Merge pull request #41 from computablee/bug-fixes

Tidy up sections / performance improvements for sections
computablee · Sep 20, 2023 · 655cd1b · 655cd1b
2 parents 88c0b58 + 4bce611
commit 655cd1b
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Showing 2 changed files with 16 additions and 18 deletions.
diff --git a/DotMP/Parallel.cs b/DotMP/Parallel.cs
@@ -365,6 +365,7 @@ public static void ParallelForReduction<T>(int start, int end, Operations op, re
         public static void Sections(params Action[] actions)
         {
             var freg = new ForkedRegion();
+            bool successful;
 
             if (!freg.in_parallel)
             {
@@ -375,19 +376,13 @@ public static void Sections(params Action[] actions)
 
             Barrier();
 
-            while (sc.actions.Count > 0)
+            do
             {
-                Action do_action;
-
-                lock (sc.actions)
-                {
-                    if (sc.actions.Count > 0)
-                        do_action = sc.actions.Dequeue();
-                    else break;
-                }
+                Action do_action = sc.GetNextItem(out successful);
 
-                do_action();
+                if (successful) do_action();
             }
+            while (successful);
 
             Barrier();
         }

diff --git a/DotMP/Sections.cs b/DotMP/Sections.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 
 namespace DotMP
@@ -14,23 +15,25 @@ internal class SectionsContainer
         /// <summary>
         /// The actions submitted by the individual `section` directives.
         /// </summary>
-        private static Queue<Action> actions_pv;
+        private static ConcurrentBag<Action> actions_pv;
+
         /// <summary>
-        /// Getter for singleton queue SectionsContainer.actions_pv.
+        /// Gets the next item from the actions bag.
         /// </summary>
-        internal Queue<Action> actions
+        /// <param name="successful">Whether or not fetching from the bag was successful.</param>
+        /// <returns>The action pulled from the bag, if successful. If unsuccessful, undefined.</returns>
+        internal Action GetNextItem(out bool successful)
         {
-            get
-            {
-                return actions_pv;
-            }
+            Action action;
+            successful = actions_pv.TryTake(out action);
+            return action;
         }
 
         /// <summary>
         /// Constructor which takes a list of actions and ensures the master thread assigns to SectionsContainer.actions_pv.
         /// </summary>
         /// <param name="actions">The actions that the Parallel.Sections region will perform.</param>
         internal SectionsContainer(IEnumerable<Action> actions) =>
-            Parallel.Master(() => actions_pv = new Queue<Action>(actions));
+            Parallel.Master(() => actions_pv = new ConcurrentBag<Action>(actions));
     }
 }