Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>EDIT: My original answer is rubbish. Really rubbish. I've kept it here to explain <em>why</em> it's rubbish though - it's in the comments, but they'd have been deleted with the answer.</p> <p>GC.KeepAlive only makes sure a reference is treated as a root until after the call. In the code at the bottom of this answer, the GC.KeepAlive method would be called immediately, and then the timer would still be eligible for garbage collection. Because the newly created thread is a foreground thread, the app will run as long as it's alive (whereas the timer uses a background thread, which doesn't prevent program exit). This means that the Main method exits, but the application needs to keep running.</p> <p>Arguably a <em>simpler</em> solution would be to run <code>myThreadStart</code> in the main thread, rather than creating a new one and then letting the main thread die. In other words, a simple solution would be:</p> <pre><code>using System.Threading; class Program { static void Main() { Timer timer = new Timer(myTimerCallback, new MyStateObject(), 0, 5000); myThreadStart(); GC.KeepAlive(timer); } } </code></pre> <p>I assume the <em>real</em> code is more complicated though - in which case using a private static variable as suggested in other answers is probably the way to go. It really will depend on the usage though. I personally prefer not to create a static field just for the sake of preventing something being collected if there's an alternative (like the above) but sometimes it's virtually the only way of doing it.</p> <p><strong>Original (bad) answer:</strong></p> <p>If you really want to allocate it in Main, then you can use <a href="http://msdn.microsoft.com/en-us/library/system.gc.keepalive.aspx" rel="noreferrer">GC.KeepAlive</a>:</p> <pre><code>using System.Threading; class Program { static void Main() { new Thread(myThreadStart).Start(); Timer timer = new Timer(myTimerCallback, new MyStateObject(), 0, 5000); GC.KeepAlive(timer); } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POIn C#, where should I keep my timer's reference?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USJon Skeet
    1. USJon Skeet
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    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. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThanks. According to the documentation of KeepAlive, it "references the specified object, which makes it ineligible for garbage collection from the start of the current routine to the point where this method is called." Doesn't this mean that, by the end of the main method, the object can be GC'd?
      singulars
      1. PO
      1. USHosam Aly
    2. CO@Hosam - you'll need to keep your Main() method active somehow anyway - returning from it will terminate your program.
      singulars
      1. PO
      1. USMichael Burr
    3. CO@Michael Burr, program won't exit whild thread created via (new Tread...) is running.
      singulars
      1. PO
      1. USaku
 

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