# HG changeset patch
# User cin
# Date 1425645926 -10800
# Node ID 8c0b950690662b1cca3deaae264076e8861258ed
# Parent  16f926ee499d91fae9e74e4799b33bc37a8c4086
DRAFT: refactoring

diff -r 16f926ee499d -r 8c0b95069066 Implab/AbstractEvent.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/AbstractEvent.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,350 @@
+using System;
+using Implab.Parallels;
+using System.Threading;
+using System.Reflection;
+
+namespace Implab {
+    public abstract class AbstractEvent<THandler> : ICancelationToken, ICancellable { 
+
+        const int UNRESOLVED_SATE = 0;
+        const int TRANSITIONAL_STATE = 1;
+        const int SUCCEEDED_STATE = 2;
+        const int REJECTED_STATE = 3;
+        const int CANCELLED_STATE = 4;
+
+        const int CANCEL_NOT_REQUESTED = 0;
+        const int CANCEL_REQUESTING = 1;
+        const int CANCEL_REQUESTED = 2;
+
+        const int RESERVED_HANDLERS_COUNT = 4;
+
+        int m_state;
+        Exception m_error;
+        int m_handlersCount;
+
+        readonly THandler[] m_handlers = new THandler[RESERVED_HANDLERS_COUNT];
+        MTQueue<THandler> m_extraHandlers;
+        int m_handlerPointer = -1;
+        int m_handlersCommited;
+
+        int m_cancelRequest;
+        Exception m_cancelationReason;
+        MTQueue<Action<Exception>> m_cancelationHandlers;
+
+
+        #region state managment
+        bool BeginTransit() {
+            return UNRESOLVED_SATE == Interlocked.CompareExchange(ref m_state, TRANSITIONAL_STATE, UNRESOLVED_SATE);
+        }
+
+        void CompleteTransit(int state) {
+            if (TRANSITIONAL_STATE != Interlocked.CompareExchange(ref m_state, state, TRANSITIONAL_STATE))
+                throw new InvalidOperationException("Can't complete transition when the object isn't in the transitional state");
+        }
+
+        void WaitTransition() {
+            while (m_state == TRANSITIONAL_STATE) {
+                Thread.MemoryBarrier();
+            }
+        }
+
+        protected bool BeginSetResult() {
+            if (!BeginTransit()) {
+                WaitTransition();
+                if (m_state != CANCELLED_STATE)
+                    throw new InvalidOperationException("The promise is already resolved");
+                return false;
+            }
+            return true;
+        }
+
+        protected void EndSetResult() {
+            CompleteTransit(SUCCEEDED_STATE);
+            OnSuccess();
+        }
+
+
+
+        /// <summary>
+        /// Выполняет обещание, сообщая об ошибке
+        /// </summary>
+        /// <remarks>
+        /// Поскольку обещание должно работать в многопточной среде, при его выполнении сразу несколько потоков
+        /// могу вернуть ошибку, при этом только первая будет использована в качестве результата, остальные
+        /// будут проигнорированы.
+        /// </remarks>
+        /// <param name="error">Исключение возникшее при выполнении операции</param>
+        /// <exception cref="InvalidOperationException">Данное обещание уже выполнено</exception>
+        protected void SetError(Exception error) {
+            if (BeginTransit()) {
+                if (error is OperationCanceledException) {
+                    CompleteTransit(CANCELLED_STATE);
+                    m_error = error.InnerException;
+                    OnCancelled();
+                } else {
+                    m_error = error is PromiseTransientException ? error.InnerException : error;
+                    CompleteTransit(REJECTED_STATE);
+                    OnError();
+                }
+            } else {
+                WaitTransition();
+                if (m_state == SUCCEEDED_STATE)
+                    throw new InvalidOperationException("The promise is already resolved");
+            }
+        }
+
+        /// <summary>
+        /// Отменяет операцию, если это возможно.
+        /// </summary>
+        /// <remarks>Для определения была ли операция отменена следует использовать свойство <see cref="IsCancelled"/>.</remarks>
+        protected void SetCancelled(Exception reason) {
+            if (BeginTransit()) {
+                m_error = reason;
+                CompleteTransit(CANCELLED_STATE);
+                OnCancelled();
+            }
+        }
+
+        protected abstract void SignalSuccess(THandler handler);
+
+        protected abstract void SignalError(THandler handler, Exception error);
+
+        protected abstract void SignalCancelled(THandler handler, Exception reason);
+
+        void OnSuccess() {
+            var hp = m_handlerPointer;
+            var slot = hp +1 ;
+            while (slot < m_handlersCommited) {
+                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
+                    SignalSuccess(m_handlers[slot]);
+                }
+                hp = m_handlerPointer;
+                slot = hp +1 ;
+            }
+
+
+            if (m_extraHandlers != null) {
+                THandler handler;
+                while (m_extraHandlers.TryDequeue(out handler))
+                    SignalSuccess(handler);
+            }
+        }
+
+        void OnError() {
+            var hp = m_handlerPointer;
+            var slot = hp +1 ;
+            while (slot < m_handlersCommited) {
+                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
+                    SignalError(m_handlers[slot],m_error);
+                }
+                hp = m_handlerPointer;
+                slot = hp +1 ;
+            }
+
+            if (m_extraHandlers != null) {
+                THandler handler;
+                while (m_extraHandlers.TryDequeue(out handler))
+                    SignalError(handler, m_error);
+            }
+        }
+
+        void OnCancelled() {
+            var hp = m_handlerPointer;
+            var slot = hp +1 ;
+            while (slot < m_handlersCommited) {
+                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
+                    SignalCancelled(m_handlers[slot], m_error);
+                }
+                hp = m_handlerPointer;
+                slot = hp +1 ;
+            }
+
+            if (m_extraHandlers != null) {
+                THandler handler;
+                while (m_extraHandlers.TryDequeue(out handler))
+                    SignalCancelled(handler, m_error);
+            }
+        }
+
+        #endregion
+
+        protected abstract Signal GetResolveSignal();
+
+        #region synchronization traits
+        protected void WaitResult(int timeout) {
+            if (!IsResolved)
+                GetResolveSignal().Wait(timeout);
+
+            switch (m_state) {
+                case SUCCEEDED_STATE:
+                    return;
+                case CANCELLED_STATE:
+                    throw new OperationCanceledException();
+                case REJECTED_STATE:
+                    throw new TargetInvocationException(m_error);
+                default:
+                    throw new ApplicationException(String.Format("Invalid promise state {0}", m_state));
+            }
+        }
+        #endregion
+
+        #region handlers managment
+
+        protected void AddHandler(THandler handler) {
+
+            if (m_state > 1) {
+                // the promise is in the resolved state, just invoke the handler
+                InvokeHandler(handler);
+            } else {
+                var slot = Interlocked.Increment(ref m_handlersCount) - 1;
+
+                if (slot < RESERVED_HANDLERS_COUNT) {
+
+                    m_handlers[slot] = handler;
+
+                    while (slot != Interlocked.CompareExchange(ref m_handlersCommited, slot + 1, slot)) {
+                    }
+
+                    if (m_state > 1) {
+                        do {
+                            var hp = m_handlerPointer;
+                            slot = hp + 1;
+                            if (slot < m_handlersCommited) {
+                                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) != hp)
+                                    continue;
+                                InvokeHandler(m_handlers[slot]);
+                            }
+                            break;
+                        } while(true);
+                    }
+                } else {
+                    if (slot == RESERVED_HANDLERS_COUNT) {
+                        m_extraHandlers = new MTQueue<THandler>();
+                    } else {
+                        while (m_extraHandlers == null)
+                            Thread.MemoryBarrier();
+                    }
+
+                    m_extraHandlers.Enqueue(handler);
+
+                    if (m_state > 1 && m_extraHandlers.TryDequeue(out handler))
+                    // if the promise have been resolved while we was adding the handler to the queue
+                    // we can't guarantee that someone is still processing it
+                    // therefore we need to fetch a handler from the queue and execute it
+                    // note that fetched handler may be not the one that we have added
+                    // even we can fetch no handlers at all :)
+                    InvokeHandler(handler);
+                }
+            }
+        }
+
+        protected void InvokeHandler(THandler handler) {
+            switch (m_state) {
+                case SUCCEEDED_STATE:
+                    SignalSuccess(handler);
+                    break;
+                case CANCELLED_STATE:
+                    SignalCancelled(handler, m_error);
+                    break;
+                case REJECTED_STATE:
+                    SignalError(handler, m_error);
+                    break;
+                default:
+                    throw new Exception(String.Format("Invalid promise state {0}", m_state));
+            }
+        }
+
+        #endregion
+
+        #region IPromise implementation
+
+        public bool IsResolved {
+            get {
+                Thread.MemoryBarrier();
+                return m_state > 1;
+            }
+        }
+
+        public bool IsCancelled {
+            get {
+                Thread.MemoryBarrier();
+                return m_state == CANCELLED_STATE;
+            }
+        }
+
+        #endregion
+
+        public Exception Error {
+            get {
+                return m_error;
+            }
+        }
+
+        public bool AcceptIfRequested() {
+            if (IsCancelRequested)
+                CancelOperation(CancelReason);
+        }
+
+        public virtual void CancelOperation(Exception reason) {
+            SetCancelled(reason);
+        }
+
+        public void CancelationRequested(Action<Exception> handler) {
+            Safe.ArgumentNotNull(handler, "handler");
+            if (IsCancelRequested)
+                handler(CancelReason);
+
+            if (m_cancelationHandlers == null)
+                Interlocked.CompareExchange(ref m_cancelationHandlers, new MTQueue<Action<Exception>>(), null);
+
+            m_cancelationHandlers.Enqueue(handler);
+
+            if (IsCancelRequested && m_cancelationHandlers.TryDequeue(out handler))
+                // TryDeque implies MemoryBarrier()
+                handler(m_cancelationReason);
+        }
+
+        public bool IsCancelRequested {
+            get {
+                do {
+                    if (m_cancelRequest == CANCEL_NOT_REQUESTED)
+                        return false;
+                    if (m_cancelRequest == CANCEL_REQUESTED)
+                        return true;
+                    Thread.MemoryBarrier();
+                } while(true);
+            }
+        }
+
+        public Exception CancelReason {
+            get {
+                do {
+                    Thread.MemoryBarrier();
+                } while(m_cancelRequest == CANCEL_REQUESTING);
+
+                return m_cancelationReason;
+            }
+        }
+
+        #region ICancellable implementation
+
+        public void Cancel() {
+            Cancel(null);
+        }
+
+        public void Cancel(Exception reason) {
+            if (CANCEL_NOT_REQUESTED == Interlocked.CompareExchange(ref m_cancelRequest, CANCEL_REQUESTING)) {
+                m_cancelationReason = reason;
+                m_cancelRequest = CANCEL_REQUESTED;
+                if (m_cancelationHandlers != null) {
+                    Action<Exception> handler;
+                    while (m_cancelationHandlers.TryDequeue(out handler))
+                        handler(m_cancelationReason);
+                }
+            }
+        }
+
+        #endregion
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/AbstractPromise.cs
--- a/Implab/AbstractPromise.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/AbstractPromise.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -1,295 +1,135 @@
 using System;
 using Implab.Parallels;
-using System.Threading;
-using System.Reflection;
 
