Windows 8 Store Apps Learning (47) Multi-thread thread synchronization: semaphore etc.

Multi-thread thread synchronization: Semaphore, Countdownevent, Barrier, ManualResetEvent, AutoResetEvent

Introduced

Re-visualize the thread sync for Windows 8 Store Apps

Semaphore-Signal Volume

Countdownevent-thread synchronization via semaphore number

Barrier-Barrier

ManualResetEvent-Manual traffic lights

AutoResetEvent-Automatic traffic lights

Example

1. Demonstrate the use of semaphore

Thread/lock/semaphoredemo.xaml

<page
    x:class= "XamlDemo.Thread.Lock.SemaphoreDemo"
    xmlns= "http://schemas.microsoft.com/winfx/2006/ Xaml/presentation "
    xmlns:x=" Http://schemas.microsoft.com/winfx/2006/xaml "
    xmlns:local=" using: XamlDemo.Thread.Lock "
    xmlns:d=" http://schemas.microsoft.com/expression/blend/2008 "
    xmlns:mc=" http:// schemas.openxmlformats.org/markup-compatibility/2006 "
    mc:ignorable=" D ">
    
    <grid background=" Transparent ">
        <stackpanel margin=" 0 0 0 ">
    
            <textblock name=" lblmsg "fontsize=" 14.667 "/>
    
        </StackPanel>
    </Grid>
</Page>

Thread/lock/semaphoredemo.xaml.cs

* * Demo Semaphore use * * semaphore-semaphore * Semaphoreslim-Lightweight Semaphore * * Note: * Literal translation semaphore words not very good understanding, can be Sem Aphore understood as a license center, the number of licenses in the License center is limited * threads want to execute first obtain a license from the License Center (if the license center's license has been issued, wait, wait for the other thread to return the license), and then go back./using Sy
Stem
Using System.Collections.Generic;
Using System.Threading;
Using System.Threading.Tasks;
Using Windows.UI.Xaml.Controls;
    
Using Windows.UI.Xaml.Navigation; Namespace XamlDemo.Thread.Lock {public sealed partial class Semaphoredemo:page {* * * semaphor E (int initialcount, int maximumcount, string name) * Initialcount-the number of licenses initially owned by the license center, that is, the number of licenses already issued in the initial case is MAXIMUMC Ount-initialcount * Maximumcount-Total number of licenses owned by the license centre * name-License Center name * Semaphore Open Existing (string name)-Opens the license center with the specified name//instantiates a license center with a license number of 2 private semaphore _se
    
        Maphore = new Semaphore (2, 2); Public Semaphoredemo () {this. InitializEcomponent (); } protected async override void Onnavigatedto (NavigationEventArgs e) {list<task> T
    
            asks = new list<task> (); Simulate 5 threads executing in parallel, the thread that gets the license to run, and the license center has only 2 licenses for (int i = 0; i < 5; i++) {Canc Ellationtoken token = new CancellationTokenSource ().
    
                Token; Task task = Task.run (() => {outmsg () string.
                        Format ("task {0} waits for a license", Task.currentid)); Token.
    
                        WaitHandle.WaitOne (5000); WaitOne ()-Apply for license _semaphore.
                        WaitOne (); Outmsg (String.
    
                        Format ("task {0} applies to a license", Task.currentid)); Token.
    
                        WaitHandle.WaitOne (1000); Outmsg (String.
                        Format ("task {0} returned a license", Task.currentid)); int release ()-return license, return value is: Release ()Number of licenses available to the license center int ignored = _semaphore.
                        Release ();
    
                int release (int releasecount)-Specifies the number of semaphores to be released (as per this article, specify the number of licenses returned)}, token); Tasks.
            ADD (Task);
        } await Task.whenall (tasks); } private void Outmsg (String msg) {var ignored = Dispatcher.runasync (Wi Ndows. Ui.
                    Core.CoreDispatcherPriority.High, () => {lblmsg.text = msg;
                Lblmsg.text + = Environment.NewLine;
        }); }
    }
}