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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
// **********************************************************************
//
// Copyright (c) 2003-2007 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
#include <Freeze/TransactionI.h>
#include <Freeze/ConnectionI.h>
#include <Freeze/Exception.h>
#include <Freeze/Initialize.h>
#include <Ice/LoggerUtil.h>
using namespace std;
using namespace Ice;
DbTxn*
Freeze::getTxn(const Freeze::TransactionPtr& tx)
{
return dynamic_cast<Freeze::TransactionI*>(tx.get())->dbTxn();
}
void
Freeze::TransactionI::commit()
{
if(_txn == 0)
{
throw DatabaseException(__FILE__, __LINE__, "inactive transaction");
}
long txnId = 0;
try
{
_connection->closeAllIterators();
if(_txTrace >= 1)
{
txnId = (_txn->id() & 0x7FFFFFFF) + 0x80000000L;
}
_txn->commit(0);
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "committed transaction " << hex << txnId << dec;
}
}
catch(const ::DbDeadlockException& dx)
{
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "failed to commit transaction " << hex << txnId << dec << ": " << dx.what();
}
postCompletion(false, true);
// After postCompletion is called the transaction may be
// dead. Beware!
DeadlockException ex(__FILE__, __LINE__);
ex.message = dx.what();
throw ex;
}
catch(const ::DbException& dx)
{
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "failed to commit transaction " << hex << txnId << dec << ": " << dx.what();
}
postCompletion(false, false);
// After postCompletion is called the transaction may be
// dead. Beware!
DatabaseException ex(__FILE__, __LINE__);
ex.message = dx.what();
throw ex;
}
postCompletion(true, false);
// After postCompletion is called the transaction may be
// dead. Beware!
}
void
Freeze::TransactionI::rollback()
{
if(_txn != 0)
{
long txnId = 0;
try
{
_connection->closeAllIterators();
if(_txTrace >= 1)
{
txnId = (_txn->id() & 0x7FFFFFFF) + 0x80000000L;
}
_txn->abort();
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "rolled back transaction " << hex << txnId << dec;
}
}
catch(const ::DbDeadlockException& dx)
{
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "failed to rollback transaction " << hex << txnId << dec << ": " << dx.what();
}
postCompletion(false, true);
// After postCompletion is called the transaction may be
// dead. Beware!
throw DeadlockException(__FILE__, __LINE__, dx.what());
}
catch(const ::DbException& dx)
{
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "failed to rollback transaction " << hex << txnId << dec << ": " << dx.what();
}
postCompletion(false, false);
// After postCompletion is called the transaction may be
// dead. Beware!
throw DatabaseException(__FILE__, __LINE__, dx.what());
}
postCompletion(true, false);
// After postCompletion is called the transaction may be
// dead. Beware!
}
}
Freeze::ConnectionPtr
Freeze::TransactionI::getConnection() const
{
return _connection;
}
//
// External refcount operations, from code holding a Transaction[I]Ptr
//
void
Freeze::TransactionI::__decRef()
{
// If dropping the second to last reference and there is still a
// transaction then this means the last reference is held by the
// connection. In this case we must rollback the transaction.
bool rb = false;
if(__getRef() == 2 && _txn)
{
rb = true;
}
Shared::__decRef();
if(rb)
{
rollback();
// After this the transaction is dead.
}
}
void
Freeze::TransactionI::setPostCompletionCallback(const Freeze::PostCompletionCallbackPtr& cb)
{
_postCompletionCallback = cb;
}
Freeze::TransactionI::TransactionI(const ConnectionIPtr& connection) :
_communicator(connection->communicator()),
_connection(connection),
_txTrace(connection->txTrace()),
_txn(0)
{
try
{
_connection->dbEnv()->getEnv()->txn_begin(0, &_txn, 0);
if(_txTrace >= 1)
{
long txnId = (_txn->id() & 0x7FFFFFFF) + 0x80000000L;
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "started transaction " << hex << txnId << dec;
}
}
catch(const ::DbException& dx)
{
if(_txTrace >= 1)
{
Trace out(_communicator->getLogger(), "Freeze.Transaction");
out << "failed to start transaction: " << dx.what();
}
DatabaseException ex(__FILE__, __LINE__);
ex.message = dx.what();
throw ex;
}
}
Freeze::TransactionI::~TransactionI()
{
if(_txn != 0)
{
try
{
rollback();
}
catch(const IceUtil::Exception& e)
{
Error error(_communicator->getLogger());
error << "transaction rollback raised :" << e;
}
}
}
void
Freeze::TransactionI::postCompletion(bool committed, bool deadlock)
{
// The order of assignment in this method is very important as
// calling both the post completion callback and
// Connection::clearTransaction may alter the transaction
// reference count which checks _txn.
_txn = 0;
if(_postCompletionCallback != 0)
{
_postCompletionCallback->postCompletion(committed, deadlock);
}
// Its necessary here to copy the connection before calling
// clearTransaction because this may release the last reference. This specifically
// occurs in the following scenario:
//
// TransactionalEvictorContext holds the _tx. It calls
// _tx->commit(). This comes into this method, and calls
// _postCompletionCallback. This causes the context to drop the
// _tx reference (reference count is now 1). The
// connection->clearTransaction() is then called which drops its
// reference causing the transaction to be deleted.
//
ConnectionIPtr con = _connection;
_connection = 0; // Drop the connection
con->clearTransaction();
// At this point the transaction may be dead.
}
|
