From 41563b49a235ce84419024abcef0825e44e28877 Mon Sep 17 00:00:00 2001
From: Jonathan Rochkind <jonathan@dnil.net>
Date: Tue, 13 Mar 2012 18:00:55 -0400
Subject: ConnectionPool.checkout takes account of ruby using 'non-blocking
condition variables' in mutex ConditionVariables
---
.../abstract/connection_pool.rb | 27 ++++++++++++++--------
1 file changed, 18 insertions(+), 9 deletions(-)
(limited to 'activerecord/lib')
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 f198be0802..3af285c7c8 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -226,8 +226,9 @@ connection. For example: ActiveRecord::Base.connection.close
# - ConnectionTimeoutError: no connection can be obtained from the pool
# within the timeout period.
def checkout
- # Checkout an available connection
synchronize do
+ waited_time = 0
+
loop do
conn = @connections.find { |c| c.lease }
@@ -243,17 +244,25 @@ connection. For example: ActiveRecord::Base.connection.close
return conn
end
- @queue.wait(@timeout)
+ if waited_time >= @timeout
+ raise ConnectionTimeoutError, "could not obtain a database connection#{" within #{@timeout} seconds" if @timeout} (waited #{waited_time} seconds). The max pool size is currently #{@size}; consider increasing it."
+ end
- if(active_connections.size < @connections.size)
- next
- else
+ # Sometimes our wait can end because a connection is available,
+ # but another thread can snatch it up first. If timeout hasn't
+ # passed but no connection is avail, looks like that happened --
+ # loop and wait again, for the time remaining on our timeout.
+ before_wait = Time.now
+ @queue.wait( [@timeout - waited_time, 0].max )
+ waited_time += (Time.now - before_wait)
+
+ # Will go away in Rails 4, when we don't clean up
+ # after leaked connections automatically anymore. Right now, clean
+ # up after we've returned from a 'wait' if it looks like it's
+ # needed, then loop and try again.
+ if(active_connections.size >= @connections.size)
clear_stale_cached_connections!
- if @size == active_connections.size
- raise ConnectionTimeoutError, "could not obtain a database connection#{" within #{@timeout} seconds" if @timeout}. The max pool size is currently #{@size}; consider increasing it."
- end
end
-
end
end
end
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