nuclex-shared-dotnet/Nuclex.Support
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SetProgression partially working; wrote several unit tests using the NMock library; lots of smaller improvements to the progression classes

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git-svn-id: file:///srv/devel/repo-conversion/nusu@12 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
Markus Ewald 2007-04-19 18:18:34 +00:00
parent cefbc78868
commit 71b6dc90a2
8 changed files with 452 additions and 36 deletions
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27
Source/Tracking/Progression.cs
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@ -52,17 +52,21 @@ namespace Nuclex.Support.Tracking {
public event EventHandler AsyncEnded;
/// <summary>Whether the progression has ended already</summary>
public virtual bool Ended {
public bool Ended {
get { return this.ended; }
}
/// <summary>WaitHandle that can be used to wait for the progression to end</summary>
public WaitHandle WaitHandle {
get {
// The WaitHandle will only be created when someone asks for it!
// See the Double-Check Locking idiom on why the condition is checked twice
// (primarily, it avoids an expensive lock when it isn't needed)
//
// We can *not* optimize this lock away since we absolutely must not create
// two doneEvents -- someone might call .WaitOne() on the first one when only
// the second one is assigned to this.doneEvent and gets set in the end.
if(this.doneEvent == null) {
lock(this.syncRoot) {
@ -109,16 +113,27 @@ namespace Nuclex.Support.Tracking {
/// seperately.
/// </remarks>
protected virtual void OnAsyncEnded() {
// TODO: Find a way around this. Interlocked.Exchange would be best!
// We do not lock here since we require this method to be called only once
// in the object's lifetime. If someone really badly wanted to break this
// he'd probably have a one-in-a-million chance of getting through.
if(this.ended)
throw new InvalidOperationException("The progression has already been ended");
this.ended = true;
lock(this.syncRoot) {
if(this.doneEvent != null)
this.doneEvent.Set();
}
// Doesn't need a lock. If another thread wins the race and creates the event
// after we just saw it being null, it would be created in an already set
// state due to the ended flag (see above) being set to true beforehand!
if(this.doneEvent != null)
this.doneEvent.Set();
// Finally, fire the AsyncEnded event
EventHandler copy = AsyncEnded;
if(copy != null)
copy(this, EventArgs.Empty);
}
/// <summary>Used to synchronize multithreaded accesses to this object</summary>