/// <summary>
/// 10/20/2011
/// Initializes a new instance of the <see cref = "Site" /> class.
/// </summary>
/// <remarks>
/// Side effects: lastFailed, lockManager, messageBuffQueue, status are all initialized
/// </remarks>
public Site()
{
lastFailed = new List<int>();
lockManager = new LockManager();
messageBuffQueue = new Queue<Operation>();
status = Enumerations.SiteStatus.Active;
}
/// <summary>
/// 11/20/2011
/// Simulates a site recovery by recovering the lock and data manager and changing the site status
/// </summary>
/// <remarks>
/// Side effects:
/// The site status is modified.
/// The LM forgot all previous lock information and set "fake" locks on all replicated data items.
/// The DM forgot all dirty writes.
/// </remarks>
public void Recover()
{
// Some assumptions: I have to protect the application from a user entering recover(i) if site i is not failed.
// Because otherwise a user can wipe out all lock information and dirty writes at whim (i.e. without having to fail
// the site).
if (status != Enumerations.SiteStatus.Active)
{
status = Enumerations.SiteStatus.Active;
// lock all replicated data items for reading
lockManager.Recover();
// remove all uncommitted values from data manager
dataManager.Recover();
}
}
/// <summary>
/// 11/20/2011
/// Simulates a site failure by changing the status of the site
/// </summary>
/// <param name = "ts">The timestamp at which this site has failed.</param>
/// <remarks>
/// Side effects:
/// the site.status is modified,
/// a new timestamp is added to lastFailed,
/// the message buffer is cleared
/// </remarks>
public void Fail(int ts)
{
status = Enumerations.SiteStatus.Failed;
lastFailed.Add(ts);
messageBuffQueue.Clear();
}
