Index: includes/bootstrap.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/bootstrap.inc,v
retrieving revision 1.60
diff -u -p -r1.60 bootstrap.inc
--- includes/bootstrap.inc	5 Aug 2005 00:49:02 -0000	1.60
+++ includes/bootstrap.inc	19 Aug 2005 11:27:57 -0000
@@ -233,10 +233,10 @@ function variable_get($name, $default) {
 function variable_set($name, $value) {
   global $conf;
 
-  db_query('LOCK TABLES {variable} WRITE');
+  db_lock_table('variable');
   db_query("DELETE FROM {variable} WHERE name = '%s'", $name);
   db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", $name, serialize($value));
-  db_query('UNLOCK TABLES');
+  db_unlock_tables();
 
   cache_clear_all('variables');
 
@@ -320,12 +320,12 @@ function cache_get($key) {
 function cache_set($cid, $data, $expire = CACHE_PERMANENT, $headers = NULL) {
   $data = db_encode_blob($data);
 
-  db_query('LOCK TABLES {cache} WRITE');
+  db_lock_table('cache');
   db_query("UPDATE {cache} SET data = '%s', created = %d, expire = %d, headers = '%s' WHERE cid = '%s'", $data, time(), $expire, $headers, $cid);
   if (!db_affected_rows()) {
     @db_query("INSERT INTO {cache} (cid, data, created, expire, headers) VALUES ('%s', '%s', %d, %d, '%s')", $cid, $data, time(), $expire, $headers);
   }
-  db_query('UNLOCK TABLES');
+  db_unlock_tables();
 }
 
 /**
@@ -879,4 +879,4 @@ function drupal_maintenance_theme() {
   $theme = '';
 }
 
-?>
\ No newline at end of file
+?>
Index: includes/database.mysql.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database.mysql.inc,v
retrieving revision 1.34
diff -u -p -r1.34 database.mysql.inc
--- includes/database.mysql.inc	11 Aug 2005 13:51:07 -0000	1.34
+++ includes/database.mysql.inc	19 Aug 2005 11:27:57 -0000
@@ -270,6 +270,21 @@ function db_escape_string($text) {
 }
 
 /**
+ * Lock a table.
+ */
+function db_lock_table($table) {
+  db_query("LOCK TABLES {$table} WRITE");
+}
+
+/**
+ * Unlock all locked tables.
+ */
+function db_unlock_tables() {
+  db_query('UNLOCK TABLES');
+}
+
+
+/**
  * @} End of "ingroup database".
  */
 
Index: includes/database.pgsql.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database.pgsql.inc,v
retrieving revision 1.12
diff -u -p -r1.12 database.pgsql.inc
--- includes/database.pgsql.inc	11 Aug 2005 13:51:07 -0000	1.12
+++ includes/database.pgsql.inc	19 Aug 2005 11:27:57 -0000
@@ -256,6 +256,22 @@ function db_escape_string($text) {
 }
 
 /**
+ * Lock a table. 
+ * This function automatically starts a transaction.
+ */
+function db_lock_table($table) {
+  db_query("BEGIN; LOCK TABLE {$table} IN EXCLUSIVE MODE");
+}
+
+/**
+ * Unlock all locked tables.
+ * This function automatically commits a transation.
+ */
+function db_unlock_tables() {
+  db_query('COMMIT');
+}
+
+/**
  * @} End of "ingroup database".
  */