ActiveRecord::Base.connection_pool.with_connection(&block), which + # {ActiveRecord::Base.connection_pool.checkin(connection)}[rdoc-ref:#checkin]. + # 3. Use {ActiveRecord::Base.connection_pool.with_connection(&block)}[rdoc-ref:#with_connection], which # obtains a connection, yields it as the sole argument to the block, # and returns it to the pool after the block completes. # @@ -140,7 +142,7 @@ module ActiveRecord # become available. # # Raises: - # - ConnectionTimeoutError if +timeout+ is given and no element + # - ActiveRecord::ConnectionTimeoutError if +timeout+ is given and no element # becomes available within +timeout+ seconds, def poll(timeout = nil) synchronize { internal_poll(timeout) } @@ -195,7 +197,7 @@ module ActiveRecord elapsed = Time.now - t0 if elapsed >= timeout - msg = 'could not obtain a database connection within %0.3f seconds (waited %0.3f seconds)' % + msg = 'could not obtain a connection from the pool within %0.3f seconds (waited %0.3f seconds); all pooled connections were in use' % [timeout, elapsed] raise ConnectionTimeoutError, msg end @@ -331,18 +333,18 @@ module ActiveRecord # of the cache is to speed-up +connection+ method, it is not the authoritative # registry of which thread owns which connection, that is tracked by # +connection.owner+ attr on each +connection+ instance. - # The invariant works like this: if there is mapping of +thread => conn+, + # The invariant works like this: if there is mapping of <tt>thread => conn</tt>, # then that +thread+ does indeed own that +conn+, however an absence of a such # mapping does not mean that the +thread+ doesn't own the said connection, in # that case +conn.owner+ attr should be consulted. # Access and modification of +@thread_cached_conns+ does not require # synchronization. - @thread_cached_conns = ThreadSafe::Cache.new(:initial_capacity => @size) + @thread_cached_conns = Concurrent::Map.new(:initial_capacity => @size) @connections = [] @automatic_reconnect = true - # Connection pool allows for concurrent (outside the main `synchronize` section) + # Connection pool allows for concurrent (outside the main +synchronize+ section) # establishment of new connections. This variable tracks the number of threads # currently in the process of independently establishing connections to the DB. @now_connecting = 0 @@ -364,7 +366,7 @@ module ActiveRecord # Is there an open connection that is being used for the current thread? # - # This method only works for connections that have been abtained through + # This method only works for connections that have been obtained through # #connection or #with_connection methods, connections obtained through # #checkout will not be detected by #active_connection? def active_connection? @@ -406,9 +408,9 @@ module ActiveRecord # Disconnects all connections in the pool, and clears the pool. # # Raises: - # - +ExclusiveConnectionTimeoutError+ if unable to gain ownership of all + # - ActiveRecord::ExclusiveConnectionTimeoutError if unable to gain ownership of all # connections in the pool within a timeout interval (default duration is - # +spec.config[:checkout_timeout] * 2+ seconds). + # <tt>spec.config[:checkout_timeout] * 2</tt> seconds). def disconnect(raise_on_acquisition_timeout = true) with_exclusively_acquired_all_connections(raise_on_acquisition_timeout) do synchronize do @@ -426,8 +428,8 @@ module ActiveRecord # # The pool first tries to gain ownership of all connections, if unable to # do so within a timeout interval (default duration is - # +spec.config[:checkout_timeout] * 2+ seconds), the pool is forcefully - # disconneted wihout any regard for other connection owning threads. + # <tt>spec.config[:checkout_timeout] * 2</tt> seconds), the pool is forcefully + # disconnected without any regard for other connection owning threads. def disconnect! disconnect(false) end @@ -436,9 +438,9 @@ module ActiveRecord # require reloading. # # Raises: - # - +ExclusiveConnectionTimeoutError+ if unable to gain ownership of all + # - ActiveRecord::ExclusiveConnectionTimeoutError if unable to gain ownership of all # connections in the pool within a timeout interval (default duration is - # +spec.config[:checkout_timeout] * 2+ seconds). + # <tt>spec.config[:checkout_timeout] * 2</tt> seconds). def clear_reloadable_connections(raise_on_acquisition_timeout = true) num_new_conns_required = 0 @@ -474,7 +476,7 @@ module ActiveRecord # # The pool first tries to gain ownership of all connections, if unable to # do so within a timeout interval (default duration is - # +spec.config[:checkout_timeout] * 2+ seconds), the pool forcefully + # <tt>spec.config[:checkout_timeout] * 2</tt> seconds), the pool forcefully # clears the cache and reloads connections without any regard for other # connection owning threads. def clear_reloadable_connections! @@ -494,7 +496,7 @@ module ActiveRecord # Returns: an AbstractAdapter object. # # Raises: - # - ConnectionTimeoutError: no connection can be obtained from the