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
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2001-2002
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: txn_util.c,v 11.18 2002/08/06 06:25:12 bostic Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <string.h>
#endif
#include "db_int.h"
#include "dbinc/db_shash.h"
#include "dbinc/lock.h"
#include "dbinc/txn.h"
typedef struct __txn_event TXN_EVENT;
struct __txn_event {
TXN_EVENT_T op;
TAILQ_ENTRY(__txn_event) links;
union {
struct {
/* Delayed remove. */
char *name;
u_int8_t *fileid;
} r;
struct {
/* Lock event. */
DB_LOCK lock;
u_int32_t locker;
DB *dbp;
} t;
} u;
};
/*
* __txn_remevent --
*
* Creates a remove event that can be added to the commit list.
*
* PUBLIC: int __txn_remevent __P((DB_ENV *,
* PUBLIC: DB_TXN *, const char *, u_int8_t*));
*/
int
__txn_remevent(dbenv, txn, name, fileid)
DB_ENV *dbenv;
DB_TXN *txn;
const char *name;
u_int8_t *fileid;
{
int ret;
TXN_EVENT *e;
e = NULL;
if ((ret = __os_calloc(dbenv, 1, sizeof(TXN_EVENT), &e)) != 0)
return (ret);
if ((ret = __os_strdup(dbenv, name, &e->u.r.name)) != 0)
goto err;
if (fileid != NULL) {
if ((ret = __os_calloc(dbenv,
1, DB_FILE_ID_LEN, &e->u.r.fileid)) != 0)
return (ret);
memcpy(e->u.r.fileid, fileid, DB_FILE_ID_LEN);
}
e->op = TXN_REMOVE;
TAILQ_INSERT_TAIL(&txn->events, e, links);
return (0);
err: if (e != NULL)
__os_free(dbenv, e);
return (ret);
}
/*
* __txn_lockevent --
*
* Add a lockevent to the commit-queue. The lock event indicates a locker
* trade.
*
* PUBLIC: int __txn_lockevent __P((DB_ENV *,
* PUBLIC: DB_TXN *, DB *, DB_LOCK *, u_int32_t));
*/
int
__txn_lockevent(dbenv, txn, dbp, lock, locker)
DB_ENV *dbenv;
DB_TXN *txn;
DB *dbp;
DB_LOCK *lock;
u_int32_t locker;
{
int ret;
TXN_EVENT *e;
if (!LOCKING_ON(dbenv))
return (0);
e = NULL;
if ((ret = __os_calloc(dbenv, 1, sizeof(TXN_EVENT), &e)) != 0)
return (ret);
e->u.t.locker = locker;
e->u.t.lock = *lock;
e->u.t.dbp = dbp;
e->op = TXN_TRADE;
TAILQ_INSERT_TAIL(&txn->events, e, links);
return (0);
}
/*
* __txn_remlock --
* Remove a lock event because the locker is going away. We can remove
* by lock (using offset) or by locker_id (or by both).
*
* PUBLIC: void __txn_remlock __P((DB_ENV *, DB_TXN *, DB_LOCK *, u_int32_t));
*/
void
__txn_remlock(dbenv, txn, lock, locker)
DB_ENV *dbenv;
DB_TXN *txn;
DB_LOCK *lock;
u_int32_t locker;
{
TXN_EVENT *e, *next_e;
for (e = TAILQ_FIRST(&txn->events); e != NULL; e = next_e) {
next_e = TAILQ_NEXT(e, links);
if ((e->op != TXN_TRADE && e->op != TXN_TRADED) ||
(e->u.t.lock.off != lock->off && e->u.t.locker != locker))
continue;
TAILQ_REMOVE(&txn->events, e, links);
__os_free(dbenv, e);
}
return;
}
/*
* __txn_doevents --
* Process the list of events associated with a transaction. On commit,
* apply the events; on abort, just toss the entries.
*
* PUBLIC: int __txn_doevents __P((DB_ENV *, DB_TXN *, int, int));
*/
#define DO_TRADE do { \
memset(&req, 0, sizeof(req)); \
req.lock = e->u.t.lock; \
req.op = DB_LOCK_TRADE; \
t_ret = __lock_vec(dbenv, e->u.t.locker, 0, &req, 1, NULL); \
if (t_ret == 0) \
e->u.t.dbp->cur_lid = e->u.t.locker; \
else if (t_ret == DB_NOTFOUND) \
t_ret = 0; \
if (t_ret != 0 && ret == 0) \
ret = t_ret; \
e->op = TXN_TRADED; \
} while (0)
int
__txn_doevents(dbenv, txn, is_commit, preprocess)
DB_ENV *dbenv;
DB_TXN *txn;
int is_commit, preprocess;
{
DB_LOCKREQ req;
TXN_EVENT *e;
int ret, t_ret;
ret = 0;
/*
* This phase only gets called if we have a phase where we
* release read locks. Since not all paths will call this
* phase, we have to check for it below as well. So, when
* we do the trade, we update the opcode of the entry so that
* we don't try the trade again.
*/
if (preprocess) {
for (e = TAILQ_FIRST(&txn->events);
e != NULL; e = TAILQ_NEXT(e, links)) {
if (e->op != TXN_TRADE)
continue;
DO_TRADE;
}
return (ret);
}
while ((e = TAILQ_FIRST(&txn->events)) != NULL) {
TAILQ_REMOVE(&txn->events, e, links);
if (!is_commit)
goto dofree;
switch (e->op) {
case TXN_REMOVE:
if (e->u.r.fileid != NULL) {
if ((t_ret = dbenv->memp_nameop(dbenv,
e->u.r.fileid,
NULL, e->u.r.name, NULL)) != 0 && ret == 0)
ret = t_ret;
__os_free(dbenv, e->u.r.fileid);
} else if ((t_ret =
__os_unlink(dbenv, e->u.r.name)) != 0 && ret == 0)
ret = t_ret;
__os_free(dbenv, e->u.r.name);
break;
case TXN_TRADE:
DO_TRADE;
/* Fall through */
case TXN_TRADED:
/* Downgrade the lock. */
if ((t_ret = __lock_downgrade(dbenv,
&e->u.t.lock, DB_LOCK_READ, 0)) != 0 && ret == 0)
ret = t_ret;
break;
default:
/* This had better never happen. */
DB_ASSERT(0);
}
dofree: __os_free(dbenv, e);
}
return (ret);
}
|
