;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
-;;;; Name: pool.cl
+;;;; Name: pool.lisp
;;;; Purpose: Support function for connection pool
;;;; Programmers: Kevin M. Rosenberg, Marc Battyani
;;;; Date Started: Apr 2002
;;;;
-;;;; $Id: pool.lisp,v 1.1 2002/09/30 10:19:23 kevin Exp $
+;;;; $Id$
;;;;
-;;;; This file, part of CLSQL, is Copyright (c) 2002 by Kevin M. Rosenberg
+;;;; This file, part of CLSQL, is Copyright (c) 2002-2003 by Kevin M. Rosenberg
;;;;
;;;; CLSQL users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;; *************************************************************************
-(declaim (optimize (debug 3) (speed 3) (safety 1) (compilation-speed 0)))
-(in-package :clsql-sys)
+(in-package clsql-sys)
+
+(defun make-process-lock (name)
+ #+allegro (mp:make-process-lock :name name)
+ #+scl (thread:make-lock name)
+ #+lispworks (mp:make-lock :name name)
+ #-(or allegro scl lispworks) (declare (ignore name))
+ #-(or allegro scl lispworks) nil)
+
+(defmacro with-process-lock ((lock desc) &body body)
+ #+scl `(thread:with-lock-held (,lock ,desc) ,@body)
+ #+(or allegro lispworks)
+ (declare (ignore desc))
+ #+(or allegro lispworks)
+ (let ((l (gensym)))
+ `(let ((,l ,lock))
+ #+allegro (mp:with-process-lock (,l) ,@body)
+ #+lispworks (mp:with-lock (,l) ,@body)))
+ #-(or scl allegro lispworks) (declare (ignore lock desc))
+ #-(or scl allegro lispworks) `(progn ,@body))
(defvar *db-pool* (make-hash-table :test #'equal))
+(defvar *db-pool-lock* (make-process-lock "DB Pool lock"))
(defclass conn-pool ()
((connection-spec :accessor connection-spec :initarg :connection-spec)
(free-connections :accessor free-connections
:initform (make-array 5 :fill-pointer 0 :adjustable t))
(all-connections :accessor all-connections
- :initform (make-array 5 :fill-pointer 0 :adjustable t))))
+ :initform (make-array 5 :fill-pointer 0 :adjustable t))
+ (lock :accessor conn-pool-lock
+ :initform (make-process-lock "Connection pool"))))
(defun acquire-from-conn-pool (pool)
- (if (zerop (length (free-connections pool)))
- (let ((conn (connect (connection-spec pool)
- :database-type (database-type pool) :if-exists :new)))
- (vector-push-extend conn (all-connections pool))
- (setf (conn-pool conn) pool)
- conn)
- (vector-pop (free-connections pool))))
+ (or (with-process-lock ((conn-pool-lock pool) "Acquire from pool")
+ (and (plusp (length (free-connections pool)))
+ (vector-pop (free-connections pool))))
+ (let ((conn (connect (connection-spec pool)
+ :database-type (database-type pool)
+ :if-exists :new)))
+ (with-process-lock ((conn-pool-lock pool) "Acquire from pool")
+ (vector-push-extend conn (all-connections pool))
+ (setf (conn-pool conn) pool))
+ conn)))
(defun release-to-conn-pool (conn)
- (vector-push-extend conn (free-connections (conn-pool conn))))
+ (let ((pool (conn-pool conn)))
+ (with-process-lock ((conn-pool-lock pool) "Release to pool")
+ (vector-push-extend conn (free-connections pool)))))
(defun clear-conn-pool (pool)
- (loop for conn across (all-connections pool)
- do (setf (conn-pool conn) nil)
- (disconnect :database conn))
- (setf (fill-pointer (free-connections pool)) 0)
- (setf (fill-pointer (all-connections pool)) 0))
+ (with-process-lock ((conn-pool-lock pool) "Clear pool")
+ (loop for conn across (all-connections pool)
+ do (setf (conn-pool conn) nil)
+ (disconnect :database conn))
+ (setf (fill-pointer (free-connections pool)) 0)
+ (setf (fill-pointer (all-connections pool)) 0))
+ nil)
(defun find-or-create-connection-pool (connection-spec database-type)
"Find connection pool in hash table, creates a new connection pool if not found"
- (let* ((key (list connection-spec database-type))
- (conn-pool (gethash key *db-pool*)))
- (unless conn-pool
- (setq conn-pool (make-instance 'conn-pool
- :connection-spec connection-spec
- :database-type database-type))
- (setf (gethash key *db-pool*) conn-pool))
- conn-pool))
+ (with-process-lock (*db-pool-lock* "Find-or-create connection")
+ (let* ((key (list connection-spec database-type))
+ (conn-pool (gethash key *db-pool*)))
+ (unless conn-pool
+ (setq conn-pool (make-instance 'conn-pool
+ :connection-spec connection-spec
+ :database-type database-type))
+ (setf (gethash key *db-pool*) conn-pool))
+ conn-pool)))
(defun acquire-from-pool (connection-spec database-type &optional pool)
(unless (typep pool 'conn-pool)
(defun disconnect-pooled (&optional clear)
"Disconnects all connections in the pool"
- (maphash
- #'(lambda (key conn-pool)
- (declare (ignore key))
- (clear-conn-pool conn-pool))
- *db-pool*)
- (when clear (clrhash *db-pool*))
+ (with-process-lock (*db-pool-lock* "Disconnect pooled")
+ (maphash
+ #'(lambda (key conn-pool)
+ (declare (ignore key))
+ (clear-conn-pool conn-pool))
+ *db-pool*)
+ (when clear (clrhash *db-pool*)))
t)
-