 namespace Implab {
-    public abstract class AbstractPromise<THandler> { 
+    public abstract class AbstractPromise : AbstractEvent<AbstractPromise.HandlerDescriptor>, IPromise {
+        public struct HandlerDescriptor {
+            readonly Action m_handler;
+            readonly Action<Exception> m_error;
+            readonly Action<Exception> m_cancel;
+            readonly PromiseEventType m_mask;
 
-        const int UNRESOLVED_SATE = 0;
-        const int TRANSITIONAL_STATE = 1;
-        const int SUCCEEDED_STATE = 2;
-        const int REJECTED_STATE = 3;
-        const int CANCELLED_STATE = 4;
-
-        const int RESERVED_HANDLERS_COUNT = 4;
+            public HandlerDescriptor(Action success, Action<Exception> error, Action<Exception> cancel) {
+                m_handler = success;
+                m_error = error;
+                m_cancel = cancel;
+                m_mask = PromiseEventType.Success;
+            }
 
-        int m_state;
-        Exception m_error;
-        int m_handlersCount;
+            public HandlerDescriptor(Action handler, PromiseEventType mask) {
+                m_handler = handler;
+                m_mask = mask;
+            }
 
-        readonly THandler[] m_handlers = new THandler[RESERVED_HANDLERS_COUNT];
-        MTQueue<THandler> m_extraHandlers;
-        int m_handlerPointer = -1;
-        int m_handlersCommited;
-
-        #region state managment
-        bool BeginTransit() {
-            return UNRESOLVED_SATE == Interlocked.CompareExchange(ref m_state, TRANSITIONAL_STATE, UNRESOLVED_SATE);
-        }
+            public void SignalSuccess() {
+                if (m_mask & PromiseEventType.Success && m_handler != null) {
+                    try {
+                        m_handler();
+                    } catch (Exception err) {
+                        // avoid calling handler twice in case of error
+                        if (m_error != null)
+                            SignalError(err);
+                    }
+                }
+            }
 
-        void CompleteTransit(int state) {
-            if (TRANSITIONAL_STATE != Interlocked.CompareExchange(ref m_state, state, TRANSITIONAL_STATE))
-                throw new InvalidOperationException("Can't complete transition when the object isn't in the transitional state");
-        }
-
-        void WaitTransition() {
-            while (m_state == TRANSITIONAL_STATE) {
-                Thread.MemoryBarrier();
+            public void SignalError(Exception err) {
+                if (m_error != null) {
+                    try {
+                        m_error(err);
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                } else if (m_mask & PromiseEventType.Error && m_handler != null) {
+                    try {
+                        m_handler();
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                }
             }
-        }
 
-        protected bool BeginSetResult() {
-            if (!BeginTransit()) {
-                WaitTransition();
-                if (m_state != CANCELLED_STATE)
-                    throw new InvalidOperationException("The promise is already resolved");
-                return false;
+            public void SignalCancel(Exception reason) {
+                if (m_cancel != null) {
+                    try {
+                        m_cancel(reason);
+                    } catch (Exception err) {
+                        SignalError(err);
+                    }
+                } else if (m_mask & PromiseEventType.Cancelled && m_handler != null) {
+                    try {
+                        m_handler();
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                }
             }
-            return true;
-        }
-
-        protected void EndSetResult() {
-            CompleteTransit(SUCCEEDED_STATE);
-            OnSuccess();
         }
 
