Merge remote-tracking branch 'refs/remotes/origin/master' into dev-po…

…mma89

CHANGELOG.md

@@ -1,8 +1,10 @@
 # Changelog for CodeProject.ObjectPool #
 
-### v3.0.4 (2017-06-24) ###
+### v3.1.0 (2017-06-24) ###
 
 * Removed dependency on Thrower.
+* Pooled objects can now specify a validation step (PR#4 by uliian).
+* Removed CannotResetStateException class, not needed with new validation step.
 
 ### v3.0.3 (2017-04-08) ###
 

README.md

@@ -5,7 +5,7 @@
 
 ## Summary ##
 
-* Latest release version: `v3.0.4`
+* Latest release version: `v3.1.0`
 * Build status on [AppVeyor](https://ci.appveyor.com): [![Build status](https://ci.appveyor.com/api/projects/status/r4qnqaqj9ri6cicn?svg=true)](https://ci.appveyor.com/project/pomma89/objectpool)
 * [Doxygen](http://www.stack.nl/~dimitri/doxygen/index.html) documentation: 
     + [HTML](http://pomma89.altervista.org/objectpool/doc/html/index.html)

appveyor.yml

@@ -9,7 +9,7 @@
 #---------------------------------#
 
 # version format
-version: 3.0.4.{build}
+version: 3.1.0.{build}
 
 # branches to build
 branches:
@@ -25,7 +25,7 @@ branches:
 assembly_info:
   patch: true
   file: AssemblyInfo.*
-  assembly_version: "3.0.4.{build}"
+  assembly_version: "3.1.0.{build}"
   assembly_file_version: "{version}"
   assembly_informational_version: "{version}"
 

src/CodeProject.ObjectPool/CodeProject.ObjectPool.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <AssemblyName>CodeProject.ObjectPool</AssemblyName>
     <AssemblyTitle>Generic and concurrent Object Pool</AssemblyTitle>
-    <VersionPrefix>3.0.4</VersionPrefix>
+    <VersionPrefix>3.1.0</VersionPrefix>
     <TargetFrameworks>netstandard1.0;netstandard1.3;net35;net40;net45</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyOriginatorKeyFile>../../pomma89.snk</AssemblyOriginatorKeyFile>

src/CodeProject.ObjectPool/Core/CannotResetStateException.cs → src/CodeProject.ObjectPool/Core/PooledObjectDirection.cs

@@ -1,4 +1,4 @@
-// File name: CannotResetStateException.cs
+// File name: PooledObjectDirection.cs
 //
 // Author(s): Alessio Parma <alessio.parma@gmail.com>
 //
@@ -21,23 +21,21 @@
 // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
 // OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-using System;
-
 namespace CodeProject.ObjectPool.Core
 {
     /// <summary>
-    ///   This exception can be used to signal that the object whose state is being reset cannot be
-    ///   added back to the pool for some reason.
+    ///   Direction of a pooled object.
     /// </summary>
-    public sealed class CannotResetStateException : Exception
+    public enum PooledObjectDirection
     {
         /// <summary>
-        ///   Builds the exception using given message.
+        ///   An object is returning to the pool.
+        /// </summary>
+        Inbound,
+
+        /// <summary>
+        ///   An object is getting out of the pool.
         /// </summary>
-        /// <param name="message">The message.</param>
-        public CannotResetStateException(string message)
-            : base(message)
-        {
-        }
+        Outbound
     }
 }

