IMEX.mes.plc/Curtain.Net.Sockets/PLC/ThreadLock/WaiterThreadLock.cs


using System.Threading;

namespace Curtain.Net.Sockets.PLC.ThreadLock
{
    internal class WaiterThreadLock : IThreadLock
    {
        public bool Locked
        {
            get;
            private set;
        }
        private int _interlocke = 0;
        private readonly AutoResetEvent _waiterLock = new AutoResetEvent(false);

        public bool HasWaiter
        {
            get
            {
                return (_interlocke != 0);
            }
        }

        public void Dispose()
        {
            _waiterLock?.Close();
        }

        public bool Lock(int timeout = -1)
        {
            if (Interlocked.Increment(ref _interlocke) == 1)
            {
                return Locked = true;
            }
            if (timeout < 0)
            {
                //_waiterLock.WaitOne();
                return Locked = _waiterLock.WaitOne();
            }
            else
            {
                return Locked = _waiterLock.WaitOne(timeout);
            }
        }

        public void Unlock()
        {
            if (Interlocked.Decrement(ref _interlocke) == 0)
            {
                Locked = false;
                return;
            }
            _waiterLock.Set();
            Locked = false;
        }
    }
}