 
+        #region implemented abstract members of AbstractPromise
 
-        /// <summary>
-        /// Выполняет обещание, сообщая об ошибке
-        /// </summary>
-        /// <remarks>
-        /// Поскольку обещание должно работать в многопточной среде, при его выполнении сразу несколько потоков
-        /// могу вернуть ошибку, при этом только первая будет использована в качестве результата, остальные
-        /// будут проигнорированы.
-        /// </remarks>
-        /// <param name="error">Исключение возникшее при выполнении операции</param>
-        /// <exception cref="InvalidOperationException">Данное обещание уже выполнено</exception>
-        protected void SetError(Exception error) {
-            if (BeginTransit()) {
-                if (error is OperationCanceledException) {
-                    CompleteTransit(CANCELLED_STATE);
-                    m_error = error.InnerException;
-                    OnCancelled();
-                } else {
-                    m_error = error is PromiseTransientException ? error.InnerException : error;
-                    CompleteTransit(REJECTED_STATE);
-                    OnError();
-                }
-            } else {
-                WaitTransition();
-                if (m_state == SUCCEEDED_STATE)
-                    throw new InvalidOperationException("The promise is already resolved");
-            }
-        }
-
-        /// <summary>
-        /// Отменяет операцию, если это возможно.
-        /// </summary>
-        /// <remarks>Для определения была ли операция отменена следует использовать свойство <see cref="IsCancelled"/>.</remarks>
-        protected void SetCancelled(Exception reason) {
-            if (BeginTransit()) {
-                m_error = reason;
-                CompleteTransit(CANCELLED_STATE);
-                OnCancelled();
-            }
+        protected override void SignalSuccess(HandlerDescriptor handler) {
+            handler.SignalSuccess();
         }
 
-        protected abstract void SignalSuccess(THandler handler);
-
-        protected abstract void SignalError(THandler handler, Exception error);
-
-        protected abstract void SignalCancelled(THandler handler, Exception reason);
-
-        void OnSuccess() {
-            var hp = m_handlerPointer;
-            var slot = hp +1 ;
-            while (slot < m_handlersCommited) {
-                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
-                    SignalSuccess(m_handlers[slot]);
-                }
-                hp = m_handlerPointer;
-                slot = hp +1 ;
-            }
-
-
-            if (m_extraHandlers != null) {
-                THandler handler;
-                while (m_extraHandlers.TryDequeue(out handler))
-                    SignalSuccess(handler);
-            }
+        protected override void SignalError(HandlerDescriptor handler, Exception error) {
+            handler.SignalError(error);
         }
 
-        void OnError() {
-            var hp = m_handlerPointer;
-            var slot = hp +1 ;
-            while (slot < m_handlersCommited) {
-                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
-                    SignalError(m_handlers[slot],m_error);
-                }
-                hp = m_handlerPointer;
-                slot = hp +1 ;
-            }
-
-            if (m_extraHandlers != null) {
-                THandler handler;
-                while (m_extraHandlers.TryDequeue(out handler))
-                    SignalError(handler, m_error);
-            }
+        protected override void SignalCancelled(HandlerDescriptor handler, Exception reason) {
+            handler.SignalCancel(reason);
         }
 
-        void OnCancelled() {
-            var hp = m_handlerPointer;
-            var slot = hp +1 ;
-            while (slot < m_handlersCommited) {
-                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) == hp) {
-                    SignalCancelled(m_handlers[slot], m_error);
-                }
-                hp = m_handlerPointer;
-                slot = hp +1 ;
-            }
-
-            if (m_extraHandlers != null) {
-                THandler handler;
-                while (m_extraHandlers.TryDequeue(out handler))
-                    SignalCancelled(handler, m_error);
-            }
+        protected override Signal GetResolveSignal() {
+            var signal = new Signal();
+            On(signal.Set, PromiseEventType.All);
         }
 
         #endregion
 
-        protected abstract void Listen(PromiseEventType events, Action handler);
 
-        #region synchronization traits
-        protected void WaitResult(int timeout) {
-            if (!IsResolved) {
-                var lk = new object();
-
-                Listen(PromiseEventType.All, () => {
-                    lock(lk) {
-                        Monitor.Pulse(lk);
-                    }
-                });
-
-                lock (lk) {
-                    while(!IsResolved) {
-                        if(!Monitor.Wait(lk,timeout))
-                            throw new TimeoutException();
-                    }
-                }
-
-            }
-            switch (m_state) {
-                case SUCCEEDED_STATE:
-                    return;
-                case CANCELLED_STATE:
-                    throw new OperationCanceledException();
-                case REJECTED_STATE:
-                    throw new TargetInvocationException(m_error);
-                default:
-                    throw new ApplicationException(String.Format("Invalid promise state {0}", m_state));
-            }
-        }
-        #endregion
-
-        #region handlers managment
-
-        protected void AddHandler(THandler handler) {
-
-            if (m_state > 1) {
-                // the promise is in the resolved state, just invoke the handler
-                InvokeHandler(handler);
-            } else {
-                var slot = Interlocked.Increment(ref m_handlersCount) - 1;
-
-                if (slot < RESERVED_HANDLERS_COUNT) {
-                    m_handlers[slot] = handler;
-
-                    while (slot != Interlocked.CompareExchange(ref m_handlersCommited, slot + 1, slot)) {
-                    }
-
-                    if (m_state > 1) {
-                        do {
-                            var hp = m_handlerPointer;
-                            slot = hp + 1;
-                            if (slot < m_handlersCommited) {
-                                if (Interlocked.CompareExchange(ref m_handlerPointer, slot, hp) != hp)
-                                    continue;
-                                InvokeHandler(m_handlers[slot]);
-                            }
-                            break;
-                        } while(true);
-                    }
-                } else {
-                    if (slot == RESERVED_HANDLERS_COUNT) {
-                        m_extraHandlers = new MTQueue<THandler>();
-                    } else {
-                        while (m_extraHandlers == null)
-                            Thread.MemoryBarrier();
-                    }
-
-                    m_extraHandlers.Enqueue(handler);
-
-                    if (m_state > 1 && m_extraHandlers.TryDequeue(out handler))
-                    // if the promise have been resolved while we was adding the handler to the queue
-                    // we can't guarantee that someone is still processing it
-                    // therefore we need to fetch a handler from the queue and execute it
-                    // note that fetched handler may be not the one that we have added
-                    // even we can fetch no handlers at all :)
-                    InvokeHandler(handler);
-                }
+        public Type PromiseType {
+            get {
+                return typeof(void);
             }
         }
 
-        protected void InvokeHandler(THandler handler) {
-            switch (m_state) {
-                case SUCCEEDED_STATE:
-                    SignalSuccess(handler);
-                    break;
-                case CANCELLED_STATE:
-                    SignalCancelled(handler, m_error);
-                    break;
-                case REJECTED_STATE:
-                    SignalError(handler, m_error);
-                    break;
-                default:
-                    throw new Exception(String.Format("Invalid promise state {0}", m_state));
-            }
+        public IPromise On(Action success, Action<Exception> error, Action<Exception> cancel) {
+            AddHandler(new HandlerDescriptor(success, error, cancel));
+            return this;
+        }
+
+        public IPromise On(Action success, Action<Exception> error) {
+            AddHandler(new HandlerDescriptor(success, error, null));
+            return this;
         }
 
