mcs/class/referencesource/System.Activities/System/Activities/WorkflowPersistenceContext.cs

   1 //-----------------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //-----------------------------------------------------------------------------
   4
   5 namespace System.Activities
   6 {
   7     using System.Collections.Generic;
   8     using System.Transactions;
   9     using System.Runtime;
  10
  11     class WorkflowPersistenceContext
  12     {
  13         CommittableTransaction contextOwnedTransaction;
  14         Transaction clonedTransaction;
  15
  16         public WorkflowPersistenceContext(bool transactionRequired, TimeSpan transactionTimeout)
  17             : this(transactionRequired, CloneAmbientTransaction(), transactionTimeout)
  18         {
  19         }
  20
  21         public WorkflowPersistenceContext(bool transactionRequired, Transaction transactionToUse, TimeSpan transactionTimeout)
  22         {
  23             if (transactionToUse != null)
  24             {
  25                 this.clonedTransaction = transactionToUse;
  26             }
  27             else if (transactionRequired)
  28             {
  29                 this.contextOwnedTransaction = new CommittableTransaction(transactionTimeout);
  30                 // Clone it so that we don't pass a CommittableTransaction to the participants
  31                 this.clonedTransaction = this.contextOwnedTransaction.Clone();
  32             }
  33         }
  34
  35         public Transaction PublicTransaction
  36         {
  37             get
  38             {
  39                 return this.clonedTransaction;
  40             }
  41         }
  42
  43         public void Abort()
  44         {
  45             if (this.contextOwnedTransaction != null)
  46             {
  47                 try
  48                 {
  49                     this.contextOwnedTransaction.Rollback();
  50                 }
  51                 catch (Exception e)
  52                 {
  53                     if (Fx.IsFatal(e))
  54                     {
  55                         throw;
  56                     }
  57
  58                     // ---- these exceptions as we are already on the error path
  59                 }
  60             }
  61         }
  62
  63         public void Complete()
  64         {
  65             if (this.contextOwnedTransaction != null)
  66             {
  67                 this.contextOwnedTransaction.Commit();
  68             }
  69         }
  70
  71         // Returns true if end needs to be called
  72         // Note: this is side effecting even if it returns false
  73         public bool TryBeginComplete(AsyncCallback callback, object state, out IAsyncResult result)
  74         {
  75             // In the interest of allocating less objects we don't implement
  76             // the full async pattern here.  Instead, we've flattened it to
  77             // do the sync part and then optionally delegate down to the inner
  78             // BeginCommit.
  79
  80             if (this.contextOwnedTransaction != null)
  81             {
  82                 result = this.contextOwnedTransaction.BeginCommit(callback, state);
  83                 return true;
  84             }
  85             else
  86             {
  87                 result = null;
  88                 return false;
  89             }
  90         }
  91
  92         public void EndComplete(IAsyncResult result)
  93         {
  94             Fx.Assert(this.contextOwnedTransaction != null, "We must have a contextOwnedTransaction if we are calling End");
  95
  96             this.contextOwnedTransaction.EndCommit(result);
  97         }
  98
  99         // We might as well clone the ambient transaction so that PersistenceParticipants
 100         // can't cast to a CommittableTransaction.
 101         static Transaction CloneAmbientTransaction()
 102         {
 103             Transaction ambientTransaction = Transaction.Current;
 104             return ambientTransaction == null ? null : ambientTransaction.Clone();
 105         }
 106     }
 107 }