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
|
# 2011 May 06
#
# The author disclaims copyright to this source code. In place of
# a legal notice, here is a blessing:
#
# May you do good and not evil.
# May you find forgiveness for yourself and forgive others.
# May you share freely, never taking more than you give.
#
#***********************************************************************
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix e_wal
db close
forcedelete test.db-shm
testvfs oldvfs -iversion 1
# EVIDENCE-OF: R-58297-14483 WAL databases can be created, read, and
# written even if shared memory is unavailable as long as the
# locking_mode is set to EXCLUSIVE before the first attempted access.
#
# EVIDENCE-OF: R-00449-33772 This feature allows WAL databases to be
# created, read, and written by legacy VFSes that lack the "version 2"
# shared-memory methods xShmMap, xShmLock, xShmBarrier, and xShmUnmap on
# the sqlite3_io_methods object.
#
# 1.1: "create" tests.
# 1.2: "read" tests.
# 1.3: "write" tests.
#
# All three done with VFS "oldvfs", which has iVersion==1 and so does
# not support shared memory.
#
sqlite3 db test.db -vfs oldvfs
do_execsql_test 1.1.1 {
PRAGMA journal_mode = WAL;
} {delete}
do_execsql_test 1.1.2 {
PRAGMA locking_mode = EXCLUSIVE;
PRAGMA journal_mode = WAL;
} {exclusive wal}
do_execsql_test 1.1.3 {
CREATE TABLE t1(x, y);
INSERT INTO t1 VALUES(1, 2);
} {}
do_test 1.1.4 {
list [file exists test.db-shm] [file exists test.db-wal]
} {0 1}
do_test 1.2.1 {
db close
sqlite3 db test.db -vfs oldvfs
catchsql { SELECT * FROM t1 }
} {1 {unable to open database file}}
do_test 1.2.2 {
execsql { PRAGMA locking_mode = EXCLUSIVE }
execsql { SELECT * FROM t1 }
} {1 2}
do_test 1.2.3 {
list [file exists test.db-shm] [file exists test.db-wal]
} {0 1}
do_test 1.3.1 {
db close
sqlite3 db test.db -vfs oldvfs
catchsql { INSERT INTO t1 VALUES(3, 4) }
} {1 {unable to open database file}}
do_test 1.3.2 {
execsql { PRAGMA locking_mode = EXCLUSIVE }
execsql { INSERT INTO t1 VALUES(3, 4) }
execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test 1.3.3 {
list [file exists test.db-shm] [file exists test.db-wal]
} {0 1}
# EVIDENCE-OF: R-31969-57825 If EXCLUSIVE locking mode is set prior to
# the first WAL-mode database access, then SQLite never attempts to call
# any of the shared-memory methods and hence no shared-memory wal-index
# is ever created.
#
db close
sqlite3 db test.db
do_execsql_test 2.1.1 {
PRAGMA locking_mode = EXCLUSIVE;
SELECT * FROM t1;
} {exclusive 1 2 3 4}
do_test 2.1.2 {
list [file exists test.db-shm] [file exists test.db-wal]
} {0 1}
# EVIDENCE-OF: R-36328-16367 In that case, the database connection
# remains in EXCLUSIVE mode as long as the journal mode is WAL; attempts
# to change the locking mode using "PRAGMA locking_mode=NORMAL;" are
# no-ops.
#
do_execsql_test 2.2.1 {
PRAGMA locking_mode = NORMAL;
SELECT * FROM t1;
