Where possible use a reset command against the DB to verify a pooled connection.

[clsql.git] / sql / pool.lisp

diff --git a/sql/pool.lisp b/sql/pool.lisp
index 7aa3c994b4a0f7a1ea7e45766dcc93457a0009e5..d1c0a230bc43255f8d9b3940286e1545c3e7d50d 100644 (file)
--- a/sql/pool.lisp
+++ b/sql/pool.lisp
@@ -32,15 +32,25 @@
          :initform (make-process-lock "Connection pool"))))
 
 (defun acquire-from-conn-pool (pool)
+  "Try to find a working database connection in the pool or create a new
+one if needed. This performs 1 query against the DB to ensure it's still
+valid. When possible (postgres, mssql) that query will be a reset
+command to put the connection back into its default state."
   (or (with-process-lock ((conn-pool-lock pool) "Acquire from pool")
         (when (plusp (length (free-connections pool)))
           (let ((pconn (vector-pop (free-connections pool))))
             ;; test if connection still valid.
            ;; (e.g. db reboot -> invalid connection )
            (handler-case
-               (case (database-type pconn)
-                 (:mysql 
+               (case (database-underlying-type pconn)
+                 (:postgresql
+                    (database-execute-command "RESET ALL" pconn))
+                 (:mysql
                     (database-query "SHOW ERRORS LIMIT 1" pconn nil nil))
+                 (:mssql
+                    ;; rpc escape sequence since this can't be called as a normal sp.
+                    ;;http://msdn.microsoft.com/en-us/library/aa198358%28SQL.80%29.aspx
+                    (database-execute-command "{rpc sp_reset_connection}" pconn))
                  (T
                     (database-query "SELECT 1;"  pconn '(integer) nil)))
              (sql-database-error (e)