private bool TryPickUpFork(ChandyMisraFork fork)
{
lock (fork)
{
if (fork.Owner != this)
{
if (fork.IsDirty)
{
// Other Philosopher just put down fork. Get it immediately.
fork.IsDirty = false;
fork.Owner = this;
fork.RequestedOwner = null;
}
else
{
// Fork is clean. Just ask to give this fork to me.
fork.RequestedOwner = this;
return(false);
}
}
else
{
// I already own this fork. Just clean it.
fork.IsDirty = false;
}
}
return(true);
}
public void AssignFork(ChandyMisraFork fork)
{
var ownedForks = new ChandyMisraFork[forks_.Length + 1];
Array.Copy(forks_, ownedForks, forks_.Length);
ownedForks[ownedForks.Length - 1] = fork;
forks_ = ownedForks;
}
public void PutDownForks()
{
bool anyForkMoved = false;
for (int i = 0; i < forks_.Length; i++)
{
ChandyMisraFork fork = forks_[i];
if (PutDownFork(fork))
{
anyForkMoved = true;
}
}
if (anyForkMoved)
{
Thread.Yield();
}
}
public void PickUpForks()
{
bool result;
do
{
result = true;
for (int i = 0; i < forks_.Length; i++)
{
ChandyMisraFork fork = forks_[i];
if (!TryPickUpFork(fork))
{
result = false;
break;
}
}
} while (!result);
}
private bool PutDownFork(ChandyMisraFork fork)
{
lock (fork)
{
// Assert I am still in a good condition.
Debug.Assert(fork.Owner == this);
Debug.Assert(fork.IsDirty == false);
if (fork.RequestedOwner != null)
{
// Someone requested this fork. Clean and give it to requester.
fork.IsDirty = false;
fork.Owner = fork.RequestedOwner;
fork.RequestedOwner = null;
return(true);
}
else
{
// Just mark fork dirty and do not touch.
fork.IsDirty = true;
return(false);
}
}
}
