using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace WinDll.Utils
{
    /// <summary>
    /// A class to control access to a particulair value, Threadsafe
    /// </summary>
    public class LockedValue<T> : IDisposable
    {
        private T value;
        private Semaphore sem;

        /// <summary>
        /// Create a new LockedValue and allow only 1 thing to access it at a time
        /// </summary>
        /// <param name="value">The value to monitor</param>
        public LockedValue(T value):this(value, 1){
         }

        /// <summary>
        /// Create a new LockedValue and allow @max@ things to access it at a time
        /// </summary>
        /// <param name="value">The value to monitor</param>
        /// <param name="max"></param>
        public LockedValue(T value, int max)
        {
            this.value = value;
            this.sem = new Semaphore(max, 10, "LockedValue" + this.GetHashCode());
        }

        /// <summary>
        /// Retreive the LockedValue
        /// </summary>
        /// <returns>LockedValue</returns>
        public T pull()
        {
            this.sem.WaitOne();
            return this.value;
        }

        /// <summary>
        /// Release the LockedValue
        /// </summary>
        public void pulse()
        {
            this.sem.Release();
        }

        /// <summary>
        /// Unsafe retreiving of the value. This should not be used under normal conditions!
        /// </summary>
        /// <returns>LockedValue</returns>
        public T unsafePull()
        {
            return this.value;
        }

        public void Dispose()
        {
            this.sem.Close();
        }
    }
}