pool. + # - ActiveRecord::ConnectionTimeoutError no connection can be obtained from the pool. def checkout(checkout_timeout = @checkout_timeout) checkout_and_verify(acquire_connection(checkout_timeout)) end @@ -503,12 +505,12 @@ module ActiveRecord # no longer need this connection. # # +conn+: an AbstractAdapter object, which was obtained by earlier by - # calling +checkout+ on this pool. + # calling #checkout on this pool. def checkin(conn) synchronize do remove_connection_from_thread_cache conn - conn.run_callbacks :checkin do + conn._run_checkin_callbacks do conn.expire end @@ -516,7 +518,7 @@ module ActiveRecord end end - # Remove a connection from the connection pool. The connection will + # Remove a connection from the connection pool. The connection will # remain open and active but will no longer be managed by this pool. def remove(conn) needs_new_connection = false @@ -547,7 +549,7 @@ module ActiveRecord bulk_make_new_connections(1) if needs_new_connection end - # Recover lost connections for the pool. A lost connection can occur if + # Recover lost connections for the pool. A lost connection can occur if # a programmer forgets to checkin a connection at the end of a thread # or a thread dies unexpectedly. def reap @@ -587,7 +589,7 @@ module ActiveRecord end #-- - # From the discussion on Github: + # From the discussion on GitHub: # https://github.com/rails/rails/pull/14938#commitcomment-6601951 # This hook-in method allows for easier monkey-patching fixes needed by # JRuby users that use Fibers. @@ -628,10 +630,10 @@ module ActiveRecord end end rescue ExclusiveConnectionTimeoutError - # `raise_on_acquisition_timeout == false` means we are directed to ignore any + # <tt>raise_on_acquisition_timeout == false</tt> means we are directed to ignore any # timeouts and are expected to just give up: we've obtained as many connections # as possible, note that in a case like that we don't return any of the - # `newly_checked_out` connections. + # +newly_checked_out+ connections. if raise_on_acquisition_timeout release_newly_checked_out = true @@ -688,18 +690,18 @@ module ActiveRecord # queue for a connection to become available. # # Raises: - # - ConnectionTimeoutError if a connection could not be acquired + # - ActiveRecord::ConnectionTimeoutError if a connection could not be acquired # #-- # Implementation detail: the connection returned by +acquire_connection+ # will already be "+connection.lease+ -ed" to the current thread. def acquire_connection(checkout_timeout) - # NOTE: we rely on `@available.poll` and `try_to_checkout_new_connection` to - # `conn.lease` the returned connection (and to do this in a `synchronized` + # NOTE: we rely on +@available.poll+ and +try_to_checkout_new_connection+ to + # +conn.lease+ the returned connection (and to do this in a +synchronized+ # section), this is not the cleanest implementation, as ideally we would - # `synchronize { conn.lease }` in this method, but by leaving it to `@available.poll` - # and `try_to_checkout_new_connection` we can piggyback on `synchronize` sections - # of the said methods and avoid an additional `synchronize` overhead. + # <tt>synchronize { conn.lease }</tt> in this method, but by leaving it to +@available.poll+ + # and +try_to_checkout_new_connection+ we can piggyback on +synchronize+ sections + # of the said methods and avoid an additional +synchronize+ overhead. if conn = @available.poll || try_to_checkout_new_connection conn else @@ -764,7 +766,7 @@ module ActiveRecord end def checkout_and_verify(c) - c.run_callbacks :checkout do + c._run_checkout_callbacks do c.verify! end c @@ -824,11 +826,11 @@ module ActiveRecord # These caches are keyed by klass.name, NOT klass. Keying them by klass # alone would lead to memory leaks in development mode as all previous # instances of the class would stay in memory. - @owner_to_pool = ThreadSafe::Cache.new(:initial_capacity => 2) do |h,k| - h[k] = ThreadSafe::Cache.new(:initial_capacity => 2) + @owner_to_pool = Concurrent::Map.new(:initial_capacity => 2) do |h,k| + h[k] = Concurrent::Map.new(:initial_capacity => 2) end - @class_to_pool = ThreadSafe::Cache.new(:initial_capacity => 2) do |h,k| - h[k] = ThreadSafe::Cache.new + @class_to_pool = Concurrent::Map.new(:initial_capacity => 2) do |h,k| + h[k] = Concurrent::Map.new end end @@ -857,6 +859,8 @@ module ActiveRecord end # Clears the cache which maps classes. + # + # See ConnectionPool#clear_reloadable_connections! for details. def clear_reloadable_connections! connection_pool_list.each(&:clear_reloadable_connections!) end @@ -956,12 +960,11 @@ module ActiveRecord def call(env) testing = env['rack.test'] - response = @app.call(env) - response[2] = ::Rack::BodyProxy.new(response[2]) do + status, headers, body = @app.call(env) + proxy = ::Rack::BodyProxy.new(body) do ActiveRecord::Base.clear_active_connections! unless testing end - - response + [status, headers, proxy] rescue Exception ActiveRecord::Base.clear_active_connections! unless testing raise |