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//
// Mono.Data.TdsClient.TdsConnectionPool.cs
//
// Author:
// Lluis Sanchez Gual (lluis@ximian.com)
//
// Copyright (C) 2004 Novell, Inc.
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using Mono.Data.Tds.Protocol;
using System;
using System.Collections;
using System.Threading;
namespace Mono.Data.Tds.Protocol
{
public class TdsConnectionPoolManager
{
Hashtable pools = new Hashtable ();
TdsVersion version;
public TdsConnectionPoolManager (TdsVersion version)
{
this.version = version;
}
public TdsConnectionPool GetConnectionPool (string connectionString, TdsConnectionInfo info)
{
lock (pools)
{
TdsConnectionPool pool = (TdsConnectionPool) pools [connectionString];
if (pool == null) {
pool = new TdsConnectionPool (this, info);
pools [connectionString] = pool;
}
return pool;
}
}
public virtual ITds CreateConnection (TdsConnectionInfo info)
{
switch (version)
{
case TdsVersion.tds42:
return new Tds42 (info.DataSource, info.Port, info.PacketSize, info.Timeout);
case TdsVersion.tds50:
return new Tds50 (info.DataSource, info.Port, info.PacketSize, info.Timeout);
case TdsVersion.tds70:
return new Tds70 (info.DataSource, info.Port, info.PacketSize, info.Timeout);
case TdsVersion.tds80:
return new Tds80 (info.DataSource, info.Port, info.PacketSize, info.Timeout);
}
throw new NotSupportedException ();
}
}
public class TdsConnectionInfo
{
public TdsConnectionInfo (string dataSource, int port, int packetSize, int timeout, int minSize, int maxSize)
{
DataSource = dataSource;
Port = port;
PacketSize = packetSize;
Timeout = timeout;
PoolMinSize = minSize;
PoolMaxSize = maxSize;
}
public string DataSource;
public int Port;
public int PacketSize;
public int Timeout;
public int PoolMinSize;
public int PoolMaxSize;
}
public class TdsConnectionPool
{
ArrayList list = new ArrayList ();
TdsConnectionInfo info;
bool initialized;
int activeConnections = 0;
TdsConnectionPoolManager manager;
public TdsConnectionPool (TdsConnectionPoolManager manager, TdsConnectionInfo info)
{
this.info = info;
this.manager = manager;
}
#region Methods
public ITds GetConnection ()
{
ITds connection = null;
lock (list)
{
if (!initialized)
{
for (int n=0; n<info.PoolMinSize; n++)
list.Add (CreateConnection ());
initialized = true;
}
do {
if (list.Count > 0)
{
// There are available connections
connection = (ITds) list [list.Count - 1];
list.RemoveAt (list.Count - 1);
if (!connection.Reset ()) {
try {
connection.Disconnect ();
} catch {}
connection = null;
continue;
}
}
if (connection == null && activeConnections < info.PoolMaxSize)
{
// No connections available, but the connection limit
// has not been reached yet, so a new one can be created
connection = CreateConnection();
}
// No available connections in the pool
// Wait for somewone to release one.
if (connection == null)
{
Monitor.Wait (list);
}
}
while (connection == null);
}
return connection;
}
public void ReleaseConnection (ITds tds)
{
lock (list)
{
list.Add (tds);
Monitor.Pulse (list);
}
}
ITds CreateConnection ()
{
activeConnections++;
return manager.CreateConnection (info);
}
#endregion // Methods
}
}
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