Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>You can use a long running Task to process items from a BlockingCollection as suggested by Wilka. Here's an example which pretty much meets your applications requirements. You'll see output something like this:</p> <pre><code>Log from task B Log from task A Log from task B1 Log from task D Log from task C </code></pre> <p>Not that outputs from A, B, C &amp; D appear random because they depend on the start time of the threads but B always appears before B1.</p> <pre><code>public class LogItem { public string Message { get; private set; } public LogItem (string message) { Message = message; } } public void Example() { BlockingCollection&lt;LogItem&gt; _queue = new BlockingCollection&lt;LogItem&gt;(); // Start queue listener... CancellationTokenSource canceller = new CancellationTokenSource(); Task listener = Task.Factory.StartNew(() =&gt; { while (!canceller.Token.IsCancellationRequested) { LogItem item; if (_queue.TryTake(out item)) Console.WriteLine(item.Message); } }, canceller.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default); // Add some log messages in parallel... Parallel.Invoke( () =&gt; { _queue.Add(new LogItem("Log from task A")); }, () =&gt; { _queue.Add(new LogItem("Log from task B")); _queue.Add(new LogItem("Log from task B1")); }, () =&gt; { _queue.Add(new LogItem("Log from task C")); }, () =&gt; { _queue.Add(new LogItem("Log from task D")); }); // Pretend to do other things... Thread.Sleep(1000); // Shut down the listener... canceller.Cancel(); listener.Wait(); } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POHow (and if) to write a single-consumer queue using the TPL?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USabatishchev
    1. USAde Miller
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow (and if) to write a single-consumer queue using the TPL?
      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. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO+1 for concise and useful example of TPL functionality without overengineering. I implemented this in conjunction with a ConcurrentQueue<T> in order to queue file-write operations onto one thread (multiple threads write to queue, only the listener thread reads from and processes queue items)
      singulars
      1. PO
      1. USDmitriy Khaykin
    2. COUPDATE: In my implementation, I noticed that this listener task with the ConcurrentQueue<T> was eating 12% of one core on an i7-870 and 25% of one core on a dual core Xeon 2.4ghz server. The while loop which perpetually calls TryDequeue was killing the CPU. This may or may not be the same case with the BlockingCollection, but I wanted to report on it... I ended up not using a Queue and using TPL instead, so in this example, every _queue.Add call would be a Task.ContinueWith() call (except the first one would be a TaskFactory.StartNew() call, in an If statement)...it worked like a charm for me.
      singulars
      1. PO
      1. USDmitriy Khaykin
    3. CODoes using the following help reduce the cpu spin on the while? LogItem item = _queue.Take(canceller.Token); Console.WriteLine(item.Message);
      singulars
      1. PO
      1. USMattC
 

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