Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p><code>connection.Thread.Start(connection)</code> starts a new thread with a call to <code>ProcessConnection</code>, passing <code>connection</code> as the <code>state</code> argument. Execution in the current thread continues immediately with the next line while <code>ProcessConnection</code> is executed in the new thread. </p> <p><code>ProcessConnection</code> gets the <code>Socket</code> object from the <code>ConnectionInfo</code> object passed to it by <code>AcceptConnections</code> and waits to receive data from the socket. When it receives data, it loops through all of the other <code>ConnectionInfo</code> objects in the <code>connections</code> collection and sends this data to each of them in sequence.</p> <p>So what's running concurrently here? Well, we have the initial thread (call it Thread 0) executing <code>AcceptConnections</code> in an endless loop. And then for each socket connection that we've accepted, we have a thread executing <code>ProcessConnection</code>.</p> <p>The locks are needed because <code>ProcessConnection</code> uses <code>foreach</code> to loop through the known connections to send them data. If Thread 0 were to add a new connection to the collection while the collection is being enumerated in the <code>foreach</code>, an <code>InvalidOperationException</code> would be thrown in <code>ProcessConnection</code>.</p> <p>The <code>lock</code> does prevent the concurrency issue in this case, but it also causes a potential performance problem. It doesn't only prevent <code>AcceptConnections</code> from modifying the collection while <code>ProcessConnection</code> is enumerating it. It also prevents any two threads executing <code>ProcessConnection</code> from enumerating the collection at the same time. A better choice in this case would be a <a href="http://msdn.microsoft.com/en-us/library/system.threading.readerwriterlockslim.aspx" rel="nofollow noreferrer"><code>ReaderWriterLockSlim</code></a> which would allow multiple threads to read the collection concurrently.</p>
    singulars
    1. This table or related slice is empty.
    1. POHow to use Multithreading, locks, Socket Programming
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USJack Leitch
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow to use Multithreading, locks, Socket Programming
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO`lock (_connections) { foreach (ConnectionInfo conn in _connections) { if (conn != connection) { conn.Socket.Send( buffer, bytesRead, SocketFlags.None); } } }` This has been used to broadcast same message to every socket ? As explained in your second paragraph
      singulars
      1. PO
      1. USShantanu Gupta
    2. COGreat explanation, making all the points clear here. Still reading your answer along with taking article as a reference. Will back to you as i read it completely.
      singulars
      1. PO
      1. USShantanu Gupta
    3. CO@Shantanu: Yes, that foreach loop is the one that broadcasts the received message to every other socket.
      singulars
      1. PO
      1. USJack Leitch
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload