public static MasterVote Choose(MasterVote v1, MasterVote v2)
{
if (v1 == null) return v2;
if (v2 == null) return v1;
if (v1.clock == v2.clock)
{
if (string.Compare(v1.Id, v2.Id) >= 0)
{
return v2;
}
else
{
return v1;
}
}
else if (v1.clock > v2.clock)
{
return v1;
}
else
{
return v2;
}
}
public static MasterVote Choose(MasterVote v1, MasterVote v2)
{
if (v1 == null)
{
return(v2);
}
if (v2 == null)
{
return(v1);
}
if (v1.clock == v2.clock)
{
if (string.Compare(v1.Id, v2.Id) >= 0)
{
return(v2);
}
else
{
return(v1);
}
}
else if (v1.clock > v2.clock)
{
return(v1);
}
else
{
return(v2);
}
}
public MasterVote Uprising(MasterVote vote, bool force = false)
{
if (fail) throw new ProcessFailedException(id);
Console.WriteLine("UPRISING");
MasterVote newMaster;
// if force writes the vote id as master
if (force)
{
master = vote.Id;
newMaster = vote;
}
else
{
MasterVote myVote = new MasterVote(id, clock);
newMaster = MasterVote.Choose(myVote, vote);
}
return newMaster;
}
// Tries to elect himself as the new master sending a vote to
// each alive metadata with its id:clock
// Other metadatas compare the votes, the one with the highest clock / lowest id
// wins, and returns that vote
public string Master()
{
if (fail) throw new ProcessFailedException(id);
Console.WriteLine("MASTER ELECTION");
// if I'm the master
if (ImMaster) return id;
// checks if the master I know is down
try
{
return metadatas[master].Master();
}
catch (ProcessFailedException) { }
// previous master is down, starting Uprising
MasterVote masterVote = new MasterVote(id, clock);
foreach (var entry in metadatas)
{
IMetadataToMetadata metadata = entry.Value;
try
{
// chooses better vote between previous master and the one from the metadata
masterVote = MasterVote.Choose(metadata.Uprising(masterVote), masterVote);
}
catch (ProcessFailedException) { }
}
// second round to confirm votes
foreach (var entry in metadatas)
{
IMetadataToMetadata metadata = entry.Value;
try
{
// chooses better vote between previous master and the one from the metadata
metadata.Uprising(masterVote, true);
}
catch (ProcessFailedException) { }
}
master = masterVote.Id;
return master;
}
