annotate Implab/FuncChainTaskBase.cs @ 160:5802131432e4 v2

fixed regression: race condition in Promise DFA refactoring
author cin
date Thu, 18 Feb 2016 19:38:54 +0300
parents eb793fbbe4ea
children dd4a3590f9c6
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1 using System;
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2 using System.Threading;
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3
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4 namespace Implab {
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5 public class FuncChainTaskBase<TResult> : AbstractPromise<TResult> {
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6 readonly Func<Exception, IPromise<TResult>> m_error;
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7 readonly Func<Exception, IPromise<TResult>> m_cancel;
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8
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9 int m_cancelationLock;
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10
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11 protected FuncChainTaskBase( Func<Exception, IPromise<TResult>> error, Func<Exception, IPromise<TResult>> cancel, bool autoCancellable) {
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12 m_error = error;
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13 m_cancel = cancel;
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14 if (autoCancellable)
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15 CancellationRequested(CancelOperation);
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16 }
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18 public void Reject(Exception error) {
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19 if (LockCancelation())
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20 HandleErrorInternal(error);
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21 }
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22
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23 public override void CancelOperation(Exception reason) {
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24 if (LockCancelation()) {
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25 if (m_cancel != null) {
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26 try {
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27 m_cancel(reason).On(SetResult, HandleErrorInternal, SetCancelled);
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28 } catch (Exception err) {
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29 HandleErrorInternal(err);
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30 }
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31 } else {
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32 SetCancelled(reason);
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33 }
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34 }
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35
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36 }
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38 protected void HandleErrorInternal(Exception error) {
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39 if (m_error != null) {
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40 try {
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41 var operation = m_error(error);
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42
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43 operation.On(SetResult, SetError, SetCancelled);
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44 CancellationRequested(operation.Cancel);
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45 } catch(Exception err) {
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46 SetError(err);
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47 }
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48 } else {
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49 SetError(error);
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50 }
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51 }
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53 protected bool LockCancelation() {
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54 return 0 == Interlocked.CompareExchange(ref m_cancelationLock, 1, 0);
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55 }
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56 }
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57 }
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