Initial checkin of gRPC to third_party/

third_party/grpc/src/csharp/Grpc.Core/GrpcEnvironment.cs

+#region Copyright notice and license
+
+// Copyright 2015-2016, Google Inc.
+// All rights reserved.
+//
+// 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 Google Inc. 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "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 COPYRIGHT
+// OWNER OR 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.
+
+#endregion
+
+using System;
+using System.Runtime.InteropServices;
+using System.Threading.Tasks;
+using Grpc.Core.Internal;
+using Grpc.Core.Logging;
+using Grpc.Core.Utils;
+
+namespace Grpc.Core
+{
+    /// <summary>
+    /// Encapsulates initialization and shutdown of gRPC library.
+    /// </summary>
+    public class GrpcEnvironment
+    {
+        const int THREAD_POOL_SIZE = 4;
+
+        static object staticLock = new object();
+        static GrpcEnvironment instance;
+        static int refCount;
+
+        static ILogger logger = new ConsoleLogger();
+
+        readonly GrpcThreadPool threadPool;
+        readonly CompletionRegistry completionRegistry;
+        readonly DebugStats debugStats = new DebugStats();
+        bool isClosed;
+
+        /// <summary>
+        /// Returns a reference-counted instance of initialized gRPC environment.
+        /// Subsequent invocations return the same instance unless reference count has dropped to zero previously.
+        /// </summary>
+        internal static GrpcEnvironment AddRef()
+        {
+            lock (staticLock)
+            {
+                refCount++;
+                if (instance == null)
+                {
+                    instance = new GrpcEnvironment();
+                }
+                return instance;
+            }
+        }
+
+        /// <summary>
+        /// Decrements the reference count for currently active environment and shuts down the gRPC environment if reference count drops to zero.
+        /// (and blocks until the environment has been fully shutdown).
+        /// </summary>
+        internal static void Release()
+        {
+            lock (staticLock)
+            {
+                GrpcPreconditions.CheckState(refCount > 0);
+                refCount--;
+                if (refCount == 0)
+                {
+                    instance.Close();
+                    instance = null;
+                }
+            }
+        }
+
+        internal static int GetRefCount()
+        {
+            lock (staticLock)
+            {
+                return refCount;
+            }
+        }
+
+        /// <summary>
+        /// Gets application-wide logger used by gRPC.
+        /// </summary>
+        /// <value>The logger.</value>
+        public static ILogger Logger
+        {
+            get
+            {
+                return logger;
+            }
+        }
+
+        /// <summary>
+        /// Sets the application-wide logger that should be used by gRPC.
+        /// </summary>
+        public static void SetLogger(ILogger customLogger)
+        {
+            GrpcPreconditions.CheckNotNull(customLogger, "customLogger");
+            logger = customLogger;
+        }
+
+        /// <summary>
+        /// Creates gRPC environment.
+        /// </summary>
+        private GrpcEnvironment()
+        {
+            GrpcNativeInit();
+            completionRegistry = new CompletionRegistry(this);
+            threadPool = new GrpcThreadPool(this, THREAD_POOL_SIZE);
+            threadPool.Start();
+        }
+
+        /// <summary>
+        /// Gets the completion registry used by this gRPC environment.
+        /// </summary>
+        internal CompletionRegistry CompletionRegistry
+        {
+            get
+            {
+                return this.completionRegistry;
+            }
+        }
+
+        /// <summary>
+        /// Gets the completion queue used by this gRPC environment.
+        /// </summary>
+        internal CompletionQueueSafeHandle CompletionQueue
+        {
+            get
+            {
+                return this.threadPool.CompletionQueue;
+            }
+        }
+
+        /// <summary>
+        /// Gets the completion queue used by this gRPC environment.
+        /// </summary>
+        internal DebugStats DebugStats
+        {
+            get
+            {
+                return this.debugStats;
+            }
+        }
+
+        /// <summary>
+        /// Gets version of gRPC C core.
+        /// </summary>
+        internal static string GetCoreVersionString()
+        {
+            var ptr = NativeMethods.Get().grpcsharp_version_string();  // the pointer is not owned
+            return Marshal.PtrToStringAnsi(ptr);
+        }
+
+        internal static void GrpcNativeInit()
+        {
+            NativeMethods.Get().grpcsharp_init();
+        }
+
+        internal static void GrpcNativeShutdown()
+        {
+            NativeMethods.Get().grpcsharp_shutdown();
+        }
+
+        /// <summary>
+        /// Shuts down this environment.
+        /// </summary>
+        private void Close()
+        {
+            if (isClosed)
+            {
+                throw new InvalidOperationException("Close has already been called");
+            }
+            threadPool.Stop();
+            GrpcNativeShutdown();
+            isClosed = true;
+
+            debugStats.CheckOK();
+        }
+    }
+}