-        #endregion
+        public IPromise On(Action success) {
+            AddHandler(new HandlerDescriptor(success, null, null));
+            return this;
+        }
 
-        #region IPromise implementation
+        public IPromise On(Action handler, PromiseEventType events) {
+            AddHandler(new HandlerDescriptor(handler,events));
+            return this;
+        }
 
-        public void Join(int timeout) {
-            WaitResult(timeout);
+        public IPromise<T> Cast<T>() {
+            throw new InvalidCastException();
         }
 
         public void Join() {
             WaitResult(-1);
         }
 
-        public bool IsResolved {
-            get {
-                Thread.MemoryBarrier();
-                return m_state > 1;
-            }
+        public void Join(int timeout) {
+            WaitResult(timeout);
         }
 
-        public bool IsCancelled {
-            get {
-                Thread.MemoryBarrier();
-                return m_state == CANCELLED_STATE;
-            }
-        }
-
-        #endregion
-
-        public Exception Error {
-            get {
-                return m_error;
-            }
+        protected void SetResult() {
+            BeginSetResult();
+            EndSetResult();
         }
     }
 }
diff -r 16f926ee499d -r 8c0b95069066 Implab/AbstractPromiseT.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/AbstractPromiseT.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,185 @@
+using System;
+using Implab.Parallels;
+
+namespace Implab {
+    public abstract class AbstractPromise<T> : AbstractEvent<AbstractPromise<T>.HandlerDescriptor>, IPromise<T> {
+        public struct HandlerDescriptor {
+            readonly Action m_handler;
+            readonly Action<T> m_success;
+            readonly Action<Exception> m_error;
+            readonly Action<Exception> m_cancel;
+            readonly PromiseEventType m_mask;
+
+            public HandlerDescriptor(Action<T> success, Action<Exception> error, Action<Exception> cancel) {
+                m_success = success;
+                m_error = error;
+                m_cancel = cancel;
+            }
+
+            public HandlerDescriptor(Action success, Action<Exception> error, Action<Exception> cancel) {
+                m_handler = success;
+                m_error = error;
+                m_cancel = cancel;
+                m_mask = PromiseEventType.Success;
+            }
+
+            public HandlerDescriptor(Action handler, PromiseEventType mask) {
+                m_handler = handler;
+                m_mask = mask;
+            }
+
+            public void SignalSuccess(T result) {
+                if (m_success != null) {
+                    try {
+                        m_success(result);
+                    } catch(Exception err) {
+                        SignalError(err);
+                    }
+                } else if (m_mask & PromiseEventType.Success && m_handler != null) {
+                    try {
+                        m_handler();
+                    } catch(Exception err) {
+                        // avoid calling handler twice in case of error
+                        if (m_error != null)
+                            SignalError(err);
+                    }
+                }
+            }
+
+            public void SignalError(Exception err) {
+                if (m_error != null) {
+                    try {
+                        m_error(err);
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                } else if (m_mask & PromiseEventType.Error && m_handler != null) {
+                    try {
+                        m_handler();
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                }
+            }
+
+            public void SignalCancel(Exception reason) {
+                if (m_cancel != null) {
+                    try {
+                        m_cancel(reason);
+                    } catch (Exception err) {
+                        SignalError(err);
+                    }
+                } else if (m_mask & PromiseEventType.Cancelled && m_handler != null) {
+                    try {
+                        m_handler();
+                        // Analysis disable once EmptyGeneralCatchClause
+                    } catch {
+                    }
+                }
+            }
+        }
+
+
+
+        public Type PromiseType {
+            get {
+                return typeof(T);
+            }
+        }
+
+        public new T Join() {
+            WaitResult(-1);
+            return m_result;
+        }
+        public new T Join(int timeout) {
+            WaitResult(timeout);
+            return m_result;
+        }
+
+        public IPromise<T> On(Action<T> success, Action<Exception> error, Action<Exception> cancel) {
+            AddHandler(new HandlerDescriptor(success, error, cancel));
+            return this;
+        }
+
+        public IPromise<T> On(Action<T> success, Action<Exception> error) {
+            AddHandler(new HandlerDescriptor(success, error, null));
+            return this;
+        }
+
+        public IPromise<T> On(Action<T> success) {
+            AddHandler(new HandlerDescriptor(success, null, null));
+            return this;
+        }
+
+        public IPromise<T> On(Action handler, PromiseEventType events) {
+            AddHandler(new HandlerDescriptor(handler, events));
+            return this;
+        }
+
+        public IPromise<T> On(Action success, Action<Exception> error, Action<Exception> cancel) {
+            AddHandler(new HandlerDescriptor(success, error, cancel));
+            return this;
+        }
+
+        public IPromise<T> On(Action success, Action<Exception> error) {
+            AddHandler(new HandlerDescriptor(success, error, null));
+            return this;
+        }
+
+        public IPromise<T> On(Action success) {
+            AddHandler(new HandlerDescriptor(success, null, null));
+            return this;
+        }
+
+        IPromise IPromise.On(Action success, Action<Exception> error, Action<Exception> cancel) {
+            AddHandler(new HandlerDescriptor(success, error, cancel));
+            return this;
+        }
+
+        IPromise IPromise.On(Action success, Action<Exception> error) {
+            AddHandler(new HandlerDescriptor(success, error, null));
+            return this;
+        }
+
+        IPromise IPromise.On(Action success) {
+            AddHandler(new HandlerDescriptor(success, null, null));
+            return this;
+        }
+
+        public IPromise<T2> Cast<T2>() {
+            return (IPromise<T2>)this;
+        }
+
+        #region implemented abstract members of AbstractPromise
+
+        protected override Signal GetResolveSignal() {
+            var signal = new Signal();
+            AddHandler(new HandlerDescriptor(signal.Set, PromiseEventType.All));
+            return signal;
+        }
+
+        protected override void SignalSuccess(HandlerDescriptor handler) {
+            handler.SignalSuccess(m_result);
+        }
+
+        protected override void SignalError(HandlerDescriptor handler, Exception error) {
+            handler.SignalError(error);
+        }
+
+        protected override void SignalCancelled(HandlerDescriptor handler, Exception reason) {
+            handler.SignalCancel(reason);
+        }
+
+        #endregion
+
+        T m_result;
+
+        protected void SetResult(T value) {
+            if (BeginSetResult()) {
+                m_result = value;
+                EndSetResult();
+            }
+        }
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/ChainTask.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/ChainTask.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,54 @@
+using System;
+using System.Threading;
+
+namespace Implab {
+    public class ChainTask : AbstractPromise, IDeferred {
+        readonly Func<IPromise> m_task;
+        readonly Action<Exception> m_error;
+        readonly Action<Exception> m_cancel;
+
+        int m_cancelationLock;
+
+        public ChainTask(Func<IPromise> task, Func<Exception> error, Func<Exception> cancel) {
+            m_task = task;
+        }
+
+        public void Resolve() {
+            if (m_task != null && LockCancelation()) {
+                try {
+                    var operation = m_task();
+                    if (operation == null)
+                        throw new NullReferenceException("The task returned null promise");
+                        
+                    operation.On(SetResult, SetError, SetCancelled);
+
+                    CancelationRequested(operation.Cancel);
+                } catch(Exception err) {
+                    HandleErrorInternal(err);
+                }
+            }
+        }
+
+        public void Reject(Exception error) {
+            throw new NotImplementedException();
+        }
+
+        protected void HandleErrorInternal(Exception error) {
+            if (m_error != null) {
+                try {
+                    m_error(error);
+                    SetResult();
+                } catch(Exception err) {
+                    SetError(err);
+                }
+            } else {
+                SetError(error);
+            }
+        }
+
+        protected bool LockCancelation() {
+            return 0 == Interlocked.CompareExchange(ref m_cancelationLock, 1, 0);
+        }
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/FuncTask.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/FuncTask.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,23 @@
+using System;
+using System.Threading;
+
+namespace Implab {
+    public class FuncTask<T> : FuncTaskBase<T>, IDeferred {
+        readonly Func<T> m_task;
+
+        public FuncTask(Func<T> task, Func<Exception, T> error, Func<Exception, T> cancel) : base(error,cancel) {
+            m_task = task;
+        }
+
+        public void Resolve() {
+            if (m_task != null && LockCancelation()) {
+                try {
+                    SetResult(m_task());
+                } catch(Exception err) {
+                    HandleErrorInternal(err);
+                }
+            }
+        }
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/FuncTaskBase.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/FuncTaskBase.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,53 @@
+using System;
+using System.Threading;
+
+namespace Implab {
+    public class FuncTaskBase<TResult> : AbstractPromise<TResult> {
+        readonly Func<Exception, TResult> m_cancel;
+        readonly Func<Exception, TResult> m_error;
+
+        int m_cancelationLock;
+
+        protected FuncTaskBase( Func<Exception, TResult> error, Func<Exception, TResult> cancel) {
+            m_error = error;
+            m_cancel = cancel;
+        }
+
+        public void Reject(Exception error) {
+            Safe.ArgumentNotNull(error, "error");
+            if (LockCancelation())
+                HandleErrorInternal(error);
+        }
+
+        protected void HandleErrorInternal(Exception error) {
+            if (m_error != null) {
+                try {
+                    SetResult(m_error(error));
+                } catch(Exception err) {
+                    SetError(err);
+                }
+            } else {
+                SetError(error);
+            }
+        }
+
+        public override void CancelOperation(Exception reason) {
+            if (LockCancelation()) {
+                if (m_cancel != null) {
+                    try {
+                        SetResult(m_cancel(reason));
+                    } catch (Exception err) {
+                        HandleErrorInternal(err);
+                    }
+                } else {
+                    SetCancelled(reason);
+                }
+            }
+        }
+
+        protected bool LockCancelation() {
+            return 0 == Interlocked.CompareExchange(ref m_cancelationLock, 1, 0);
+        }
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/FuncTaskT.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/FuncTaskT.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -0,0 +1,22 @@
+using System;
+
+namespace Implab {
+    public class FuncTask<TArg, TResult> : FuncTaskBase<TResult>, IDeferred<TArg> {
+        readonly Func<TArg, TResult> m_task;
+
+        public FuncTask(Func<TArg, TResult> task, Func<Exception, TResult> error,Func<Exception, TResult> cancel) :  base(error,cancel) {
+            m_task = task;
+        }
+
+        public void Resolve(TArg value) {
+            if (m_task != null && LockCancelation()) {
+                try {
+                    SetResult(m_task(value));
+                } catch (Exception err) {
+                    HandleErrorInternal(err);
+                }
+            }
+        }
+    }
+}
+
diff -r 16f926ee499d -r 8c0b95069066 Implab/ICancelationToken.cs
--- a/Implab/ICancelationToken.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/ICancelationToken.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -22,14 +22,14 @@
         /// Sets the token to cancelled state.
         /// </summary>
         /// <param name="reason">The reason why the operation was cancelled.</param>
-        void SetCancelled(Exception reason);
+        void CancelOperation(Exception reason);
 
