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author | Matthew Draper <matthew@trebex.net> | 2018-08-24 01:42:22 +0930 |
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committer | GitHub <noreply@github.com> | 2018-08-24 01:42:22 +0930 |
commit | 1f05cc58d5c098a626bdb4a43025815d3cef5bac (patch) | |
tree | 10bebb0f00ed3e5bae2962703d4f152e209d651c /activerecord | |
parent | a0b57bbb21ce81071220bd8c6cfd8cdda342c6c6 (diff) | |
parent | 0a1ed447999d0092e8d0e86729666fc3b4577151 (diff) | |
download | rails-1f05cc58d5c098a626bdb4a43025815d3cef5bac.tar.gz rails-1f05cc58d5c098a626bdb4a43025815d3cef5bac.tar.bz2 rails-1f05cc58d5c098a626bdb4a43025815d3cef5bac.zip |
Merge pull request #31696 from BrentWheeldon/bmw-connection-pool-load-deadlock
Prevent deadlocks when waiting for connection from pool.
Diffstat (limited to 'activerecord')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb | 4 | ||||
-rw-r--r-- | activerecord/test/cases/connection_pool_test.rb | 38 |
2 files changed, 41 insertions, 1 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 f721e91203..e977d36cb9 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb @@ -188,7 +188,9 @@ module ActiveRecord t0 = Time.now elapsed = 0 loop do - @cond.wait(timeout - elapsed) + ActiveSupport::Dependencies.interlock.permit_concurrent_loads do + @cond.wait(timeout - elapsed) + end return remove if any? diff --git a/activerecord/test/cases/connection_pool_test.rb b/activerecord/test/cases/connection_pool_test.rb index 6aecf5fa35..06869eeab0 100644 --- a/activerecord/test/cases/connection_pool_test.rb +++ b/activerecord/test/cases/connection_pool_test.rb @@ -111,6 +111,44 @@ module ActiveRecord assert_equal connection, t.join.value end + def test_full_pool_blocking_shares_load_interlock + @pool.instance_variable_set(:@size, 1) + + load_interlock_latch = Concurrent::CountDownLatch.new + connection_latch = Concurrent::CountDownLatch.new + + able_to_get_connection = false + able_to_load = false + + thread_with_load_interlock = Thread.new do + ActiveSupport::Dependencies.interlock.running do + load_interlock_latch.count_down + connection_latch.wait + + @pool.with_connection do + able_to_get_connection = true + end + end + end + + thread_with_last_connection = Thread.new do + @pool.with_connection do + connection_latch.count_down + load_interlock_latch.wait + + ActiveSupport::Dependencies.interlock.loading do + able_to_load = true + end + end + end + + thread_with_load_interlock.join + thread_with_last_connection.join + + assert able_to_get_connection + assert able_to_load + end + def test_removing_releases_latch cs = @pool.size.times.map { @pool.checkout } t = Thread.new { @pool.checkout } |