/// <summary>
/// Event handler that is called when the timer elapses.
/// </summary>
private void keepAliveTimer_Elapsed(
object sender,
System.Timers.ElapsedEventArgs e )
{
lock ( this )
{
using ( AdoNetSqlUpdater upd = new AdoNetSqlUpdater(
@"SELECT *
FROM [KeepAlives]
WHERE [Username]=@UserName
AND [UserDomainName]=@UserDomainName
AND [UserWorkstationName]=@UserWorkstationName
AND [MainWindowHandle]=@MainWindowHandle
",
new AdoNetSqlParamCollection(
AdoNetSqlParamCollection.CreateParameter( "@UserName", System.Environment.UserName, DbType.String, System.Environment.UserName.Length ),
AdoNetSqlParamCollection.CreateParameter( "@UserDomainName", System.Environment.UserDomainName, DbType.String, System.Environment.UserDomainName.Length ),
AdoNetSqlParamCollection.CreateParameter( "@UserWorkstationName", System.Environment.MachineName, DbType.String, System.Environment.MachineName.Length ),
AdoNetSqlParamCollection.CreateParameter( "@MainWindowHandle", MainWindowHandle, DbType.Int32 )
) ) )
{
DataRow row = upd.CheckGetOrAddNewRow();
row["LastDate"] = DBHelper.WriteField( DateTime.Now );
row["Username"] = DBHelper.WriteField( System.Environment.UserName );
row["UserDomainName"] = DBHelper.WriteField( System.Environment.UserDomainName );
row["UserWorkstationName"] = DBHelper.WriteField( System.Environment.MachineName );
row["MainWindowHandle"] = DBHelper.WriteField( MainWindowHandle );
upd.Update( AdoNetSqlUpdater.IdentityControl.DontGet );
}
}
}
/// <summary>
/// Mark as locked. Throws if already locked.
/// </summary>
private void Lock()
{
if ( true )
{
DateTime dt = DateTime.Now.AddSeconds(
-ApplicationConfiguration.Current.KeepAliveSeconds * 2 );
DataRow row = AdoNetSqlHelper.ExecuteRow(
@"SELECT *
FROM [Locks] L
WHERE L.[ObjectType]=@ObjectType
AND L.[ObjectID]=@ObjectID
AND L.[MainWindowHandle]=
(
SELECT [MainWindowHandle]
FROM [KeepAlives] K
WHERE K.[MainWindowHandle]=L.[MainWindowHandle]
AND K.[LastDate]>=@LastDate
)",
new AdoNetSqlParamCollection(
AdoNetSqlParamCollection.CreateParameter( "@ObjectType", objectType.FullName ),
AdoNetSqlParamCollection.CreateParameter( "@ObjectID", objectID ),
AdoNetSqlParamCollection.CreateParameter( "@LastDate", dt ) ) );
// Last chance, try window handle if on this machine.
if ( row!=null )
{
string userName;
string userWorkstationName;
DBHelper.ReadField( out userName, row["UserName"] );
DBHelper.ReadField( out userWorkstationName, row["UserWorkstationName"] );
if ( userWorkstationName==Environment.MachineName )
{
int mainWindowHandle;
DBHelper.ReadField( out mainWindowHandle, row["MainWindowHandle"] );
if ( IsWindow( new IntPtr( mainWindowHandle ) ) )
{
throw new LockException( userName );
}
else
{
LogCentral.Current.LogDebug(
string.Format(
"Returned row is NON-NULL, window handle is on local machine and does not exist anymore. Not locked for '{0}', '{1}'.",
objectType.FullName,
objectID ) );
}
}
else
{
throw new LockException( userName );
}
}
else
{
LogCentral.Current.LogDebug(
string.Format(
"Returned row is NULL. Not locked for '{0}', '{1}'.",
objectType.FullName,
objectID ) );
}
}
// --
AdoNetSqlHelper.ExecuteNonQuery(
@"DELETE
FROM [Locks]
WHERE [ObjectType]=@ObjectType
AND [ObjectID]=@ObjectID",
new AdoNetSqlParamCollection(
AdoNetSqlParamCollection.CreateParameter( "@ObjectType", objectType.FullName ),
AdoNetSqlParamCollection.CreateParameter( "@ObjectID", objectID )
) );
// --
using ( AdoNetSqlUpdater upd = new AdoNetSqlUpdater(
@"SELECT *
FROM [Locks]
WHERE [ObjectType]=@ObjectType
AND [ObjectID]=@ObjectID",
new AdoNetSqlParamCollection(
AdoNetSqlParamCollection.CreateParameter( "@ObjectType", objectType.FullName, DbType.String ),
AdoNetSqlParamCollection.CreateParameter( "@ObjectID", objectID, DbType.Int32 ) ) ) )
{
// If here, everything is OK. No other lock is set or lock is
// invalid. Set new lock now.
DataRow row = upd.CheckGetOrAddNewRow();
row["LockDate"] = DBHelper.WriteField( lockDate );
row["UserName"] = DBHelper.WriteField( userName );
row["UserDomainName"] = DBHelper.WriteField( userDomainName );
row["UserWorkstationName"] = DBHelper.WriteField( userWorkstationName );
row["ObjectType"] = DBHelper.WriteField( objectType.FullName );
row["ObjectID"] = DBHelper.WriteField( objectID );
row["MainWindowHandle"] = DBHelper.WriteField( mainWindowHandle );
upd.Update( AdoNetSqlUpdater.IdentityControl.DontGet );
}
}