         /// <summary>
         /// Adds the listener for the cancellation request, is the cancellation was requested the <paramref name="handler"/>
         /// is executed immediatelly.
         /// </summary>
         /// <param name="handler">The handler which will be executed if the cancel occurs.</param>
-        void CancellationRequested(Action<Exception> handler);
+        void CancelationRequested(Action<Exception> handler);
 
     }
 }
diff -r 16f926ee499d -r 8c0b95069066 Implab/IPromise.cs
--- a/Implab/IPromise.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/IPromise.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -58,13 +58,13 @@
         /// exception it will be passed to the dependent promise.
         /// </para>
         /// </remarks>
-        IPromise Then(Action success, Action<Exception> error, Action<Exception> cancel);
+        /* IPromise Then(Action success, Action<Exception> error, Action<Exception> cancel);
         IPromise Then(Action success, Action<Exception> error);
         IPromise Then(Action success);
 
         IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error, Func<Exception, IPromise> cancel);
         IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error);
-        IPromise Chain(Func<IPromise> chained);
+        IPromise Chain(Func<IPromise> chained);*/
 
         /// <summary>
         /// Adds specified listeners to the current promise.
diff -r 16f926ee499d -r 8c0b95069066 Implab/IPromiseT.cs
--- a/Implab/IPromiseT.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/IPromiseT.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -3,28 +3,23 @@
 namespace Implab {
     public interface IPromise<out T> : IPromise {
 
-        new T Join();
-
-        new T Join(int timeout);
-
         IPromise<T> On(Action<T> success, Action<Exception> error, Action<Exception> cancel);
         
         IPromise<T> On(Action<T> success, Action<Exception> error);
 
         IPromise<T> On(Action<T> success);
 
+        new T Join();
+
+        new T Join(int timeout);
+
+        new IPromise<T> On(Action success, Action<Exception> error, Action<Exception> cancel);
+
+        new IPromise<T> On(Action success, Action<Exception> error);
+
+        new IPromise<T> On(Action success);
+
         new IPromise<T> On(Action handler, PromiseEventType events);
 
-        IPromise<T2> Then<T2>(Func<T, T2> mapper, Func<Exception, T2> error, Func<Exception, T2> cancel);
-
-        IPromise<T2> Then<T2>(Func<T, T2> mapper, Func<Exception, T2> error);
-
-        IPromise<T2> Then<T2>(Func<T, T2> mapper);
-
-        IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained, Func<Exception, IPromise<T2>> error, Func<Exception, IPromise<T2>> cancel);
-
-        IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained, Func<Exception, IPromise<T2>> error);
-
-        IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained);
     }
 }
diff -r 16f926ee499d -r 8c0b95069066 Implab/Implab.csproj
--- a/Implab/Implab.csproj	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/Implab.csproj	Fri Mar 06 15:45:26 2015 +0300
@@ -150,7 +150,6 @@
     <Compile Include="PromiseT.cs" />
     <Compile Include="IDeferred.cs" />
     <Compile Include="IDeferredT.cs" />
-    <Compile Include="AbstractPromise.cs" />
     <Compile Include="Promise.cs" />
     <Compile Include="PromiseTransientException.cs" />
     <Compile Include="Parallels\Signal.cs" />
@@ -159,6 +158,13 @@
     <Compile Include="Diagnostics\ListenerBase.cs" />
     <Compile Include="Parallels\BlockingQueue.cs" />
     <Compile Include="ICancelationToken.cs" />
+    <Compile Include="AbstractEvent.cs" />
+    <Compile Include="AbstractPromise.cs" />
+    <Compile Include="AbstractPromiseT.cs" />
+    <Compile Include="FuncTask.cs" />
+    <Compile Include="FuncTaskBase.cs" />
+    <Compile Include="FuncTaskT.cs" />
+    <Compile Include="ChainTask.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup />
diff -r 16f926ee499d -r 8c0b95069066 Implab/Promise.cs
--- a/Implab/Promise.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/Promise.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -1,222 +1,22 @@
 using System;
-using System.Diagnostics;
+using Implab.Parallels;
 