src/CodeProject.ObjectPool/Core/PooledObjectValidationContext.cs

@@ -0,0 +1,52 @@
+// File name: PooledObjectValidationContext.cs
+//
+// Author(s): Alessio Parma <alessio.parma@gmail.com>
+//
+// The MIT License (MIT)
+//
+// Copyright (c) 2013-2018 Alessio Parma <alessio.parma@gmail.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+// associated documentation files (the "Software"), to deal in the Software without restriction,
+// including without limitation the rights to use, copy, modify, merge, publish, distribute,
+// sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+// NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+// OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+namespace CodeProject.ObjectPool.Core
+{
+    /// <summary>
+    ///   Contains additional info which might be useful when performing an object validation step.
+    /// </summary>
+    public sealed class PooledObjectValidationContext
+    {
+        /// <summary>
+        ///   Used when an object is returning to the pool.
+        /// </summary>
+        internal static PooledObjectValidationContext Inbound { get; } = new PooledObjectValidationContext
+        {
+            Direction = PooledObjectDirection.Inbound
+        };
+
+        /// <summary>
+        ///   Used when an object is going out of the pool.
+        /// </summary>
+        internal static PooledObjectValidationContext Outbound { get; } = new PooledObjectValidationContext
+        {
+            Direction = PooledObjectDirection.Outbound
+        };
+
+        /// <summary>
+        ///   Whether an object is going out of the pool or into the pool.
+        /// </summary>
+        public PooledObjectDirection Direction { get; private set; }
+    }
+}

src/CodeProject.ObjectPool/ObjectPool.cs

@@ -176,24 +176,30 @@ public void Clear()
         /// <returns>A monitored object from the pool.</returns>
         public T GetObject()
         {
-            if (PooledObjects.TryDequeue(out T pooledObject))
+            while (true)
             {
-                // Object found in pool.
-                if (Diagnostics.Enabled) Diagnostics.IncrementPoolObjectHitCount();
-            }
-            else
-            {
-                // This should not happen normally, but could be happening when there is stress on
-                // the pool. No available objects in pool, create a new one and return it to the caller.
-                if (Diagnostics.Enabled) Diagnostics.IncrementPoolObjectMissCount();
-                pooledObject = CreatePooledObject();
-            }
-
-            // Change the state of the pooled object, marking it as reserved. We will mark it as
-            // available as soon as the object will return to the pool.
-            pooledObject.PooledObjectInfo.State = PooledObjectState.Reserved;
+                if (PooledObjects.TryDequeue(out T pooledObject))
+                {
+                    // Object found in pool.
+                    if (Diagnostics.Enabled) Diagnostics.IncrementPoolObjectHitCount();
+                }
+                else
+                {
+                    // This should not happen normally, but could be happening when there is stress
+                    // on the pool. No available objects in pool, create a new one and return it to
+                    // the caller.
+                    if (Diagnostics.Enabled) Diagnostics.IncrementPoolObjectMissCount();
+                    pooledObject = CreatePooledObject();
+                }
+                if (pooledObject.ValidateObject(PooledObjectValidationContext.Outbound))
+                {
+                    // Change the state of the pooled object, marking it as reserved. We will mark it
+                    // as available as soon as the object will return to the pool.
+                    pooledObject.PooledObjectInfo.State = PooledObjectState.Reserved;
 
-            return pooledObject;
+                    return pooledObject;
+                }
+            }
         }
 
         void IObjectPoolHandle.ReturnObjectToPool(PooledObject objectToReturnToPool, bool reRegisterForFinalization)

src/CodeProject.ObjectPool/PooledObject.cs

@@ -10,7 +10,6 @@
 
 using CodeProject.ObjectPool.Core;
 using System;
-using System.Collections.Generic;
 
 #if !NET35
 
@@ -48,15 +47,40 @@ public abstract class PooledObject : IDisposable, IEquatable<PooledObject>
 
