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
254
255
256
257
258
259
260
261
|
/******************************************************
Rollback segment
(c) 1996 Innobase Oy
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "trx0rseg.h"
#ifdef UNIV_NONINL
#include "trx0rseg.ic"
#endif
#include "trx0undo.h"
#include "fut0lst.h"
#include "srv0srv.h"
#include "trx0purge.h"
/**********************************************************************
Looks for a rollback segment, based on the rollback segment id. */
trx_rseg_t*
trx_rseg_get_on_id(
/*===============*/
/* out: rollback segment */
ulint id) /* in: rollback segment id */
{
trx_rseg_t* rseg;
rseg = UT_LIST_GET_FIRST(trx_sys->rseg_list);
ut_ad(rseg);
while (rseg->id != id) {
rseg = UT_LIST_GET_NEXT(rseg_list, rseg);
ut_ad(rseg);
}
return(rseg);
}
/********************************************************************
Creates a rollback segment header. This function is called only when
a new rollback segment is created in the database. */
ulint
trx_rseg_header_create(
/*===================*/
/* out: page number of the created segment,
FIL_NULL if fail */
ulint space, /* in: space id */
ulint max_size, /* in: max size in pages */
ulint* slot_no, /* out: rseg id == slot number in trx sys */
mtr_t* mtr) /* in: mtr */
{
ulint page_no;
trx_rsegf_t* rsegf;
trx_sysf_t* sys_header;
ulint i;
page_t* page;
ut_ad(mtr);
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
ut_ad(mtr_memo_contains(mtr, fil_space_get_latch(space),
MTR_MEMO_X_LOCK));
sys_header = trx_sysf_get(mtr);
*slot_no = trx_sysf_rseg_find_free(mtr);
if (*slot_no == ULINT_UNDEFINED) {
return(FIL_NULL);
}
/* Allocate a new file segment for the rollback segment */
page = fseg_create(space, 0, TRX_RSEG + TRX_RSEG_FSEG_HEADER, mtr);
if (page == NULL) {
/* No space left */
return(FIL_NULL);
}
#ifdef UNIV_SYNC_DEBUG
buf_page_dbg_add_level(page, SYNC_RSEG_HEADER_NEW);
#endif /* UNIV_SYNC_DEBUG */
page_no = buf_frame_get_page_no(page);
/* Get the rollback segment file page */
rsegf = trx_rsegf_get_new(space, page_no, mtr);
/* Initialize max size field */
mlog_write_ulint(rsegf + TRX_RSEG_MAX_SIZE, max_size, MLOG_4BYTES, mtr);
/* Initialize the history list */
mlog_write_ulint(rsegf + TRX_RSEG_HISTORY_SIZE, 0, MLOG_4BYTES, mtr);
flst_init(rsegf + TRX_RSEG_HISTORY, mtr);
/* Reset the undo log slots */
for (i = 0; i < TRX_RSEG_N_SLOTS; i++) {
trx_rsegf_set_nth_undo(rsegf, i, FIL_NULL, mtr);
}
/* Add the rollback segment info to the free slot in the trx system
header */
trx_sysf_rseg_set_space(sys_header, *slot_no, space, mtr);
trx_sysf_rseg_set_page_no(sys_header, *slot_no, page_no, mtr);
return(page_no);
}
/***************************************************************************
Creates and initializes a rollback segment object. The values for the
fields are read from the header. The object is inserted to the rseg
list of the trx system object and a pointer is inserted in the rseg
array in the trx system object. */
static
trx_rseg_t*
trx_rseg_mem_create(
/*================*/
/* out, own: rollback segment object */
ulint id, /* in: rollback segment id */
ulint space, /* in: space where the segment placed */
ulint page_no, /* in: page number of the segment header */
mtr_t* mtr) /* in: mtr */
{
trx_rsegf_t* rseg_header;
trx_rseg_t* rseg;
trx_ulogf_t* undo_log_hdr;
fil_addr_t node_addr;
ulint sum_of_undo_sizes;
ulint len;
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
rseg = mem_alloc(sizeof(trx_rseg_t));
rseg->id = id;
rseg->space = space;
rseg->page_no = page_no;
mutex_create(&(rseg->mutex));
mutex_set_level(&(rseg->mutex), SYNC_RSEG);
UT_LIST_ADD_LAST(rseg_list, trx_sys->rseg_list, rseg);
trx_sys_set_nth_rseg(trx_sys, id, rseg);
rseg_header = trx_rsegf_get_new(space, page_no, mtr);
rseg->max_size = mtr_read_ulint(rseg_header + TRX_RSEG_MAX_SIZE,
MLOG_4BYTES, mtr);
/* Initialize the undo log lists according to the rseg header */
sum_of_undo_sizes = trx_undo_lists_init(rseg);
rseg->curr_size = mtr_read_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE,
MLOG_4BYTES, mtr)
+ 1 + sum_of_undo_sizes;
len = flst_get_len(rseg_header + TRX_RSEG_HISTORY, mtr);
if (len > 0) {
trx_sys->rseg_history_len += len;
node_addr = trx_purge_get_log_from_hist(
flst_get_last(rseg_header + TRX_RSEG_HISTORY,
mtr));
rseg->last_page_no = node_addr.page;
rseg->last_offset = node_addr.boffset;
undo_log_hdr = trx_undo_page_get(rseg->space, node_addr.page,
mtr)
+ node_addr.boffset;
rseg->last_trx_no = mtr_read_dulint(
undo_log_hdr + TRX_UNDO_TRX_NO, mtr);
rseg->last_del_marks = mtr_read_ulint(
undo_log_hdr + TRX_UNDO_DEL_MARKS,
MLOG_2BYTES, mtr);
} else {
rseg->last_page_no = FIL_NULL;
}
return(rseg);
}
/*************************************************************************
Creates the memory copies for rollback segments and initializes the
rseg list and array in trx_sys at a database startup. */
void
trx_rseg_list_and_array_init(
/*=========================*/
trx_sysf_t* sys_header, /* in: trx system header */
mtr_t* mtr) /* in: mtr */
{
ulint i;
ulint page_no;
ulint space;
UT_LIST_INIT(trx_sys->rseg_list);
trx_sys->rseg_history_len = 0;
for (i = 0; i < TRX_SYS_N_RSEGS; i++) {
page_no = trx_sysf_rseg_get_page_no(sys_header, i, mtr);
if (page_no == FIL_NULL) {
trx_sys_set_nth_rseg(trx_sys, i, NULL);
} else {
space = trx_sysf_rseg_get_space(sys_header, i, mtr);
trx_rseg_mem_create(i, space, page_no, mtr);
}
}
}
/********************************************************************
Creates a new rollback segment to the database. */
trx_rseg_t*
trx_rseg_create(
/*============*/
/* out: the created segment object, NULL if
fail */
ulint space, /* in: space id */
ulint max_size, /* in: max size in pages */
ulint* id, /* out: rseg id */
mtr_t* mtr) /* in: mtr */
{
ulint page_no;
trx_rseg_t* rseg;
mtr_x_lock(fil_space_get_latch(space), mtr);
mutex_enter(&kernel_mutex);
page_no = trx_rseg_header_create(space, max_size, id, mtr);
if (page_no == FIL_NULL) {
mutex_exit(&kernel_mutex);
return(NULL);
}
rseg = trx_rseg_mem_create(*id, space, page_no, mtr);
mutex_exit(&kernel_mutex);
return(rseg);
}
|