 namespace Implab {
-    public class Promise : AbstractPromise<Promise.HandlerDescriptor>, IPromise, IDeferred {
-
-        public struct HandlerDescriptor {
-            readonly Action m_success;
-            readonly Action<Exception> m_error;
-            readonly Action<Exception> m_cancel;
-            readonly IDeferred m_deferred;
-
-            public HandlerDescriptor(Action success, Action<Exception> error, Action<Exception> cancel, IDeferred deferred) {
-                m_success = success;
-                m_error = error;
-                m_cancel = cancel;
-                m_deferred = deferred;
-            }
-
-            public void SignalSuccess() {
-                if (m_success != null) {
-                    try {
-                        m_success();
-                        if (m_deferred != null)
-                            m_deferred.Resolve();
-                    } catch (Exception err) {
-                        SignalError(err);
-                    }
-                }
-            }
+    public class Promise : AbstractPromise, IDeferred {
+        public static readonly Promise SUCCESS;
 
-            public void SignalError(Exception err) {
-                if (m_error != null) {
-                    try {
-                        m_error(err);
-                        if (m_deferred != null)
-                            m_deferred.Resolve();
-                    } catch (Exception err2) {
-                        if (m_deferred != null)
-                            m_deferred.Reject(err2);
-                    }
-                } else {
-                    if (m_deferred != null)
-                        m_deferred.Reject(err);
-                }
-            }
-
-            public void SignalCancel(Exception reason) {
-                if (m_cancel != null) {
-                    try {
-                        m_cancel(reason);
-                        if (m_deferred != null)
-                            m_deferred.Resolve();
-                    } catch (Exception err) {
-                        SignalError(err);
-                    }
-                } else if (reason != null && m_error != null) {
-                    try {
-                        m_error(new OperationCanceledException("The operation was canceled.", reason));
-                        if (m_deferred != null)
-                            m_deferred.Resolve();
-                    } catch (Exception err) {
-                        SignalError(err);
-                    }
-                } else {
-                    if (m_deferred != null)
-                        m_deferred.Cancel(reason);
-                }
-            }
+        static Promise() {
+            SUCCESS = new Promise();
+            SUCCESS.Resolve();
         }
 
         public void Resolve() {
-            BeginSetResult();
-            EndSetResult();
+            SetResult();
         }
 
         public void Reject(Exception error) {
             SetError(error);
         }
-
-        #region implemented abstract members of AbstractPromise
-
-        protected override void SignalSuccess(HandlerDescriptor handler) {
-            handler.SignalSuccess();
-        }
-
-        protected override void SignalError(HandlerDescriptor handler, Exception error) {
-            handler.SignalError(error);
-        }
-
-        protected override void SignalCancelled(HandlerDescriptor handler, Exception reason) {
-            handler.SignalCancel(reason);
-        }
-
-        protected override void Listen(PromiseEventType events, Action handler) {
-            AddHandler(new HandlerDescriptor(
-                events.HasFlag(PromiseEventType.Success) ? handler : null,
-                events.HasFlag(PromiseEventType.Error) ? new Action<Exception>(err => handler()) : null,
-                events.HasFlag(PromiseEventType.Cancelled) ? new Action<Exception>(reason => handler()) : null,
-                null
-            ));
-        }
-
-        #endregion
-
-
-        public Type PromiseType {
-            get {
-                return typeof(void);
-            }
-        }
-
-        public IPromise Then(Action success, Action<Exception> error, Action<Exception> cancel) {
-            var promise = new Promise();
-            if (success != null)
-                promise.On(Cancel, PromiseEventType.Cancelled);
-
-            AddHandler(new HandlerDescriptor(success, error, cancel, promise));
-
-            return promise;
-        }
-
-        public IPromise Then(Action success, Action<Exception> error) {
-            return Then(success, error, null);
-        }
-
-        public IPromise Then(Action success) {
-            return Then(success, null, null);
-        }
-
-        public IPromise On(Action success, Action<Exception> error, Action<Exception> cancel) {
-            AddHandler(new HandlerDescriptor(success, error, cancel, null));
-            return this;
-        }
-
-        public IPromise On(Action success, Action<Exception> error) {
-            return On(success, error, null);
-        }
-
-        public IPromise On(Action success) {
-            return On(success, null, null);
-        }
-
-        public IPromise On(Action handler, PromiseEventType events) {
-            return On(
-                events.HasFlag(PromiseEventType.Success) ? handler : null,
-                events.HasFlag(PromiseEventType.Error) ? new Action<Exception>(err => handler()) : null,
-                events.HasFlag(PromiseEventType.Cancelled) ? new Action<Exception>(reason => handler()) : null
-            );
-        }
-
-        public IPromise<T> Cast<T>() {
-            throw new InvalidCastException();
-        }
-
-        public IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error, Func<Exception,IPromise> cancel) {
-            var medium = new Promise();
-
-            On(
-                () => {
-                    if (medium.IsCancelled)
-                        return;
-                    if (chained != null)
-                        ConnectPromise(chained(), medium);
-                },
-                ex => {
-                    if (medium.IsCancelled)
-                        return;
-                    if (error != null) {
-                        try {
-                            ConnectPromise(error(ex), medium);
-                        } catch (Exception ex2) {
-                            medium.Reject(ex2);
-                        }
-                    } else {
-                        medium.Reject(ex);
-                    }
-                },
-                reason => {
-                    if (medium.IsCancelled)
-                        return;
-                    if (cancel != null)
-                        ConnectPromise(cancel(reason), medium);
-                    else
-                        medium.Cancel(reason);
-                }
-            );
-
-            if (chained != null)
-                medium.On(Cancel, PromiseEventType.Cancelled);
-
-            return medium;
-        }
-
-        static void ConnectPromise(IPromise result, Promise medium) {
-            if (result != null) {
-                result.On(
-                    medium.Resolve,
-                    medium.Reject,
-                    medium.Cancel
-                );
-                medium.On(null,null,result.Cancel);
-            } else {
-                medium.Reject(
-                    new NullReferenceException(
-                        "The chained asynchronous operation returned" +
-                        " 'null' where the promise instance is expected"
-                    )
-                );
-            }
-        }
-
-        public IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error) {
-            return Chain(chained, error, null);
-        }
-
-        public IPromise Chain(Func<IPromise> chained) {
-            return Chain(chained, null, null);
-        }
     }
 }
 
diff -r 16f926ee499d -r 8c0b95069066 Implab/PromiseT.cs
--- a/Implab/PromiseT.cs	Wed Mar 04 18:05:39 2015 +0300
+++ b/Implab/PromiseT.cs	Fri Mar 06 15:45:26 2015 +0300
@@ -1,5 +1,6 @@
 using System;
 using System.Diagnostics;
+using Implab.Parallels;
 
