The AffineThreadPool class will now work on Mono as well; fixed naming inconsistency for the EnumHelper class; inverted the counting direction used by the Semaphore class so it is easier to read (most other Semaphores count in the direction it is using now)

git-svn-id: file:///srv/devel/repo-conversion/nusu@187 d2e56fa2-650e-0410-a79f-9358c0239efd

Source/AffineThreadPool.cs

@@ -198,18 +198,20 @@ namespace Nuclex.Support {
       // be called from the thread whose affinity is being changed.
       Thread.CurrentThread.SetProcessorAffinity(new int[] { hardwareThreadIndex });
 #else
-      // Prevent this managed thread from impersonating another system thread.
-      // In .NET, managed threads can supposedly be moved to different system threads
-      // and, more worryingly, even fibers. This should make sure we're sitting on
-      // a normal system thread and stay with that thread during our lifetime.
-      Thread.BeginThreadAffinity();
+      if(Environment.OSVersion.Platform == PlatformID.Win32NT) {
+        // Prevent this managed thread from impersonating another system thread.
+        // In .NET, managed threads can supposedly be moved to different system threads
+        // and, more worryingly, even fibers. This should make sure we're sitting on
+        // a normal system thread and stay with that thread during our lifetime.
+        Thread.BeginThreadAffinity();
 
-      // Assign the ideal processor, but don't force it. It's not a good idea to
-      // circumvent the thread scheduler of a desktop machine, so we try to play nice.
-      int threadId = GetCurrentThreadId();
-      ProcessThread thread = GetProcessThread(threadId);
-      if(thread != null) {
-        thread.IdealProcessor = hardwareThreadIndex;
+        // Assign the ideal processor, but don't force it. It's not a good idea to
+        // circumvent the thread scheduler of a desktop machine, so we try to play nice.
+        int threadId = GetCurrentThreadId();
+        ProcessThread thread = GetProcessThread(threadId);
+        if(thread != null) {
+          thread.IdealProcessor = hardwareThreadIndex;
+        }
       }
 #endif
 
@@ -280,7 +282,7 @@ namespace Nuclex.Support {
     /// <summary>Delegate used to handle assertion checks in the code</summary>
     public static volatile ExceptionDelegate ExceptionHandler = DefaultExceptionHandler;
 
-#if !XBOX360
+#if !XBOX360 // Only called if platform is Win32NT
     /// <summary>Retrieves the calling thread's thread id</summary>
     /// <returns>The thread is of the calling thread</returns>
     [DllImport("kernel32.dll")]

Source/EnumHelper.cs

@@ -70,14 +70,14 @@ namespace Nuclex.Support {
       // Look for the lowest value in the enumeration. We initialize the lowest value
       // to the first enumeration value so we don't have to use some arbitrary starting
       // value which might actually appear in the enumeration.
-      EnumType lowest = values[0];
+      EnumType lowestValue = values[0];
       for(int index = 1; index < values.Length; ++index) {
-        if(values[index].CompareTo(lowest) < 0) {
-          lowest = values[index];
+        if(values[index].CompareTo(lowestValue) < 0) {
+          lowestValue = values[index];
         }
       }
 
-      return lowest;
+      return lowestValue;
     }
 
     /// <summary>Retrieves a list of all values contained in an enumeration</summary>
@@ -85,6 +85,10 @@ namespace Nuclex.Support {
     ///   Type of the enumeration whose values will be returned
     /// </typeparam>
     /// <returns>All values contained in the specified enumeration</returns>
+    /// <remarks>
+    ///   This method produces collectable garbage so it's best to only call it once
+    ///   and cache the result.
+    /// </remarks>
     public static EnumType[] GetValues<EnumType>() {
 #if XBOX360
       return GetValuesXbox360<EnumType>();

Source/Semaphore.cs

@@ -68,7 +68,7 @@ namespace Nuclex.Support {
     ///   Number of users that can access the resource at the same time
     /// </param>
     public Semaphore(int count) {
-      this.users = -count;
+      this.free = count;
 
       createEvent();
     }
@@ -87,7 +87,7 @@ namespace Nuclex.Support {
         );
       }
 
-      this.users = initialCount - maximumCount; // should be negative!
+      this.free = maximumCount - initialCount;
       createEvent();
     }
 
@@ -129,11 +129,11 @@ namespace Nuclex.Support {
 
         // Lock the resource - even if it is full. We will correct out mistake later
         // if we overcomitted the resource.
-        int newUsers = Interlocked.Increment(ref this.users);
+        int newFree = Interlocked.Decrement(ref this.free);
 
         // If we got the resource, let the thread pass without further processing.
-        if(newUsers <= 0) {
-          if(newUsers < 0) {
+        if(newFree >= 0) {
+          if(newFree > 0) {
             this.manualResetEvent.Set();
           }
 
@@ -144,16 +144,17 @@ namespace Nuclex.Support {
         // moments ago, the resource was busy, so block the event.
         this.manualResetEvent.Reset();
         Thread.MemoryBarrier();
-        newUsers = Interlocked.Decrement(ref this.users);
+        newFree = Interlocked.Increment(ref this.free);
 
         // Unless we have been preempted by a Release(), we now have to wait for the
         // resource to become available.
-        if(newUsers >= 0) {
+        if(newFree >= 0) {
           if(!this.manualResetEvent.WaitOne(millisecondsTimeout, exitContext)) {
             return false;
           }
         }
-      }
+
+      } // for(; ; )
     }
 
 #if XBOX360
@@ -198,12 +199,12 @@ namespace Nuclex.Support {
 
     /// <summary>
     ///   Releases a lock on the resource. Note that for a reverse counting semaphore,
-    ///   it is legal to Release() the resource before before locking it.
+    ///   it is legal to Release() the resource before locking it.
     /// </summary>
     public void Release() {
 
       // Release one lock on the resource
-      int newUsers = Interlocked.Decrement(ref this.users);
+      int newFree = Interlocked.Increment(ref this.free);
 
       // Wake up any threads waiting for the resource to become available
       this.manualResetEvent.Set();
@@ -227,7 +228,7 @@ namespace Nuclex.Support {
     ///   Since this is a reverse counting semaphore, it will be negative if
     ///   the resource is available and 0 if the semaphore is full.
     /// </remarks>
-    private int users;
+    private int free;
 
   }