rdbms: make LoadBalancer::getConnection() ignore CONN_TRX_AUTO when unusable

[lhc/web/wiklou.git] / includes / libs / rdbms / loadbalancer / ILoadBalancer.php

diff --git a/includes/libs/rdbms/loadbalancer/ILoadBalancer.php b/includes/libs/rdbms/loadbalancer/ILoadBalancer.php
index 7bbb530..8210507 100644 (file)
--- a/includes/libs/rdbms/loadbalancer/ILoadBalancer.php
+++ b/includes/libs/rdbms/loadbalancer/ILoadBalancer.php
@@ -172,7 +172,9 @@ interface ILoadBalancer {
        /**
         * Get a connection handle by server index
         *
-        * Avoid using CONN_TRX_AUTO with sqlite (e.g. check getServerType() first)
+        * The CONN_TRX_AUTO flag is ignored for databases with ATTR_DB_LEVEL_LOCKING
+        * (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes()
+        * can be used to check such flags beforehand.
         *
         * If the caller uses $domain or sets CONN_TRX_AUTO in $flags, then it must also
         * call ILoadBalancer::reuseConnection() on the handle when finished using it.
@@ -206,7 +208,9 @@ interface ILoadBalancer {
         *
         * The handle's methods simply wrap those of a Database handle
         *
-        * Avoid using CONN_TRX_AUTO with sqlite (e.g. check getServerType() first)
+        * The CONN_TRX_AUTO flag is ignored for databases with ATTR_DB_LEVEL_LOCKING
+        * (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes()
+        * can be used to check such flags beforehand.
         *
         * @see ILoadBalancer::getConnection() for parameter information
         *
@@ -223,7 +227,9 @@ interface ILoadBalancer {
         *
         * The handle's methods simply wrap those of a Database handle
         *
-        * Avoid using CONN_TRX_AUTO with sqlite (e.g. check getServerType() first)
+        * The CONN_TRX_AUTO flag is ignored for databases with ATTR_DB_LEVEL_LOCKING
+        * (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes()
+        * can be used to check such flags beforehand.
         *
         * @see ILoadBalancer::getConnection() for parameter information
         *
@@ -240,7 +246,9 @@ interface ILoadBalancer {
         *
         * The handle's methods simply wrap those of a Database handle
         *
-        * Avoid using CONN_TRX_AUTO with sqlite (e.g. check getServerType() first)
+        * The CONN_TRX_AUTO flag is ignored for databases with ATTR_DB_LEVEL_LOCKING
+        * (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes()
+        * can be used to check such flags beforehand.
         *
         * @see ILoadBalancer::getConnection() for parameter information
         *
@@ -258,7 +266,9 @@ interface ILoadBalancer {
         * The index must be an actual index into the array. If a connection to the server is
         * already open and not considered an "in use" foreign connection, this simply returns it.
         *
-        * Avoid using CONN_TRX_AUTO with sqlite (e.g. check getServerType() first)
+        * Avoid using CONN_TRX_AUTO for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in
+        * order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check
+        * such flags beforehand.
         *
         * If the caller uses $domain or sets CONN_TRX_AUTO in $flags, then it must also
         * call ILoadBalancer::reuseConnection() on the handle when finished using it.
@@ -319,6 +329,13 @@ interface ILoadBalancer {
         */
        public function getServerType( $i );
 
+       /**
+        * @param int $i Server index
+        * @return array (Database::ATTRIBUTE_* constant => value) for all such constants
+        * @since 1.31
+        */
+       public function getServerAttributes( $i );
+
        /**
         * Get the current master position for chronology control purposes
         * @return DBMasterPos|bool Returns false if not applicable