Merge pull request #25707 from matthewd/double-reap

Don't reap connections that have already been reassigned

2 files changed, 39 insertions, 10 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 a006e4f50f..9b74c3a10f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -415,7 +415,10 @@ module ActiveRecord
         with_exclusively_acquired_all_connections(raise_on_acquisition_timeout) do
           synchronize do
             @connections.each do |conn|
-              checkin conn
+              if conn.in_use?
+                conn.steal!
+                checkin conn
+              end
               conn.disconnect!
             end
             @connections = []
@@ -447,7 +450,10 @@ module ActiveRecord
         with_exclusively_acquired_all_connections(raise_on_acquisition_timeout) do
           synchronize do
             @connections.each do |conn|
-              checkin conn
+              if conn.in_use?
+                conn.steal!
+                checkin conn
+              end
               conn.disconnect! if conn.requires_reloading?
             end
             @connections.delete_if(&:requires_reloading?)
@@ -556,17 +562,17 @@ module ActiveRecord
         stale_connections = synchronize do
           @connections.select do |conn|
             conn.in_use? && !conn.owner.alive?
+          end.each do |conn|
+            conn.steal!
           end
         end
 
         stale_connections.each do |conn|
-          synchronize do
-            if conn.active?
-              conn.reset!
-              checkin conn
-            else
-              remove conn
-            end
+          if conn.active?
+            conn.reset!
+            checkin conn
+          else
+            remove conn
           end
         end
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index d4b9e301bc..5747e4d1ee 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -184,7 +184,30 @@ module ActiveRecord
 
       # this method must only be called while holding connection pool's mutex
       def expire
-        @owner = nil
+        if in_use?
+          if @owner != Thread.current
+            raise ActiveRecordError, "Cannot expire connection, " <<
+              "it is owned by a different thread: #{@owner}. " <<
+              "Current thread: #{Thread.current}."
+          end
+
+          @owner = nil
+        else
+          raise ActiveRecordError, 'Cannot expire connection, it is not currently leased.'
+        end
+      end
+
+      # this method must only be called while holding connection pool's mutex (and a desire for segfaults)
+      def steal! # :nodoc:
+        if in_use?
+          if @owner != Thread.current
+            pool.send :remove_connection_from_thread_cache, self, @owner
+
+            @owner = Thread.current
+          end
+        else
+          raise ActiveRecordError, 'Cannot steal connection, it is not currently leased.'
+        end
       end
 
       def unprepared_statement