Class | Sequel::ThreadedConnectionPool |
In: |
lib/sequel/connection_pool/threaded.rb
|
Parent: | Sequel::ConnectionPool |
A connection pool allowing multi-threaded access to a pool of connections.
make_new | -> | default_make_new |
Alias the default make_new method, so subclasses can call it directly. |
allocated | [R] | A hash with thread keys and connection values for currently allocated connections. |
available_connections | [R] | An array of connections that are available for use by the pool. |
max_size | [R] | The maximum number of connections this pool will create (per shard/server if sharding). |
The following additional options are respected:
# File lib/sequel/connection_pool/threaded.rb, line 21 21: def initialize(opts = {}, &block) 22: super 23: @max_size = Integer(opts[:max_connections] || 4) 24: raise(Sequel::Error, ':max_connections must be positive') if @max_size < 1 25: @mutex = Mutex.new 26: @available_connections = [] 27: @allocated = {} 28: @timeout = Integer(opts[:pool_timeout] || 5) 29: @sleep_time = Float(opts[:pool_sleep_time] || 0.001) 30: end
Removes all connection currently available on all servers, optionally yielding each connection to the given block. This method has the effect of disconnecting from the database, assuming that no connections are currently being used. If connections are being used, they are scheduled to be disconnected as soon as they are returned to the pool.
Once a connection is requested using hold, the connection pool creates new connections to the database.
# File lib/sequel/connection_pool/threaded.rb, line 46 46: def disconnect(opts={}, &block) 47: block ||= @disconnection_proc 48: sync do 49: @available_connections.each{|conn| block.call(conn)} if block 50: @available_connections.clear 51: end 52: end
Chooses the first available connection to the given server, or if none are available, creates a new connection. Passes the connection to the supplied block:
pool.hold {|conn| conn.execute('DROP TABLE posts')}
Pool#hold is re-entrant, meaning it can be called recursively in the same thread without blocking.
If no connection is immediately available and the pool is already using the maximum number of connections, Pool#hold will block until a connection is available or the timeout expires. If the timeout expires before a connection can be acquired, a Sequel::PoolTimeout is raised.
# File lib/sequel/connection_pool/threaded.rb, line 68 68: def hold(server=nil) 69: t = Thread.current 70: if conn = owned_connection(t) 71: return yield(conn) 72: end 73: begin 74: unless conn = acquire(t) 75: time = Time.now 76: timeout = time + @timeout 77: sleep_time = @sleep_time 78: sleep sleep_time 79: until conn = acquire(t) 80: raise(::Sequel::PoolTimeout) if Time.now > timeout 81: sleep sleep_time 82: end 83: end 84: yield conn 85: rescue Sequel::DatabaseDisconnectError 86: @disconnection_proc.call(conn) if @disconnection_proc && conn 87: @allocated.delete(t) 88: conn = nil 89: raise 90: ensure 91: sync{release(t)} if conn 92: end 93: end