         #region Internal Methods - resource and state management
 
+        /// <summary>
+        ///   Validates pooled object state. An invalid object will not get into the pool and it will
+        ///   not be returned to consumers.
+        /// </summary>
+        /// <param name="validationContext">The validation context.</param>
+        /// <returns>True if current pooled object is valid, false otherwise.</returns>
+        internal bool ValidateObject(PooledObjectValidationContext validationContext)
+        {
+            if (OnValidateObject != null)
+            {
+                try
+                {
+                    return OnValidateObject(validationContext);
+                }
+                catch (Exception ex)
+                {
+#if !NET35
+                    if (Log.IsWarnEnabled()) Log.WarnException("[ObjectPool] An unexpected error occurred while validating an object", ex);
+#else
+                    System.Diagnostics.Debug.Assert(ex != null); // Placeholder to avoid warnings
+#endif
+                    return false;
+                }
+            }
+            return true;
+        }
+
         /// <summary>
         ///   Releases the object resources. This method will be called by the pool manager when
         ///   there is no need for this object anymore (decreasing pooled objects count, pool is
         ///   being destroyed).
         /// </summary>
         internal bool ReleaseResources()
         {
-            var successFlag = true;
-
             if (OnReleaseResources != null)
             {
                 try
@@ -66,18 +90,14 @@ internal bool ReleaseResources()
                 catch (Exception ex)
                 {
 #if !NET35
-                    if (Log.IsWarnEnabled())
-                    {
-                        Log.WarnException("[ObjectPool] An unexpected error occurred while releasing resources", ex);
-                    }
+                    if (Log.IsWarnEnabled()) Log.WarnException("[ObjectPool] An unexpected error occurred while releasing resources", ex);
 #else
                     System.Diagnostics.Debug.Assert(ex != null); // Placeholder to avoid warnings
 #endif
-                    successFlag = false;
+                    return false;
                 }
             }
-
-            return successFlag;
+            return true;
         }
 
         /// <summary>
@@ -86,47 +106,39 @@ internal bool ReleaseResources()
         /// </summary>
         internal bool ResetState()
         {
-            var successFlag = true;
-
+            if (!ValidateObject(PooledObjectValidationContext.Inbound))
+            {
+                return false;
+            }
             if (OnResetState != null)
             {
                 try
                 {
                     OnResetState();
                 }
-                catch (CannotResetStateException crsex)
-                {
-#if !NET35
-                    if (Log.IsDebugEnabled())
-                    {
-                        Log.DebugException("[ObjectPool] Object state could not be reset", crsex);
-                    }
-#else
-                    System.Diagnostics.Debug.Assert(crsex != null); // Placeholder to avoid warnings
-#endif
-                    successFlag = false;
-                }
                 catch (Exception ex)
                 {
 #if !NET35
-                    if (Log.IsWarnEnabled())
-                    {
-                        Log.WarnException("[ObjectPool] An unexpected error occurred while resetting state", ex);
-                    }
+                    if (Log.IsWarnEnabled()) Log.WarnException("[ObjectPool] An unexpected error occurred while resetting state", ex);
 #else
                     System.Diagnostics.Debug.Assert(ex != null); // Placeholder to avoid warnings
 #endif
-                    successFlag = false;
+                    return false;
                 }
             }
-
-            return successFlag;
+            return true;
         }
 
         #endregion Internal Methods - resource and state management
 
         #region Events - extending resource and state management
 
+        /// <summary>
+        ///   Validates pooled object state. An invalid object will not get into the pool and it will
+        ///   not be returned to consumers.
+        /// </summary>
+        public Func<PooledObjectValidationContext, bool> OnValidateObject { get; set; }
+
         /// <summary>
         ///   Reset the object state to allow this object to be re-used by other parts of the application.
         /// </summary>
@@ -167,10 +179,7 @@ private void HandleReAddingToPool(bool reRegisterForFinalization)
             catch (Exception ex)
             {
 #if !NET35
-                if (Log.IsWarnEnabled())
-                {
-                    Log.WarnException("[ObjectPool] An error occurred while re-adding to pool", ex);
-                }
+                if (Log.IsWarnEnabled()) Log.WarnException("[ObjectPool] An error occurred while re-adding to pool", ex);
 #else
                 System.Diagnostics.Debug.Assert(ex != null); // Placeholder to avoid warnings
 #endif