xref: /sqlite-3.40.0/test/wal9.test (revision 0fbb50ee)
1# 2012 October 15
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11#
12# This test case tests that a problem causing a failing assert() has
13# been fixed. The problem occurred if a writer process with a subset
14# of the *shm file mapped rolled back a transaction begun after the
15# entire WAL file was checkpointed into the db file (i.e. a transaction
16# that would have restarted the WAL file from the beginning).
17#
18
19set testdir [file dirname $argv0]
20source $testdir/tester.tcl
21set testprefix wal9
22
23sqlite3 db2 test.db
24
25do_execsql_test 1.0 {
26  PRAGMA page_size = 1024;
27  PRAGMA journal_mode = WAL;
28  PRAGMA wal_autocheckpoint = 0;
29  CREATE TABLE t(x);
30} {wal 0}
31
32do_test 1.1 {
33  execsql "SELECT * FROM t" db2
34} {}
35
36do_execsql_test 1.2 {
37  BEGIN;
38    INSERT INTO t VALUES(randomblob(100));
39    INSERT INTO t SELECT randomblob(100) FROM t;
40    INSERT INTO t SELECT randomblob(100) FROM t;
41    INSERT INTO t SELECT randomblob(100) FROM t;
42    INSERT INTO t SELECT randomblob(100) FROM t;
43    INSERT INTO t SELECT randomblob(100) FROM t;
44    INSERT INTO t SELECT randomblob(100) FROM t;
45    INSERT INTO t SELECT randomblob(100) FROM t;
46
47    INSERT INTO t SELECT randomblob(100) FROM t;
48    INSERT INTO t SELECT randomblob(100) FROM t;
49    INSERT INTO t SELECT randomblob(100) FROM t;
50    INSERT INTO t SELECT randomblob(100) FROM t;
51    INSERT INTO t SELECT randomblob(100) FROM t;
52    INSERT INTO t SELECT randomblob(100) FROM t;
53    INSERT INTO t SELECT randomblob(100) FROM t;
54    INSERT INTO t SELECT randomblob(100) FROM t;
55
56    INSERT INTO t SELECT randomblob(100) FROM t;
57    INSERT INTO t SELECT randomblob(100) FROM t;
58  COMMIT;
59} {}
60
61# Check file sizes are as expected. The real requirement here is that
62# the *shm file is now more than one chunk (>32KiB).
63do_test 1.3 { file size test.db     } {1024}
64do_test 1.4 { file size test.db-wal } {15421352}
65do_test 1.5 { expr {[file size test.db-shm]>32768} } {1}
66
67do_execsql_test 1.6 { PRAGMA wal_checkpoint } {0 14715 14715}
68
69# At this point connection [db2] has mapped the first 32KB of the *shm file
70# only. Because the entire WAL file has been checkpointed, it is not
71# necessary to map any more of the *-shm file to read or write the database
72# (since all data will be read directly from the db file).
73#
74# However, at one point if a transaction that had not yet written to the
75# WAL file was rolled back an assert() attempting to verify that the entire
76# *-shm file was mapped would fail. If NDEBUG was defined (and the assert()
77# disabled) this bug caused SQLite to ignore the return code of a mmap()
78# call.
79#
80do_test 1.7 {
81  execsql {
82    BEGIN;
83      INSERT INTO t VALUES('hello');
84    ROLLBACK;
85  } db2
86} {}
87db2 close
88
89finish_test
90