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
|
/*-
* Copyright (c) 2014-2015 MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
static int __ckpt_server_start(WT_CONNECTION_IMPL *);
/*
* __ckpt_server_config --
* Parse and setup the checkpoint server options.
*/
static int
__ckpt_server_config(WT_SESSION_IMPL *session, const char **cfg, int *startp)
{
WT_CONFIG_ITEM cval;
WT_CONNECTION_IMPL *conn;
WT_DECL_ITEM(tmp);
WT_DECL_RET;
char *p;
conn = S2C(session);
/*
* The checkpoint configuration requires a wait time and/or a log
* size -- if one is not set, we're not running at all.
* Checkpoints based on log size also require logging be enabled.
*/
WT_RET(__wt_config_gets(session, cfg, "checkpoint.wait", &cval));
conn->ckpt_usecs = (uint64_t)cval.val * 1000000;
WT_RET(__wt_config_gets(session, cfg, "checkpoint.log_size", &cval));
conn->ckpt_logsize = (wt_off_t)cval.val;
__wt_log_written_reset(session);
if ((conn->ckpt_usecs == 0 && conn->ckpt_logsize == 0) ||
(conn->ckpt_logsize && conn->ckpt_usecs == 0 &&
!FLD_ISSET(conn->log_flags, WT_CONN_LOG_ENABLED))) {
*startp = 0;
return (0);
}
*startp = 1;
/*
* The application can specify a checkpoint name, which we ignore if
* it's our default.
*/
WT_RET(__wt_config_gets(session, cfg, "checkpoint.name", &cval));
if (cval.len != 0 &&
!WT_STRING_MATCH(WT_CHECKPOINT, cval.str, cval.len)) {
WT_RET(__wt_checkpoint_name_ok(session, cval.str, cval.len));
WT_RET(__wt_scr_alloc(session, cval.len + 20, &tmp));
WT_ERR(__wt_buf_fmt(
session, tmp, "name=%.*s", (int)cval.len, cval.str));
WT_ERR(__wt_strdup(session, tmp->data, &p));
__wt_free(session, conn->ckpt_config);
conn->ckpt_config = p;
}
err: __wt_scr_free(session, &tmp);
return (ret);
}
/*
* __ckpt_server --
* The checkpoint server thread.
*/
static WT_THREAD_RET
__ckpt_server(void *arg)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_SESSION *wt_session;
WT_SESSION_IMPL *session;
session = arg;
conn = S2C(session);
wt_session = (WT_SESSION *)session;
while (F_ISSET(conn, WT_CONN_SERVER_RUN) &&
F_ISSET(conn, WT_CONN_SERVER_CHECKPOINT)) {
/*
* Wait...
* NOTE: If the user only configured logsize, then usecs
* will be 0 and this wait won't return until signalled.
*/
WT_ERR(
__wt_cond_wait(session, conn->ckpt_cond, conn->ckpt_usecs));
/* Checkpoint the database. */
WT_ERR(wt_session->checkpoint(wt_session, conn->ckpt_config));
/* Reset. */
if (conn->ckpt_logsize) {
__wt_log_written_reset(session);
conn->ckpt_signalled = 0;
/*
* In case we crossed the log limit during the
* checkpoint and the condition variable was already
* signalled, do a tiny wait to clear it so we don't do
* another checkpoint immediately.
*/
WT_ERR(__wt_cond_wait(session, conn->ckpt_cond, 1));
}
}
if (0) {
err: WT_PANIC_MSG(session, ret, "checkpoint server error");
}
return (WT_THREAD_RET_VALUE);
}
/*
* __ckpt_server_start --
* Start the checkpoint server thread.
*/
static int
__ckpt_server_start(WT_CONNECTION_IMPL *conn)
{
WT_SESSION_IMPL *session;
/* Nothing to do if the server is already running. */
if (conn->ckpt_session != NULL)
return (0);
F_SET(conn, WT_CONN_SERVER_CHECKPOINT);
/* The checkpoint server gets its own session. */
WT_RET(__wt_open_internal_session(
conn, "checkpoint-server", 1, 1, &conn->ckpt_session));
session = conn->ckpt_session;
/*
* Checkpoint does enough I/O it may be called upon to perform slow
* operations for the block manager.
*/
F_SET(session, WT_SESSION_CAN_WAIT);
WT_RET(
__wt_cond_alloc(session, "checkpoint server", 0, &conn->ckpt_cond));
/*
* Start the thread.
*/
WT_RET(__wt_thread_create(
session, &conn->ckpt_tid, __ckpt_server, session));
conn->ckpt_tid_set = 1;
return (0);
}
/*
* __wt_checkpoint_server_create --
* Configure and start the checkpoint server.
*/
int
__wt_checkpoint_server_create(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_CONNECTION_IMPL *conn;
int start;
conn = S2C(session);
start = 0;
/* If there is already a server running, shut it down. */
if (conn->ckpt_session != NULL)
WT_RET(__wt_checkpoint_server_destroy(session));
WT_RET(__ckpt_server_config(session, cfg, &start));
if (start)
WT_RET(__ckpt_server_start(conn));
return (0);
}
/*
* __wt_checkpoint_server_destroy --
* Destroy the checkpoint server thread.
*/
int
__wt_checkpoint_server_destroy(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_SESSION *wt_session;
conn = S2C(session);
F_CLR(conn, WT_CONN_SERVER_CHECKPOINT);
if (conn->ckpt_tid_set) {
WT_TRET(__wt_cond_signal(session, conn->ckpt_cond));
WT_TRET(__wt_thread_join(session, conn->ckpt_tid));
conn->ckpt_tid_set = 0;
}
WT_TRET(__wt_cond_destroy(session, &conn->ckpt_cond));
__wt_free(session, conn->ckpt_config);
/* Close the server thread's session. */
if (conn->ckpt_session != NULL) {
wt_session = &conn->ckpt_session->iface;
WT_TRET(wt_session->close(wt_session, NULL));
}
/*
* Ensure checkpoint settings are cleared - so that reconfigure doesn't
* get confused.
*/
conn->ckpt_session = NULL;
conn->ckpt_tid_set = 0;
conn->ckpt_cond = NULL;
conn->ckpt_config = NULL;
conn->ckpt_usecs = 0;
return (ret);
}
/*
* __wt_checkpoint_signal --
* Signal the checkpoint thread if sufficient log has been written.
* Return 1 if this signals the checkpoint thread, 0 otherwise.
*/
int
__wt_checkpoint_signal(WT_SESSION_IMPL *session, wt_off_t logsize)
{
WT_CONNECTION_IMPL *conn;
conn = S2C(session);
WT_ASSERT(session, WT_CKPT_LOGSIZE(conn));
if (logsize >= conn->ckpt_logsize && !conn->ckpt_signalled) {
WT_RET(__wt_cond_signal(session, conn->ckpt_cond));
conn->ckpt_signalled = 1;
}
return (0);
}
|