} {exclusive 1 2 3 4}
do_test 2.2.2 {
sqlite3 db2 test.db
catchsql {SELECT * FROM t1} db2
} {1 {database is locked}}
db2 close
# EVIDENCE-OF: R-63522-46088 The only way to change out of EXCLUSIVE
# locking mode is to first change out of WAL journal mode.
#
do_execsql_test 2.3.1 {
PRAGMA journal_mode = DELETE;
SELECT * FROM t1;
} {delete 1 2 3 4}
do_test 2.3.2 {
sqlite3 db2 test.db
catchsql {SELECT * FROM t1} db2
} {1 {database is locked}}
do_execsql_test 2.3.3 {
PRAGMA locking_mode = NORMAL;
SELECT * FROM t1;
} {normal 1 2 3 4}
do_test 2.3.4 {
sqlite3 db2 test.db
catchsql {SELECT * FROM t1} db2
} {0 {1 2 3 4}}
db2 close
db close
# EVIDENCE-OF: R-57239-11845 If NORMAL locking mode is in effect for the
# first WAL-mode database access, then the shared-memory wal-index is
# created.
#
do_test 3.0 {
sqlite3 db test.db
execsql { PRAGMA journal_mode = WAL }
db close
} {}
do_test 3.1 {
sqlite3 db test.db
execsql { SELECT * FROM t1 }
list [file exists test.db-shm] [file exists test.db-wal]
} {1 1}
# EVIDENCE-OF: R-13779-07711 As long as exactly one connection is using
# a shared-memory wal-index, the locking mode can be changed freely
# between NORMAL and EXCLUSIVE.
#
do_execsql_test 3.2.1 {
PRAGMA locking_mode = EXCLUSIVE;
PRAGMA locking_mode = NORMAL;
PRAGMA locking_mode = EXCLUSIVE;
INSERT INTO t1 VALUES(5, 6);
} {exclusive normal exclusive}
do_test 3.2.2 {
sqlite3 db2 test.db
catchsql { SELECT * FROM t1 } db2
} {1 {database is locked}}
# EVIDENCE-OF: R-10993-11647 It is only when the shared-memory wal-index
# is omitted, when the locking mode is EXCLUSIVE prior to the first
# WAL-mode database access, that the locking mode is stuck in EXCLUSIVE.
#
do_execsql_test 3.2.3 {
PRAGMA locking_mode = NORMAL;
SELECT * FROM t1;
} {normal 1 2 3 4 5 6}
do_test 3.2.4 {
catchsql { SELECT * FROM t1 } db2
} {0 {1 2 3 4 5 6}}
do_catchsql_test 3.2.5 {
PRAGMA locking_mode = EXCLUSIVE;
INSERT INTO t1 VALUES(7, 8);
} {1 {database is locked}}
db2 close
# EVIDENCE-OF: R-46197-42811 This means that the underlying VFS must
# support the "version 2" shared-memory.
#
# EVIDENCE-OF: R-55316-21772 If the VFS does not support shared-memory
# methods, then the attempt to open a database that is already in WAL
# mode, or the attempt convert a database into WAL mode, will fail.
#
db close
do_test 3.4.1 {
sqlite3 db test.db -vfs oldvfs
catchsql { SELECT * FROM t1 }
} {1 {unable to open database file}}
db close
do_test 3.4.2 {
forcedelete test.db2
sqlite3 db test.db2 -vfs oldvfs
catchsql { PRAGMA journal_mode = WAL }
} {0 delete}
db close
# EVIDENCE-OF: R-45540-25505 To prevent older versions of SQLite (prior
# to version 3.7.0, 2010-07-22) from trying to recover a WAL-mode
# database (and making matters worse) the database file format version
# numbers (bytes 18 and 19 in the database header) are increased from 1
# to 2 in WAL mode.
#
reset_db
do_execsql_test 4.1.1 { CREATE TABLE t1(x, y) }
do_test 4.1.2 { hexio_read test.db 18 2 } {0101}
do_execsql_test 4.1.3 { PRAGMA journal_mode = wAL } {wal}
do_test 4.1.4 { hexio_read test.db 18 2 } {0202}
# EVIDENCE-OF: R-02535-05811 One can explicitly change out of WAL mode
# using a pragma such as this: PRAGMA journal_mode=DELETE;
#
do_execsql_test 4.2.1 { INSERT INTO t1 VALUES(1, 1); } {}
do_test 4.2.2 { file exists test.db-wal } {1}
do_execsql_test 4.2.3 { PRAGMA journal_mode = delete } {delete}
do_test 4.2.4 { file exists test.db-wal } {0}
# EVIDENCE-OF: R-60175-02388 Deliberately changing out of WAL mode
# changes the database file format version numbers back to 1 so that
# older versions of SQLite can once again access the database file.
#
do_test 4.3 { hexio_read test.db 18 2 } {0101}
finish_test
|