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
262
263
264
265
266
267
268
269
270
|
/*-
* 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"
/*
* __sweep_remove_handles --
* Remove closed dhandles from the connection list.
*/
static int
__sweep_remove_handles(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
WT_DATA_HANDLE *dhandle, *dhandle_next;
WT_DECL_RET;
conn = S2C(session);
dhandle = SLIST_FIRST(&conn->dhlh);
for (; dhandle != NULL; dhandle = dhandle_next) {
dhandle_next = SLIST_NEXT(dhandle, l);
if (WT_IS_METADATA(dhandle))
continue;
if (F_ISSET(dhandle, WT_DHANDLE_OPEN))
continue;
/* Make sure we get exclusive access. */
if ((ret =
__wt_try_writelock(session, dhandle->rwlock)) == EBUSY)
continue;
WT_RET(ret);
/*
* If there are no longer any references to the handle in any
* sessions, attempt to discard it.
*/
if (F_ISSET(dhandle, WT_DHANDLE_OPEN) ||
dhandle->session_inuse != 0 || dhandle->session_ref != 0) {
WT_RET(__wt_writeunlock(session, dhandle->rwlock));
continue;
}
WT_WITH_DHANDLE(session, dhandle,
ret = __wt_conn_dhandle_discard_single(session, 0));
/* If the handle was not successfully discarded, unlock it. */
if (ret != 0)
WT_TRET(__wt_writeunlock(session, dhandle->rwlock));
WT_RET_BUSY_OK(ret);
WT_STAT_FAST_CONN_INCR(session, dh_conn_ref);
}
return (ret == EBUSY ? 0 : ret);
}
/*
* __sweep --
* Close unused dhandles on the connection dhandle list.
*/
static int
__sweep(WT_SESSION_IMPL *session)
{
WT_BTREE *btree;
WT_CONNECTION_IMPL *conn;
WT_DATA_HANDLE *dhandle;
WT_DECL_RET;
time_t now;
int closed_handles;
conn = S2C(session);
closed_handles = 0;
/* Don't discard handles that have been open recently. */
WT_RET(__wt_seconds(session, &now));
WT_STAT_FAST_CONN_INCR(session, dh_conn_sweeps);
SLIST_FOREACH(dhandle, &conn->dhlh, l) {
if (WT_IS_METADATA(dhandle))
continue;
if (!F_ISSET(dhandle, WT_DHANDLE_OPEN) &&
dhandle->session_inuse == 0 && dhandle->session_ref == 0) {
++closed_handles;
continue;
}
if (dhandle->session_inuse != 0 ||
now <= dhandle->timeofdeath + conn->sweep_idle_time)
continue;
if (dhandle->timeofdeath == 0) {
dhandle->timeofdeath = now;
WT_STAT_FAST_CONN_INCR(session, dh_conn_tod);
continue;
}
/*
* We have a candidate for closing; if it's open, acquire an
* exclusive lock on the handle and close it.
*
* The close would require I/O if an update cannot be written
* (updates in a no-longer-referenced file might not yet be
* globally visible if sessions have disjoint sets of files
* open). In that case, skip it: we'll retry the close the
* next time, after the transaction state has progressed.
*
* We don't set WT_DHANDLE_EXCLUSIVE deliberately, we want
* opens to block on us rather than returning an EBUSY error to
* the application.
*/
if ((ret =
__wt_try_writelock(session, dhandle->rwlock)) == EBUSY)
continue;
WT_RET(ret);
/* Only sweep clean trees where all updates are visible. */
btree = dhandle->handle;
if (btree->modified ||
!__wt_txn_visible_all(session, btree->rec_max_txn))
goto unlock;
/* If the handle is open, try to close it. */
if (F_ISSET(dhandle, WT_DHANDLE_OPEN)) {
WT_WITH_DHANDLE(session, dhandle, ret =
__wt_conn_btree_sync_and_close(session, 0, 0));
/* We closed the btree handle, bump the statistic. */
if (ret == 0)
WT_STAT_FAST_CONN_INCR(
session, dh_conn_handles);
}
if (dhandle->session_inuse == 0 && dhandle->session_ref == 0)
++closed_handles;
unlock: WT_TRET(__wt_writeunlock(session, dhandle->rwlock));
WT_RET_BUSY_OK(ret);
}
if (closed_handles) {
WT_WITH_DHANDLE_LOCK(session,
ret = __sweep_remove_handles(session));
WT_RET(ret);
}
return (0);
}
/*
* __sweep_server --
* The handle sweep server thread.
*/
static WT_THREAD_RET
__sweep_server(void *arg)
{
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_SESSION_IMPL *session;
session = arg;
conn = S2C(session);
/*
* Sweep for dead handles.
*/
while (F_ISSET(conn, WT_CONN_SERVER_RUN) &&
F_ISSET(conn, WT_CONN_SERVER_SWEEP)) {
/* Wait until the next event. */
WT_ERR(__wt_cond_wait(session, conn->sweep_cond,
(uint64_t)conn->sweep_interval * WT_MILLION));
/* Sweep the handles. */
WT_ERR(__sweep(session));
}
if (0) {
err: WT_PANIC_MSG(session, ret, "handle sweep server error");
}
return (WT_THREAD_RET_VALUE);
}
/*
* __wt_sweep_config --
* Pull out sweep configuration settings
*/
int
__wt_sweep_config(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_CONFIG_ITEM cval;
WT_CONNECTION_IMPL *conn;
conn = S2C(session);
/* Pull out the sweep configurations. */
WT_RET(__wt_config_gets(session,
cfg, "file_manager.close_idle_time", &cval));
conn->sweep_idle_time = (time_t)cval.val;
WT_RET(__wt_config_gets(session,
cfg, "file_manager.close_scan_interval", &cval));
conn->sweep_interval = (time_t)cval.val;
return (0);
}
/*
* __wt_sweep_create --
* Start the handle sweep thread.
*/
int
__wt_sweep_create(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
conn = S2C(session);
/* Set first, the thread might run before we finish up. */
F_SET(conn, WT_CONN_SERVER_SWEEP);
WT_RET(__wt_open_internal_session(
conn, "sweep-server", 1, 1, &conn->sweep_session));
session = conn->sweep_session;
/*
* Handle sweep 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, "handle sweep server", 0, &conn->sweep_cond));
WT_RET(__wt_thread_create(
session, &conn->sweep_tid, __sweep_server, session));
conn->sweep_tid_set = 1;
return (0);
}
/*
* __wt_sweep_destroy --
* Destroy the handle-sweep thread.
*/
int
__wt_sweep_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_SWEEP);
if (conn->sweep_tid_set) {
WT_TRET(__wt_cond_signal(session, conn->sweep_cond));
WT_TRET(__wt_thread_join(session, conn->sweep_tid));
conn->sweep_tid_set = 0;
}
WT_TRET(__wt_cond_destroy(session, &conn->sweep_cond));
if (conn->sweep_session != NULL) {
wt_session = &conn->sweep_session->iface;
WT_TRET(wt_session->close(wt_session, NULL));
conn->sweep_session = NULL;
}
return (ret);
}
|