1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
//----------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//----------------------------------------------------------------
namespace System.ServiceModel.Activities.Dispatcher
{
using System.Runtime;
using System.Transactions;
//1) On Tx.Prepare
// Persist the instance.
// When Persist completes Tx.Prepared called.
// When Persist fails Tx.ForceRollback called.
//2) On Tx.Commit
// DurableInstance.OnTransactionCompleted().
//3) On Tx.Abort
// DurableInstance.OnTransactionAborted()
class TransactionContext : IEnlistmentNotification
{
static AsyncCallback handleEndPrepare = Fx.ThunkCallback(new AsyncCallback(HandleEndPrepare));
Transaction currentTransaction;
WorkflowServiceInstance durableInstance;
public TransactionContext(WorkflowServiceInstance durableInstance, Transaction currentTransaction)
{
Fx.Assert(durableInstance != null, "Null DurableInstance passed to TransactionContext.");
Fx.Assert(currentTransaction != null, "Null Transaction passed to TransactionContext.");
this.currentTransaction = currentTransaction.Clone();
this.durableInstance = durableInstance;
this.currentTransaction.EnlistVolatile(this, EnlistmentOptions.EnlistDuringPrepareRequired);
}
public Transaction CurrentTransaction
{
get
{
return this.currentTransaction;
}
}
void IEnlistmentNotification.Commit(Enlistment enlistment)
{
enlistment.Done();
this.durableInstance.TransactionCommitted();
}
void IEnlistmentNotification.InDoubt(Enlistment enlistment)
{
enlistment.Done();
Fx.Assert(this.currentTransaction.TransactionInformation.Status == TransactionStatus.InDoubt, "Transaction state should be InDoubt at this point");
TransactionException exception = this.GetAbortedOrInDoubtTransactionException();
Fx.Assert(exception != null, "Need a valid TransactionException at this point");
this.durableInstance.OnTransactionAbortOrInDoubt(exception);
}
void IEnlistmentNotification.Prepare(PreparingEnlistment preparingEnlistment)
{
bool success = false;
try
{
IAsyncResult result = new PrepareAsyncResult(this, TransactionContext.handleEndPrepare, preparingEnlistment);
if (result.CompletedSynchronously)
{
PrepareAsyncResult.End(result);
preparingEnlistment.Prepared();
}
success = true;
}
//we need to swollow the TransactionException as it could because another party aborting it
catch (TransactionException)
{
}
finally
{
if (!success)
{
preparingEnlistment.ForceRollback();
}
}
}
void IEnlistmentNotification.Rollback(Enlistment enlistment)
{
enlistment.Done();
Fx.Assert(this.currentTransaction.TransactionInformation.Status == TransactionStatus.Aborted, "Transaction state should be Aborted at this point");
TransactionException exception = this.GetAbortedOrInDoubtTransactionException();
Fx.Assert(exception != null, "Need a valid TransactionException at this point");
this.durableInstance.OnTransactionAbortOrInDoubt(exception);
}
TransactionException GetAbortedOrInDoubtTransactionException()
{
try
{
TransactionHelper.ThrowIfTransactionAbortedOrInDoubt(this.currentTransaction);
}
catch (TransactionException exception)
{
return exception;
}
return null;
}
static void HandleEndPrepare(IAsyncResult result)
{
PreparingEnlistment preparingEnlistment = (PreparingEnlistment)result.AsyncState;
bool success = false;
try
{
if (!result.CompletedSynchronously)
{
PrepareAsyncResult.End(result);
preparingEnlistment.Prepared();
}
success = true;
}
//we need to swollow the TransactionException as it could because another party aborting it
catch (TransactionException)
{
}
finally
{
if (!success)
{
preparingEnlistment.ForceRollback();
}
}
}
class PrepareAsyncResult : TransactedAsyncResult
{
static readonly AsyncCompletion onEndPersist = new AsyncCompletion(OnEndPersist);
readonly TransactionContext context;
public PrepareAsyncResult(TransactionContext context, AsyncCallback callback, object state)
: base(callback, state)
{
this.context = context;
IAsyncResult result = null;
using (PrepareTransactionalCall(this.context.currentTransaction))
{
result = this.context.durableInstance.BeginPersist(TimeSpan.MaxValue, PrepareAsyncCompletion(PrepareAsyncResult.onEndPersist), this);
}
if (SyncContinue(result))
{
Complete(true);
}
}
public static void End(IAsyncResult result)
{
AsyncResult.End<PrepareAsyncResult>(result);
}
static bool OnEndPersist(IAsyncResult result)
{
PrepareAsyncResult thisPtr = (PrepareAsyncResult)result.AsyncState;
thisPtr.context.durableInstance.EndPersist(result);
thisPtr.context.durableInstance.OnTransactionPrepared();
return true;
}
}
}
}
|
