1 files changed, 207 insertions, 0 deletions

diff --git a/OpenSim/Framework/Parallel.cs b/OpenSim/Framework/Parallel.cs
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+++ b/OpenSim/Framework/Parallel.cs
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+
+namespace OpenSim.Framework
+{
+    /// <summary>
+    /// Provides helper methods for parallelizing loops
+    /// </summary>
+    public static class Parallel
+    {
+        private static readonly int processorCount = System.Environment.ProcessorCount;
+
+        /// <summary>
+        /// Executes a for loop in which iterations may run in parallel
+        /// </summary>
+        /// <param name="fromInclusive">The loop will be started at this index</param>
+        /// <param name="toExclusive">The loop will be terminated before this index is reached</param>
+        /// <param name="body">Method body to run for each iteration of the loop</param>
+        public static void For(int fromInclusive, int toExclusive, Action<int> body)
+        {
+            For(processorCount, fromInclusive, toExclusive, body);
+        }
+
+        /// <summary>
+        /// Executes a for loop in which iterations may run in parallel
+        /// </summary>
+        /// <param name="threadCount">The number of concurrent execution threads to run</param>
+        /// <param name="fromInclusive">The loop will be started at this index</param>
+        /// <param name="toExclusive">The loop will be terminated before this index is reached</param>
+        /// <param name="body">Method body to run for each iteration of the loop</param>
+        public static void For(int threadCount, int fromInclusive, int toExclusive, Action<int> body)
+        {
+            int counter = threadCount;
+            AutoResetEvent threadFinishEvent = new AutoResetEvent(false);
+            Exception exception = null;
+
+            --fromInclusive;
+
+            for (int i = 0; i < threadCount; i++)
+            {
+                ThreadPool.QueueUserWorkItem(
+                    delegate(object o)
+                    {
+                        int threadIndex = (int)o;
+
+                        while (exception == null)
+                        {
+                            int currentIndex = Interlocked.Increment(ref fromInclusive);
+
+                            if (currentIndex >= toExclusive)
+                                break;
+
+                            try { body(currentIndex); }
+                            catch (Exception ex) { exception = ex; break; }
+                        }
+
+                        if (Interlocked.Decrement(ref counter) == 0)
+                            threadFinishEvent.Set();
+                    }, i
+                );
+            }
+
+            threadFinishEvent.WaitOne();
+
+            if (exception != null)
+                throw new Exception(exception.Message, exception);
+        }
+
+        /// <summary>
+        /// Executes a foreach loop in which iterations may run in parallel
+        /// </summary>
+        /// <typeparam name="T">Object type that the collection wraps</typeparam>
+        /// <param name="enumerable">An enumerable collection to iterate over</param>
+        /// <param name="body">Method body to run for each object in the collection</param>
+        public static void ForEach<T>(IEnumerable<T> enumerable, Action<T> body)
+        {
+            ForEach<T>(processorCount, enumerable, body);
+        }
+
+        /// <summary>
+        /// Executes a foreach loop in which iterations may run in parallel
+        /// </summary>
+        /// <typeparam name="T">Object type that the collection wraps</typeparam>
+        /// <param name="threadCount">The number of concurrent execution threads to run</param>
+        /// <param name="enumerable">An enumerable collection to iterate over</param>
+        /// <param name="body">Method body to run for each object in the collection</param>
+        public static void ForEach<T>(int threadCount, IEnumerable<T> enumerable, Action<T> body)
+        {
+            int counter = threadCount;
+            AutoResetEvent threadFinishEvent = new AutoResetEvent(false);
+            IEnumerator<T> enumerator = enumerable.GetEnumerator();
+            Exception exception = null;
+
+            for (int i = 0; i < threadCount; i++)
+            {
+                ThreadPool.QueueUserWorkItem(
+                    delegate(object o)
+                    {
+                        int threadIndex = (int)o;
+
+                        while (exception == null)
+                        {
+                            T entry;
+
+                            lock (enumerator)
+                            {
+                                if (!enumerator.MoveNext())
+                                    break;
+                                entry = (T)enumerator.Current; // Explicit typecast for Mono's sake
+                            }
+
+                            try { body(entry); }
+                            catch (Exception ex) { exception = ex; break; }
+                        }
+
+                        if (Interlocked.Decrement(ref counter) == 0)
+                            threadFinishEvent.Set();
+                    }, i
+                );
+            }
+
+            threadFinishEvent.WaitOne();
+
+            if (exception != null)
+                throw new Exception(exception.Message, exception);
+        }
+
+        /// <summary>
+        /// Executes a series of tasks in parallel
+        /// </summary>
+        /// <param name="actions">A series of method bodies to execute</param>
+        public static void Invoke(params Action[] actions)
+        {
+            Invoke(processorCount, actions);
+        }
+
+        /// <summary>
+        /// Executes a series of tasks in parallel
+        /// </summary>
+        /// <param name="threadCount">The number of concurrent execution threads to run</param>
+        /// <param name="actions">A series of method bodies to execute</param>
+        public static void Invoke(int threadCount, params Action[] actions)
+        {
+            int counter = threadCount;
+            AutoResetEvent threadFinishEvent = new AutoResetEvent(false);
+            int index = -1;
+            Exception exception = null;
+
+            for (int i = 0; i < threadCount; i++)
+            {
+                ThreadPool.QueueUserWorkItem(
+                    delegate(object o)
+                    {
+                        int threadIndex = (int)o;
+
+                        while (exception == null)
+                        {
+                            int currentIndex = Interlocked.Increment(ref index);
+
+                            if (currentIndex >= actions.Length)
+                                break;
+
+                            try { actions[currentIndex](); }
+                            catch (Exception ex) { exception = ex; break; }
+                        }
+
+                        if (Interlocked.Decrement(ref counter) == 0)
+                            threadFinishEvent.Set();
+                    }, i
+                );
+            }
+
+            threadFinishEvent.WaitOne();
+
+            if (exception != null)
+                throw new Exception(exception.Message, exception);
+        }
+    }
+}