private bool TryEating(Philosopher philosopher)
{
if (Monitor.TryEnter(table.forks))
{
if (philosopher.left.isFree && philosopher.right.isFree)
{
lock (philosopher.left)
{
lock (philosopher.right)
{
philosopher.TakeForks();
Monitor.Exit(table.forks);
philosopher.Eat();
return(true);
}
}
}
else
{
Monitor.Exit(table.forks);
}
}
return(false);
}
static void Main(string[] args)
{
Stopwatch watch = new Stopwatch();
int n, thinkingTime, eatingTime;
int waitedForFork = 0;
string consoleInput;
Console.Write("Enter number of philosophers: ");
consoleInput = Console.ReadLine();
n = int.Parse(consoleInput);
Console.Write("Enter max thinking time in ms: ");
consoleInput = Console.ReadLine();
thinkingTime = int.Parse(consoleInput);
Console.Write("Enter max eating time in ms: ");
consoleInput = Console.ReadLine();
eatingTime = int.Parse(consoleInput);
Console.WriteLine();
watch.Start();
CancellationTokenSource source = new CancellationTokenSource();
forks = new object[n];
Task[] pTasks = new Task[n];
#region Deadlock
//for (int i = 0; i < n; i++)
//{
// forks[i] = new object();
//}
//pTasks[0] = new Task(() =>
//{
// Philosopher p = new Philosopher();
// p.Eat(forks[n - 1], forks[0],
// n - 1, 0, 0, thinkingTime, eatingTime, source.Token);
//});
//pTasks[0].Start();
//for (int i = 1; i < n; i++)
//{
// int ix = i;
// pTasks[i] = new Task(() =>
// {
// Philosopher p = new Philosopher();
// p.Eat(forks[ix - 1], forks[ix],
// ix - 1, ix, ix, thinkingTime, eatingTime, source.Token);
// });
// pTasks[i].Start();
//}
#endregion
#region NoCircularWait
for (int i = 0; i < n; i++)
{
forks[i] = new object();
}
pTasks[0] = new Task(() =>
{
Philosopher p = new Philosopher();
p.Eat(forks[0], forks[n - 1],
n - 1, 0, 0, thinkingTime, eatingTime, source.Token);
Interlocked.Add(ref waitedForFork, (int)p.WaitForFork);
});
pTasks[0].Start();
for (int i = 1; i < n; i++)
{
int ix = i;
pTasks[i] = new Task(() =>
{
Philosopher p = new Philosopher();
if (n % 2 == 1)
{
p.Eat(forks[ix - 1], forks[ix],
ix - 1, ix, ix, thinkingTime, eatingTime, source.Token);
}
else
{
p.Eat(forks[ix], forks[ix - 1],
ix - 1, ix, ix, thinkingTime, eatingTime, source.Token);
}
Interlocked.Add(ref waitedForFork, (int)p.WaitForFork);
});
pTasks[i].Start();
}
#endregion
// Let them eat
Thread.Sleep(1000);
// Stop eating
source.Cancel();
// Wait till all finished
Task.WaitAll(pTasks);
watch.Stop();
Console.WriteLine($"\n{watch.ElapsedMilliseconds}ms waittime\n{waitedForFork}ms sum waited for fork\nPress any key to exit.");
Console.ReadLine();
}