Prototype of gRPC C# library (Core and API examples)

1 files changed, 129 insertions, 0 deletions

diff --git a/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs b/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs
new file mode 100644
index 0000000000..1139e54a1d
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+++ b/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs
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+using System;
+using Google.GRPC.Core.Internal;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Collections.Generic;
+
+namespace Google.GRPC.Core.Internal
+{
+    /// <summary>
+    /// Pool of threads polling on the same completion queue.
+    /// </summary>
+    internal class GrpcThreadPool
+    {
+        readonly object myLock = new object();
+        readonly List<Thread> threads = new List<Thread>();
+        readonly int poolSize;
+        readonly Action<EventSafeHandle> eventHandler;
+
+        CompletionQueueSafeHandle cq;
+
+        public GrpcThreadPool(int poolSize) {
+            this.poolSize = poolSize;
+        }
+
+        internal GrpcThreadPool(int poolSize, Action<EventSafeHandle> eventHandler) {
+            this.poolSize = poolSize;
+            this.eventHandler = eventHandler;
+        }
+
+        public void Start() {
+
+            lock (myLock)
+            {
+                if (cq != null)
+                {
+                    throw new InvalidOperationException("Already started.");
+                }
+
+                cq = CompletionQueueSafeHandle.Create();
+
+                for (int i = 0; i < poolSize; i++)
+                {
+                    threads.Add(CreateAndStartThread(i));
+                }
+            }
+        }
+
+        public void Stop() {
+
+            lock (myLock)
+            {
+                cq.Shutdown();
+
+                Console.WriteLine("Waiting for GPRC threads to finish.");
+                foreach (var thread in threads)
+                {
+                    thread.Join();
+                }
+
+                cq.Dispose();
+
+            }
+        }
+
+        internal CompletionQueueSafeHandle CompletionQueue
+        {
+            get
+            {
+                return cq;
+            }
+        }
+
+        private Thread CreateAndStartThread(int i) {
+            Action body;
+            if (eventHandler != null)
+            {
+                body = ThreadBodyWithHandler;
+            }
+            else
+            {
+                body = ThreadBodyNoHandler;
+            }
+            var thread = new Thread(new ThreadStart(body));
+            thread.IsBackground = false;
+            thread.Start();
+            if (eventHandler != null)
+            {
+                thread.Name = "grpc_server_newrpc " + i;
+            }
+            else
+            {
+                thread.Name = "grpc " + i;
+            }
+            return thread;
+        }
+
+        /// <summary>
+        /// Body of the polling thread.
+        /// </summary>
+        private void ThreadBodyNoHandler()
+        {
+            GRPCCompletionType completionType;
+            do
+            {
+                completionType = cq.NextWithCallback();
+            } while(completionType != GRPCCompletionType.GRPC_QUEUE_SHUTDOWN);
+            Console.WriteLine("Completion queue has shutdown successfully, thread " + Thread.CurrentThread.Name + " exiting.");
+        }
+
+        /// <summary>
+        /// Body of the polling thread.
+        /// </summary>
+        private void ThreadBodyWithHandler()
+        {
+            GRPCCompletionType completionType;
+            do
+            {
+                using (EventSafeHandle ev = cq.Next(Timespec.InfFuture)) {
+                    completionType = ev.GetCompletionType();
+                    eventHandler(ev);
+                }
+            } while(completionType != GRPCCompletionType.GRPC_QUEUE_SHUTDOWN);
+            Console.WriteLine("Completion queue has shutdown successfully, thread " + Thread.CurrentThread.Name + " exiting.");
+        }
+    }
+
+}
+