source: branches/3.2/sources/HeuristicLab.Hive.Server.Core/3.2/DefaultScheduler.cs @ 4042

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HeuristicLab.Hive.Server.Core.InternalInterfaces;
using HeuristicLab.Hive.Contracts.BusinessObjects;
using HeuristicLab.Hive.Server.DataAccess;
using System.Threading;
using HeuristicLab.DataAccess.Interfaces;
using System.Transactions;
using HeuristicLab.Hive.Contracts;

namespace HeuristicLab.Hive.Server.Core {
  internal class DefaultScheduler : IScheduler {
    //private ISessionFactory factory;

    private static Mutex jobLock =
      new Mutex();

    #region IScheduler Members

    public DefaultScheduler() {
      //factory = ServiceLocator.GetSessionFactory();
    }

    public bool ExistsJobForClient(HeuristicLab.Hive.Contracts.BusinessObjects.HeartBeatData hbData) {
      List<JobDto> allOfflineJobsForClient =
        new List<JobDto>(DaoLocator.JobDao.FindFittingJobsForClient(State.offline, hbData.FreeCores, hbData.FreeMemory,
                                                                    hbData.ClientId));
      return (allOfflineJobsForClient != null && allOfflineJobsForClient.Count > 0);
    }

    public HeuristicLab.Hive.Contracts.BusinessObjects.JobDto GetNextJobForClient(Guid clientId) {
      /// Critical section ///
      jobLock.WaitOne();
      JobDto jobToCalculate = null;
      using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = ApplicationConstants.ISOLATION_LEVEL_SCOPE })) {
        ClientDto client = DaoLocator.ClientDao.FindById(clientId);
        LinkedList<JobDto> allOfflineJobsForClient =
          new LinkedList<JobDto>(DaoLocator.JobDao.FindFittingJobsForClient(State.offline, client.NrOfFreeCores,
                                                                            client.FreeMemory, client.Id));        
        if (allOfflineJobsForClient != null && allOfflineJobsForClient.Count > 0) {
          jobToCalculate = allOfflineJobsForClient.First.Value;
          jobToCalculate.State = State.calculating;
          jobToCalculate.Client = client;
          jobToCalculate.Client.State = State.calculating;
          jobToCalculate.DateCalculated = DateTime.Now;
          DaoLocator.JobDao.AssignClientToJob(client.Id, jobToCalculate.Id);
          DaoLocator.JobDao.Update(jobToCalculate);
          DaoLocator.ClientDao.Update(jobToCalculate.Client);
        }
        scope.Complete();
      }
      jobLock.ReleaseMutex();
      /// End Critical section ///

      return jobToCalculate;
    }

    #endregion
  }
}