Multithreading Series 1: Classic Selling tickets

1. How to sell tickets

  classTicketrest {intTicket =1; intMax =0;  PublicTicketrest (intmax) {Max=Max; }        /// <summary>        ///not locked/// </summary>        /// <param name= "num" ></param>         Public voidSellticketnolock (intnum) {             while(Ticket <=Max) {                if(Ticket >Max) Break;//it must be judged here. Console.WriteLine ($"Window {num}| conductor {Thread.CurrentThread.ManagedThreadId}: Ticket sold [{ticket}], remaining {max-ticket}"); Ticket++; Task.delay ( $); }        }        /// <summary>        ///Locking/// </summary>        /// <param name= "num" ></param>         Public voidSellticketaddlock (intnum) {             while(Ticket <=Max) {                Lock( This)                {                    if(Ticket >Max) Break;//it must be judged here. Console.WriteLine ($"Window {num}| conductor {Thread.CurrentThread.ManagedThreadId}: Ticket sold [{ticket}], remaining {max-ticket}"); Ticket++; Task.delay ( $); }            }        }

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2. Use thred to invoke the method of selling tickets

An unlocked condition (calling method Sellticketnolock) will cause a ticket to be sold multiple times and the remainder of the ticket does not meet the situation.

3. Call the Ticket method using task

Traps for closures:

for (int i = 0; i < Windowcount; i++)
{
Tasklst. Add (Task.run (() = {Ticketrest2.sellticketaddlock (i);}));
}

The last I value is 5 instead of the original I value.

Workaround use temporary variable, instead:

for (int i = 0; i < Windowcount; i++)
{
int temp = i;
Tasklst. ADD (Task.run () = {Ticketrest2.sellticketaddlock (temp);});
}

The locking (Sellticketaddlock) ticket did not duplicate the remaining ticket and there was no error.

The complete code:

 classProgram {Static voidMain (string[] args) {            //Sellthread ();Selltaskdemo ();        Console.ReadLine (); }        Private Static intTicketcount = -;//Total 20 Tickets        Private Static intWindowcount =5;//A total of 5 windows simultaneous ticketing        /// <summary>        /////Demo multi-threaded sell ticket case-thread Way/// </summary>        Static voidSellthread () {Try{ticketrest ticketrest=Newticketrest (Ticketcount);  for(inti =0; i < Windowcount; i++) {thread thread=NewThread (() ={ticketrest.sellticketnolock (i);}); Thread.                Start (); }            }            Catch(Exception ex) {LoggerFactory.Instance.Logger_Error (ex); Console.WriteLine ($"{ex. message}| {Ex. GetType (). fullname}| {Ex. targetsite}| {Ex. StackTrace}"); }        }        /// <summary>        ///Demo multi-threaded sell ticket case-task Way/// </summary>        Static voidSelltaskdemo () {Try{Stopwatch Stopwatch1=NewStopwatch (); Stopwatch1.                Start (); Ticketrest TicketRest1=Newticketrest (Ticketcount); Ticketrest1.sellticketaddlock (0); Stopwatch1.                Stop (); Console.WriteLine ($"use a single-threaded way to consume time: {stopwatch1. Elapsedmilliseconds} milliseconds"); Stopwatch STOPWATCH2=NewStopwatch (); Stopwatch2.                Start (); Ticketrest TicketRest2=Newticketrest (Ticketcount); varTasklst =NewList<task>();  for(inti =0; i < Windowcount; i++)                {                    inttemp =i; Tasklst. ADD (Task.run ()={ticketrest2.sellticketaddlock (temp);})); } task.waitall (Tasklst.                ToArray ()); Stopwatch2.                Stop (); Console.WriteLine ($"Use Multithreading: Code snippet Run time ({stopwatch2. Elapsedmilliseconds} milliseconds)"); }            Catch(Exception ex) {LoggerFactory.Instance.Logger_Error (ex); Console.WriteLine ($"{ex. message}| {Ex. GetType (). fullname}| {Ex. targetsite}| {Ex. StackTrace}"); }        }    }    classTicketrest {intTicket =1; intMax =0;  PublicTicketrest (intmax) {Max=Max; }        /// <summary>        ///not locked/// </summary>        /// <param name= "num" ></param>         Public voidSellticketnolock (intnum) {             while(Ticket <=Max) {                if(Ticket >Max) Break;//it must be judged here. Console.WriteLine ($"Window {num}| conductor {Thread.CurrentThread.ManagedThreadId}: Ticket sold [{ticket}], remaining {max-ticket}"); Ticket++; Task.delay ( $); }        }        /// <summary>        ///Locking/// </summary>        /// <param name= "num" ></param>         Public voidSellticketaddlock (intnum) {             while(Ticket <=Max) {                Lock( This)                {                    if(Ticket >Max) Break;//it must be judged here. Console.WriteLine ($"Window {num}| conductor {Thread.CurrentThread.ManagedThreadId}: Ticket sold [{ticket}], remaining {max-ticket}"); Ticket++; //Task.delay ($);Thread.Sleep ( -);//simulate time-consuming operations                }            }        }    }

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LoggerFactory.Instance.Logger_Error (ex); This is an output exception and can be replaced with Console.WriteLine.

References:

Understanding closures in C #: https://www.cnblogs.com/jiejie_peng/p/3701070.html

Talking about concurrency and parallelism (i): http://www.cnblogs.com/yangecnu/p/Something-about-Concurrent-and-Parallel-Programming.html

Multithreading Series 1: Classic Selling tickets