/// <summary>
/// Performs a schedulation. Called by timer.
/// </summary>
/// <param name="timerState"></param>
protected override void Schedule(object timerState)
{
lock (this)
{
localTimerState.Counter++;
Stop(); //Stop timer while scheduler works
while (_cache.Count != 0)
{
SchedulerTask task = (SchedulerTask)_cache.GetKey(0);
if (task.DueTime > DateTime.Now)
{
break;
}
try
{
ExecuteTask(task);
}
catch
{
//TODO: We have to apply some policy here...
//i.e. Move failed tasks on a log, call a Module feedback interface,....
//now task is removed always
}
RemoveTask(task);
}
if (_cache.Count == 0)
{
FillCache();
if (_cache.Count == 0)
{
return; //avoid loop in case of empty tasks-queue in db.
}
Schedule(timerState);
}
Start(); //restart timer
}
}
/// <summary>
/// Compare two tasks first order by dueTime. If dueTimes are equal they are ordered by IDTask.
/// Used in sortedlist.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public int Compare(object x, object y)
{
SchedulerTask xtsk = x as SchedulerTask;
SchedulerTask ytsk = y as SchedulerTask;
if (x == null || y == null)
{
throw new ArgumentException("object is not a SchedulerTask");
}
if (xtsk.DueTime < ytsk.DueTime)
{
return(-1);
}
if (xtsk.DueTime > ytsk.DueTime)
{
return(1);
}
if (xtsk.DueTime == ytsk.DueTime)
{
if (xtsk.IDTask < ytsk.IDTask)
{
return(-1);
}
if (xtsk.IDTask > ytsk.IDTask)
{
return(1);
}
if (xtsk.IDTask == ytsk.IDTask)
{
return(0);
}
}
throw new ArgumentException("Impossible exception"); //... to compile.
}
/// <summary>
/// Inserts the task.
/// </summary>
/// <param name="task">The task.</param>
/// <returns>A int value...</returns>
public int InsertTask(SchedulerTask task)
{
if (task.DueTime < DateTime.Now)
{
throw new SchedulerException("Cannot schedule an expired task");
}
byte[] arg;
using (MemoryStream ss = new MemoryStream())
{
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ss, task.Argument);
arg = ss.ToArray();
ss.Close();
}
int idTask;
_cn.Open();
using (IDbCommand cmd = _cn.CreateCommand())
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "rb_SchedulerAddTask";
IDbDataParameter par;
par = cmd.CreateParameter();
par.ParameterName = "@IDOwner";
par.DbType = DbType.Int32;
par.Direction = ParameterDirection.Input;
par.Value = task.IDModuleOwner;
cmd.Parameters.Add(par);
par = cmd.CreateParameter();
par.ParameterName = "@IDTarget";
par.DbType = DbType.Int32;
par.Direction = ParameterDirection.Input;
par.Value = task.IDModuleTarget;
cmd.Parameters.Add(par);
par = cmd.CreateParameter();
par.ParameterName = "@DueTime";
par.DbType = DbType.DateTime;
par.Direction = ParameterDirection.Input;
par.Value = task.DueTime;
cmd.Parameters.Add(par);
par = cmd.CreateParameter();
par.ParameterName = "@Description";
par.DbType = DbType.String;
par.Size = 150;
par.Direction = ParameterDirection.Input;
par.Value = task.Description;
cmd.Parameters.Add(par);
par = cmd.CreateParameter();
par.ParameterName = "@Argument";
//par.DbType = DbType;
par.Direction = ParameterDirection.Input;
par.Value = arg;
cmd.Parameters.Add(par);
par = cmd.CreateParameter();
par.ParameterName = "@IDTask";
par.DbType = DbType.Int32;
par.Direction = ParameterDirection.Output;
cmd.Parameters.Add(par);
cmd.ExecuteNonQuery();
idTask = (int)((IDataParameter)cmd.Parameters["@IDTask"]).Value;
}
_cn.Close();
if (idTask == -1)
{
throw new SchedulerException("Task add fail in DB");
}
return(idTask);
}
