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5e024070ab
The code in `ConnectionPool#release` assumed that a single thread only
ever holds a single connection, and thus that releasing a connection
only requires the owning thread_id.
There is a trivial counterexample to this assumption: code that checks
out additional connections from the pool in the same thread. For
instance:
connection_1 = ActiveRecord::Base.connection
connection_2 = ActiveRecord::Base.connection_pool.checkout
ActiveRecord::Base.connection_pool.checkin(connection_2)
connection_3 = ActiveRecord::Base.connection
At this point, connection_1 has been removed from the
`@reserved_connections` hash, causing a NEW connection to be returned as
connection_3 and the loss of any tracking info on connection_1. As long
as the thread in this example lives, connection_1 will be inaccessible
and un-reapable. If this block of code runs more times than the size of
the connection pool in a single thread, every subsequent connection
attempt will timeout, as all of the available connections have been
leaked.
Reverts parts of 9e457a8654 and
essentially all of 4367d2f05c
81 lines
2.5 KiB
Ruby
81 lines
2.5 KiB
Ruby
require "cases/helper"
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require "models/project"
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require "timeout"
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class PooledConnectionsTest < ActiveRecord::TestCase
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self.use_transactional_fixtures = false
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def setup
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@per_test_teardown = []
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@connection = ActiveRecord::Base.remove_connection
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end
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teardown do
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ActiveRecord::Base.clear_all_connections!
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ActiveRecord::Base.establish_connection(@connection)
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@per_test_teardown.each(&:call)
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end
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# Will deadlock due to lack of Monitor timeouts in 1.9
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def checkout_checkin_connections(pool_size, threads)
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ActiveRecord::Base.establish_connection(@connection.merge({:pool => pool_size, :checkout_timeout => 0.5}))
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@connection_count = 0
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@timed_out = 0
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threads.times do
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Thread.new do
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begin
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conn = ActiveRecord::Base.connection_pool.checkout
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sleep 0.1
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ActiveRecord::Base.connection_pool.checkin conn
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@connection_count += 1
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rescue ActiveRecord::ConnectionTimeoutError
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@timed_out += 1
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end
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end.join
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end
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end
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def checkout_checkin_connections_loop(pool_size, loops)
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ActiveRecord::Base.establish_connection(@connection.merge({:pool => pool_size, :checkout_timeout => 0.5}))
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@connection_count = 0
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@timed_out = 0
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loops.times do
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begin
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conn = ActiveRecord::Base.connection_pool.checkout
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ActiveRecord::Base.connection_pool.checkin conn
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@connection_count += 1
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ActiveRecord::Base.connection.tables
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rescue ActiveRecord::ConnectionTimeoutError
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@timed_out += 1
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end
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end
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end
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def test_pooled_connection_checkin_one
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checkout_checkin_connections 1, 2
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assert_equal 2, @connection_count
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assert_equal 0, @timed_out
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assert_equal 1, ActiveRecord::Base.connection_pool.connections.size
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end
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def test_pooled_connection_checkin_two
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checkout_checkin_connections_loop 2, 3
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assert_equal 3, @connection_count
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assert_equal 0, @timed_out
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assert_equal 2, ActiveRecord::Base.connection_pool.connections.size
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end
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def test_pooled_connection_remove
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ActiveRecord::Base.establish_connection(@connection.merge({:pool => 2, :checkout_timeout => 0.5}))
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old_connection = ActiveRecord::Base.connection
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extra_connection = ActiveRecord::Base.connection_pool.checkout
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ActiveRecord::Base.connection_pool.remove(extra_connection)
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assert_equal ActiveRecord::Base.connection, old_connection
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end
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private
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def add_record(name)
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ActiveRecord::Base.connection_pool.with_connection { Project.create! :name => name }
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end
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end unless in_memory_db?
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