 namespace Implab {
 
@@ -37,538 +38,26 @@
     /// только инициатор обещания иначе могут возникнуть противоречия.
     /// </para>
     /// </remarks>
-    public class Promise<T> : AbstractPromise<IDeferred<T>>, IPromise<T>, IDeferred<T> {
-
-        class StubDeferred : IDeferred, IDeferred<T> {
-            public static readonly StubDeferred instance = new StubDeferred();
-
-            StubDeferred() {
-            }
-
-            #region IDeferred implementation
-
-            public void Resolve(T value) {
-            }
-
-            public void Resolve() {
-            }
-
-            public void Reject(Exception error) {
-            }
-
-            #endregion
-
-            #region ICancellable implementation
-
-            public void Cancel() {
-            }
-
-            public void Cancel(Exception reason) {
-            }
-
-            #endregion
-
-
-        }
-
-        class RemapDescriptor<T2> : IDeferred<T> {
-            readonly Func<T,T2> m_remap;
-            readonly Func<Exception, T2> m_failed;
-            readonly Func<Exception, T2> m_cancel;
-            readonly IDeferred<T2> m_deferred;
-
-            public RemapDescriptor(Func<T,T2> remap, Func<Exception,T2> failed, Func<Exception, T2> cancel, IDeferred<T2> deferred ) {
-                Debug.Assert(deferred != null);
-                m_remap = remap;
-                m_failed = failed;
-                m_cancel = cancel;
-                m_deferred = deferred;
-            }
+    public class Promise<T> : AbstractPromise<T>, IDeferred<T> {
 
-
-
-            #region IDeferred implementation
-
-            public void Resolve(T value) {
-                if (m_remap != null) {
-                    try {
-                        m_deferred.Resolve(m_remap(value));
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                }
-            }
-
-            public void Reject(Exception error) {
-                if (m_failed != null) {
-                    try {
-                        m_deferred.Resolve(m_failed(error));
-                    } catch (Exception ex) {
-                        m_deferred.Reject(ex);
-                    }
-                } else {
-                    m_deferred.Reject(error);
-                }
-            }
-
-
-            #endregion
-
-            #region ICancellable implementation
-
-            public void Cancel(Exception reason) {
-                if (m_cancel != null) {
-                    try {
-                        m_deferred.Resolve(m_cancel(reason));
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                } else {
-                    m_deferred.Cancel(reason);
-                }
-            }
-
-            public void Cancel() {
-                Cancel(null);
-            }
-            #endregion
+        public static IPromise<T> FromResult(T value) {
+            var p = new Promise<T>();
+            p.Resolve(value);
+            return p;
         }
 
-        class ListenerDescriptor : IDeferred<T> {
-            readonly Action m_handler;
-            readonly PromiseEventType m_events;
-
-            public ListenerDescriptor(Action handler, PromiseEventType events) {
-                Debug.Assert(handler != null);
-
-                m_handler = handler;
-                m_events = events;
-            }
-
-            #region IDeferred implementation
-
-            public void Resolve(T value) {
-                if (m_events.HasFlag(PromiseEventType.Success)) {
-                    try {
-                        m_handler();
-                    // Analysis disable once EmptyGeneralCatchClause
-                    } catch {
-                    }
-                }
-            }
-
-            public void Reject(Exception error) {
-                if (m_events.HasFlag(PromiseEventType.Error)){
-                    try {
-                        m_handler();
-                        // Analysis disable once EmptyGeneralCatchClause
-                    } catch {
-                    }
-                }
-            }
-
-            #endregion
-
-            #region ICancellable implementation
-
-            public void Cancel() {
-                Cancel(null);
-            }
-
-            public void Cancel(Exception reason) {
-                if (m_events.HasFlag(PromiseEventType.Cancelled)){
-                    try {
-                        m_handler();
-                        // Analysis disable once EmptyGeneralCatchClause
-                    } catch {
-                    }
-                }
-            }
-
-            #endregion
+        public static IPromise<T> FromException(Exception error) {
+            var p = new Promise<T>();
+            p.Reject(error);
+            return p;
         }
 
-        class ValueEventDescriptor : IDeferred<T> {
-            readonly Action<T> m_success;
-            readonly Action<Exception> m_failed;
-            readonly Action<Exception> m_cancelled;
-            readonly IDeferred<T> m_deferred;
-
-            public ValueEventDescriptor(Action<T> success, Action<Exception> failed, Action<Exception> cancelled, IDeferred<T> deferred) {
-                Debug.Assert(deferred != null);
-
-                m_success = success;
-                m_failed = failed;
-                m_cancelled = cancelled;
-                m_deferred = deferred;
-            }
-
-            #region IDeferred implementation
-
-            public void Resolve(T value) {
-                if (m_success != null) {
-                    try {
-                        m_success(value);
-                        m_deferred.Resolve(value);
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                }
-            }
-
-            public void Reject(Exception error) {
-                if (m_failed != null) {
-                    try {
-                        m_failed(error);
-                        m_deferred.Resolve(default(T));
-                    } catch(Exception ex) {
-                        m_deferred.Reject(ex);
-                    }
-                } else {
-                    m_deferred.Reject(error);
-                }
-            }
-
-            #endregion
-
-            #region ICancellable implementation
-
-            public void Cancel(Exception reason) {
-                if (m_cancelled != null) {
-                    try {
-                        m_cancelled(reason);
-                        m_deferred.Resolve(default(T));
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                } else {
-                    m_deferred.Cancel(reason);
-                }
-            }
-
-            public void Cancel() {
-                Cancel(null);
-            }
-
-            #endregion
-        }
-
-        public class EventDescriptor : IDeferred<T> {
-            readonly Action m_success;
-            readonly Action<Exception> m_failed;
-            readonly Action<Exception> m_cancelled;
-            readonly IDeferred m_deferred;
-
-            public EventDescriptor(Action success, Action<Exception> failed, Action<Exception> cancelled, IDeferred deferred) {
-                Debug.Assert(deferred != null);
-
-                m_success = success;
-                m_failed = failed;
-                m_cancelled = cancelled;
-                m_deferred = deferred;
-            }
-
-            #region IDeferred implementation
-
-            public void Resolve(T value) {
-                if (m_success != null) {
-                    try {
-                        m_success();
-                        m_deferred.Resolve();
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                }
-            }
-
-            public void Reject(Exception error) {
-                if (m_failed != null) {
-                    try {
-                        m_failed(error);
-                        m_deferred.Resolve();
-                    } catch (Exception ex) {
-                        m_deferred.Reject(ex);
-                    }
-                } else {
-                    m_deferred.Reject(error);
-                }
-            }
-
-            #endregion
-
-            #region ICancellable implementation
-
-            public void Cancel(Exception reason) {
-                if (m_cancelled != null) {
-                    try {
-                        m_cancelled(reason);
-                        m_deferred.Resolve();
-                    } catch (Exception ex) {
-                        Reject(ex);
-                    }
-                } else {
-                    m_deferred.Cancel(reason);
-                }
-            }
-
-            public void Cancel() {
-                Cancel(null);
-            }
-
-            #endregion
-        }
-
-        T m_result;
-
         public virtual void Resolve(T value) {
-            if (BeginSetResult()) {
-                m_result = value;
-                EndSetResult();
-            }
+            SetResult(value);
         }
 
         public void Reject(Exception error) {
             SetError(error);
         }
-
-        public Type PromiseType {
-            get {
-                return typeof(T);
-            }
-        }
-
-        public new T Join() {
-            WaitResult(-1);
-            return m_result;
-        }
-        public new T Join(int timeout) {
-            WaitResult(timeout);
-            return m_result;
-        }
-            
-        public IPromise<T> On(Action<T> success, Action<Exception> error, Action<Exception> cancel) {
-            AddHandler(new ValueEventDescriptor(success, error, cancel, StubDeferred.instance));
-            return this;
-        }
-
-        public IPromise<T> On(Action<T> success, Action<Exception> error) {
-            AddHandler(new ValueEventDescriptor(success, error, null, StubDeferred.instance));
-            return this;
-        }
-
-        public IPromise<T> On(Action<T> success) {
-            AddHandler(new ValueEventDescriptor(success, null, null, StubDeferred.instance));
-            return this;
-        }
-
-        public IPromise<T> On(Action handler, PromiseEventType events) {
-            Listen(events, handler);
-            return this;
-        }
-
-        public IPromise<T2> Then<T2>(Func<T, T2> mapper, Func<Exception, T2> error, Func<Exception, T2> cancel) {
-            var promise = new Promise<T2>();
-            if (mapper != null)
-                promise.On((Action)null, null, Cancel);
-            AddHandler(new RemapDescriptor<T2>(mapper, error, cancel, promise));
-            return promise;
-        }
-
-        public IPromise<T2> Then<T2>(Func<T, T2> mapper, Func<Exception, T2> error) {
-            var promise = new Promise<T2>();
-            if (mapper != null)
-                promise.On((Action)null, null, Cancel);
-            AddHandler(new RemapDescriptor<T2>(mapper, error, null, promise));
-            return promise;
-        }
-
-        public IPromise<T2> Then<T2>(Func<T, T2> mapper) {
-            var promise = new Promise<T2>();
-            if (mapper != null)
-                promise.On((Action)null, null, Cancel);
-            AddHandler(new RemapDescriptor<T2>(mapper, null, null, promise));
-            return promise;
-        }
-
-        public IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained, Func<Exception, IPromise<T2>> error, Func<Exception, IPromise<T2>> cancel) {
-            // this promise will be resolved when an asyc operation is started
-            var promise = new Promise<IPromise<T2>>();
-
-            AddHandler(new RemapDescriptor<IPromise<T2>>(
-                chained,
-                error,
-                cancel,
-                promise
-            ));
-
-            var medium = new Promise<T2>();
-
-            if (chained != null)
-                medium.On(Cancel, PromiseEventType.Cancelled);
-
-            // we need to connect started async operation with the medium
-            // if the async operation hasn't been started by the some reason
-            // report is to the medium
-            promise.On(
-                result => ConnectPromise<T2>(result, medium),
-                medium.Reject,
-                medium.Cancel
-            );
-
-            return medium;
-        }
-
-        static void ConnectPromise<T2>(IPromise<T2> result, Promise<T2> medium) {
-            if (result != null) {
-                result.On(
-                    medium.Resolve,
-                    medium.Reject,
-                    medium.Cancel
-                );
-                medium.On(result.Cancel, PromiseEventType.Cancelled);
-            } else {
-                medium.Reject(
-                    new NullReferenceException(
-                        "The chained asynchronous operation returned" +
-                        " 'null' where the promise instance is expected"
-                    )
-                );
-            }
-        }
-
-        public IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained, Func<Exception, IPromise<T2>> error) {
-            return Chain(chained, error, null);
-        }
-
-        public IPromise<T2> Chain<T2>(Func<T, IPromise<T2>> chained) {
-            return Chain(chained, null, null);
-        }
-
-        public IPromise Then(Action success, Action<Exception> error, Action<Exception> cancel) {
-            var promise = new Promise();
-            if (success != null)
-                promise.On(null, null, Cancel);
-
-            AddHandler(new EventDescriptor(success, error, cancel, promise));
-
-            return promise;
-        }
-
-        public IPromise Then(Action success, Action<Exception> error) {
-            return Then(success, error, null);
-        }
-
-        public IPromise Then(Action success) {
-            return Then(success, null, null);
-        }
-
-        public IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error, Func<Exception, IPromise> cancel) {
-            var promise = new Promise<IPromise>();
-
-            AddHandler(
-                new RemapDescriptor<IPromise>(
-                    x => chained(),
-                    error,
-                    cancel,
-                    promise
-                )
-            );
-
-            var medium = new Promise();
-            if (chained != null)
-                medium.On(null, null, Cancel);
-
-            promise.On(
-                result => ConnectPromise(result, medium),
-                medium.Reject,
-                medium.Cancel
-            );
-
-            return medium;
-        }
-
-        static void ConnectPromise(IPromise result, Promise medium) {
-            if (result != null) {
-                result.On(
-                    medium.Resolve,
-                    medium.Reject,
-                    medium.Cancel
-                );
-                medium.On(null, null, result.Cancel);
-            } else {
-                medium.Reject(
-                    new NullReferenceException(
-                        "The chained asynchronous operation returned" +
-                        " 'null' where the promise instance is expected"
-                    )
-                );
-            }
-        }
-
-        public IPromise Chain(Func<IPromise> chained, Func<Exception, IPromise> error) {
-            return Chain(chained, error, null);
-        }
-
-        public IPromise Chain(Func<IPromise> chained) {
-            return Chain(chained, null, null);
-        }
-
-        public IPromise On(Action success, Action<Exception> error, Action<Exception> cancel) {
-            AddHandler(new EventDescriptor(success,error,cancel, StubDeferred.instance));
-            return this;
-        }
-
-        public IPromise On(Action success, Action<Exception> error) {
-            AddHandler(new EventDescriptor(success, error, null, StubDeferred.instance));
-            return this;
-        }
-
-        public IPromise On(Action success) {
-            Listen(PromiseEventType.Success, success);
-            return this;
-        }
-
-        IPromise IPromise.On(Action handler, PromiseEventType events) {
-            Listen(events,handler);
-            return this;
-        }
-
-        public IPromise<T2> Cast<T2>() {
-            return (IPromise<T2>)this;
-        }
-
-        #region implemented abstract members of AbstractPromise
-
-        protected override void SignalSuccess(IDeferred<T> handler) {
-            handler.Resolve(m_result);
-        }
-
-        protected override void SignalError(IDeferred<T> handler, Exception error) {
-            handler.Reject(error);
-        }
-
-        protected override void SignalCancelled(IDeferred<T> handler, Exception reason) {
-            handler.Cancel(reason);
-        }
-
-        protected override void Listen(PromiseEventType events, Action handler) {
-            if (handler != null)
-                AddHandler(new ListenerDescriptor(handler, events));
-        }
-            
-        #endregion
-
-        public static IPromise<T> ResultToPromise(T value) {
-            var p = new Promise<T>();
-            p.Resolve(value);
-            return p;
-        }
-
-        public static IPromise<T> ExceptionToPromise(Exception error) {
-            var p = new Promise<T>();
-            p.Reject(error);
-            return p;
-        }
-
     }
 }